Dataset Viewer
idx
int64 0
2.93M
| text
stringlengths 128
42.5k
|
|---|---|
0 | title: Generation and Detection of Surface Plasmon Polaritons by Transition Metal Dichalcogenides for Chip-level Electronic-Photonic Integrated Circuits abstract: The monolithic integration of electronics and photonics has attracted enormous attention due to its potential applications. However, the realization of such hybrid circuits has remained a challenge because it requires optical communication at nanometer scales. A major challenge to this integration is the identification of a suitable material. After discussing the material aspect of the challenge, we identified atomically thin transition metal dichalcogenides (TMDs) as a perfect material platform to implement the circuit. The selection of TMDs is based on their very distinct property: monolayer TMDs are able to emit and absorb light at the same wavelength determined by direct exciton transitions. To prove the concept, we fabricated simple devices consisting of silver nanowires as plasmonic waveguides and monolayer TMDs as active optoelectronic media. Using photoexcitation, direct optical imaging and spectral analysis, we demonstrated generation and detection of surface plasmon polaritons by monolayer TMDs. Regarded as novel materials for electronics and photonics, transition metal dichalcogenides are expected to find new applications in next generation integrated circuits. |
1 | title: Theory of surface plasmons and surface-plasmon polaritons abstract: Collective electronic excitations at metal surfaces are well known to play a key role in a wide spectrum of science, ranging from physics and materials science to biology. Here we focus on a theoretical description of the many-body dynamical electronic response of solids, which underlines the existence of various collective electronic excitations at metal surfaces, such as the conventional surface plasmon, multipole plasmons and the recently predicted acoustic surface plasmon. We also review existing calculations, experimental measurements and applications. |
2 | title: Novel variable separation solutions and exotic localized excitations via the ETM in nonlinear soliton systems abstract: In this paper, first, the ETM is applied to obtain variable separation solutions of (2+1)-dimensional systems. A common formula with some arbitrary functions is derived to describe suitable physical quantities for some (2+1)-dimensional models such as the generalized Nizhnik-Novikov-Veselov, Davey-Stewartson, Broer-Kaup-Kupershmidt, Boiti-Leon-Pempinelli, integrable Kortweg-de Vries (KdV), breaking soliton and Burgers models. The universal formula in Tang, Lou, and Zhang [Phys. Rev. E 66, 046601 (2002)] can be simplified to the common formula in the present paper, which indicates that redundant process is included there since the easier variable separation form can be employed without loss of generality. Second, this method is successfully generalized to (1+1)-dimensional systems, such as coupled integrable dispersionless, long-wave–short-wave resonance interaction and negative KdV models, and obtain another common formula to describe suitable physical fields or potentials of these (1+1)-dimensional model... |
3 | title: The van hove singularity and two-dimensional superconductivity. Exact analytical results abstract: We investigate a weak-coupling approach to superconductivity in the density of states that develops in the two-dimensional lattice with the van Hove singularity located at the Fermi level. Exact analytical expressions forthe superconducting order parameter at zero temperature (Δ(0)) and for discontinuity in the specific heat at critical temperature (ΔC) were derived. We show that the presence of the logarithmic singularity hardly affects the ratio 2Δ(0)/kT c , whereas the temperature dependence of ΔC can pronouncedly deviate from the standard BCS result. |
4 | title: Slowing-down of neutrons by mixtures abstract: In this paper the exact and asymptotic solutions of the transport equation which governs the stationary energy distribution of neutrons slowed down by a mixture of different elements is obtained in the case of a general scattering and capture law. Specific results are shown for particular cases of the dependence of the cross-sections on the neutron velocity. |
5 | title: Magnetization and Lyapunov exponents on a kagome chain with multi-site exchange interaction abstract: Abstract The Ising approximation of the Heisenberg model in a strong magnetic field, with two, three and six spin exchange interactions is studied on a kagome chain. The kagome chain can be considered as an approximation of the third layer of 3 He absorbed on the surface of graphite (kagome lattice). By using dynamical approach we have found one- and multi-dimensional mappings (recursion relations) for the partition function. The magnetization diagrams are plotted and they show that the kagome chain is separating into four sublattices with different magnetizations. Magnetization curves of two sublattices exhibit plateaus at zero and 2/3 of the saturation field. The maximal Lyapunov exponent for multi-dimensional mapping is considered and it is shown that near the magnetization plateaus the maximal Lyapunov exponent also exhibits plateaus. |
6 | title: Longitudinal Instabilities in the Fermilab 400-GeV Main Accelerator abstract: At beam intensities greater than 8 × 1012 protons per pulse longitudinal bunch instabilities are observed in the Fermilab main accelerator. The oscillations are primarily dipole coherent bunch motion with small mixtures of higher order modes. The oscillations grow during acceleration to amplitudes of about ± twenty degrees and remain constant at that amplitude, apparently in equilibrium with the Landau damping process. If sufficient bucket area exists there is no significant beam loss associated with the longitudinal motion but selective extraction and irregular spill structure occurs. \"Mountain range\" data on bunch motion and spectrum analysis of Fourier components of the circulating beam have indicated that the primary sources of the observed instabilities are resonances with high shunt impedances within the accelerating cavities. Although the RF cavities had already been provided with spurious mode damping devices additional damping systems consisting of ferrite loaded coaxial waveguide filters have been designed and are being installed on all accelerating cavities. |
7 | title: Method for producing correct fingerprints. abstract: The conventional method of producing fingerprints by total internal reflection using a right-angle prism does not give true size images. In this case an anamorphic real image is formed by the Scheimpflug condition with keystone distortion. A method of combining a single prism with the right-angle prism for anamorphic stretching to get the correct fingerprint image is described. The method of constructing such a type of an optical system is discussed in detail. The method is useful to directly obtain the correct fingerprints using a CCD camera. |
8 | title: A High Intensity E.C.R. Stripped Ion Source abstract: An ion source based on E.C.R. heating in a magnetic bottle works in our Laboratory since 1964. The characteristics of the plasma are: n = 1012 cm-3; w-\u003e 1 keV ; W+ ~10 eV ; p \u003e 10-5 torr. The microwave power P \u003c 2 1KW at 10 GHz is coupled to the electrons either by a standing wave or a propagating wave. Our preliminary results with a 16 nA beam gave N+ = 44 %; N2+ = 36 % ; N3+ = 14 % ; N4+ = 4 % ; N5+ + N6++ N7+= 2 %. However due to the presence of H+2 the rate of N6+ and N7+ could not be measured correctly. |
9 | title: Effect of Wave Motions in the Active Region of the Solar Surface on Convection abstract: The results of the observations of the active region (facula) near the center of the solar disk obtained with the German Vacuum Tower Telescope (VTT; Tenerife, Spain), are discussed. We have determined that the decrease in the contrast (brightness) of the facula with the magnetic field increasing from 130 to 160 mT is due to the fact that the V_V phase shift of waves in this range of magnetic field densities is close to zero (Φ\n VV\n ≈ 0), i.e., the wave becomes stationary and does not transfer energy from the photosphere to the chromosphere. The sound waves that propagate from the chromosphere towards the photosphere significantly affect the temperature characteristics of turbulent vortices at the level of formation of the continuous spectrum. In particular, the contrast of granules under the influence of these waves can increase by 25%. |
11 | title: Exotic-Hadron Signature by Constituent-Counting Rule in Perturbative QCD abstract: We explain a method to find internal quark configurations of exotic hadron candidates by using the constituent counting rule. The counting rule was theoretically predicted in perturbative QCD for hard exclusive hadron reactions, and it has been tested in experiments for stable hadrons including compound systems of hadrons such as the deuteron, $^3$H, and $^3$He. It indicates that the cross section scales as $d\\sigma /dt \\sim 1/s^{n-2}$, where $s$ is the center-of-mass energy squared and $n$ is the total number of constituents. We apply this method for finding internal configurations of exotic hadron candidates, especially $\\Lambda (1405)$. There is a possibility that $\\Lambda (1405)$ could be five-quark state or a $\\bar K N$ molecule, and scaling properties should be different between the ordinary three-quark state or five-quark one. We predict such a difference in $\\pi^- + p \\to K^0 + \\Lambda (1405)$, and it could be experimentally tested, for example, at J-PARC. On the other hand, there are already measurements for $\\gamma + p \\to K^+ + \\Lambda (1405)$ as well as the ground $\\Lambda$ in photoproduction reactions. Analyzing such data, we found an interesting indication that $\\Lambda (1405)$ looks like a five-quark state at medium energies and a three-quark one at high energies. However, accurate higher-energy measurements are necessary for drawing a solid conclusion, and it should be done at JLab by using the updated 12 GeV electron beam. Furthermore, we discuss studies of exotic hadron candidates, such as $f_0 (980)$ and $a_0 (980)$, in electron-positron annihilation by using generalized distribution amplitudes and the counting rule. These studies should be possible as a KEKB experiment. |
12 | title: A new fast four-dimensional convolution algorithm for the interpretation of neutron scattering data abstract: For inelastic neutron scattering experiments on triple-axis spextrometers, we present a new method for a fast four-dimensional convolution of the scattering function of arbitrary functional form with the resolution function of the instrument for which a Gaussian form is assumed. To demonstrate the capability of this method, it is used for the analysis of experimental data obtained from the magnetic mixed system Rb2Mn0.2Cr0.8Cl4. |
13 | title: Observation of Tunneling Current in Semiconducting Graphene p-n Junctions abstract: We demonstrate a tunneling and rectification behavior in bilayer graphene. A stepped dielectric top gate creates a spatially modulated electric field, which opens the band gap in the graphene and produces an insulating region at the p-n interface. A current-voltage relationship exhibiting differential resistance peak at forward bias stems from the tunneling current through the insulating region at the p-n interface. The tunneling current reflects singularities in the density of states modified by the electric field. This work suggests that the effect of carrier charge tuning by external electric field in 2D semiconductors is analogously to that by impurity doping in 3D semiconductors. |
14 | title: Fiber grating pressure sensor with enhanced sensitivity abstract: ABSTRACT A novel pressure sensor with FBG partly packaged by a metal tube is presented. The thermal-strain cross effect can be avoided. Moreover, its pressure sensitivity is -2.44 10 -3 /MPa with the range from 0 to 0.44 MPa, which is 1200 times as that of a bare fiber grating. The linearity of this sensor reaches 0.9986. Index Terms: Pressure sensor, package, polymer, fiber grating 1. INTRODUCTION Fiber Bragg gratings (FBGs) are widely applied in the field of optical communications and optical sensing technologies 1 . FBG has become an indispensable important sensing component in some fields for its prominent advantages and potential industrial applications 2, 3 . A bare FBG, however, has very low pressure sensitivity ~-2.05 10 -6 /Mpa 4 . Thus improving pressure sensitivity of FBG will contribute to the increase of its precision. The method of enhancing sensitivity is to package FBGs with different materials and structures 5, 6 . The sensitivity can be increased by three orders of magnitude as Zhang |
15 | title: Fabrication and magnetic studies of (Co, Zn)-doped /spl gamma/-Fe/sub 2/O/sub 3/ thin films abstract: A fabrication process for the sputtered (Co, Zn)-doped /spl gamma/-Fe/sub 2/O/sub 3/ thin films with quite a short reduction time (10 minutes) at temperature between 350-370/spl deg/C and with oxidation time about 20 minutes at temperature between 310-330/spl deg/C has been established. It has been observed that, with a few percent of Co and Zn content, the Zn dopant has the effect of producing higher saturation magnetization and better thermal stability of coercivity, as well as better suppressing grain growth effect during the heat treatments when these films are compared to /spl gamma/-Fe/sub 2/O/sub 3/ thin films doped with Co only. \u003e |
16 | title: Clebsch-type coordinates for nonlinear gyrokinetics in generic toroidal configurations abstract: The nonlinear gyrokinetic equations are frequently used as a basis for simulations of small-scale turbulence in magnetized toroidal plasmas. In this context, field-aligned coordinates are usually employed in order to minimize the number of necessary grid points. The present work proposes a system of Clebsch-type coordinates which does not depend on the existence of flux surfaces. The construction and use of these coordinates is explained, and the corresponding formulation of the nonlinear gyrokinetic equations is accomplished. This setup paves the way toward the investigation of nonaxisymmetric toroidal geometries, also in the region of magnetic islands as well as inside the ergodic layer where flux surfaces cease to exist. For testing purposes, in the axisymmetric, large aspect ratio case, the well-known s-α expressions are recovered for closed flux surfaces. Moreover, geometric data for a specific stellarator configuration are computed and discussed. |
17 | title: APPROXIMATE BOUND DIRAC STATES FOR PSEUDOSCALAR HULTHÉN POTENTIAL abstract: In this paper, we present approximate analytical solutions of the Dirac equation with the pseudoscalar Hulthen potential under spin and pseudospin (p-spin) symmetry limits in (3+1) dimensions. The energy eigenvalues and corresponding eigenfunctions are given in their closed forms by using the Nikiforov–Uvarov (NU) method. Numerical results of the energy eigenvalue equations are presented to show the effects of the potential parameters on the bound-state energies. |
18 | title: Solar Convection and Self-Similar Atmosphere’s Structures abstract: We present a new model of large-scale multilayer convection in solar type stars. This model allows us to understand such self-similar structures observed at solar surface as granulation, supergranulation and giant cells. We study the slow-rotated hydrogen star without magnetic field with the spherically-symmetric convective zone. The photons flux comes to the convective zone from the central thermonuclear zone of the star. The interaction of these photons with the fully ionized hydrogen plasma with T\u003e 105K is carried out by the Thompson scattering of photon flux on protons and electrons. Under these conditions plasma is optically thick relative to the Thompson scattering. We find the stationary solution of the convective zone structure. This solution describes the convective layers responsible to the formation of the structures on the stars surface. |
19 | title: Algebro-Geometric Solution to Two New (2+1)-Dimensional Modified Kadomtsev–Petviashvili Equations abstract: Two new (2+1)-dimensional modified Kadomtsev–Petviashvili (mKP) equations are presented, which are related to a hierarchy of (1+1)-dimensional soliton equations. Through the nonlinearization of Lax pair and the Riemann–Jacobi inversion technique, the algebro-geometric solutions of both the mKP equations are obtained. |
20 | title: Future constraints on dynamical dark-energy using gravitational-wave standard sirens abstract: The detection of gravitational waves (GW) by the LIGO and Virgo collaborations offers a whole new range of possible tests and opens up a new window that may shed light on the nature of dark energy and dark matter. In the present work we investigate how future gravitational-wave data could help to constrain different dynamical dark energy models. In particular, we perform cosmological forecastings of a class of well-known and most used dynamical dark energy models using the third-generation gravitational wave detector, the Einstein Telescope. We have considered 1000 simulated GW events in order to constrain the parameter space of the dynamical dark energy models. Our analyses show that the inclusion of the GW data from the Einstein Telescope significantly improves the parameter space of the dynamical dark energy models compared to their constraints extracted from the standard cosmological probes, namely, the cosmic microwave observations, baryon acoustic oscillations distance measurements, supernove type Ia, and the Hubble parameter measurements. |
21 | title: Practical coherent integration with the NPOI abstract: ABSTRACT In this paper we will discuss the current status of coherent integration with the Navy Prototype Optical Inter-ferometer (NPOI). 1 Coherent integration relies on being able to phase reference interferometric measurements,which in turn relies onmakingmeasurementsat multiple wav elengths.We rstdiscuss th e generalizedgroup-delayapproach, then the meaning of the resulting complex visib ilities and then demonstrate how coherent integrationcan be used to perform very precision measurement of ste llar properties. For example, we demonstrate how wecan measure the diameter of a star to a precision of one part in 350, and measure properties of binary stars. Thecomplex phase is particularly attractive as a data product because it is not biased in the same way as visibilityamplitudes. 1. INTRODUCTION At the 2004 and 2006 SPIE meetings we demonstratedhow to coherently integrate NPOI 1 data by tting amodel of the fringes to the raw data and using the t-ting parametersto coherentlyintegratethe complexvis-ibilities from individual frames. |
22 | title: Dominant intrinsic acceptors in GaN and ZnO abstract: Positron annihilation measurements reveal negatively charged Ga vacancies in n-type GaN and Zn vacancies in n-type ZnO. Positron trapping at other negative defects is not observed, indicating that cation vacancies are the dominant acceptors in these materials. The vacancy concentrations are the same as the total acceptor densities determined in Hall experiments, confirming the dominant role of the vacancy defects. The Ga vacancy in GaN is found as the main compensating centre over the range of four orders of magnitude of intentional oxygen doping. |
23 | title: A theoretical study of spin level crossing induced by an external magnetic field of ring molecule magnet models abstract: Abstract The dependence of the magnetization of model systems on an external magnetic field has been investigated. An ab initio path integral Monte Carlo method is used to study the spin level crossing phenomena of molecules with ring structures such as those in the ferric wheel [Fe(OMe)2(O2CCH2Cl)]10. The ab initio treatment is essential to calculate the magnetization in a system with a large contribution from next-neighbor interactions. A possible use as a molecular device for switching or molecular recognition is suggested. |
24 | title: Numerical simulation of charged wire interferometer for atoms abstract: In recent paper, Nowak et al. report a charged wire interferometer for atoms, and employ analytical method to explain the interference patterns [Phys. Rev. Lett. 81 (1998) 5792]. In this paper, a numerical calculation with semi-classical method is carried out and the experimental patterns are rebuilt very well. The interference patterns are interpreted by path integral. We also calculate the fringe period for different voltages and the agreement with experiment is more rigorous than the analytical expression. Besides, the fringe visibility of the interference patterns at different applied voltages and degrees is also discussed. |
25 | title: A Planar CMOS Field-Emission Vacuum Magnetic Sensor abstract: We have fabricated a CMOS vacuum magnetic sensor that exploits the deflection of an electron beam produced by field emission by a perpendicular magnetic field. The device is planar and fabricated by conventional lithography and etching processes. An extremely high magnetic field sensitivity of 4times103%/T is reported. |
26 | title: Advantages and Disadvantages of the MERIT Campaigns abstract: The campaigns of the programme of international cooperation, called MERIT, for the determination of the earth rotation parameters are reviewed, especially about the difficulties to infer results about polar motion from such short intervals of observations. It is pointed out the need to employ the same models and standards in order to facilitate the comparison of data obtained by classical and modern techniques.\r\n\r\n\r\n\r\nLes campagnes du programme de cooperation internationale, appelle Merit, pour la determination des parametres de la rotation de la terre, sont analysees, specialement pour les difficultes d\u0027inferer des resultats sur le mouvement du pǒle a partir des campagnes courtes. Il est souligne la necessite d\u0027employer les měmes modeles et constants pour avoir une comparaison valable des donnees obtenues par les techniques classiques et modernes. |
27 | title: Discrete Spectrum of the Graviton in the $AdS^5$ Black Hole Background abstract: The discrete spectrum of fluctuations of the metric about an $AdS^5$ black hole background are found. These modes are the strong coupling limit of so called glueball states in a dual 3-d Yang-Mills theory with quantum numbers $J^{PC} = 2^{++}, 1^{-+}, 0^{++}$. For the ground state modes, we find the mass relation: $m(0^{++}) \u003c m(2^{++}) \u003c m(1^{-+})$. Contrary to expectation, the mass of our new $0^{++}$ state ($m^2=5.4573$) associated with the graviton is smaller than the mass of the $0^{++}$ state ($m^2=11.588$) from the dilaton. In fact the dilatonic excitations are exactly degenerate with our tensor $2^{++}$ states. We find that variational methods gives remarkably accurate mass estimates for all three low-lying levels while a WKB treatment describes the higher modes well. |
28 | title: Accelerators and x-rays in cultural heritage investigations abstract: Abstract In the following article a review is given on the use of accelerators in studies connected to our cultural heritage. It focuses on making use of the production and detection of x-rays as a general tool. At “small accelerators”, the proton induced x-ray emission (PIXE), especially when combined with Rutherford backscattering spectroscopy (RBS), has been developed to a very versatile and powerful technique for near-surface investigations. It is well complemented by larger facilities, synchrotron radiation sources as well as medium energy ion accelerators for high energy PIXE. With the development of small compact electron accelerators, a new generation of mono-energetic high-energy high-intensity x-ray sources will add a very comfortable complement in cultural heritage studies. To cite this article: H.-E. Mahnke et al., C. R. Physique 10 (2009). |
29 | title: Dimensionality effect on two-electron energy spectrum: A fractional-dimension-based formulation abstract: Abstract We analyze the spectrum of two-electron quantum dot with anisotropic parabolic confinement by using the fractional-dimension formulation which allows us to reduce the two-particle problem to two equations for independent particles in an effective space with variable dimension, ranging between two and three for ellipsoidal-shaped quantum dots and between one and two for elliptical-shaped quantum disks. The dependencies of energy levels on the heterostructure sizes for quantum dots, disks and wires are presented. |
30 | title: Zonostrophic instability driven by discrete particle noise abstract: The consequences of discrete particle noise for a system possessing a possibly unstable collective mode are discussed. It is argued that a zonostrophic instability (of homogeneous turbulence to the formation of zonal flows) occurs just below the threshold for linear instability. The scenario provides a new interpretation of the random forcing that is ubiquitously invoked in stochastic models such as the second-order cumulant expansion or stochastic structural instability theory; neither intrinsic turbulence nor coupling to extrinsic turbulence is required. A representative calculation of the zonostrophic neutral curve is made for a simple two-field model of toroidal ion-temperature-gradient-driven modes. To the extent that the damping of zonal flows is controlled by the ion–ion collision rate, the point of zonostrophic instability is independent of that rate. |
31 | title: Evanescent wave coupling for piezoelectric excitation of coherent THz acoustic phonons abstract: Abstract We introduce a technique for generating coherent acoustic phonons at THz frequencies. By employing a prism for evanescent wave coupling, we ensure that the driving laser field is present in a thin surface region of the piezoelectric crystal, but is negligible farther inside. Thus the unwanted production of incoherent acoustic phonons by two-phonon decay is greatly reduced. Preliminary experiments in quartz are described that use a germanium prism and a high power far-infrared laser. |
32 | title: A precise determination of BK in quenched QCD abstract: Abstract The B K parameter is computed in quenched lattice QCD with Wilson twisted mass fermions. Two variants of tmQCD are used; in both of them the relevant Δ S = 2 four-fermion operator is renormalised multiplicatively. The renormalisation adopted is non-perturbative, with a Schrodinger functional renormalisation condition. Renormalisation group running is also non-perturbative, up to very high energy scales. In one of the two tmQCD frameworks the computations have been performed at the physical K -meson mass, thus eliminating the need of mass extrapolations. Simulations have been performed at several lattice spacings and the continuum limit was reached by combining results from both tmQCD regularisations. Finite volume effects have been partially checked and turned out to be small. Exploratory studies have also been performed with non-degenerate valence flavours. The final result for the RGI bag parameter, with all sources of uncertainty (except quenching) under control, is B ˆ K = 0.789 ± 0.046 . |
33 | title: The Korteweg-de Vries equation on an interval abstract: The initial-boundary value problem (IBVP) for the Korteweg-de Vries (KdV) equation on an interval is studied by extending a novel approach recently developed for the well-posedness of the KdV on the half-line, which is based on the solution formula produced via Fokas’ unified transform method for the associated forced linear IBVP. Replacing in this formula the forcing by the nonlinearity and using data in Sobolev spaces suggested by the space-time regularity of the Cauchy problem of the linear KdV gives an iteration map for the IBVP which is shown to be a contraction in an appropriately chosen solution space. The proof relies on key linear estimates and a bilinear estimate similar to the one used for the KdV Cauchy problem by Kenig, Ponce, and Vega.The initial-boundary value problem (IBVP) for the Korteweg-de Vries (KdV) equation on an interval is studied by extending a novel approach recently developed for the well-posedness of the KdV on the half-line, which is based on the solution formula produced via Fokas’ unified transform method for the associated forced linear IBVP. Replacing in this formula the forcing by the nonlinearity and using data in Sobolev spaces suggested by the space-time regularity of the Cauchy problem of the linear KdV gives an iteration map for the IBVP which is shown to be a contraction in an appropriately chosen solution space. The proof relies on key linear estimates and a bilinear estimate similar to the one used for the KdV Cauchy problem by Kenig, Ponce, and Vega. |
34 | title: Dye-sensitized solar cells based on surficial TiO2 modification abstract: Abstract Dye-sensitized solar cells (DSSCs) have been more systematically studied for many years. All kinds of innovative design of photoanode materials have paved the way to improve the photoelectric conversion efficiency (η) of DSSCs. New technological advancements, like preparation of nano-TiO2 and surface modification, have had a positive effect on improving η of DSSCs in recent years. The low-cost TiO2 become promising photoanode materials due to its strong adsorption capacity, not anti-light corrosion, good acid and alkali resistance and excellent biocompatibility. Excited dye molecules transfer electrons to the conduction band of the TiO2 and then to the external circuit through the TiO2 substrates. The photoelectron production, transfer, and output are related to TiO2, the dye/TiO2 interface and electrolyte/TiO2 interface. Among them, the loss of electrons is mainly due to I3− trapping electrons on the dye/TiO2 interface and electrolyte/TiO2 interface. Therefore, it is a very effective method for modifying the surface of TiO2 to reduce the loss of electrons during the process, thereby improving η of DSSCs. This review studies the preparation of nano-TiO2 and surface modification, which have an effect on improving η of DSSCs. At the same time, according to the development situation of DSSCs based on TiO2 photoanode, the common TiO2 modification methods are summarized to analyze the effects of different modification methods on DSSCs. |
35 | title: HREM surface profile images of Bi2Sr2CaCu2O8 abstract: Surface profile images of Bi2Sr2CaCu2O8 have been obtained using high-resolution electron microscopy. The cleaved (001) surface of the crystals terminates with a single Bi-O atomic layer. The modulated structure developed in this surface atomic layer was observed directly. The (hk0) surfaces were found to decompose in air into an amorphous coating layer. This coating layer was unlikely recrystallized into the original structure under electron beam irradiation. The amorphous layer on the (hk0) surface formed in pure Ar atmosphere was relatively thin and could be recrystallized into some secondary phases in which a Bi loss was observed. The original (001) surface might also be covered by an amorphous-like layer. This disordered layer could be recrystallized under electron beam irradiation into BiSr2Ca2Cu3O9, BiSr2CuO5, etc. which intergrow with the parent crystal perfectly on the (001) planes. |
37 | title: Microscopic description of exclusive one-nucleon transfer processes at medium energies abstract: Different aspects of exclusive stripping reactions at medium energies with particular emphasis on the proton-induced pion production on a nuclei are represented. In the first part of the paper the basic ideas of the various models currently used for the description of one-nucleon transfer processes are critically discussed; their successes and failures are demonstrated in comparison with experimental results. In the second part of the article we present a sketchy outlook on experiments to clarify the present theoretical uncertainties as well as on theoretical developments to be expected in the near future. |
38 | title: Single Dirac cone on the Cs-covered topological insulator surface Sb 2 Te 3 (0001) abstract: Using angle-resolved photoelectron spectroscopy we investigate the surface electronic structure of the three-dimensional topological insulator (TI) Sb${}_{2}$Te${}_{3}$(0001). Our data show the presence of a topological surface state in the bulk energy gap with the Dirac point located above the Fermi level. The adsorption of Cs atoms on Sb${}_{2}$Te${}_{3}$(0001) gives rise to a downward energy shift of the electronic valence band states which saturates at a value of $\\ensuremath{\\sim}$200 meV. For the saturation coverage the Dirac point of the linearly dispersive surface state resides in close proximity to the Fermi level. The electronic structure of the Cs/Sb${}_{2}$Te${}_{3}$ interface therefore considerably deviates from previously studied metal-TI interfaces based on the isostructural compound Bi${}_{2}$Se${}_{3}$ which points to the importance of atomic composition in these hetero systems. |
39 | title: Fabrication of a High-Throughput Cantilever-Style Aperture Tip by the Use of the Bird’s-Beak Effect abstract: A fabrication technique for a high-throughput cantilever-style aperture tip is described. Using the bird\u0027s-beak effect due to the stress caused by Si3N4 film in the field oxidation of silicon, we fabricated a near-field aperture with a diameter of about 100 nm which has a throughput of more than 1000 times that of the pyramidal pit. |
40 | title: VII. On the velocity of second sound in liquid helium ii abstract: Abstract Some recent experiments by Atkins and Osborne (1950) in the Mond Laboratory give values for the velocity of second sound at very low temperatures in close agreement with Landau\u0027s (1941) predictions. It is shown that such results cannot be obtained from any theory of Tisza-London type, unless it is postulated that other states besides the very lowest one contribute to ρs , the density of superfluid. Landau\u0027s (1941) method of calculating ρs can be applied to any model and does imply such a postulate. It is concluded that the experimental results only throw light on the correct method of calculating ρ s and cannot be regarded as evidence in favour of Landau\u0027s quantum hydrodynamics. On the other hand, the fact that liquid He3 a does not show superfluid properties can no longer be regarded as evidence against Landau\u0027s theory, as the predictions of the Landau and Tisza-London types of theory are identical for both the perfect Bose-Einstein and the perfect Fermi-Dirac gases. |
41 | title: Marine cloud brightening abstract: The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action. |
42 | title: Inverse natural convection problem of simultaneous estimation of two boundary heat fluxes in irregular cavities abstract: Abstract This paper deals with the use of the Conjugate Gradient Method of function estimation with Adjoint Problem for the simultaneous identification of two boundary conditions in natural convection inverse problems in two-dimensional irregular cavities. The unknown boundary conditions are estimated with no a priori information about their functional forms. Irregular geometries in the physical domain are transformed into regular geometries in the computational domain by using an elliptic scheme of numerical grid generation. Therefore, the proposed formulation can be applied to the solution of inverse problems in different geometries. The methodology is applied to cases involving an annular cavity, where the position- and time-dependent heat fluxes are unknown at the inner and outer surfaces. The effects of the number and position of temperature sensors on the inverse problem solution are also addressed in the paper. |
44 | title: On wave-breaking free fiber lasers mode-locked with two saturable absorber mechanisms abstract: We propose a hybrid mode-locking scheme for wave-breaking free fiber lasers based on a saturable Bragg reflector and the nonlinear polarization evolution in the fiber section. With this scheme, the self-starting operation is ensured by the saturable Bragg reflector while the nonlinear polarization evolution acts as an additional pulse shaper in the steady state. Owing to the sensitivity of the pulse dynamics to filtering effects, a tuning range of more than 10nm as well as the suppression of undesired modes of operation became possible. The impact of the modulation depth and the non-saturated losses is discussed via comparative measurements with different saturable Bragg reflectors. |
45 | title: Mantle convection and visoelasticity abstract: The ongoing revolution in the Earth sciences, which began more than twenty years ago, was originally based upon the increasingly widespread acceptance of the idea that continental masses have moved horizontally with respect to one another throughout geological time. This hypothesis of continental \"drift,\" or at least the form of the hypothesis that came to be called seafloor spreading, now serves as the basic paradigm for the organization of most geological and geophysical research. At the center of this guiding principle is the recognition that the solid outer shell of the planet-its iron-magnesium silicate \"mantle,\" which occupies roughly half Earth\u0027s radial extent-must be able to deform as a viscous fluid when it is subjected to an applied shear stress over geological intervals of time. To the extent that this rheological ansatz is correct, it is clear that a thermally induced convective circulation must appear in the mantle in response to a radial temperature gradient that is sufficiently in excess of adiabatic. The observed spreading of the seafloor away from hot mid-oceanic ridges is presumably a surface manifestation of such deep seated mantle convection. Likewise, the deep ocean trenches are under stood to be regions where cold surface material returns to the mantle to complete the circulation. These and other aspects of the pattern of surface motions associated with mantIe convection have been described kinemati cally within the framework of a set of ideas that has come to be called \"plate tectonics.\" The development of this set of ideas has consummated the revolution at a descriptive level and has delivered as its main product a clear view of the velocity field of material at the Earth\u0027s surface at the present epoch of geological time. In so doing, it has also contributed in an |
46 | title: Über die Halbleitereigenschaften des Kupferoxyduls. VII Der Halleffekt unterhalb der Zimmertemperatur abstract: Es werden Messungen des Halleffektes und der Leitfahigkeit an Cu2O im Temperaturbereich von +50° C bis −150° C mitgeteilt, das bei 960° C und bei einem Sauerstoffdruck zwischen 30 und 1 · 10−3 Torr getempert und schnell abgekuhlt wurde. Bei 2 Torr zeigt die Hallkonstante R, die dem Vorzeichen nach positiv ist, ein Maximum, wahrend die Leitfahigkeit χ beim gleichen Druck ein Minimum aufweist. Ferner ist der Sauerstoffdruck 2 Torr dadurch ausgezeichnet, das das Produkt R·χ das ein Mas fur die Ladungstragerbeweglichkeit ist, zwischen −60° und −100° C schneller ansteigt als bei anderen Temperungsdrucken. |
47 | title: A Gaia-Enceladus Analog in the EAGLE Simulation: Insights into the Early Evolution of the Milky Way abstract: We identify a simulated Milky Way analog in the EAGLE suite of cosmological hydrodynamical simulations. This galaxy not only shares similar global properties as the Milky Way, but was specifically selected because its merger history resembles that currently known for the Milky Way. In particular we find that this Milky Way analog has experienced its last significant merger (with a stellar mass ratio $\\sim 0.2$) at $z\\sim 1.2$. We show that this merger affected both the dynamical properties of the stars present at the time, contributing to the formation of a thick disk, and also leading to a significant increase in the star formation rate of the host. This object is thus particularly suitable for understanding the early evolutionary history of the Milky Way. It is also an ideal candidate for re-simulation with much higher resolution as this would allow addressing a plethora of interesting questions such as, for example, the specific distribution of dark matter near the Sun. |
48 | title: Non-uniform field distribution in avalanching InSb crystals abstract: The electric field distribution and current–voltage characteristic in the avalanche region is calculated for InSb crystals of both n- and p-type. It is shown that space charge effects make the field distribution highly non-uniform when the transit time is short compared to the carrier lifetime. A current controlled negative differential resistance may also be developed due to the same effects.\r\n\r\n\r\n\r\nDie elektrische Feldstarke und die Strom–Spannungscharakteristik in der Lawinenzone werden fur n- und p-leitende InSb-Kristalle berechnet. Wenn die Laufzeit der Ladungstrager im Verhaltnis zur Lebensdauer klein ist, zeigen sich auf Grund von Raumladungseffekten grose Abweichungen von der Homogenitat in der elektrischen Feldstarke. Aus dem gleichen Grund entsteht ein durch den Strom kontrollierter negativer differentieller Widerstand. |
49 | title: Trapping of coherence and entanglement in photonic band-gaps abstract: Abstract We investigate the coherence trapping of a two-level atom transversally interacting with a reservoir with a photonic band-gap structure function. We then focus on the multipartite entanglement dynamics via genuinely multipartite concurrence among N independent atoms each locally coupled with its own reservoir. By considering the Lorentzian width and the system size, we find that for the resonant and near-resonant conditions, the increase of Lorentzian width and the decrease of system size can lead to the occurrence of coherence trapping and entanglement trapping. By choosing the multipartite GHZ state as atomic initial state, we show that the multipartite entanglement may exhibit entanglement sudden death depending on the initial condition and the system size. In addition, we also analyze how the crossover behaviors of two dynamical regimes are influenced by the Lorentzian width and the weight ratio, in terms of the non-Markovianity. |
50 | title: Limiting efficiency of generalized realistic c-Si solar cells coupled to ideal up-converters abstract: The detailed balance model of photovoltaic up-conversion is revised for the specific case of a c-Si solar cell under the AM1.5G solar spectrum. The limiting efficiency of an ideal solar cell with a band gap of 1.117 eV may be increased from approximately 33% to 40% with ideal up-conversion. However, real solar cells do not demonstrate the step-function absorption characteristic assumed in the standard detailed balance model. Here, we use tabulated Si refractive index data to develop a generalized model of a realistic conventional c-Si solar cell. The model incorporates optical design and material parameters such as free carrier absorption that have a non-trivial impact on the operation of the up-conversion layer. While these modifications are shown to decrease the absolute limiting efficiency, the benefit of up-conversion is shown to be relatively greater. |
51 | title: Occurrence of Maximum Quantum and Thermal Detection Efficiencies Attainable with a Planckian Radiator abstract: The occurrence of maximum quantum or thermal detection efficiency (defined here as the ratio of utilized photons or energy to the total emitted by a Planckian radiator) was determined theoretically as a function of the absorption edge and bandwidth of the detector, and the temperature of the Planckian radiator. It is assumed that the quantum or thermal efficiency of the detector is constant within the bandwidth in question and zero elsewhere. The application of the specific results derived here is limited to source–detector combinations where the source spectral energy or photon distribution approximates that of a Planckian radiator. A “noise level” and its effect on the efficiency are not considered in the present analysis. The outcome of the analysis is a series of “displacement laws” which are similar to the Wien displacement law, λmT=0.2898 cm °K.It is shown that the temperature should be increased for maximum efficiency as the bandwidth of the detector is increased. |
52 | title: Can a Hot-Carrier Solar Cell also be an Efficient Up-converter? abstract: The hot-carrier solar cell is a very ambitious device concept, which has a thermodynamic efficiency limit of around 84% when operated at the maximum power point. However, if the same device is instead operated at open circuit, then it becomes an efficient radiator of blackbody radiation at the temperature of the hot carriers. Such a configuration is similar to a thermal photovoltaic converter, but one in which the thermal gradient is maintained by a hot electron–hole gas rather than by a physically hot lattice. In this scheme (see Fig. 1 ), a low-bandgap hot-carrier material is placed behind a conventional solar cell and absorbs sub-bandgap photons, generating a hot-carrier distribution which re-radiates this energy, some of which can be collected by the solar cell located above. The additional photons have been thermally up-converted by a “hot-carrier radiator.” We will discuss the thermodynamic efficiency limit of a hot-carrier radiator placed behind a conventional single-junction solar cell, and present some experimental results toward developing a proof-of-concept device using strain-balanced quantum wells. |
53 | title: Magnetoresistance in La2/3Ca1/3MnO3/La2/3Sr1/3CoO3 bilayers abstract: Abstract Perovskite La 2/3 Ca 1/3 MnO 3 (LCMO)/La 2/3 Sr 1/3 CoO 3 (LSCO) and LSCO/LCMO bilayer films have been fabricated on single-crystal NdGaO 3 substrates (1 1 0), and their transport and magnetic properties have been investigated. The magnetoresistance of the bilayer LSCO/LCMO is about 1.7% under the field of 10 kOe at 230 K, whereas that of the bilayer LCMO/LSCO is larger and is ∼10%. A waist-like hysteresis loop occurs in LSCO/LCMO, while a single-step one in LCMO/LSCO. The behavior is explained by some magnetic coupling. |
54 | title: Polarization transfer in hyperon decays and its effect in relativistic nuclear collisions abstract: We calculate the contribution to the polarization of $\\Lambda$ hyperons in relativistic nuclear collisions at high energy from the decays of $\\Sigma^*(1385)$ and $\\Sigma^0$, which are the predominant sources of $\\Lambda$ production besides the primary component, as a function of the $\\Lambda$ momentum. Particularly, we estimate the longitudinal component of the mean spin vector as a function of the azimuthal angle in the transverse plane, assuming that primary $\\Sigma^*$ and $\\Sigma^0$ polarization follow the predictions of local thermodynamic equilibrium in a relativistic fluid. Provided that the rapidity dependence around midrapidity of polarization is negligible, we find that this component of the overall spin vector has a very similar pattern to the primary one. Therefore, we conclude that the secondary decays cannot account for the discrepancy in sign between experimental data and hydrodynamic model predictions of the longitudinal polarization of $\\Lambda$ hyperons recently measured by the STAR experiment at RHIC. |
55 | title: β-functions for the Green-Schwarz superstring abstract: Abstract We describe the calculation of one- and two-loop radiative corrections for the heterotic superstring σ-model described by the Green-Schwarz action in a supergravity-Yang-Mills background. The corresponding β-functions vanish when the superspace equations of motion for the coupled supergravity-Yang-Mills system are satisfied. |
56 | title: NUMERICAL SIMULATION OF RAREFIED SUSPENSION SEDIMENTATION IN A CONTAINER abstract: The evolution of the large-scale velocity perturbations in a homogeneous suspension sedimenting in a rectangular container with rigid horizontal walls and periodic conditions on the vertical boundaries is considered. Numerical simulation of the point-particle motion showed that the density and velocity fluctuations decrease with time. The perturbations are damped due to reshaping of the sedimentation front and the nonlinear interaction of the different modes. |
57 | title: Magnetic coupling in amorphous Co–Er films abstract: Amorphous Co100−XErX thin films have been prepared by rf sputtering and their magnetic properties have been studied. The mean field theory has been used to explain the temperature dependence of the magnetization. High-field magnetization studies performed at 4.2 K in magnetic fields up to 5.5 T on amorphous Co100−XErX alloys have revealed, for samples with stoichiometry close to that of a compensated ferrimagnet, a magnetic behavior that is characteristic of a noncollinear magnetic structure of the Er and Co sublattices. From the noncollinear regime the exchange interactions between the Co and Er magnetic sublattices have been accurately evaluated. |
58 | title: Development of low‐energy oxygen ion beams for surface studies abstract: A small microwave ion source has been constructed to generate low‐energy (5–10 eV) oxygen beams. The source is fabricated from a quartz tube and is enclosed by a microwave cavity. The source is operated without an external extraction voltage. Positive ions effuse from the source with energies equal to the plasma potential. The source has been operated in a cw mode producing an atomic oxygen ion fluence \u003e1×1014 cm−2 s−1 with energies as low as 5.5 eV. The ‘‘self‐extracted’’ ion beam can be used to simulate the oxygen environment encountered in low earth orbits. |
59 | title: Recovery time of Bi-2223/Ag HTS tape after quench by short-time over-current abstract: Recovery time of Bi-2223/Ag HTS tapes after quench by short-time AC over-current has been observed. The experiment is carried out using an electromagnetic switching circuit. In order to confirm the state of the tape, a small DC current is fed continuously to the tape. The HTS tape is immersed in liquid nitrogen bath. The duration of the over-current is about 100-200 ms (5-10 cycles in 50 Hz), and the magnitude of the transient AC current is 150 A which is about 3 times larger than the DC critical current of the tape. The experimental result shows that the normal voltage generated by the over-current disappears about 2 ms after the end of the over-current. In addition to the experiment on HTS tapes, an experiment on a HTS coil wound by Bi-2223/Ag HTS tape is carried out. Also from this experiment good superconducting-to-normal-conducting recovery characteristics are confirmed. These experimental results will encourage the possibility of many applications of HTS tapes to power apparatus. |
60 | title: Domain wall junctions as vortices: static structure abstract: For a model system with a complex scalar field static topological solutions are found analytically. Various domain wall structures are discussed and especially the junction of three different domains (called Y-type junctions) is studied in detail. It is shown that these junction structures are equivalent to a vortex with winding number k = 1. |
61 | title: Saturation-induced frequency shift in the noise spectrum of a birefringent vertical-cavity surface emitting laser. abstract: We show by means of analytical and numerical calculations that saturation, in combination with the linewidth-enhancement factor and the finite rate of spin–flip processes, causes a redshift of the spontaneous-emission peak with respect to the off-lasing-mode frequency in the optical spectrum of a quantum-well vertical-cavity surface emitting laser. |
62 | title: Position Shift Analysis in Resist Reflow Process for Sub-50 nm Contact Hole abstract: Contact hole (CH) patterning, especially for the sub-50 nm node, is one of the most difficult techniques in optical lithography. The resist reflow process (RRP) can be used to obtain smaller CHs. RRP is a simple technique in which the resist, after the development process, is baked above the glass transition temperature. Heating causes resist flow, and smaller CHs can be obtained. However, RRP is an unmanageable method because of the CH offset caused by the pattern position in random array CHs. Thus we tried optical proximity correction to find a uniform critical dimension (CD) for every CH, and we obtained uniform CDs for every CH after RRP. However, we still have a CH position shift problem. Because of the difference in the amount of resist that flows into the hole in a random array during the reflow process, position shift occurs. This position shift causes an overlay error, which may exceed the overlay error budget suggested in the ITRS roadmap. In this work, we try to determine not only uniform CD size of each CH, but also the optimum conditions for correcting CH position shift by homemade simulation. Moreover, we checked the behavior of CH position shift by e-beam lithography. Consequently, we confirmed that CHs shifted in a receding direction from each other, and obtained sub-50 nm CHs in a random array by considering the position shift by simulation and experiment. |
63 | title: A modified lattice Bhatnagar-Gross-Krook model for axisymmetric thermal flow abstract: Abstract In this paper, a modified lattice Bhatnagar-Gross-Krook (LBGK) model for axisymmetric thermal flow is proposed. In the model, two tunable parameters related to the relaxation times are available by introducing additional gradient terms into the equilibrium functions. By doing so, the values of the dimensionless relaxation times in the LBGK model can be kept in a proper range, and thus the stability of the LBGK model can be improved. Local schemes for the calculation of the additional gradient terms are presented to keep the intrinsic merit of LB. Also, some correction terms are introduced into the evolution function for the temperature field to eliminate the deviation terms exist in the previous LBGK model. Chapman-Enskog analysis demonstrates that the macro equations in the cylindrical coordinates system can be exactly recovered. Numerical tests, including thermal flow in a pipe, thermal Womersley flow and natural convection in a vertical annulus, have been carried out, and the results predicted by the present LBGK model agree well with the existing numerical data. Also, numerical results demonstrate that the present model is superior to the existing LBGK model for axisymmetric thermal flow in term of numerical stability. |
64 | title: Planar microwave imaging camera for biomedical applications: Critical and prospective analysis of reconstruction algorithms abstract: This paper is dealing with the biomedical applications of active microwave imaging. As a result of extensive preliminary evaluations conducted by means of a 2.45-GHz planar camera, it has been proven that active microwave imaging is able to provide a very sensitive means of investigation in such applications. While technological problems have been conveniently solved, the main problem still remains to determine the most efficient way to process the measured data in order to get the best quality of the reconstructed images. Until now, diffraction tomography algorithms based on a spectral approach have been used. The main limitations of this approach and some attempts to reduce them are analyzed. A more prospective discussion allows to identify the most promising reconstruction techniques. Among them, iterative space-domain formulations appear to provide a suitable base for achieving quantitative imaging thanks to a convenient use of the available a priori information. |
65 | title: Interpretation of Γ[jk]i in a Huygens Model abstract: We describe a classical field theory based on Huygens\u0027 principle which is characterized by an additional degree of freedom which, to our knowledge, has not been discussed previously. This additional degree of freedom asserts that the forward propagation cone is different from the backward cone. The purpose of this paper is to find a function which describes this degree of freedom, and next, to understand this effect in reference to other theories. We find that this additional degree of freedom can be described by means of Γ[jk]i. The object Γ[jk]i is then related to the torsion of a preferred‐frame geometric theory. The additional degree of freedom is of interest since it enables one to introduce Γ[jk]i in a framework involving characteristic equations, described by gij, and bicharacteristics described by Γ(jk)i, such that the role of Γ[jk]i can be understood. Also, the theory furnishes a generalized framework for gravitational theory. Paths with noncontinuous slopes appear also in Feynman\u0027s path‐integral... |
66 | title: Landau damping in the presence of an electrostatic field abstract: A kinetic formulation of Landau damping in the presence of a small‐scale electrostatic field is given. Magnetospheric plasma waves are often subjected to such electric field configurations. It is argued that the resulting dispersion of plasma waves and their damping or growth rate may help in developing a diagnostic tool. |
67 | title: Topological defects in the crystalline state of one-component plasmas of nonuniform density. abstract: We study the ground state properties of classical Coulomb charges interacting with a 1/r potential moving on a plane but confined either by a circular hard-wall boundary or by a harmonic potential. The charge density in the continuum limit is determined analytically and is nonuniform. Because of the nonuniform density there are both disclinations and dislocations present and their distribution across the system is calculated and shown to be in agreement with numerical studies of the ground state (or at least low-energy states) of N charges, where values of N up to 5000 have been studied. A consequence of these defects is that although the charges locally form into a triangular lattice structure, the lattice lines acquire a marked curvature. A study is made of conformal crystals to illuminate the origin of this curvature. The scaling of various terms which contribute to the overall energy of the system of charges, viz., the continuum electrostatic energy, correlation energy, surface energy (and so on) as a function of the number of particles N is determined. \"Magic number\" clusters are those at special values of N whose energies take them below the energy estimated from the scaling forms and are identified with charge arrangements of high symmetry. |
68 | title: Simultaneous optimisation of filter bandwidths and interferometer free spectral range for DPSK and DQPSK modulation abstract: The authors investigate the optimal bandwidths for transmitter and receiver filters for differential phase-shift keying (DPSK) and differential quadrature phase-shift keying (DQPSK) optical modulation in dense wavelength-division multiplexing (WDM) scenarios. Single-channel setups were investigated as reference. Simultaneously, the optimal free spectral range (FSR) of the delay interferometer (DI) needed at the receiver for both modulation formats was searched. Transmitter (Tx) and receiver (Rx) optimal setups were focused and the propagation effects were not considered. It is demonstrated that the optimal FSR, in general, is larger than the symbol rate for both DPSK and DQPSK modulation formats. |
69 | title: Collective Ferromagnetism of Fermi-Degenerate Atomic Gas abstract: We study spin asymmetry of the ground states for the trapped spin-degenerate (two-component) gases of the fermionic atoms in case that interparticle interaction between different spin components is repulsive. Density distributions are algebraically obtained from the Thomas–Fermi equation. We show that, for the system with a larger particle number than a critical value, the asymmetric (ferromagnetic) states are more stable than the spin-symmetric (paramagnetic) ones. The density profiles show that the spin-asymmetry occurs in the central regions of the trapped gas, and grows up with increasing particle number. We also discuss the realization of these ferromagnetic states in atom gases trapped in the optical potentials and suggest experimental conditions to perform it. |
71 | title: The Dynamics of Microtubule/Motor-Protein Assemblies in Biology and Physics abstract: Many important processes in the cell are mediated by stiff microtubule polymers and the active motor proteins moving on them. This includes the transport of subcellular structures (nuclei, chromosomes, organelles) and the self-assembly and positioning of the mitotic spindle. Little is understood of these processes, but they present fascinating problems in fluid-structure interactions. Microtubules and motor proteins are also the building blocks of new biosynthetic active suspensions driven by motor-protein activity. These reduced systems can be probed—and modeled—more easily than can the fully biological ones and demonstrate their own aspects of self-assembly and complex dynamics. I review recent work modeling such systems as fluid-structure interaction problems and as multiscale complex fluids. |
72 | title: The STAR Forward GEM Tracker abstract: Abstract The STAR collaboration is preparing a forward tracking detector upgrade, the Forward GEM Tracker (FGT), to provide fundamental studies of the proton spin structure and dynamics in high-energy polarized proton–proton collisions at RHIC at BNL. The FGT is based on triple-GEM technology employing the industrial production of GEM foils by Tech-Etch Inc. and a laser-etched two-dimensional readout board manufactured by Compunetics Inc. The FGT project has completed an extensive R\u0026D program of industrially produced GEM foils at Tech-Etch Inc. in comparison to GEM foils produced at CERN based on optical measurements and 55Fe source and testbeam measurements of a triple-GEM prototype detector using 10 × 10 cm 2 GEM foils. The FGT project requires large GEM foils which are currently being tested. |
73 | title: Role of Gribov's inelastic screening in the nucleus-nucleus interactions at high energies abstract: It is found that the inclusion of Gribov’s inelastic screening within the quasieikonal approach generalized to the case of nucleus-nucleus interactions leads to a significant decrease (∼18%) in the number of “wounded” nucleons and in the multiplicity of intranuclear collisions in central interactions between nuclei. This can significantly affect experimental estimates of the degree of “quenching” of jets and hydrodynamic calculations of the behavior of the quark-gluon plasma appearing in the indicated interactions. |
74 | title: Table-like magnetocaloric effect in Gd–Ni–Al amorphous/nanocrystalline composites abstract: In this work, Gd-Ni-Al amorphous/nanocrystalline composites produced by melt-spinning method with double magnetocaloric effect (MCE) plateaus have been developed. Two MCE plateaus, similar to 4.7 J kg(-1) K-1 (90-120 K) and similar to 3.60 J kg(-1) K-1 (250-275 K), were discovered in Gd80Ni11.6Al8.4 for a magnetic field change of 0 to 5 T. For Gd90Ni5.8Al4.2, the plateau values are similar to 3.90 J kg(-1) K-1 (85-120 K) and similar to 6.70 J kg(-1) K-1 (265-280 K) for a magnetic field change of 0-5 T. The reason why MCE plateau formation was investigated and discussed. These composites having two MCE plateaus are competitive candidates for the ideal Ericsson cycle. |
75 | title: Structural distortion behind the nematic superconductivity in Sr x Bi2Se3 abstract: An archetypical layered topological insulator Bi2Se3 becomes superconductive upon doping with Sr, Nb or Cu. Superconducting properties of these materials in the presence of in-plane magnetic field demonstrate spontaneous symmetry breaking: 180◦-rotation symmetry of superconductivity versus 120◦-rotation symmetry of the crystal. Such behavior brilliantly confirms nematic topological superconductivity. To what extent this nematicity is due to superconducting pairing in these materials, rather than due to crystal structure distortions? This question remains unanswered, because so far no visible deviations from the 3-fold crystal symmetry were resolved in these materials. To address this question we grow high quality single crystals of Sr x Bi2Se3, perform detailed x-ray diffraction and magnetotransport studies and reveal that the observed superconducting nematicity direction correlates with the direction of small structural distortions in these samples (~0.02% elongation in one crystallographic direction). Additional anisotropy comes from orientation of the crystallite axes. 2-fold symmetry of magnetoresistance observed in the most uniform crystals well above the critical temperature demonstrates that these structural distortions are nevertheless strong enough. Our data in combination with strong sample-to-sample variation of the superconductive anisotropy parameter are indicative for significance of the structural factor in the apparent nematic superconductivity in Sr x Bi2Se3. |
76 | title: A low thermal budget self-aligned Ti silicide technology using germanium implantation for thin-film SOI MOSFET's abstract: In this paper, a titanium salicide technology with a very low thermal annealing temperature using germanium implantation for thin film SOI MOSFET\u0027s is investigated in detail. Ti silicide formation on the amorphous silicon generated by germanium implantation is studied. Compared to the conventional Ti salicide process, the Ti silicidation temperature is significantly lowered and the silicide depth is well controlled through the pre-amorphized layer. Therefore, the potential problems of the salicide process for SOI MOSFET\u0027s such as lateral voids, dopant segregation, thermal agglomeration, and increase of resistance on narrow gate are suppressed by germanium implantation. With the Ge pre-amorphization salicide process, a very low silicide contact resistance is obtained and sub-0.25-/spl mu/m SOI MOSFET\u0027s are fabricated with good device characteristics. |
77 | title: Multi-input injection locking in single mode Fabry-Pérot laser diode and its application in optical signal processing abstract: We present a novel idea of multi-input injection locking phenomenon in single mode Fabry-Perot Laser diode (SMFP-LD).\r\nThe key principle of multi-input injection locking is the proper power management of input beams for injection\r\nlocking one of the side modes of Fabry-Perot laser diode (FP-LD) and the suppression of the dominant mode of FP-LD.\r\nThe multi-input injection locking (MIL) principle is extended to the combinational multi-input injection locking (CMIL)\r\nby which the dominant mode of SMFP-LD will be suppressed with certain combination of input beams. The proposed\r\nidea can be implemented for realizing logic gates, decision making circuit and others. MIL and CMIL are explained\r\ntheoretically and verified by realizing some of the logic gates. Experimental results for logic gates are presented with the\r\ninput data rates of 10 Gbps. |
79 | title: Electrically charged dilaton black holes in an external magnetic field abstract: In the present paper we construct a new solution to the Einstein-Maxwell-dilaton gravity equations describing electrically charged dilaton black holes immersed in a strong external magnetic field and we study its properties. The black holes described by the solution are rotating but with zero total angular momentum and possess an ergoregion confined in a neighborhood of the horizon. Our results also show that the external magnetic field does not affect the black hole thermodynamics. |
80 | title: Thermal models and noise in transition edge sensors abstract: Detectors based on transition edge sensors (TESs) must achieve theoretically predicted noise levels if they are to be suitable for the next generation of space-borne astronomical telescopes. The noise of an ideal detector is determined by the sum of three contributions: (i) thermal-fluctuation noise in the heat link to the bath, (ii) Johnson noise in the sensor itself, and (iii) noise in the electrical read-out circuit. Many groups have reported TESs with noise levels significantly above the theoretical predictions. We use two well-defined experimental configurations to measure the read-out noise spectra of Mo–Cu TESs with transition temperatures of 370 and 200mK. The TESs are geometrically simple, comprising superconducting and normal metal films on a silicon nitride (SiNx) membrane. The measurements are compared with a multiparameter noise model, which is based on a physical model of the thin-film devices. Taking into consideration separate, accurate measurements of the heat capacity of identical SiNx m... |
81 | title: An autostereoscopic liquid crystal display with a polarized parallax barrier abstract: Abstract An autostereoscopic liquid crystal display (LCD) with a polarized parallax barrier (PPB) is proposed. To separate multi-view images, the PPB and a polarizer array are added into a conventional thin film transistor (TFT) LCD. Every subpixel of the proposed autostereoscopic LCD has two independent and isometric electrodes on the surface of the color filter. The corresponding structure of the display and the calculation equations for the PPB are described in detail. A prototype of the display is developed. The luminance distribution of the prototype along the horizontal direction is measured. The simulation results indicate that the display presents stereoscopic images without crosstalk at the optimal view distance. Compared with the autostereoscopic display with conventional parallax barrier, the proposed autostereoscopic LCD provides higher quality stereoscopic images. |
82 | title: Polarization and hysteresis in low resistivity ferroelectric composites abstract: Abstract A compensating technique suitable for measuring the polarization and hysteresis in ferroelectric materials with low resistivity is reported. In this method, three different poling voltages waveforms are successively applied to a sample while the current i, is measured. These are: a sinusoidal, a positively rectified and a negatively rectified sinusoidal voltages. The polarization hysteresis loop is then computed through the integration of the difference between the current obtained during the full sinusoidal voltage loop (i.e. it ) and the sum of the other two currents (i + + i −). In this paper we use this method to determine the remanent polarization and coercive field in a ferroelectric composite of calcium modified lead titanate (PTCa), of a low resistivity formulation, and a copolymer of polyvinylidene fluoride (i.e. P(VDF/TrFE)) as a function of the temperature and field. |
83 | title: Characterization of Switching Properties of Lead-Zirconate-Titanate Thin Films in Ti-Rich Phase. abstract: Switching behaviors of lead-zirconate-titanate thin-film capacitors with Ti/Zr ratios of 60/40 and 75/25 were successfully characterized by observing their switching transient currents. The capacitor with 60/40 showed the remanent polarization density of 24.0 µ/cm2 independent of the frequency of the external switching biases. On the other hand, the remanent polarization density of the capacitor with 75/25 was reduced markedly with increasing the frequency. The remanent polarization density was lowered from 23.6 µC/cm2 at 100 Hz to 13.0 µC/cm2 at 12.5 kHz. While the switching transient currents were observed as a function of time, the lead-zirconate-titanate thin-film capacitor with 60/40 showed the typical sharp switching transient current. In sharp contrast, the capacitor with 75/25 ratio showed a monotonous transient current which suggests the presence of ferroelectric domains having long time constants. Consequently, the lead-zirconate-titanate thin film with the Ti/Zr ratio of 60/40 showed better switching behavior as compared to that with the Ti/Zr ratio of 75/25. |
84 | title: Distributions of laser radiation intensity inside gold nanoparticles during laser irradiation abstract: Theoretical investigation of the distributions of laser radiation intensities inside spherical gold nanoparticles with radiuses in the range 5-100 nm during laser irradiation for wavelengths 400, 532, 800 nm was carried out. Distributions of laser intensity are nonhomogeneous for some ranges of nanoparticle sizes and values of laser wavelengths. These results can be applied for explanation of some experimental data of laser-induced fragmentation, evaporation and formation of nanonetworks as a result of laser action on nanoparticles and for laser technologies of nanoparticles. |
85 | title: Temperature-dependent striped antiferromagnetism of LaFeAsO in a Green's function approach abstract: We use a Green\u0027s function method to study the temperature-dependent average moment and magnetic phase-transition temperature of the striped antiferromagnetism of LaFeAsO, and other similar compounds, as the parents of FeAs-based superconductors. We consider the nearest and the next-nearest couplings in the FeAs layer, and the nearest coupling for inter-layer spin interaction. The dependence of the transition temperature TN and the zero-temperature average spin on the interaction constants is investigated. We obtain an analytical expression for TN and determine our temperature-dependent average spin from zero temperature to TN in terms of unified self-consistent equations. For LaFeAsO, we obtain a reasonable estimation of the coupling interactions with the experimental transition temperature TN = 138 K. Our results also show that a non-zero antiferromagnetic (AFM) inter-layer coupling is essential for the existence of a non-zero TN, and the many-body AFM fluctuations reduce substantially the low-temperature magnetic moment per Fe towards the experimental value. Our Green\u0027s function approach can be used for other FeAs-based parent compounds and these results should be useful to understand the physical properties of FeAs-based superconductors. |
86 | title: Estimation Of Atmospheric Water Vapour Flux Profiles In The Nocturnal Unstable Urban Boundary Layer With Doppler Sodar And Raman Lidar abstract: The vertical wind profiles determined by Doppler sodar and the water vapourmixing ratio profiles obtained by Raman lidar are used to estimate the atmosphericwater vapour flux profiles in the nocturnal urban boundary layer under unstableconditions. The experiment was conducted for several nights in the central areaof Rome under a variety of moisture conditions and different urban boundary-layerflow regimes. Despite some scatter in the profiles, the latent heat flux is found tobe positive throughout the depth of the nocturnal urban boundary-layer. Thelayer-averaged flux shows a variation between -4 to +40 W m-2, whileindividual values of flux in excess of +150 W m-2 pertain to a case offree convection during cold air advection caused by the sea breeze. The qualityof flux estimates is found to be highly limited by the low sampling rates employedin the experiment resulting in errors to the order of 60%. Therefore, the results mustbe viewed as estimates rather than precise measurements. The skewness profiles ofthe turbulent fluctuations of vertical velocity and water vapour mixing ratio are alsopositive. |
87 | title: Leptonic contribution to the bulk viscosity of nuclear matter abstract: For {beta}-equilibrated nuclear matter we estimate the contribution to the bulk viscosity from purely leptonic processes, namely the conversion of electrons to and from muons. For oscillation frequencies in the kilohertz range, we find that this process provides the dominant contribution to the bulk viscosity when the temperature is well below the critical temperature for superconductivity or superfluidity of the nuclear matter. |
88 | title: Tunable dye laser configurations abstract: Abstract Various configurations for the successful operation of a continuous, tunable dye laser are described. Output powers as high as 100 milliwatts have been obtained using a 1.5 watt argon ion laser at 5145 A as the optical pump for the dye laser, with a tuning range of from 5640 A to 6150 A. |
89 | title: Chaos-Induced Breaking of the Franck–Condon Approximation for Transition Spectra in Jahn–Teller Systems abstract: We investigate the vibrational structure of electronic spectra for the transition from the nondegenerate A state to E states in E g ⊗ e g Jahn–Teller systems with the trigonal field included. By extending the analysis by Longuet-Higgins et al. [Proc. R. Soc. London, Ser. A 244 (1958) 1] to this classically chaotic system, we find that the triple-humped structure is manifest with increasing anharmonicity. Such a structure cannot be derived using the semiclassical Franck–Condon (FC) approximation, and is caused by the chaos-induced breaking of the FC principle. |
90 | title: Phase relations and the determination of static mass quadrupole moments in the scattering of polarized deuterons abstract: Abstract The scattering of 20 MeV polarized deuterons exhibits a phase behaviour between the angular distributions of elastic and inelastic scattering, which reflects the rather high transparency of the deuteron optical potential. For nuclei with closed shells we find phase relations which are opposite to the Blair rules for strongly absorptive probes. For deformed nuclei pronounced angular shifts are observed, which originate from the static mass quadrupole moment Q (2 + 1 ). |
92 | title: The influence of complex material coverings on the quality factor of simple radiating systems abstract: The influence of material coverings on the antenna quality factor is investigated for radiators formed by thin electric or magnetic line sources. It is shown that thin uniform and symmetric layers of arbitrary passive materials (including Veselago, left-handed, or double-negative materials) cannot help to overcome the bandwidth limitations imposed by the amount of energy stored in the antenna reactive field. Alternative possibilities offered by complex composite materials in the antenna design are identified. |
93 | title: Significant enhancement in self-focusing of high-power laser beam through dense plasmas by ramp density profile abstract: The effect of the ramp density profile on relativistic self-focusing of a cosh-Gaussian (ChG) laser beam in dense plasmas is investigated. For this purpose, a modified refractive index of inhomogeneous cold quantum plasma (ICQP) with the inclusion of quantum correction in the relativistic regime is considered. Contrary to earlier works on self-focusing of laser beams through quantum plasmas, higher-order terms in the expansion of the dielectric function and the eikonal are taken into account. In this situation, the envelope equation governing the beam-width parameter is derived in the cylindrical coordinate system. Particularly, the self-focusing feature and the sensitivity of decentered parameter b for the ChG laser beam in the ICQP are also illustrated by utilizing a higher-order paraxial theory. The results are presented graphically and discussed. |
94 | title: Techno-economic analysis of an air conditioning heat pump powered by photovoltaic panels and the grid abstract: Abstract This work presents an environmental and techno-economic study of an inverter air conditioner simultaneously powered by photovoltaic panels and the grid, without batteries. The unit provides the thermal demand to an office in an administrative building located in Alicante (South East Spain). In comparison with other systems which also use renewable energy for air conditioning, this one presents significant advantages. It is comparatively simple, reliable, has low maintenance needs and its renewable energy production is entirely self-consumed, which avoids problematic interaction with the grid. The system has been monitored during one year to measure the thermal energy provided to the room, the electrical consumption of the device and the photovoltaic and grid contribution to it. Experimental results of some Key Performance Indicators are presented as a result of a one year data collection campaign. The measurements show a solar contribution of 54% to the electricity consumed by the system. As a result, the ratio between the thermal energy and grid electricity consumption during one year is SPF sys = 9.6. Consequently, the primary non–renewable energy consumption is drastically reduced to a 26% of the reference system ( SPF ref = 2.5 ). Furthermore, the techno-economic study concludes that in spite of requiring a higher initial investment in the system, the saving produced by the lower electricity consumption, results in an annualized cost of 84% of the reference system cost. |
95 | title: A molecular dynamics study of Young’s modulus of multilayer graphene abstract: In this letter, we adopt the molecular dynamics method to study Young’s modulus of 1–19 layers graphene by the nanoindentation theory and the tensile theory. The results show that the number of layers has a strong influence on Young’s modulus using the nanoindentation theory, while Young’s modulus from the tensile theory is not sensitive to the number of layers. Furthermore, we analyze the structure of multilayer graphene (MLG), the loading force-layer number curves, and the breaking force of 1–19 layers graphene based on the nanoindentation theory. The results reveal that MLG transforms into bulk graphite with an increase in the number of layers, which indicates that the nanoindentation theory has reached a limitation. Moreover, we simulate the nanoindentation for circular membranes of different radii and determine the threshold layer of the nanoindentation theory. Our study plays an important role in deepening the understanding of the mechanical properties of MLG and developing the nanoindentation and tensile theories.In this letter, we adopt the molecular dynamics method to study Young’s modulus of 1–19 layers graphene by the nanoindentation theory and the tensile theory. The results show that the number of layers has a strong influence on Young’s modulus using the nanoindentation theory, while Young’s modulus from the tensile theory is not sensitive to the number of layers. Furthermore, we analyze the structure of multilayer graphene (MLG), the loading force-layer number curves, and the breaking force of 1–19 layers graphene based on the nanoindentation theory. The results reveal that MLG transforms into bulk graphite with an increase in the number of layers, which indicates that the nanoindentation theory has reached a limitation. Moreover, we simulate the nanoindentation for circular membranes of different radii and determine the threshold layer of the nanoindentation theory. Our study plays an important role in deepening the understanding of the mechanical properties of MLG and developing the nanoindentation and t... |
96 | title: Why orbitals do not exist abstract: In this paper we will address the problem of the existence of orbitals by analyzing the relationship between molecular chemistry and quantum mechanics. In particular, we will consider the concept of orbital in the light of the arguments that deny its referring character. On this basis, we will conclude that the claim that orbitals do not exist relies on a metaphysical reductionism which, if consistently sustained, would lead to consequences clashing with the effective practice of science in its different branches. |
97 | title: The black hole mass–stellar velocity dispersion correlation: bulges versus pseudo-bulges abstract: We investigate the correlation between the supermassive black holes (SMBHs) mass (Mbh) and the stellar velocity dispersion ( ) in two types of host galaxies: the early-type bulges (disk galaxies with classical bulges or elliptical galaxies) and pseudobulges. In the form log(Mbh=M ) = + log( =200 km s 1 ), the best-fit results for the 39 early-type bulges are the slope = 4:06 0:28 and the normalization = 8:28 0:05; the best-fit results for the 9 pseudobulges are = 4:5 1:3, = 7:50 0:18. Both relations have intrinsic scatter in logMbh of .0.27 dex. The Mbh- relation for pseudobulges is different from the relation in the early-type bulges over the 3 significance level. The contrasting relations indicate the formation and growth histories of SMBHs depend on their host type. The discrepancy between the slope of the Mbh- relations using different definition of velocity dispersion vanishes in our sample, a uniform slope will constrain the coevolution theories of the SMBHs and their host galaxies more effectively. We also find the slope for the “core” elliptical galaxies at the high mass range of the relation appears steeper ( ’ 5-6), which may be the imprint of their origin of dissipationless mergers. |
98 | title: Dynamic Reconfiguration of Differential Pixel Output for CMOS Imager Dedicated to WDM-SDM Indoor Optical Wireless LAN abstract: A dedicated complementary metal-oxide-semiconductor (CMOS) imager with parallel photoreceivers has been deployed for new indoor wireless local area network systems where images and communications are mixed to offer location awareness and an extended data transfer bandwidth with wavelength- and space-division multiplexing for the downlink and uplink, respectively. To realize data acquisition while capturing images, dynamic reconfiguration of differential pixel output with a small area overhead is proposed for suppressing signal contamination at the sensitive photoreceiver circuitry by common mode noise from the image readout digital circuitry. A prototype CMOS imager with 64 times 64 pixels and four parallel photoreceiver channels was fabricated in a standard 0.35-mum CMOS process, and concurrent scene image capturing and multipoint data acquisition at 10-Mb/s/channel were demonstrated. The measured signal-to-crosstalk ratio was around 18 dB. |
99 | title: Space Charge Potentials in Cylindrical Geometries Including Temperature Effects abstract: The analysis of space-charge in cylindrical geometries has been performed using kinetic theory. The current collected by central electrodes inmersed in plasmas with a discriminant grid has been determined through the Poisson equation and truncated Maxwellian distribution functions for the ions. The electrons are assumed to be repelled by the entrance grid. The non-linear adimensional equations have been solved approximately using linear expansion around the point with zero potential. |
100 | title: Magnetic properties of Fe-Co thin films deposited by ion beam sputtering. abstract: Iron-cobalt alloy thin films (0-54 at.% Co-Fe) were deposited using an ion beam sputtering apparatus and their magnetic properties were investigated in detail.All of the films have large saturation magnetic flux density above 20 kG. The films deposited at substrate temperature Ts of about 75°C have a large perpendicular magnettc anisotropy field Hk⊥ (\u003e110 Oe) and high coercive force Hc (\u003e50 Oe), while the increase of Ts shows a significant decrease in both Hk⊥ and Hc. The perpendicular magnetic anisotropy of the film deposited at Ts above 250°C disappears completely, and films with Co content of 50-54at.% have the lowest Hc, as low as 5 Oe. The decrease of Ts from 75°C to 250°C also causes a change in the internal stress of the films from compressive to tensile stress along with a growth of crystallites. Annealing the films in a vacuum has nearly the same effect on changes of their magnetic properties and internal stress as the increase of Ts. These changes in magnetic properties with Ts or annealing temperature are considered mainly caused by the change of stress induced magnetic anisotropy energy, since the Fe-Co alloy film has a large positive magnetostriction constant. |
101 | title: High current-density Josephson edge-junction capacitance abstract: Abstract Some properties of NbNb oxide-PbIn edge junctions and two-junction superconducting interferometers have been measured. From the voltage of the resonance involving the junction capacitance and interferometer inductance, we deduce that the specific capacitance of 2.5 μm2 junctions having a current density of 30 kA cm-2 is 20±4 μFcm-2. |
102 | title: Suppression of high pT hadrons in Pb + Pb collisions at LHC abstract: Abstract Hadron production and their suppression in Pb + Pb collisions at LHC at a center-of-mass energy of s NN = 2.76 TeV are studied within a multiphase transport (AMPT) model whose initial conditions are obtained from the recently updated HIJING 2.0 model. The centrality dependence of charged hadron multiplicity d N ch / d η at midrapidity was found quite sensitive to the largely uncertain gluon shadowing parameter s g that determines the nuclear modification of the gluon distribution. We find final-state parton scatterings reduce considerably hadron yield at midrapidity and enforces a smaller gluon shadowing to be consistent with d N ch / d η data at LHC. With such a constrained parton shadowing, charged hadron and neutral pion production over a wide transverse momenta range are investigated in AMPT. Relative to nucleon–nucleon collisions, the particle yield in central heavy ion collisions is suppressed due to parton energy loss. While the calculated magnitude and pattern of suppression is found consistent with that measured in Au + Au collisions at s NN = 0.2 TeV at RHIC, at the LHC energy the suppression is overpredicted which may imply the medium formed at LHC is less opaque than expected from simple RHIC extrapolations. Reduction of the QCD coupling constant α s by ∼ 30 % in the higher temperature plasma formed at LHC as compared to that at RHIC was found to reproduce the measured suppression at LHC. |
103 | title: Numerical and experimental investigation of heat transfer enhancement in a microtube using nanofluids abstract: Abstract Forced convective laminar flow of different types of nanofluids such as Al2O3 and SiO2, with a nanoparticle size of 30 nm, and different volume fractions ranging from 0.5% to 1% using water as base fluids were investigated numerically and experimentally. This investigation covers the Reynolds number in the range of 90 to 160. The results have shown that SiO2–water nanofluid has the highest Nusselt number, followed by Al2O3–water, and lastly pure water. The maximum heat transfer enhancement was about 22% when using the nanofluids and the numerical and experimental results agree well with the conventional theory. |
104 | title: Surface plasmons with phase singularities and their effects on matter abstract: is an integer [1, 2]. This brief report is concerned with optical vortices (typified by Laguerre–Gaussian (LG) beams) generating surface effects which are not only spatially confined, but which are strongly plasmonic as well [3]. The primary aim here is to find the general form of the plasmonic fields and explore their influence on atomic systems near the surface. In some beautiful recent studies, Tan et al. [4] have demonstrated surface plasmon polaritons generated by op-tical vortex beams, whilst Gorodetski et al. [5] have estab-lished that spin-based plasmonic effects can be created in nanoscale structures by the use of circularly polarized light (due to a geometric phase associated with a spatially vary-ing polarization state). These authors have also shown that a surface spiral surrounding a nanoaperture can confer the necessary phase conditions [6]. The present study aims to determine the behaviour associated with optical angular momentum whose origin is neither photon spin nor surface morphology, the necessary phase properties primarily be-ing conferred by a helical beam structure. Developing ear-lier work the present focus is on the exploitation of surface plasmonic field enhancement for the control of vi-cinal atoms. The assumption is that before the LG light is switched on, atoms are trapped vertically, for example by well-known multiple-beam optical methods [8, by a po-tential well that is larger than |
105 | title: The relationship of coronal mass ejections to streamers abstract: We have examined images from the Large-Angle and Spectrometric Coronagraph (LASCO) to study the relationship of coronal mass ejections (CMEs) to coronal streamers. We wish to test the suggestion [Low, 1996] that CMEs arise from flux ropes embedded in a streamer erupting and disrupting the streamer. The data span a period of 2 years near Sunspot minimum through a period of increased activity as Sunspot numbers increased. We have used LASCO data from the C2 coronagraph which records Thomson scattered white light from coronal electrons at heights between 1.5 and 6Rs. Maps of the coronal streamers have been constructed from LASCO C2 observations at a height of 2.5Rs at the east and west limbs. We have superposed the corresponding positions of CMEs observed with the C2 coronagraph onto the synoptic maps. We identified the different kinds of signatures CMEs leave on the streamer structure at this height (2.5Rs). We find four types of CMEs with respect to their effect on streamers: 1. CMEs that disrupt the streamer, 2. CMEs that have no effect on the streamer, even though they are related to it, 3. CMEs that create streamer-like structures and 4. CMEs that are latitudinally displaced from the streamer. CMEs in categories 3 and 4 are not related to the streamer structure. This is the most extensive observational study of the relation between CMEs and streamers to date. Previous studies using SMM data have made the general statement that CMEs are mostly associated with streamers and that they frequently disrupt it. However, we find that approximately 35% of the observed CMEs bear no relation to the preexisting streamer, while 46% have no effect on the observed streamer, even though they appear to be related to it. Our conclusions thus differ considerably from those of previous studies. |
End of preview. Expand
in Data Studio
README.md exists but content is empty.
- Downloads last month
- 10