bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggregation behavior of a gemini surfactant with a tripeptide spacer
Authors: Wang Meina , Han Yuchun , Qiao Fulin , Wang Yilin
Published: December 2014

A gemini surfactant with a tripeptide spacer shows strong pH-dependent and concentration-dependent aggregation behavior.
Series of in-fiber graphene supercapacitors for flexible wearable devices
Authors: Liang Yuan , Wang Zhi , Huang Jiao , Cheng Huhu , Zhao Fei , Hu Yue , Jiang Lan , Qu Liangti
Published: December 2014

An integrated series of in-fiber all-solid-state graphene supercapacitors have been fabricated for flexible wearable electronic devices.
Bioactive organic/inorganic hybrids with improved mechanical performance
Authors: Li Ailing , Shen Hong , Ren Huihui , Wang Chen , Wu Decheng , Martin Richard A. , Qiu Dong
Published: December 2014

New sol–gel functionalized poly-ethylene glycol (PEGM)/SiO2–CaO hybrids were prepared with interpenetrating networks of silica and PEGM through the formation of Si–O–Si bonds.
Charge transport in nanoparticular thin films of zinc oxide and aluminum-doped zinc oxide
Authors: Lenz Thomas , Richter Moses , Matt Gebhard J. , Luechinger Norman A. , Halim Samuel C. , Heiss Wolfgang , Brabec Christoph J.
Published: December 2014

In this work, we report on the electrical characterization of nanoparticular thin films of zinc oxide and aluminum-doped ZnO. Temperature-dependent current–voltage measurements revealed that charge transport is well described by the Poole–Frenkel model.
Diamond electro-optomechanical resonators integrated in nanophotonic circuits
Authors: Rath P. , Ummethala S. , Diewald S. , Lewes-Malandrakis G. , Brink D. , Heidrich N. , Nebel C. , Pernice W. H. P.
Published: December 2014

Diamond integrated photonic devices are promising candidates for emerging applications in nanophotonics and quantum optics. Here, we demonstrate active modulation of diamond nanophotonic circuits by exploiting mechanical degrees of freedom in free-standing diamond electro-optomechanical resonators. We obtain high quality factors up to 9600, allowing us to read out the driven nanomechanical response with integrated optical interferometers with high sensitivity. We are able to excite higher order mechanical modes up to 115 MHz and observe the nanomechanical response also under ambient conditions.
Numerical study of single droplet impact onto liquid metal film under a uniform magnetic field
Authors: Wang Jin-Jin , Zhang Jie , Ni Ming-Jiu , Moreau René
Published: December 2014

The impact of a three-dimensional drop onto a film of the same electrically conducting liquid, such as a molten metal, is numerically investigated. The emphasis is put on the influence of an externally applied magnetic field. A Volume-of-Fluid method combined with an Adaptive Mesh Refinement technique is applied for the interface tracking, while a consistent and conservative scheme is adopted for the computation of the induced current density and Lorentz force. A particular attention is paid to the liquid splashing during the occurrence of the impact, whose duration is of the order of 10−3 s. The main properties of the splashing are closely related to the initial droplet velocity, while the fluid flow pattern is also dependent on the film thickness. The influence of the magnetic field depends on its direction and strength. As expected, it is shown that a vertical magnetic field dampens the flow, while the horizontal one yields a significant deviation from axisymmetry. It is found that the vertical magnetic field constrains the spluttering flow, reduces the crown diameter, and tends to suppress it. When the Hartmann number is very large (above 103) the crown disappears and a slowly decreasing bulge is formed. In the presence of a horizontal magnetic field, the splashing behaviour is less modified, and the classic t12 law for the increase of the crown radius remains valid. However, in the magnetic field direction the crown growth is reduced, as well as the upward motion and the ejection of secondary droplets, whereas in the horizontal direction perpendicular to the magnetic field the crown development is only slightly affected.
Spinning out of control: Wall turbulence over rotating discs
Authors: Wise Daniel J. , Alvarenga Claudia , Ricco Pierre
Published: December 2014

The friction drag reduction in a turbulent channel flow generated by surface-mounted rotating disc actuators is investigated numerically. The wall arrangement of the discs has a complex and unexpected effect on the flow. For low disc-tip velocities, the drag reduction scales linearly with the percentage of the actuated area, whereas for higher disc-tip velocity, the drag reduction can be larger than the prediction found through the linear scaling with the actuated area. For medium disc-tip velocities, all the cases which display this additional drag reduction exhibit stationary-wall regions between discs along the streamwise direction. This effect is caused by the viscous boundary layer which develops over the portions of stationary wall due to the radial flow produced by the discs. For the highest disc-tip velocity, the drag reduction even increases by halving the number of discs. The power spent to activate the discs is instead independent of the disc arrangement and scales linearly with the actuated area for all disc-tip velocities. The Fukagata-Iwamoto-Kasagi identity and flow visualizations are employed to provide further insight into the dynamics of the streamwise-elongated structures appearing between discs. Sufficient interaction between adjacent discs along the spanwise direction must occur for the structures to be created at the disc side where the wall velocity is directed in the opposite direction to the streamwise mean flow. Novel half-disc and annular actuators are investigated to improve the disc-flow performance, resulting in a maximum of 26% drag reduction.
Basis functions for electronic structure calculations on spheres
Authors: Gill Peter M. W. , Loos Pierre-François , Agboola Davids
Published: December 2014

We introduce a new basis function (the spherical Gaussian) for electronic structure calculations on spheres of any dimension D. We find general expressions for the one- and two-electron integrals and propose an efficient computational algorithm incorporating the Cauchy-Schwarz bound. Using numerical calculations for the D = 2 case, we show that spherical Gaussians are more efficient than spherical harmonics when the electrons are strongly localized.
Loop Heisenberg-Virasoro Lie conformal algebra
Authors: Fan Guangzhe , Su Yucai , Wu Henan
Published: December 2014

Let HV be the loop Heisenberg-Virasoro Lie algebra over ℂ with basis {Lα,i, Hβ,j∣α, β, i, j ∈ ℤ} and brackets [Lα,i, Lβ,j] = (α − β) Lα+β,i+j, [Lα,i, Hβ,j] = − βHα+β,i+j, [Hα,i, Hβ,j] = 0. In this paper, a formal distribution Lie algebra of HV is constructed. Then, the associated conformal algebra CHV is studied, where CHV has a ℂ[∂]-basis {Li, Hi∣i ∈ ℤ} with λ-brackets [Li λ Lj] = (∂ + 2λ) Li+j, [Li λ Hj] = (∂ + λ) Hi+j, [Hi λ Lj] = λLi+j, and [Hi λ Hj] = 0. In particular, the conformal derivations of CHV are determined. Finally, rank one conformal modules and ℤ-graded free intermediate series modules over CHV are classified.
Nontrivial central extensions of 3-Lie algebras
Authors: Ding Lu , Yan Zhaowen , Zhang Huiping , Zhang Wei
Published: December 2014

We construct a series of infinite-dimensional 3-Lie algebras which include w∞ and SDiff(T2) 3-Lie algebras as subalgebras, and determine their nontrivial one-dimensional central extensions.
Ring-polymer molecular dynamics: Rate coefficient calculations for energetically symmetric (near thermoneutral) insertion reactions (X + H2) → HX + H(X = C(1D), S(1D))
Authors: Suleimanov Yury V. , Kong Wendi J. , Guo Hua , Green William H.
Published: December 2014

Following our previous study of prototypical insertion reactions of energetically asymmetric type with the RPMD (Ring-Polymer Molecular Dynamics) method [Y. Li, Y. Suleimanov, and H. Guo, J. Phys. Chem. Lett. 5, 700 (2014)], we extend it to two other prototypical insertion reactions with much less exothermicity (near thermoneutral), namely, X + H2 → HX + H where X = C(1D), S(1D), in order to assess the accuracy of this method for calculating thermal rate coefficients for this class of reactions. For both chemical reactions, RPMD displays remarkable accuracy and agreement with the previous quantum dynamic results that make it encouraging for the future application of the RPMD to other barrier-less, complex-forming reactions involving polyatomic reactants with any exothermicity.
Collision induced ultraviolet structure in nitrogen radar REMPI spectra
Authors: McGuire S. , Miles R.
Published: December 2014

We present 2 + 2 radar REMPI measurements in molecular nitrogen under atmospheric conditions and observe a strong interference in the (1,0) vibrational band of the a1Πg ← X1Σg+ electronic manifold. The interference is suppressed by using circularly polarized light, permitting rotational analysis of the 2 + 2 radar REMPI spectrum. It is observed in pure nitrogen, though the structure varies with gas composition. The structure also varies with temperature and pressure. These results indicate that it is collision induced. We hypothesize that the source of the interference is a 3 + 1 REMPI process through the a″1Σg+ electronic state.
Effects of incoming surface wind conditions on the wake characteristics and dynamic wind loads acting on a wind turbine model
Authors: Tian Wei , Ozbay Ahmet , Hu Hui
Published: December 2014

An experimental investigation was conducted to examine the effects of incoming surface wind conditions on the wake characteristics and dynamic wind loads acting on a wind turbine model. The experimental study was performed in a large-scale wind tunnel with a scaled three-blade Horizontal Axial Wind Turbine model placed in two different types of Atmospheric Boundary Layer (ABL) winds with distinct mean and turbulence characteristics. In addition to measuring dynamic wind loads acting on the model turbine by using a force-moment sensor, a high-resolution Particle Image Velocimetry system was used to achieve detailed flow field measurements to characterize the turbulent wake flows behind the model turbine. The measurement results reveal clearly that the discrepancies in the incoming surface winds would affect the wake characteristics and dynamic wind loads acting on the model turbine dramatically. The dynamic wind loads acting on the model turbine were found to fluctuate much more significantly, thereby, much larger fatigue loads, for the case with the wind turbine model sited in the incoming ABL wind with higher turbulence intensity levels. The turbulent kinetic energy and Reynolds stress levels in the wake behind the model turbine were also found to be significantly higher for the high turbulence inflow case, in comparison to those of the low turbulence inflow case. The flow characteristics in the turbine wake were found to be dominated by the formation, shedding, and breakdown of various unsteady wake vortices. In comparison with the case with relatively low turbulence intensities in the incoming ABL wind, much more turbulent and randomly shedding, faster dissipation, and earlier breakdown of the wake vortices were observed for the high turbulence inflow case, which would promote the vertical transport of kinetic energy by entraining more high-speed airflow from above to re-charge the wake flow and result in a much faster recovery of the velocity deficits in the turbine wake.
Seniority-based coupled cluster theory
Authors: Henderson Thomas M. , Bulik Ireneusz W. , Stein Tamar , Scuseria Gustavo E.
Published: December 2014

Doubly occupied configuration interaction (DOCI) with optimized orbitals often accurately describes strong correlations while working in a Hilbert space much smaller than that needed for full configuration interaction. However, the scaling of such calculations remains combinatorial with system size. Pair coupled cluster doubles (pCCD) is very successful in reproducing DOCI energetically, but can do so with low polynomial scaling (N3, disregarding the two-electron integral transformation from atomic to molecular orbitals). We show here several examples illustrating the success of pCCD in reproducing both the DOCI energy and wave function and show how this success frequently comes about. What DOCI and pCCD lack are an effective treatment of dynamic correlations, which we here add by including higher-seniority cluster amplitudes which are excluded from pCCD. This frozen pair coupled cluster approach is comparable in cost to traditional closed-shell coupled cluster methods with results that are competitive for weakly correlated systems and often superior for the description of strongly correlated systems.
Communication: Visible line intensities of the triatomic hydrogen ion from experiment and theory
Authors: Petrignani Annemieke , Berg Max H. , Grussie Florian , Wolf Andreas , Mizus Irina I. , Polyansky Oleg L. , Tennyson Jonathan , Zobov Nikolai F. , Pavanello Michele , Adamowicz Ludwik
Published: December 2014

The visible spectrum of H3+ is studied using high-sensitivity action spectroscopy in a cryogenic radiofrequency multipole trap. Advances are made to measure the weak ro-vibrational transitions from the lowest rotational states of H3+ up to high excitation energies providing visible line intensities and, after normalisation to an infrared calibration line, the corresponding Einstein B coefficients. Ab initio predictions for the Einstein B coefficients are obtained from a highly precise dipole moment surface of H3+ and found to be in excellent agreement, even in the region where states have been classified as chaotic.
Investigations on the electronic transport and piezoresistivity properties of Ni2−XMn1+XGa (X = 0 and 0.15) Heusler alloys under hydrostatic pressure
Authors: Devarajan U. , Singh Sanjay , Esakki Muthu S. , Kalai Selvan G. , Sivaprakash P. , Roy Barman S. , Arumugam S.
Published: December 2014

The resisitivity of Ni2−XMn1+XGa (X = 0 and 0.15) magnetic shape memory alloys has been investigated as a function of temperature (4–300 K) and hydrostatic pressure up to 30 kilobars. The resistivity is suppressed (X = 0) and enhanced (X = 0.15) with increasing pressure. A change in piezoresistivity with respect to pressure and temperature is observed. The negative and positive piezoresistivity increases with pressure for both the alloys. The residual resistivity and electron-electron scattering factor as a function of pressure reveal that for Ni2MnGa the electron-electron scattering is predominant, while the X = 0.15 specimen is dominated by the electron-magnon scattering. The value of electron-electron scattering factor is positive for both the samples, and it is decreasing (negative trend) for Ni2MnGa and increasing (positive trend) for X = 0.15 with pressure. The martensite transition temperature is found to be increased with the application of external pressure for both samples.
Note: A novel curvature-driven shape memory alloy torsional actuator
Authors: Yan Xiaojun , Huang Dawei , Zhang Xiaoyong
Published: December 2014

This paper presents a novel, extremely simple torsional actuator which employs a special shape setting treated shape memory alloy coil. The actuator works with a so-called curvature-driven principle and can directly generate a rotary motion without any motion converting mechanism. Experiments were performed to study the output performances of several actuators with different geometry parameters. The test results show the actuator can output a rotary motion fluently, and the output torque is about several mN mm.
Note: Precise phase and frequency comparator based on direct phase-time measurements
Authors: Prochazka Ivan , Panek Petr , Kodet Jan
Published: December 2014

We are reporting on the design, performance, and application results of a phase and frequency comparator based on the direct phase-time measurement using a high performance event timer. The advantages of this approach are the simple implementation, a broad frequency range, and the clear interpretation of the measured results. Primarily we analyzed the background instability of the instrument in a common-clock test when a 200 MHz clock signal was connected to both inputs and the noise bandwidth was kept at 5 Hz by a preprocessing of the measured data. The results show that the Allan deviation of the background instability follows 4 × 10−14/τ for a wide range of averaging intervals from 0.1 s up to 104 s. These results are better than background instability of commercially available state-of-the-art instruments based on the phase difference multiplication. Finally the instrument was used for comparison of two H-masers. This experiment proofed that one of possible applications is a comparison of low-noise highly stable frequency sources and measurement of their frequency stability in the time-domain. The noise background of the instrument was negligible for averaging intervals longer than 100 ms.
Strength and structural phase transitions of gadolinium at high pressure from radial X-ray diffraction
Authors: Xiong Lun , Liu Jing , Bai Ligang , Li Xiaodong , Lin Chuanlong , Lin Jung-Fu
Published: December 2014

Lattice strength and structural phase transitions of gadolinium (Gd) were determined under nonhydrostatic compression up to 55 GPa using an angle-dispersive radial x-ray diffraction technique in a diamond-anvil cell at room temperature. Three new phases of fcc structure, dfcc structure, and new monoclinic structure were observed at 25 GPa, 34 GPa, and 53 GPa, respectively. The radial x-ray diffraction data yield a bulk modulus K0 = 36(1) GPa with its pressure derivate K0′ = 3.8(1) at the azimuthal angle between the diamond cell loading axis and the diffraction plane normal and diffraction plane ψ = 54.7°. With K0′ fixed at 4, the derived K0 is 34(1) GPa. In addition, analysis of diffraction data with lattice strain theory indicates that the ratio of differential stress to shear modulus (t/G) ranges from 0.011 to 0.014 at pressures of 12–55 GPa. Together with estimated high-pressure shear moduli, our results show that Gd can support a maximum differential stress of 0.41 GPa, while it starts to yield to plastic deformation at 16 GPa under uniaxial compression. The yield strength of Gd remains approximately a constant with increasing pressure, and reaches 0.46 GPa at 55 GPa.
Self-biased large magnetoelectric coupling in co-sintered Bi0.5Na0.5TiO3 based piezoelectric and CoFe2O4 based magnetostrictive bilayered composite
Authors: Kumari Mukesh , Singh Amrita , Gupta Arti , Prakash Chandra , Chatterjee Ratnamala
Published: December 2014

In this work, magnetoelectric properties of a co-sintered bilayered composite of non-lead based piezoelectric 0.97(Bi0.5Na0.5TiO3)–0.03(K0.47Na0.47Li0.06Nb0.74Sb0.06Ta0.2O3) and magnetostrictive Co0.6Zn0.4Fe1.7Mn0.3O4 are presented. Similar optimal sintering conditions of the individual components lead to a very clean interface as evidenced in the scanning electron microscopy, angle dispersive X-ray diffraction, and energy-dispersive X-ray (EDX) results. Clean interface results in strong intimate mechanical coupling between both components and causes a maximum transfer of induced strain, leading to a large magnetoelectric coupling ∼142 mV/cm·Oe measured in longitudinally magnetized-transversely polarized configuration (L-T mode). Remnant polarization ∼32 μC/cm2, remnant magnetization ∼0.50 emu/g, and sufficiently high self biased magnetoelectricity ∼135 mV/cm Oe (L-T mode) were observed for this composite.
Effect of molecular-scale surface morphology on the surface melting of liquid crystals on self-assembled monolayers
Authors: Son Jong-Ho , Kim Soo-Dong , Vij Jagdish K. , Song Jang-Kun
Published: December 2014

We devised liquid crystal cell substrates with different surface roughnesses at the molecular scale by controlling the density of two types of trichlorosilanes with different alkyl chain lengths. We investigated surface melting of liquid crystals on these surfaces by observing the anchoring transition (change in the direction of alignment) that usually accompanies surface melting. Surface melting was observed only on substrates that had undulating surface morphologies due to either a low molecular density or interspersed arrangement of the two types of trichlorosilanes. We attributed the surface melting to the influence of molecular-level surface roughness on liquid crystal order parameters near the surface.
First stage of CoSi2 formation during a solid-state reaction
Authors: Delattre R. , Thomas O. , Perrin-Pellegrino C. , Rivero C. , Simola R.
Published: December 2014

The kinetics of CoSi2 formation via a solid-state reaction between CoSi and single crystal Si has been the object of many studies in the past. Because of the importance of nucleation, complex kinetics has been reported. In this work, we investigate CoSi2 formation kinetics with in-situ diffraction during isothermal annealing of CoSi films on Si (100). In-situ measurements allow capturing the initial stage of CoSi2 formation. An initial t3/2 time-dependent evolution is observed and attributed to 3D growth of individual nuclei. This first regime is followed after the coalescence of the nuclei by a classical parabolic t1/2 one-dimensional film growth. We evidence a marked influence of the initial Co thickness (50 nm vs 10 nm) on the growth kinetics. A significant slowdown of the CoSi2 formation kinetics is observed for the thinnest film, whereas the activation energy remains the same. These results shine a new light on the complex formation kinetics of CoSi2 during solid-state reaction between CoSi and single crystal silicon and bring new knowledge about what occurs in the ultra-thin film regime, which is important for nanotechnologies.
Communication: Does force spectroscopy of biomolecules probe their intrinsic dynamic properties?
Authors: Makarov Dmitrii E.
Published: December 2014

In single-molecule pulling experiments, the molecule of interest is attached to a much larger object such as an atomic force microscope tip or a micrometer sized bead. The measured dynamics of molecular transitions is therefore affected by the hydrodynamic drag on the pulling instrument itself. By considering the transitions within the combined system (the molecule and the instrument), it is shown here that two distinct physical regimes exist: when the intrinsic stiffness of the molecule is greater than that of the linker connecting the molecule to the pulling setup then the pulling experiment probes the intrinsic dynamics of the molecule with only relatively small (and quantifiable) corrections resulting from the pulling setup. In contrast, when the stiffness of the linker exceeds that of the molecule, the molecular transition in question involves concerted motion of the molecule and the pulling setup and the hydrodynamic drag on the pulling instrument becomes the dominant source of friction along the molecular reaction coordinate. An analytical formula interpolating between these two cases is further derived. These results explain recent conflicting observations where some single-molecule pulling measurements report anomalously low diffusion coefficients along molecular reaction coordinates while others do not.
Optimized aperiodic multilayer structures for use as narrow-angular absorbers
Authors: Granier Christopher H. , Afzal Francis O. , Lorenzo Simón G. , Reyes Mario , Dowling Jonathan P. , Veronis Georgios
Published: December 2014

In this paper, we investigate aperiodic multilayer structures for use as narrow-angular absorbers. The layer thicknesses and materials are optimized using a genetic global optimization algorithm coupled to a transfer matrix code to maximize the angular selectivity in the absorptance at a single or multiple wavelengths. We first consider structures composed of alternating layers of tungsten and silicon or silica, and find that it is not possible to achieve angular selectivity in the absorptance with such structures. We next consider structures composed of alternating layers of silicon and silica, and show that when optimized they exhibit high angular selectivity in absorptance. In addition, as the angular selectivity in absorptance increases, the wavelength range of high angular selectivity also decreases. Optimizing the material composition of the multilayer structures, in addition to optimizing the layer thicknesses, leads to marginal improvement in angular selectivity. Finally, we show that by optimizing the absorptance of the multilayer structures at multiple wavelengths, we can obtain structures exhibiting almost perfect absorptance at normal incidence and narrow angular width in absorptance at these wavelengths. Similar to the structures optimized at a single wavelength, the wavelength range of high angularly selective absorptance is narrow.
Single-walled carbon nanotube transparent conductive films fabricated by reductive dissolution and spray coating for organic photovoltaics
Authors: Ostfeld Aminy E. , Catheline Amélie , Ligsay Kathleen , Kim Kee-Chan , Chen Zhihua , Facchetti Antonio , Fogden Siân , Arias Ana Claudia
Published: December 2014

Solutions of unbundled and unbroken single-walled carbon nanotubes have been prepared using a reductive dissolution process. Transparent conductive films spray-coated from these solutions show a nearly twofold improvement in the ratio of electrical conductivity to optical absorptivity versus those deposited from conventional aqueous dispersions, due to substantial de-aggregation and sizable nanotube lengths. These transparent electrodes have been utilized to fabricate P3HT-PCBM organic solar cells achieving power conversion efficiencies up to 2.3%, comparable to those of solar cells using indium tin oxide transparent electrodes.
Strain-driven growth of GaAs(111) quantum dots with low fine structure splitting
Authors: Yerino Christopher D. , Simmonds Paul J. , Liang Baolai , Jung Daehwan , Schneider Christian , Unsleber Sebastian , Vo Minh , Huffaker Diana L. , Höfling Sven , Kamp Martin , Lee Minjoo Larry
Published: December 2014

Symmetric quantum dots (QDs) on (111)-oriented surfaces are promising candidates for generating polarization-entangled photons due to their low excitonic fine structure splitting (FSS). However, (111) QDs are difficult to grow. The conventional use of compressive strain to drive QD self-assembly fails to form 3D nanostructures on (111) surfaces. Instead, we demonstrate that (111) QDs self-assemble under tensile strain by growing GaAs QDs on an InP(111)A substrate. Tensile GaAs self-assembly produces a low density of QDs with a symmetric triangular morphology. Coherent, tensile QDs are observed without dislocations, and the QDs luminescence at room temperature. Single QD measurements reveal low FSS with a median value of 7.6 μeV, due to the high symmetry of the (111) QDs. Tensile self-assembly thus offers a simple route to symmetric (111) QDs for entangled photon emitters.
Propagation direction reversal of ionization zones in the transition between high and low current magnetron sputtering
Authors: Yang Yuchen , Liu Jason , Liu Lin , Anders André
Published: December 2014

Past research has revealed the propagation of dense, asymmetric ionization zones in both high and low current magnetron discharges. Here, we report about the direction reversal of ionization zone propagation as observed with fast cameras. At high currents, zones move in the E×B direction with velocities of 103–104 m/s. However, at lower currents, ionization zones are observed to move in the opposite, the −E×B direction, with velocities ∼103 m/s. It is proposed that the direction reversal is associated with the local balance of ionization and supply of neutrals in the ionization zone.
Dispersion characteristics of a nonlinear elastic metamaterial
Authors: Khajehtourian R. , Hussein M. I.
Published: December 2014

We study wave dispersion in a one-dimensional nonlinear elastic metamaterial consisting of a thin rod with periodically attached local resonators. Our model is based on an exact finite-strain dispersion relation for a homogeneous solid, utilized in conjunction with the standard transfer matrix method for a periodic medium. The nonlinearity considered stems from large elastic deformation in the thin rod, whereas the metamaterial behavior is associated with the dynamics of the local resonators. We derive an approximate dispersion relation for this system and provide an analytical prediction of band-gap characteristics. The results demonstrate the effect of the nonlinearity on the characteristics of the band structure, including the size, location, and character of the band gaps. For example, large deformation alone may cause a pair of isolated Bragg-scattering and local-resonance band gaps to coalesce. We show that for a wave amplitude on the order of one-eighth of the unit cell size, the effect of the nonlinearity in the structure considered is no longer negligible when the unit-cell size is one-fourteenth of the wavelength or larger.
Annealing-induced change in quantum dot chain formation mechanism
Authors: Park Tyler D. , Colton John S. , Farrer Jeffrey K. , Yang Haeyeon , Kim Dong Jun
Published: December 2014

Self-assembled InGaAs quantum dot chains were grown using a modified Stranski-Krastanov method in which the InGaAs layer is deposited under a low growth temperature and high arsenic overpressure, which suppresses the formation of dots until a later annealing process. The dots are capped with a 100 nm GaAs layer. Three samples, having three different annealing temperatures of 460°C, 480°C, and 500°C, were studied by transmission electron microscopy. Results indicate two distinct types of dot formation processes: dots in the 460°C and 480°C samples form from platelet precursors in a one-to-one ratio whereas the dots in the sample annealed at 500°C form through the strain-driven self-assembly process, and then grow larger via an additional Ostwald ripening process whereby dots grow into larger dots at the expense of smaller seed islands. There are consequently significant morphological differences between the two types of dots, which explain many of the previously-reported differences in optical properties. Moreover, we also report evidence of indium segregation within the dots, with little or no indium intermixing between the dots and the surrounding GaAs barrier.
A surface acoustic wave micropump to pump fluids from a droplet into a closed microchannel using evaporation and capillary effects
Authors: Zhang Anliang , Zha Yan , Zhang Jiansheng
Published: December 2014

A new method for converting a microdroplet on a piezoelectric substrate into continuous fluid flow in microchannels is presented. An interdigital transducer with 27.5 MHz center frequency is fabricated on a 1280 yx-LiNbO3 piezoelectric substrate for exciting surface acoustic wave. A PDMS (Polydimethylsiloxane) microchannel is mounted on the piezoelectric substrate. One end of the microchannel is connected with water absorbing paper, while the other end of the microchannel is in touch with a droplet to be converted. The surface acoustic wave is used for controlling the evaporation velocity of the fluid in the microchannel. Part of fluid in the droplet can be entered into the microchannel and transported there due to the evaporation and capillary effects. Red dye solution is used to demonstrate the conversion of the droplet and the transportation of the fluid in the microchannel. Results show that the droplet on the piezoelectric substrate can successfully be converted into continuous fluid. The flow velocity is increased with the power of the electric signal applied to the interdigital transducer. Average flow velocity is 0.0235μl/s when the power of the electric signal is 30.0dBm. The work is helpful for piezoelectric microfluidic devices for biochemical analysis.
Microstructure fabrication process induced modulations in CVD graphene
Authors: Matsubayashi Akitomo , Zhang Zhenjun , Lee Ji Ung , LaBella Vincent P.
Published: December 2014

The systematic Raman spectroscopic study of a “mimicked” graphene device fabrication is presented. Upon photoresist baking, compressive stress is induced in the graphene which disappears after it is removed. The indirect irradiation from the electron beam (through the photoresist) does not significantly alter graphene characteristic Raman peaks indicating that graphene quality is preserved upon the exposure. The 2D peak shifts and the intensity ratio of 2D and G band, I(2D)/I(G), decreases upon direct metal deposition (Co and Py) suggesting that the electronic modulation occurs due to sp2 C-C bond weakening. In contrast, a thin metal oxide film deposited graphene does not show either the significant 2D and G peaks shift or I(2D)/I(G) decrease upon the metal deposition suggesting the oxide protect the graphene quality in the fabrication process.
“You sayouchand I sayaya”
Authors: Park Joseph Sung-Yul
Published: December 2014

This paper explores the notion of linguistic insecurity as a way of exploring the link between language ideologies and the subjective experiences of transnational workers in the new economy. Focusing on two contrasting ideologies that characterize how language and identity is understood under neoliberalism — the newer ideology which presumes a flexible link between language and identity, and the older ideology which posits an essentialist connection — I analyze how a Korean mid-level manager working at a multinational corporation in Singapore deploys these ideologies in a narrative about his experience of transnational work, and discuss how such discursive practice can be understood in terms of linguistic insecurity.
An ethnographic multiple-case study of mother–child interaction strategies in Singapore-based Chinese families
Authors: Ren Li , Hu Guangwei
Published: December 2014

Previous research has shown that differences in the speech that children are exposed to can lead to differences in their language, literacy and cognitive development, and may even affect subsequent success at school. Informed by Vygotsky’s sociocultural theory of language learning in early childhood and Sigel’s Psychological Distancing Model, this ethnographic multiple-case study analyzes maternal interaction strategies in four Chinese families in Singapore — two local and two immigrant families — to explore factors that influence choice of interaction strategies. Cross-case comparisons are made in terms of the mothers’ professional and cultural backgrounds, and within-case comparisons are made along the lines of contextual factors. The comparisons reveal both important similarities and differences in the mothers’ use of interaction strategies which was shaped by an array of social, cultural, and contextual factors.
La production des scenarios contrefactuels par des apprenants adultes hispanophones
Authors: Repiso Isabel
Published: December 2014

The production of alternatives to factual events implies a counterfactual thinking in which reality is compared to an imagined view of what might have been. Previous studies in linguistics have analyzed counterfactuality in the context of conditional constructionsif P (then) Q(Bates 1976; Bloom 1981; Reilly 1982; Au 1983; Liu 1985; Bernini 1994; Chini 1995; Schouten 2000; Yeh & Gentner 2005). This article aims to describe the use of simple conditional sentences in a mutation task by 30 Spanish-speaking learners of French. In quantitative terms, the frequency of use of the conditional tense in the learner group is similar to that of the French control group for the same task. In qualitative terms, however, the way in which learners use the conditional differs from the native pattern in several ways: the use of the conjunction-queat the head of the mutation core (i.e.,Qu’elle aurait pu choisir son repas ‘That she could have chosen her meal’); the omission of a modal in the mutation core (i.e.,Son supérieur aurait choisi les moules‘Her superior would have chosen the mussels’) or the use of a modal verb elsewhere than in the past participle position (i.e.,Elle pourrait avoir commandé elle-même‘She could have ordered herself’). Our results show that in the production of counterfactual scenarios, the learners combine flexional features that match the native pattern with syntactic and lexical elements dominant in the organizational principles of information in the L1
Cross-linguistic influence in an oral translation task by L3 French learners
Authors: Mutta Maarit
Published: December 2014

This article addresses multilingual students’ lexical retrieval in L3 French at the university level. The aim was to study how Finnish L3 learners construct the meaning of cognate words that induce a high probability of cross-linguistic or intra-linguistic influence. The task was to orally translate 40 French words into L1 words (Finnish). These words were used to deliberately activate L3, L2 or L1 cognates. The corpus consisted of the productions of 12 first-year students (480 cases). The results show that participants gave the correct answer to a given word in 40% of cases. The results also show that intra-linguistic influence is the most probable source of both negative and positive effects and that cross-linguistic influence from L2 English was more important than that of L1. Nevertheless, well-learned common words seemed to resist this (combined) cross-linguistic influence. On the basis of the task, it can be concluded that cross-linguistic influence can vary considerably and that the source of the influence is not always clear. The analysis also revealed that on an oral translation task, the participants had recourse to different strategies based on form or form and meaning at various levels of success.
Osmotic surveillance mediates rapid wound closure through nucleotide release
Authors: Gault William J. , Enyedi Balázs , Niethammer Philipp
Published: December 2014

Osmotic cues from the environment mediate rapid detection of epithelial breaches by leukocytes in larval zebrafish tail fins. Using intravital luminescence and fluorescence microscopy, we now show that osmolarity differences between the interstitial fluid and the external environment trigger ATP release at tail fin wounds to initiate rapid wound closure through long-range activation of basal epithelial cell motility. Extracellular nucleotide breakdown, at least in part mediated by ecto-nucleoside triphosphate diphosphohydrolase 3 (Entpd3), restricts the range and duration of osmotically induced cell migration after injury. Thus, in zebrafish larvae, wound repair is driven by an autoregulatory circuit that generates pro-migratory tissue signals as a function of environmental exposure of the inside of the tissue.
Strong colorings yield 𝜅-bounded spaces with discretely untouchable points
Authors: Juhász István , Shelah Saharon
Published: December 2014

It is well known that every non-isolated point in a compact Hausdorff space is the accumulation point of a discrete subset. Answering a question raised by Z. Szentmiklóssy and the first author, we show that this statement fails for countably compact regular spaces, and even forω\omega-bounded regular spaces. In fact, there areκ\kappa-bounded counterexamples for every infinite cardinalκ\kappa. The proof makes essential use of the so-calledstrong coloringsthat were invented by the second author.
The role of word decoding, vocabulary knowledge and meta‐cognitive knowledge in monolingual and bilingual low‐achieving adolescents' reading comprehension
Authors: van Steensel Roel , Oostdam Ron , van Gelderen Amos , van Schooten Erik
Published: December 2014

In this study, we analysed the relationships between word decoding, vocabulary knowledge, meta‐cognitive knowledge and reading comprehension in low‐achieving adolescents and examined whether the strength of these relationships differed between Grade 7 and 9 students and between monolingual and bilingual students. Tests were administered to 328 students in Dutch prevocational education. Multilevel analyses showed positive effects of vocabulary and meta‐cognitive knowledge on reading comprehension that were consistent across grades and across monolinguals and bilinguals. Additionally, we found a positive effect of word decoding for seventh graders, but no effect for ninth graders. There was also a positive effect of bilingualism on reading comprehension when vocabulary differences were controlled. This finding suggests that for bilingual students, reading comprehension is hampered by limited second‐language vocabulary knowledge and that these students will profit more from an increase in vocabulary knowledge than their monolingual peers. The results underline the importance of vocabulary and meta‐cognitive instruction for low‐achieving adolescents.
Orthographic learning in Spanish children
Authors: Suárez‐Coalla Paz , Álvarez‐Cañizo Marta , Cuetos Fernando
Published: December 2014

In order to read fluently, children have to form orthographic representations. Despite numerous investigations, there is no clear answer to the question of the number of times they need to read a word to form an orthographic representation. We used length effect on reading times as a measure, because there are large differences between long and short words for unknown words, differences that disappear when reading frequent words. Two lists of new words (half short and half long) were presented to 102 second‐grade to sixth‐grade Spanish children, to be read aloud six times. One of the lists was presented as part of a story and the other in isolation. Comparison of the length effect at the first and sixth exposure showed large differences between short and long words in the first presentation and small differences at the sixth presentation, indicating that Spanish children develop representations of words after just a few repetitions.
Influence of Enzymatic Extrusion Liquefaction Pretreatment for Chinese Rice Wine on the Volatiles Generated from Extruded Rice
Authors: Xu Enbo , Li Hongyan , Wu Zhengzong , Wang Fang , Xu Xueming , Jin Zhengyu , Jiao Aiquan
Published: December 2014

Volatile compounds in enzymatic extruded rice, produced under different conditions of varying barrel temperature (BT), α‐amylase concentration (AC) and moisture content (MC), were extracted and identified by headspace solid phase microextraction (HS‐SPME) and gas chromatography‐linked mass spectrometry (GC‐MS). Statistical analyses reflected that the Maillard reaction could be inhibited both by the mild extrusion conditions and the enhanced hydrolysis caused by thermostable α‐amylase. Relative amounts of total volatiles in enzymatic extruded rice were far less than those in severe processed extruded rice. Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) showed that the amino acids (AAs) involved in Maillrad reaction were utmostly preserved in extruded rice with highest amylase concentration by comparison of total AA content of different extrudates. These results suggest that enzymatic extrusion liquefaction is an effective way to control the generation of volatiles from extruded rice for Chinese rice wine production.
Application of Autochthonous Mixed Starter for Controlled Kedong Sufu Fermentation in Pilot Plant Tests
Authors: Feng Zhen , Xu Miao , Zhai Shuang , Chen Hong , Li Ai‐li , Lv Xin‐tong , Deng Hong‐ling
Published: December 2014

Traditional sufu is fermented by back‐slopping and back‐slopping has many defects. The objective of this study was to apply autochthonous mixed starter to control Kedong sufu fermentation. Sufu was manufactured using back‐slopping (batch A) and autochthonous mixed starter (batch B) with Kocuria kristinae F7, Micrococcus luteus KDF1, and Staphylococcus carnosus KDFR1676. Considering physicochemical properties of sufu, 150‐day sufu samples from batch A and 90‐day sufu samples from batch B met the standard requirements, respectively. Considering sensory characteristics of sufu, 150‐day sufu samples from batch A and 90‐day sufu samples from batch B showed no significant differences (P > 0.05). The maturation period of sufu was shortened by 60 d. Profiles of free amino acids and peptides partly revealed the mechanism of typical sensory quality and shorter ripening time of sufu manufactured by autochthonous mixed starter. In final products, content of total biogenic amines was reduced by 48%. Autochthonous mixed starter performed better than back‐slopping. Fermentation had a positive influence on the quality, safety, and sensory properties of sufu. The application of autochthonous mixed starter does not change the sensory characteristics of traditional fermented sufu. In addition, it reduces maturation period and improves their homogeneity and safety. It is possible to substitute autochthonous mixed starter for back‐slopping in the manufacture of sufu.
Multimodality imaging in adnexal torsion
Authors: Patil Aruna R , Nandikoor Shrivalli , Rao Anuradha , M Janardan Govindarajan , Kheda AmithaVikrama , Hari Mahesh , Basappa Sharana
Published: December 2014

Adnexal torsions are one among the causes of acute pelvic pain in females. Commonly occurring adnexal torsions are ovarian either involving the normal ovary with functional cysts or an associated mass. Fallopian tube torsions, torsions involving paraovarian, fimbrial cysts and subserosal fibroids are rare. Here we discuss the multimodality imaging approach for the diagnosis of adnexal torsion, its limitations and mimics.
A polymorphism in the porcine miR‐208b is associated with microRNA biogenesis and expressions of SOX‐6 and MYH7 with effects on muscle fibre characteristics and meat quality
Authors: Kim J. M. , Lim K. S. , Hong J. S. , Kang J. H. , Lee Y. S. , Hong K. C.
Published: December 2014

MicroRNAs (miRNAs) encoded by the myosin heavy chain (MHC) genes are muscle‐specific miRNAs (myomiRs) and regulate the expression of MHC isoforms in skeletal muscle. These miRNAs have been implicated in muscle fibre types and their characteristics by affecting the heterogeneity of myosin. In pigs, miR‐208b and miR‐499 are embedded in introns of MYH7 and MYH7b respectively. Here, we identified a novel single nucleotide polymorphism (SNP) in intron 30 of MYH7 by which porcine miR‐208b is encoded. Based on the association study using a total of 487 pigs including Berkshire (n = 164), Landrace (n = 121) and Yorkshire (n = 202), the miR‐208b SNP (g.17104G>A) had significant effects on the proportions of types I and IIb fibre numbers (P < 0.010) among muscle fibre characteristics and on drip loss (P = 0.012) in meat quality traits. Moreover, the SNP affected the processing of primary miR‐208b into precursor miR‐208b with a marginal trend towards significance (P = 0.053), thereby leading to significant changes in the levels of mature miR‐208b (P = 0.009). These SNP‐dependent changes in mature miR‐208b levels were negatively correlated with the expression levels of its target gene, SOX‐6 (P = 0.038), and positively associated with the expression levels of its host gene, MYH7 (P = 0.046). Taken together, our data suggest that the porcine miR‐208b SNP differentially represses the expression of SOX‐6 by regulating miRNA biogenesis, thereby affecting the expression of MYH7 and the traits of muscle fibre characteristics and meat quality.