bluuebunny/crossref_metadata_2025 huggingface dataset:
Arbitration as the Best Option for the Settlement of China-African Trade and Investment Disputes
Authors: Zhu Weidong
Published: April 2013

The effective resolution of trade disputes related to Sino-African investments will have a major impact on the development of trade and investment between China and African states. Arbitration is considered the best option for the settlement of disputes between China and African states as it offers unique benefits and is both suited to the current environment in African countries and accepted by Chinese and Africans. To make full use of this dispute settlement approach, the Chinese government should take active measures to promote the knowledge of arbitral legal systems in Africa among the Chinese businesses investing or trading locally. Beijing should encourage them to settle disputes with their African counterparts through arbitration. It is also important for Chinese companies to learn about arbitration laws in African states, and choose a favourable arbitral institution and proper arbitration seat.
Meeting defined benefit pension obligations: measurement, risk and flight paths ‐ Abstract of the Edinburgh discussion
Authors: Hatchett Jon
Published: April 2013

This abstract relates to the following paper:

HatchettJ., HurdM. and ClacherI.Meeting defined benefit pension obligations: measurement, risk and flight paths.British Actuarial Journal, doi:10.1017/S1357321712000335
Motivationale Veränderung von Grundschulkindern in Englisch, Deutsch und Mathematik im Immersions- und Regelunterricht
Authors: Zaunbauer Anna C. M. , Gebauer S. Kristina , Retelsdorf Jan , Möller Jens
Published: April 2013

Der vorliegende Beitrag befasst sich mit der Veränderung von Selbstkonzept und Interesse in der Grundschule. Dabei werden immersiv unterrichtete Kinder (englischsprachiger Unterricht in allen Fächern außer Deutsch) mit monolingual unterrichteten Kindern im Regelunterricht verglichen. Es wurde bei N = 590 Schülern (51.7 % immersiv) längsschnittlich von der zweiten bis zur vierten Jahrgangsstufe die Veränderung des Selbstkonzepts und des Interesses in den Domänen Englisch, Deutsch und Mathematik bei Kontrolle von Intelligenz, Geschlecht und Selbstkonzept/Interesse im ersten Schuljahr untersucht. Analysen von latenten Wachstumskurvenmodellen zeigen ein höheres Ausgangsniveau im Englischselbstkonzept bei immersiv unterrichteten Schülern. Für das Englischselbstkonzept lässt sich in beiden Gruppen eine identische Zunahme nachweisen. Das Deutsch- und Mathematikselbstkonzept sowie das Englisch-, Deutsch- und Mathematikinteresse unterscheiden sich nicht bedeutsam zwischen den Gruppen und erweisen sich als stabil über die Zeit. Die Ergebnisse sprechen gegen die Annahme, dass während der Grundschulzeit Verluste im Selbstkonzept und Interesse zu verzeichnen sind.
Hysteresis measurement of individual multilayered Fe-Ga/Cu nanowires using magnetic force microscopy
Authors: Jin Park Jung , Reddy Madhukar , Stadler Bethanie J. H. , Flatau Alison B.
Published: April 2013

We have investigated nano-scale magnetic structures to learn how magnetic behaviors differ from what is observed in bulk materials. In this study, we have measured the magnetic hysteresis of individual multilayered nanowire using a magnetic force microscopy (MFM). The nanowires were composed of low-aspect ratio segments of iron-gallium (Galfenol, Fe80Ga20) and copper layers. Individual wires were released from nano-porous anodized aluminum oxide (AAO) templates and separated from other nanowires to avoid significant interactions between nearby nanowires. In this experiment, structures with aspects ratios c/a of ∼3 were studied. Different MFM phase magnitudes in response to the interaction of magnetic film coated MFM tips and Fe-Ga/Cu nanowire were observed as a function of applied external magnetic field (−850 Oe < H < 850 Oe). Amplitude differences between bright and dark responses in MFM images were used to demonstrate hysteresis. Coercivity measured was about 125 Oe, which is almost same as the coercivity value (∼150 Oe) of a nanowire array measured with a vibrating sample magnetometer (VSM). When fields are applied perpendicular to the nanowires, the hysteresis loops sheared, indicating that the easy axis is along the nanowire axis. Remanence magnetizations of an individual nanowire and a nanowire array were compared to demonstrate inter-wire magnetostatic dipolar interaction.
Unrestricted absolutely localized molecular orbitals for energy decomposition analysis: Theory and applications to intermolecular interactions involving radicals
Authors: Horn Paul R. , Sundstrom Eric Jon , Baker Thomas A. , Head-Gordon Martin
Published: April 2013

Radical-closed shell and radical-radical intermolecular interactions are less well-understood than those between closed shell species. With the objective of gaining additional insight, this work reports a generalization of the absolutely localized molecular orbital (ALMO) energy decomposition analysis (EDA) to open shell fragments, described by self-consistent field methods, such as standard density functional theory. The ALMO-EDA variationally partitions an intermolecular interaction energy into three separate contributions; frozen orbital interactions, polarization, and charge transfer. The first examples involve comparison of the interactions of alkanes and alkyl radicals (methyl radical, methane, tertiary butyl radical, and isobutane) with sodium, potassium, hydronium, and ammonium cations. A second series of examples involve benzene cation interacting with a series of nucleophiles in both on-top and side-on geometries. The ALMO-EDA yields a variety of interesting insights into the relative roles of its component contributions as the interacting partners and their geometries are changed.
A novel instrument for quantitative nanoanalytics involving complementary X-ray methodologies
Authors: Lubeck J. , Beckhoff B. , Fliegauf R. , Holfelder I. , Hönicke P. , Müller M. , Pollakowski B. , Reinhardt F. , Weser J.
Published: April 2013

A novel ultra-high vacuum instrument for X-ray reflectometry and spectrometry-related techniques for nanoanalytics by means of synchrotron radiation has been constructed and commissioned. This versatile instrument was developed by the Physikalisch-Technische Bundesanstalt, Germany's national metrology institute, and includes a 9-axis manipulator that allows for an independent alignment of the samples with respect to all degrees of freedom. In addition, a rotational and translational movement of several photodiodes as well as a translational movement of an aperture system in and out of the beam is provided. Thus, the new instrument enables various analytical techniques based on energy dispersive X-ray detectors such as reference-free X-ray fluorescence analysis (XRF), total-reflection XRF, grazing-incidence XRF in addition to optional X-ray reflectometry measurements or polarization-dependent X-ray absorption fine structure analyses. With this instrument samples having a size of up to 100 mm × 100 mm can be analyzed with respect to their mass deposition, elemental or spatial composition, or the species in order to probe surface contamination, layer composition and thickness, the depth profile of matrix elements or implants, the species of nanolayers, nanoparticles or buried interfaces as well as the molecular orientation of bonds. Selected applications of this advanced ultra-high vacuum instrument demonstrate both its flexibility and capability.
Localized excitons mediate defect emission in ZnO powders
Authors: Foreman J. V. , Simmons J. G. , Baughman W. E. , Liu J. , Everitt H. O.
Published: April 2013

A series of continuous-wave spectroscopic measurements elucidates the mechanism responsible for the technologically important green emission from deep-level traps in ZnO:Zn powders. Analysis of low-temperature photoluminescence (PL) and PL excitation spectra for bound excitons compared to the temperature-dependent behavior of the green emission reveals a deep correlation between green PL and specific donor-bound excitons. Direct excitation of these bound excitons produces highly efficient green emission from near-surface defects. When normalized by the measured external quantum efficiency, the integrated PL for both excitonic and green emission features grows identically with excitation intensity, confirming the strong connection between green emission and excitons. The implications of these findings are used to circumscribe operational characteristics of doped ZnO-based white light phosphors whose quantum efficiency is almost twice as large when the bound excitons are directly excited.
Insight into the molecular mechanism of water evaporation via the finite temperature string method
Authors: Musolino Nicholas , Trout Bernhardt L.
Published: April 2013

The process of water's evaporation at its liquid/air interface has proven challenging to study experimentally and, because it constitutes a rare event on molecular time scales, presents a challenge for computer simulations as well. In this work, we simulated water's evaporation using the classical extended simple point charge model water model, and identified a minimum free energy path for this process in terms of 10 descriptive order parameters. The measured free energy change was 7.4 kcal/mol at 298 K, in reasonable agreement with the experimental value of 6.3 kcal/mol, and the mean first-passage time was 1375 ns for a single molecule, corresponding to an evaporation coefficient of 0.25. In the observed minimum free energy process, the water molecule diffuses to the surface, and tends to rotate so that its dipole and one O–H bond are oriented outward as it crosses the Gibbs dividing surface. As the water molecule moves further outward through the interfacial region, its local density is higher than the time-averaged density, indicating a local solvation shell that protrudes from the interface. The water molecule loses donor and acceptor hydrogen bonds, and then, with its dipole nearly normal to the interface, stops donating its remaining hydrogen bond. At that point, when the final, accepted hydrogen bond is broken, the water molecule is free. We also analyzed which order parameters are most important in the process and in reactive trajectories, and found that the relative orientation of water molecules near the evaporating molecule, and the number of accepted hydrogen bonds, were important variables in reactive trajectories and in kinetic descriptions of the process.
Non-abelian vortices on $\mathbb {CP}^{1}$CP1 and Grassmannians
Authors: Rink Norman A.
Published: April 2013

Many properties of the moduli space of abelian vortices on a compact Riemann surface Σ are known. For non-abelian vortices the moduli space is less well understood. Here we consider non-abelian vortices on the Riemann sphere $\mathbb {CP}^{1}$CP1, and we study their moduli spaces near the Bradlow limit. We give an explicit description of the moduli space as a Kähler quotient of a finite-dimensional linear space. The dimensions of some of these moduli spaces are derived. Strikingly, there exist non-abelian vortex configurations on $\mathbb {CP}^{1}$CP1, with non-trivial vortex number, for which the moduli space is a point. This is in stark contrast to the moduli space of abelian vortices. For a special class of non-abelian vortices the moduli space is a Grassmannian, and the metric near the Bradlow limit is a natural generalization of the Fubini–Study metric on complex projective space. We use this metric to investigate the statistical mechanics of non-abelian vortices. The partition function is found to be analogous to the one for abelian vortices.
Model for Mn in 6H-SiC from first-principle studies
Authors: Al Azri M. , Elzain M. , Bouziane K. , Chérif S. M. , Declémy A. , Thomé L.
Published: April 2013

The electronic and magnetic properties of 6H-SiC with Mn impurities have been calculated using generalized gradient approximation formalism. Various configurations of Mn sites and Si and C vacancies were considered. It was found that 6H-SiC doped with Mn atoms possess a moment for both types of substitution. The Mn atom at Si site possesses larger magnetic moment than Mn atom at C site. The energy levels appearing in the band gap due to vacancies and due to Mn impurities are determined and the calculated densities of states are used to analyze the different values of the magnetic moments for different types of substitution. A model that explains the magnetic moment at Mn site is proposed.
Mechanical properties of polymer/carbon nanotube composite micro-electromechanical systems bridges
Authors: Sousa P. M. , Chu V. , Conde J. P.
Published: April 2013

Microelectromechanical systems with all-polymer structural layers are expected to allow novel MEMS applications due to their mechanical, optical, electronic, and chemical properties, which are tunable and distinct from the standard inorganic layers currently used. The mechanical properties of micro-electromechanical bridge resonators (pMEMS) based on a polymer/carbon-nanotubes (CNT) composite structural material are presented. The structural material of the electrostatically actuated pMEMS microresonators are multilayers of a conductive polymer based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to which carboxylated multi-wall CNTs monolayers are electrostatically attached after surface functionalization. The effects of measurement pressure, temperature, and applied load on the resonance frequency and on the quality factor, Q, of the pMEMS are studied. The long term reliability of the pMEMS resonators is also investigated, and the resonators were subjected to above 1011 actuation cycles without significant performance deterioration. The mechanical properties of the pMEMS are systematically compared to those of a doped hydrogenated amorphous silicon (n+-a-Si:H) MEMS. While the CNT multilayers increase the rigidity (and hence the resonance frequency) as well as the electrical conductivity of the structural layer, they decrease the energy dissipation (and hence increase Q). Changes in CNT-polymer matrix adhesion result in reversible changes of the resonator properties during operation, requiring monitoring and control.
Efficient tree tensor network states (TTNS) for quantum chemistry: Generalizations of the density matrix renormalization group algorithm
Authors: Nakatani Naoki , Chan Garnet Kin-Lic
Published: April 2013

We investigate tree tensor network states for quantum chemistry. Tree tensor network states represent one of the simplest generalizations of matrix product states and the density matrix renormalization group. While matrix product states encode a one-dimensional entanglement structure, tree tensor network states encode a tree entanglement structure, allowing for a more flexible description of general molecules. We describe an optimal tree tensor network state algorithm for quantum chemistry. We introduce the concept of half-renormalization which greatly improves the efficiency of the calculations. Using our efficient formulation we demonstrate the strengths and weaknesses of tree tensor network states versus matrix product states. We carry out benchmark calculations both on tree systems (hydrogen trees and π-conjugated dendrimers) as well as non-tree molecules (hydrogen chains, nitrogen dimer, and chromium dimer). In general, tree tensor network states require much fewer renormalized states to achieve the same accuracy as matrix product states. In non-tree molecules, whether this translates into a computational savings is system dependent, due to the higher prefactor and computational scaling associated with tree algorithms. In tree like molecules, tree network states are easily superior to matrix product states. As an illustration, our largest dendrimer calculation with tree tensor network states correlates 110 electrons in 110 active orbitals.
Comparison of modified driver circuit and capacitor-transfer circuit in longitudinally excited N2 laser
Authors: Uno Kazuyuki , Akitsu Tetsuya , Nakamura Kenshi , Jitsuno Takahisa
Published: April 2013

We developed a modified driver circuit composed of a capacitance and a spark gap, called a direct-drive circuit, for a longitudinally excited gas laser. The direct-drive circuit uses a large discharge impedance caused by a long discharge length of the longitudinal excitation scheme and eliminates the buffer capacitance used in the traditional capacitor-transfer circuit. We compared the direct-drive circuit and the capacitor-transfer circuit in a longitudinally excited N2 laser (wavelength: 337 nm). Producing high output energy with the capacitor-transfer circuit requires a large storage capacitance and a discharge tube with optimum dimensions (an inner diameter of 4 mm and a length of 10 cm in this work); in contrast, the direct-drive circuit requires a high breakdown voltage, achieved with a small storage capacitance and a large discharge tube. Additionally, for the same input energy of 792 mJ, the maximum output energy of the capacitor-transfer circuit was 174.2 μJ, and that of the direct-drive circuit was 344.7 μJ.
Global solvability and blow up for the convective Cahn-Hilliard equations with concave potentials
Authors: Eden A. , Kalantarov V. K. , Zelik S. V.
Published: April 2013

We study initial boundary value problems for the unstable convective Cahn-Hilliard (CH) equation, i.e., the Cahn Hilliard equation whose energy integral is not bounded below. It is well-known that without the convective term, the solutions of the unstable CH equation \documentclass[12pt]{minimal}\begin{document}$\partial _tu +\partial _{x}^4u +\partial _{x}^2(|u|^pu)=0$\end{document}∂tu+∂x4u+∂x2(|u|pu)=0 may blow up in finite time for any p > 0. In contrast to that, we show that the presence of the convective term u∂xu in the Cahn-Hilliard equation prevents blow up at least for \documentclass[12pt]{minimal}\begin{document}$0<p<\frac{4}{9}$\end{document}0<p<49. We also show that the blowing up solutions still exist if p is large enough (p ⩾ 2). The related equations like Kolmogorov-Sivashinsky-Spiegel equation, sixth order convective Cahn-Hilliard equation, are also considered.
Exchange biased magnetoelectric composites for vector field magnetometers
Authors: Lage Enno , Woltering Frederik , Quandt Eckhard , Meyners Dirk
Published: April 2013

Magnetoelectric (ME) vector field sensors can be realized by combining individual sensors with anisotropic sensitivity. Following this approach, exchange biased ME thin film composites were incorporated into two dimensional vector magnetometers. These self biased composites do not need magnetic dc bias fields for their operation, which allows a high degree of miniaturization since interference of individual bias fields is avoided. The successful detection of a two dimensional magnetic vector field opens the path to full three dimensional vector sensing.
Buckling of a thin, viscous film in an axisymmetric geometry
Authors: Bhattacharya S. , Craster R. V. , Flynn M. R.
Published: April 2013

By adapting the Föppl-von Kàrmàn equation, which describes the deformation of a thin elastic membrane, we present an analysis of the buckling pattern of a thin, very viscous fluid layer subject to shear in an axisymmetric geometry. A linear stability analysis yields a differential eigenvalue problem, whose solution, obtained using spectral techniques, yields the most unstable azimuthal wave-number, m⋆. Contrary to the discussion of Slim et al. [J. Fluid Mech. 694, 5–28 (2012)]10.1017/jfm.2011.437, it is argued that the axisymmetric problem shares the same degeneracy as its rectilinear counterpart, i.e., at the onset of instability, m⋆ is indefinitely large. Away from this point, however, a comparison with analogue experimental results is both possible and generally favorable. In this vein, we describe the laboratory apparatus used to make new measurements of m⋆, the phase speed and the wave amplitude; note that no prediction concerning the latter two quantities can be made using the present theory. Experiments reveal a limited range of angular velocities wherein waves of either small or large amplitude may be excited. Transition from one to the other regime does not appear to be associated with a notable change in m⋆.
Mass transport in CuInSe2 from first principles
Authors: Oikkonen L. E. , Ganchenkova M. G. , Seitsonen A. P. , Nieminen R. M.
Published: April 2013

The wide scatter in experimental results has not allowed drawing solid conclusions on self-diffusion in the chalcopyrite CuInSe2 (CIS). In this work, the defect-assisted mass transport mechanisms operating in CIS are clarified using first-principles calculations. We present how the stoichiometry of the material and temperature affect the dominant diffusion mechanisms. The most mobile species in CIS is shown to be copper, whose migration proceeds either via copper vacancies or interstitials. Both of these mass-mediating agents exist in the material abundantly and face rather low migration barriers (1.09 and 0.20 eV, respectively). Depending on chemical conditions, selenium mass transport relies either solely on selenium dumbbells, which diffuse with a barrier of 0.24 eV, or also on selenium vacancies whose diffusion is hindered by a migration barrier of 2.19 eV. Surprisingly, indium plays no role in long-range mass transport in CIS; instead, indium vacancies and interstitials participate in mechanisms that promote the formation of antisites on the cation sublattice. Our results help to understand how compositional inhomogeneities arise in CIS.
Dielectric properties of stoichiometric and defect-induced hydroxyapatite
Authors: Horiuchi N. , Endo J. , Wada N. , Nozaki K. , Nakamura M. , Nagai A. , Katayama K. , Yamashita K.
Published: April 2013

Dehydrated hydroxyapatite (HAp), OH− ion-defect induced hydroxyapatite, was prepared for dielectric measurements. We evaluated the dielectric properties of HAp in 100–500 °C, and found dielectric relaxations of two kinds. At lower temperature, relaxation that was attributed to the reorientations of OH− ions was observed, where the relaxation strengths were influenced strongly by the OH− concentrations. The activation energy of the OH− reorientation, which was unaffected by the OH− concentrations, was ascertained as 0.62–0.63 eV. However, in a higher temperature range, relaxations that had larger relaxation strength were observed and were regarded as originating from the displacement of OH− ions and O2− ions. The activation energies of the larger relaxation, which were affected by the OH− concentrations, were ascertained as 0.73 eV and 0.81 eV. Those values are comparable to the activation energy of proton conduction, implying that the proton conduction in HAp starts at a low temperature.
Chemical trends of defects at HfO2:GaAs and Al2O3:GaAs/InAs/InP/GaSb interfaces
Authors: Lin Liang , Guo Yuzheng , Gillen Roland , Robertson John
Published: April 2013

We have calculated the chemical trends of the main interfacial defects expected for III-V semiconductor:oxide interfaces, for GaAs, InGaAs, InP, and GaSb. This includes the anion-anion dimer bond, the cation (Ga) dangling bond, and the anion (As) dangling bond. The anion-anion dimer bond state is found to lie below the cation dangling bond state in each system and is the first to enter the gap from the conduction band. The anion dangling bond state can lie just above the valence band edge if partially filled and is the likely cause of gap states above the valence band edge.
Modeling of ferroelectric control of magnetic domain pattern and domain wall properties
Authors: Chen H. T. , Ni Y. , Soh A. K.
Published: April 2013

In the field of spintronics, various approaches via spin-polarized currents have been proven effective in controlling the direction of magnetization in ferromagnetic layers. However, overheating problems are unavoidable in view of the high current densities involved. Alternatively, electric field control of magnetization in multiferroics, which couple the electric and magnetic order parameters, could be a promising approach due to the possibility of “zero-current” operations. In the present study, we investigated transferring of domain patterns from a ferroelectric substrate onto a ferromagnetic thin film. Under an applied electric field, the magnetic domain patterns could be maintained or erased depending on the field direction. The thickness and motion of the magnetic domain walls could also be manipulated by the applied electric field. The possibility of ferroelectric control of local magnetism is a new approach for producing electric-field controlled spintronics devices.
Hydrodynamic mechanisms of cell and particle trapping in microfluidics
Authors: Karimi A. , Yazdi S. , Ardekani A. M.
Published: April 2013

Focusing and sorting cells and particles utilizing microfluidic phenomena have been flourishing areas of development in recent years. These processes are largely beneficial in biomedical applications and fundamental studies of cell biology as they provide cost-effective and point-of-care miniaturized diagnostic devices and rare cell enrichment techniques. Due to inherent problems of isolation methods based on the biomarkers and antigens, separation approaches exploiting physical characteristics of cells of interest, such as size, deformability, and electric and magnetic properties, have gained currency in many medical assays. Here, we present an overview of the cell/particle sorting techniques by harnessing intrinsic hydrodynamic effects in microchannels. Our emphasis is on the underlying fluid dynamical mechanisms causing cross stream migration of objects in shear and vortical flows. We also highlight the advantages and drawbacks of each method in terms of throughput, separation efficiency, and cell viability. Finally, we discuss the future research areas for extending the scope of hydrodynamic mechanisms and exploring new physical directions for microfluidic applications.
Graphene oxide gate dielectric for graphene-based monolithic field effect transistors
Authors: Eda Goki , Nathan Arokia , Wöbkenberg Paul , Colleaux Florian , Ghaffarzadeh Khashayar , Anthopoulos Thomas D. , Chhowalla Manish
Published: April 2013

We report unique electrical anisotropy and dielectric properties of graphene oxide (GO) thin films, which allow facile implementation of GO-based monolithic field effect transistors (FETs). We demonstrate that exposure of GO films to hydrogen plasma leads to self-limiting reduction of only the uppermost layers such that a semiconductor-on-insulator type heterostructure is realized. In such heterostructures, the reduced uppermost layers and the unmodified bulk GO layers serve as the channel and gate dielectric components, respectively, of a thin film FET.
Large inherent optical gain from the direct gap transition of Ge thin films
Authors: Wang Xiaoxin , Kimerling Lionel C. , Michel Jurgen , Liu Jifeng
Published: April 2013

The recent demonstration of Ge-on-Si diode lasers renews the interest in the unique carrier dynamics of Ge involving both direct (Γ) and indirect (L) valleys. Here, we report a large inherent direct gap optical gain ≥1300 cm−1 at room temperature from both tensile-strained n+ Ge-on-Si films and intrinsic Ge-on-insulator using femtosecond transmittance spectroscopy captured before direct-to-indirect valley scattering. This inherent direct gap gain is comparable to III-V semiconductors. For n+ Ge, this transient gain is ∼25× larger than its steady state gain, suggesting that reducing Γ→L or enhancing L→Γ intervalley scattering may significantly increase the optical gain of Ge lasers.
Electric field and photo-excited control of the carrier concentration in GdN
Authors: Warring H. , Ruck B. J. , Trodahl H. J. , Natali F.
Published: April 2013

We present both electric-field and photo-excited control of the carrier concentration in GdN. There is no evidence in the results of a carrier-mediated contribution to the Gd-Gd exchange interaction that has been suggested to explain a measured Curie temperature that is much higher than obtained within theoretical treatments. Persistent carrier concentrations seen in both the field-effect and photo-induced conductivities point to a distribution of long-lived trap states below the conduction band, very likely centered at nitrogen vacancies.
Stress-versus temperature-induced structural evolution in metallic glasses
Authors: Peng H. L. , Li M. Z. , Wang W. H.
Published: April 2013

Structure evolution induced by shear deformation was investigated via molecular dynamic simulation on CuZr metallic glass system and compared with that induced by temperature. Voronoi tessellation analysis found that the local structures evolve to a liquid-like state as shear stress increases, similar to the temperature-induced structure evolution. However, shear stress induces little change to the radial distribution functions (RDFs) compared to temperature, indicating that the global glassy state still sustains. This is in contrast to the opinion that shear deformation may be similar to temperature increase and induce a metallic glass system to experience glass-liquid transition. The analysis of anisotropic part of RDFs reveals that shear deformation can induce significant anisotropic structural evolution, while pure increase of temperature cannot. Our findings demonstrate that shear deformation may induce different structural evolution in metallic glasses compared to temperature.
Tuning multiple Fano resonances in plasmonic pentamer clusters
Authors: Liu Shao-Ding , Zhang Ming-Jiang , Wang Wen-Jie , Wang Yun-Cai
Published: April 2013

Multiple Fano resonances in plasmonic pentamer clusters composed of nanorings are observed and investigated. Molecular point group theory is used to understand the formation of multiple Fano resonances. By modifying the radius of the center ring or the angle between the center and the surrounding rings, the modulation depths and the spectral positions of the multiple Fano resonances can be tuned within a wide range. For pentamers composed of split nanorings, another Fano resonance can be excited because of the excitation of the quadrupole mode of the surrounding split nanorings.
Compositional study of defects in microcrystalline silicon solar cells using spectral decomposition in the scanning transmission electron microscope
Authors: Duchamp M. , Lachmann M. , Boothroyd C. B. , Kovács A. , Haug F.-J. , Ballif C. , Dunin-Borkowski R. E.
Published: April 2013

The chemical compositions of defective regions in microcrystalline thin film Si solar cells are studied using energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope. Nanometer-resolved chemical analysis reveals the presence of ZnO in micrometer-long defective regions. Due to the recent application of unmixing algorithm to EELS, the chemical compositions of the defective regions are determined objectively, without introducing artefacts from the fitting procedures. It is shown that the defective regions in the Si layer are filled by ZnO, which diffuses along voids that propagate from the bottom up to the top ZnO contacts.
Fabrication and electrical properties of LiNbO3/ZnO/n-Si heterojunction
Authors: Hao Lanzhong , Li Yanrong , Zhu Jun , Wu Zhipeng , Deng Jie , Liu Xingzhao , Zhang Wanli
Published: April 2013

Lithium niobate (LiNbO3 or LN) ferroelectricfilms were grown on n-type Si (100) substrates using ZnO as buffer layers by pulse laser deposition technique. The microstructures and electrical properties of the heterojunctions were studied. X-ray diffraction results showed that single (001) orientation for the LN films can be promoted on Si (100) substrates with the buffer effect of the ZnO layers. Due to the ferroelectricpolarizations of the LN films,hysteretic characteristicswere observed from the capacitance-voltage (C-V) curves of the LN/ZnO/n-Si heterojunctions. Obvious photoresponse characteristics were exhibited in the fabricated heterojunction. High performance of the photoresponse of the heterojunction was shown, such as a large ON/OFF ratio, short photoresponse time, steady ON or OFF states, and well reversible. These characteristics make it possible for the heterojunctions to develop multifunctional applications, such as memory devices,eletro-optic devices, and etc. The studied results show that the electrical properties of the heterojunctions were dependent greatly on the thickness of the ZnO buffers and the structural composition of the LN films. The results were discussed in terms of the band diagrams of the LN/ZnO/Si heterojunctions in this work.
Mixture formation of ErxYb2-xSi2O7 and ErxYb2-xO3 on Si for broadening the C-band in an optical amplifier
Authors: Omi Hiroo , Abe Yoshiyuki , Anagnosti Maria , Tawara Takehiko
Published: April 2013

Thin films composed of polycrystalline ErxYb2-xO3 grains and crystalline ErxYb2-xSi2O7 layers were formed on a Si(111) substrate by RF - sputtering and subsequent thermal annealing in Ar gas ambient up to 1100 °C. The films were characterized by synchrotron radiation grazing incidence X-ray diffraction, cross-sectional transmission microscopy, energy dispersive X-ray spectrometry and micro photoluminescence measurements. In the annealed film of 950 °C it is observed that the I15/2 - I13/2 Er3+photoluminescent transition exhibits simultaneously maximum intensity and peak width at room temperature. This effect satisfies the requirements for broadening the C-band of an optical amplifier on Si.
Atomic layer deposition of Zn(O,S) thin films with tunable electrical properties by oxygen annealing
Authors: Hejin Park Helen , Heasley Rachel , Gordon Roy G.
Published: April 2013

Zinc oxysulfide, Zn(O,S), films grown by atomic layer deposition were annealed in oxygen to adjust the carrier concentration. The electron carrier concentration of Zn(O,S) can be reduced by several orders of magnitude from 1019 to 1015 cm−3 by post-deposition annealing in oxygen at temperatures from 200 °C to 290 °C. In the case of Zn(O,S) with S/Zn = 0.37, despite the considerable change in the electron carrier concentration, the bandgap energy decreased by only ∼0.1 eV, and the crystallinity did not change much after annealing. The oxygen/zinc ratio increased by 0.05 after annealing, but the stoichiometry remained uniform throughout the film.
Modulation of mid-infrared light using graphene-metal plasmonic antennas
Authors: Li Zhaoyi , Yu Nanfang
Published: April 2013

We show that large modulation of the amplitude and phase of mid-infrared light can be achieved by dynamically shifting the resonance of graphene-metal plasmonic antennas via electrical tuning of the optical conductivity of graphene. Intensity modulation with on-off extinction ratio exceeding 100 and phase modulation over a range of 240° are demonstrated by simulations of scattered light from arrays of such antennas. The modulation rate is estimated to be on the order of a few GHz. These properties are promising for creating reconfigurable flat optical components such as spatial light modulators in the mid-infrared spectral range.
Ion beam irradiation induced fabrication of vertical coupling waveguides
Authors: Liang H. D. , Kumar V. S. , Wu J. F. , Breese M. B. H.
Published: April 2013

Vertically coupled waveguides have been fabricated on a silicon-on-insulator platform using a combination of reactive ion etching to pattern the device layer and high-energy proton beam irradiation followed by electrochemical etching to pattern the substrate. Infra-red light can be coupled from the lower rib waveguide within the substrate into the upper waveguide within the device layer. By varying the proton energy along the lower waveguide, we have fabricated a tapered profile which is thin at the coupling region for higher efficiency and thicker towards the outer ends for easier coupling of light. A typical coupling efficiency of 26% has been achieved.
Limit of light coupling strength in solar cells
Authors: Naqavi A. , Haug F.-J. , Ballif C. , Scharf T. , Herzig H. P.
Published: April 2013

We introduce a limit for the strength of coupling light into the modes of solar cells. This limit depends on both a cell's thickness and its modal properties. For a cell with refractive index n and thickness d, we obtain a maximal coupling rate of 2cn2−1/d, where c is speed of light. Our method can be used in the design of solar cells and in calculating their efficiency limits; besides, it can be applied to a broad variety of resonant phenomena and devices.
Band alignment in SnS thin-film solar cells: Possible origin of the low conversion efficiency
Authors: Burton Lee A. , Walsh Aron
Published: April 2013

Tin sulfide is an attractive absorber material for low-cost thin-film solar cells. Despite the ideal physical properties of bulk SnS, the photovoltaic conversion efficiencies achieved in devices to date have been no greater than 2%. Assessment of the valence band energy of the stable orthorhombic phase of SnS reveals a low ionisation potential (4.7 eV) in comparison to typical absorber materials (CdTe, CuInSe2, and Cu2ZnSnS4). A band mis-alignment is therefore predicted with commonly used back contact and buffer layers. Alternative configurations are proposed that should improve device performance.
Bright single-photon source based on an InAs quantum dot in a silver-embedded nanocone structure
Authors: Liu X. , Asano T. , Odashima S. , Nakajima H. , Kumano H. , Suemune I.
Published: April 2013

High photon-extraction efficiency is strongly required for a practical single-photon source. We succeed in fabricating metal (sliver)-embedded nanocone structure incorporating an InAs quantum dot. Efficient photon emission of ∼200 000 photons per second is detected and single-photon emission is demonstrated using autocorrelation measurements. The photon-extraction efficiency as high as 24.6% is obtained from the structure.
Simultaneous measurement of electron and heavy particle temperatures in He laser-induced plasma by Thomson and Rayleigh scattering
Authors: Dzierżęga K. , Mendys A. , Pokrzywka B. , Zawadzki W. , Pellerin S.
Published: April 2013

Thomson and Rayleigh scattering methods were applied to quantify the electron and heavy particle temperatures, as well as electron number density, in a laser spark in helium at atmospheric pressure. Plasma was created using 4.5 ns, 25 mJ pulses from Nd:YAG laser at 532 nm. Measurements, performed for the time interval between 20 ns and 800 ns after breakdown, show electron density and temperature to decrease from 7.8×1023 m−3 to 2.6×1022 m−3 and from 95 900 K to 10 350 K, respectively. At the same time, the heavy particle temperature drops from only 47 000 K down to 4100 K which indicates a two temperature plasma out of local isothermal equilibrium.
Pulse plating of copper germanide
Authors: Joi Aniruddha , Akolkar Rohan , Landau Uziel
Published: April 2013

Electrodeposition of copper germanide (Cu3Ge) thin films from an alkaline tartrate-complexed electrolyte is described. Current pulsing is shown to enable co-deposition of copper and germanium in the stoichiometric ratio Cu:Ge = 3:1, while providing smooth and compact electrodeposits. The presence of ε-Cu3Ge phase with a monoclinic crystal structure is confirmed by X-ray diffraction of the as-deposited films. After annealing, Cu3Ge films exhibit an electrical resistivity of 45 μΩ cm; a value higher than previously reported resistivity of e-beam evaporated Cu3Ge films (∼10 μΩ cm). The higher electrical resistivity of the electrodeposited Cu3Ge films is attributed to smaller grain size and elevated impurity levels.
Classical subjective expected utility
Authors: Cerreia-Vioglio Simone , Maccheroni Fabio , Marinacci Massimo , Montrucchio Luigi
Published: April 2013

We consider decision makers who know that payoff-relevant observations are generated by a process that belongs to a given class
M
, as postulated in Wald [Wald A (1950)
Statistical Decision Functions
(Wiley, New York)]. We incorporate this Waldean piece of objective information within an otherwise subjective setting à la Savage [Savage LJ (1954)
The Foundations of Statistics
(Wiley, New York)] and show that this leads to a two-stage subjective expected utility model that accounts for both state and model uncertainty.
High‐ Versus Low‐Volume Polyethylene Glycol Plus Laxative Versus Sennosides for Colonoscopy Preparation in Children
Authors: Kierkus Jaroslaw , Horvath Andrea , Szychta Monika , Woynarowski Marek , Wegner Agnieszka , Wiernicka Anna , Dadalski Maciej , Teisseyre Mikolaj , Dziechciarz Piotr
Published: April 2013

Objective:

Many protocols of bowel preparation are available for use in children; however, none of them is commonly accepted. The aim of the study was to evaluate the efficacy and acceptability of high‐volume polyethylene glycol (PEG) versus low‐volume PEG combined with bisacodyl (BPEG) versus sennosides for colonoscopy preparation in children.

Methods:

Participants ages 10 to 18 years were randomly assigned to receive either PEG 60 or PEG 30 mL kg−1 day−1 plus oral bisacodyl 10 to 15 mg/day or sennosides 2 mg kg−1 day−1 for 2 days. A blinded assessment of bowel cleansing was made by the endoscopist according to the Aronchick and Ottawa scales. Patient acceptability was evaluated with the visual‐analog scale. Analysis was done on an available case analysis basis.

Results:

Of 240 patients enrolled in the study 234 patients were available for analysis of the efficacy of colon cleansing. There were no significant differences found among the 3 groups for the proportions of participants with excellent/good (PEG: 35/79, BPEG: 26/79, sennosides 25/76) and poor/inadequate (PEG: 20/79, BPEG: 28/79, sennosides 28/76) bowel preparation evaluated with the Aronchick scale and for the mean Ottawa total score (PEG: 5.47 ± 3.63, BPEG: 6.22 ± 3.3, sennosides: 6.18 ± 3.53). Acceptability of bowel cleansing protocol was similar in all of the groups (P = 0.8).

Conclusions:

All 3 cleansing methods showed similar efficacy and tolerability; however, none of them was satisfactory.
Suppressor of cytokine signalling protein SOCS1 and UBP43 regulate the expression of type I interferon-stimulated genes in human microvascular endothelial cells infected with Rickettsia conorii
Authors: Colonne Punsiri M. , Sahni Abha , Sahni Sanjeev K.
Published: April 2013

Rickettsia conorii, the causative agent of Mediterranean spotted fever, preferentially infects human microvascular endothelium and activates pro-inflammatory innate immune responses as evidenced by enhanced expression and secretion of cytokines and chemokines. Our recent studies reveal that human microvascular endothelial cells (HMECs) infected with R. conorii also launch ‘antiviral’ host defence mechanisms typically governed by type I interferons. To summarize, infected HMECs secrete IFN-β to activate STAT1 in an autocrine/paracrine manner and display increased expression of IFN-stimulated genes, for example ISG15, which in turn activate innate responses to interfere with intracellular replication of rickettsiae. We now present evidence that UBP43 and SOCS1, known negative regulators of JAK/STAT signalling, are also induced in R. conorii-infected HMECs, of which UBP43 but not SOCS1 functions to negatively regulate STAT1 activation. Interestingly, UBP43 induction is almost completely abolished in the presence of IFN-β-neutralizing antibody, implicating an important role for UBP43 as a feedback inhibitor for IFN-β-mediated STAT1 activation. In contrast, SOCS1 expression is only partially affected by IFN-β neutralization, implicating potential involvement of as-yet-unidentified IFN-independent mechanism(s) in SOCS1 induction during R. conorii infection. A number of IFN-stimulated genes, including ISG15, OAS1, MX1, IRF1, IRF9 and TAP1 are also induced in an IFN-β-dependent manner, whereas GBP1 remains unaffected by IFN-β neutralization. Increased STAT1 phosphorylation in HMECs subjected to UBP43 knockdown led to transcriptional activation of OAS1, MX1 and GBP1, confirming the negative regulatory role of UBP43. Although IRF1, IRF9 and TAP1 were induced by IFN-β, siRNA-mediated silencing of UBP43 or SOCS1 did not significantly affect their transcriptional activation. Expression of ISG15 was, however, increased in HMECs transfected with siRNA for UBP43 and SOCS1. Thus, unique regulatory patterns of induced expression of UBP43, SOCS1 and IFN-stimulated genes represent pathogen-specific responses underlying IFN-β-mediated host endothelial signalling during the pathogenesis of spotted fever group rickettsiosis.
An infectious recombinant foot-and-mouth disease virus expressing a fluorescent marker protein
Authors: Seago Julian , Juleff Nicholas , Moffat Katy , Berryman Stephen , Christie John M. , Charleston Bryan , Jackson Terry
Published: April 2013

Foot-and-mouth disease virus (FMDV) is one of the most extensively studied animal pathogens because it remains a major threat to livestock economies worldwide. However, the dynamics of FMDV infection are still poorly understood. The application of reverse genetics provides the opportunity to generate molecular tools to further dissect the FMDV life cycle. Here, we have used reverse genetics to determine the capsid packaging limitations for a selected insertion site in the FMDV genome. We show that exogenous RNA up to a defined length can be stably introduced into the FMDV genome, whereas larger insertions are excised by recombination events. This led us to construct a recombinant FMDV expressing the fluorescent marker protein, termed iLOV. Characterization of infectious iLOV-FMDV showed the virus has a plaque morphology and rate of growth similar to the parental virus. In addition, we show that cells infected with iLOV-FMDV are easily differentiated by flow cytometry using the inherent fluorescence of iLOV and that cells infected with iLOV-FMDV can be monitored in real-time with fluorescence microscopy. iLOV-FMDV therefore offers a unique tool to characterize FMDV infection in vitro, and its applications for in vivo studies are discussed.
Control of myogenesis by rodent SINE-containing lncRNAs
Authors: Wang Jiashi , Gong Chenguang , Maquat Lynne E.
Published: April 2013

Staufen1-mediated mRNA decay (SMD) degrades mRNAs that harbor a Staufen1-binding site (SBS) in their 3′ untranslated regions (UTRs). Human SBSs can form by intermolecular base-pairing between a 3′ UTR Alu element and an Alu element within a long noncoding RNA (lncRNA) called a ½-sbsRNA. Since Alu elements are confined to primates, it was unclear how SMD occurs in rodents. Here we identify mouse mRNA 3′ UTRs and lncRNAs that contain a B1, B2, B4, or identifier (ID) element. We show that SMD occurs in mouse cells via mRNA–lncRNA base-pairing of partially complementary elements and that mouse ½-sbsRNA (m½-sbsRNA)-triggered SMD regulates C2C12 cell myogenesis. Our findings define new roles for lncRNAs as well as B and ID short interspersed elements (SINEs) in mice that undoubtedly influence many developmental and homeostatic pathways.
Immigration status and the salaries of Asian chemists in the United States
Authors: Broyles Philip A. , Schock Timothy
Published: April 2013

Purpose

In this research, we examine the effects of immigration status on the Asian‐white wage gap of one STEM profession, chemistry. Asians chemists are classified into four groups based on immigration status: Native born Asian citizens, naturalized Asian citizens, Asian with permanent visas, and Asians with temporary visas.

Design/methodology/approach

Data for this study were obtained from the American Chemical Society (ACS) 2010 census of its membership. Only white and Asian men and women were included in our sample. The final sample consisted of 12,705 male chemists and 4,233 women chemists working full‐time in industry.

Findings

It was found that the wage gap between Asians and whites increases with the recency of immigration. That is, the wage gap is larger for Asian immigrants with visas. The authors discuss the factors that may explain this wage gap.

Research limitations/implications

It was not possible to distinguish Asians in the sample by nationality.

Practical implications

Social policy cannot effectively address the inequities between Asians and whites without a better understanding of the impact of immigration.

Originality/value

Most recent research on the Asian‐white earning gap examines immigration in the context of place of education. In this paper, the authors go beyond this practice by examining immigration in the context of citizenship status.