bluuebunny/crossref_metadata_2025 huggingface dataset:
Zur Rolle der Familie bei Essanfällen im Kindes- und Jugendalter
Authors: Tetzlaff Anne , Hilbert Anja
Published: December 2013

Fragestellung: Während der Einfluss der Familie bei Anorexia Nervosa und Bulimia Nervosa im Kindes- und Jugendalter belegt ist und bereits in Übersichtsarbeiten zusammengefasst wurde, liegen derzeit wenige Befunde zum Zusammenhang zu Essanfällen ohne kompensatorische Verhaltensweisen vor. Ziel dieser systematischen Übersichtsarbeit ist es daher, familiäre Einflussfaktoren auf die Entstehung und Aufrechterhaltung von Essanfällen zu beschreiben. Methodik: Eine systematische Datenbanksuche für Studien zum Zusammenhang von familiären Faktoren und Essanfällen wurde durchgeführt. Ergebnisse: Die eingeschlossenen Studien zeigten einheitlich, dass eine unsichere Bindung des Kindes, eine geringere Familienfunktionalität und geringere emotionale Unterstützung mit Essanfällen querschnittlich assoziiert sind, elterliche Arbeitslosigkeit sowie elterliche Depressionen retrospektive Korrelate darstellen und weniger Familienmahlzeiten und häufige kritische Kommentare über Figur und Gewicht innerhalb der Familie variable Risikofaktoren für Essanfälle sind. Inkonsistente Befunde fanden sich hingegen bezüglich der Familienstrukturen, dem Vorliegen elterlicher Essstörungen und Diäthalten sowie dem Erkennen von Essanfällen beim eigenen Kind. Geschlechterunterschiede hinsichtlich familiärer Beziehungen und gewichtsbezogener Stigmatisierung wurden identifiziert. Schlussfolgerungen: Ebenso wie bei anderen Essstörungen im Kindes- und Jugendalter spielen familiäre Einflussfaktoren auch bei Essanfällen eine wichtige Rolle. Daher könnten eine Diagnostik familiärer Einflüsse und familientherapeutische Interventionen in der Behandlung von Essanfällen im Kindes- und Jugendalter hilfreich sein. Mithilfe von prospektiven Studiendesigns könnten die divergierenden Ergebnisse aufgeklärt werden.
Immunity against a Chlamydia infection and disease may be determined by a balance of IL‐17 signaling
Authors: O'Meara Connor P , Armitage Charles W , Harvie Marina CG , Andrew Dean W , Timms Peter , Lycke Nils Y , Beagley Kenneth W
Published: December 2013

Most vaccines developed against Chlamydia using animal models provide partial protection against a genital tract infection. However, protection against the oviduct pathology associated with infertility is highly variable and often has no defining immunological correlate. When comparing two adjuvants (CTA1‐DD and a combination of Cholera toxin plus CpG‐oligodeoxynucleotide–CT/CpG) combined with the chlamydial major outer membrane protein (MOMP) antigen and delivered via the intranasal (IN), sublingual (SL) or transcutaneous (TC) routes, we identified two vaccine groups with contrasting outcomes following infection. SL immunization with MOMP/CTA1‐DD induced a 70% reduction in the incidence of oviduct pathology, without significantly altering the course of infection. Conversely, IN immunization with MOMP/CT/CpG prevented an ascending infection, but not the oviduct pathology. This anomaly presented a unique opportunity to study the mechanisms by which vaccines can prevent oviduct pathology, other than by controlling the infection. The IL‐17 signaling in the oviducts was found to associate with both the enhancement of immunity to infection and the development of oviduct pathology. This conflicting role of IL‐17 may provide some explanation for the discordance in protection between infection and disease and suggests that controlling immunopathology, as opposed to the rapid eradication of the infection, may be essential for an effective human chlamydial vaccine that prevents infertility.
Consistent changes in electronic states and photocatalytic activities of metal (Au, Pd, Pt)-modified TiO2studied by far-ultraviolet spectroscopy
Authors: Tanabe Ichiro , Ozaki Yukihiro
Published: December 2013

TiO2and TiO2modified with metal (Pt, Pd, and Au) nanoparticles showed consistent changes in electronic states and photocatalytic activities.
Multi-stimuli responsive self-healing metallo-hydrogels: tuning of the gel recovery property
Authors: Basak Shibaji , Nanda Jayanta , Banerjee Arindam
Published: December 2013

Self-healable, multi-stimuli responsive metallo-hydrogels based on a series of tyrosine containing amphiphiles have been discovered. Formation of these metallo-gels is highly selective to Ni2+ ions. Moreover, the self-healing property can be modulated by varying the chain length of the corresponding gelator amphiphiles.
Synergetic plasmonic effect of Al and Au nanoparticles for efficiency enhancement of air processed organic photovoltaic devices
Authors: Kakavelakis George , Stratakis Emmanuel , Kymakis Emmanuel
Published: December 2013

Small diameter Au NPs and large diameter Al NPs are dispersed into the photoactive layer of OPVs in order to synergistically contribute to optical absorption enhancement by plasmonic and scattering effects respectively.
An unsupported metal hydroxide for the design of molecular μ-oxo bridged heterobimetallic complexes
Authors: Falzone A. J. , Nguyen J. , Weare W. W. , Sommer R. D. , Boyle P. D.
Published: December 2013

A terminal and unsupported chromium(iii) hydroxide is reported.
Characterization of tetra-n-butylphosphonium bromide semiclathrate hydrate by crystal structure analysis
Authors: Muromachi Sanehiro , Takeya Satoshi , Yamamoto Yoshitaka , Ohmura Ryo
Published: December 2013

The crystal structure of the semiclathrate hydrate of tetra-n-butylphosphonium bromide is reported, and the thermophysical property is characterized by comparison with an analogous hydrate.
Synthesis and characterization of copper(ii) 4′-phenyl-terpyridine compounds and catalytic application for aerobic oxidation of benzylic alcohols
Authors: Ma Zhen , Wei Lijuan , Alegria Elisabete C. B. A. , Martins Luísa M. D. R. S. , Guedes da Silva M. Fátima C. , Pombeiro Armando J. L.
Published: December 2013

Cu(ii)-terpyridine complexes in combination with TEMPO exhibit catalytic activity, under mild conditions and in alkaline aqueous solution, for the aerobic oxidation of benzylic alcohols.
Synthesis and photovoltaic performances of a conjugated polymer based on a new naphthodifuran monomer
Authors: Li Shugang , Yuan Zhongcheng , Deng Ping , Sun Baoquan , Zhang Qing
Published: December 2013

A new naphthodifuran monomer was studied as a building block for the conjugated polymer (PNDFT-DTBT). The power conversion efficiency of 5.22% was achieved in a polymer solar cell device based on the polymer.
Self-assembly of an amphiphilic macromolecule under spherical confinement: An efficient route to generate hollow nanospheres
Authors: Glagoleva A. A. , Vasilevskaya V. V. , Yoshikawa K. , Khokhlov A. R.
Published: December 2013

In general, bio-macromolecules are composed of hydrophilic and hydrophobic moieties and are confined within small cavities, such as cell membranes and intracellular organelles. Here, we studied the self-organization of macromolecules having groups with different affinities to solvents under spherical nano-scale confinement by means of computer modeling. It is shown that depending on the interaction parameters of monomer units composed of side- and main-chain monomer groups along a single linear macromolecule and on cavity size, such amphiphilic polymers undergo the conformational transitions between hollow nanospheres, rod-like and folded cylindrical structures, and a necklace conformation with and without a particular ordering of beads. The diagram of the conformations in the variables the incompatibility parameter of monomer units and the cavity radius is constructed.
Fourier-transform spectroscopy of (4)1Σ+ → A 1Σ+ − b 3Π, A 1Σ+ − b 3Π → X1Σ+, and $(1)^3\Delta _1\rightarrow b{\,}^3\Pi _{0^\pm }$(1)3Δ1→bΠ±3 transitions in KCs and deperturbation treatment of A 1Σ+ and b 3Π states
Authors: Kruzins A. , Klincare I. , Nikolayeva O. , Tamanis M. , Ferber R. , Pazyuk E. A. , Stolyarov A. V.
Published: December 2013

High resolution Fourier-transform spectroscopy data of term values in the spin-orbit (SO) coupled first excited A 1Σ+ and b 3Π states in KCs were obtained from (4)1Σ+ → A 1Σ+ − b 3Π, A 1Σ+ − b 3Π → X1Σ+, and $(1)^3\Delta _1\rightarrow b{\,}^3\Pi _{0^\pm }$(1)3Δ1→bΠ0±3 spectra of laser-induced fluorescence (LIF). About 3000 new rovibronic term values of the A 1Σ+ and $b{\,}^3\Pi _\Omega$b3ΠΩ states were obtained with an uncertainty about 0.01 cm−1 and added to the previously obtained 3439 term values in Kruzins et al. [Phys. Rev. A 81, 042509 (2010)] and 30 term values of the $b{\,}^3\Pi _{0^+}$b3Π0+ state levels below the A 1Σ+ state in Tamanis et al. [Phys. Rev. A 82, 032506 (2010)]. The data field was extended considerably, going down to vibrational level vb = 0 and up in energy to 13 814 cm−1, as compared to previously achieved vb = 14 and E = 13 250 cm−1. Overall 6431 e-symmetry term values of 39K133Cs were included in 4 × 4 coupled-channel deperturbation analysis. The analytical Morse-Long-Range (MLR) function yielded empirical diabatic potentials for the A 1Σ+ and $b{\,}^3\Pi _{0^+}$b3Π0+ states while the morphing of the SO ab initio points [J. T. Kim et al., J. Mol. Spectrosc. 256, 57 (2009)] provided the empirical diagonal and off-diagonal SO functions. Overall 98.5% of the fitted term values were reproduced with a rms (root mean square) uncertainty of 0.004 cm−1. The reliability of the model is proved by a good agreement of predicted and measured term values of the 41K133Cs isotopologue, as well as of measured and calculated intensities of (4)1Σ+ → A 1Σ+ − b 3Π LIF progressions. Direct-potential-fit of low-lying vb levels of the $b{\,}^3\Pi _{0^-}$b3Π0− component yielded the MLR potential which represents the 204 f-symmetry experimental term values with a rms uncertainty of 0.002 cm−1. The Ω-doubling of the b 3Π0 sub-state demonstrates a pronounced vb-dependent increase.
Effective lifetimes exceeding 300 μs in gettered p-type epitaxial kerfless silicon for photovoltaics
Authors: Powell D. M. , Hofstetter J. , Fenning D. P. , Hao R. , Ravi T. S. , Buonassisi T.
Published: December 2013

We evaluate defect concentrations and investigate the lifetime potential of p-type single-crystal kerfless silicon produced via epitaxy for photovoltaics. In gettered material, low interstitial iron concentrations (as low as (3.2 ± 2.2) × 109 cm−3) suggest that minority-carrier lifetime is not limited by dissolved iron. An increase in gettered lifetime from <20 to >300 μs is observed after increasing growth cleanliness. This improvement coincides with reductions in the concentration of Mo, V, Nb, and Cr impurities, but negligible change in the low area-fraction (<5%) of dislocated regions. Device simulations indicate that the high bulk lifetime of this material could support solar cell efficiencies >23%.
Conformational disorder in alkylsiloxane monolayers at elevated temperatures
Authors: Weber Jan , Balgar Thorsten , Hasselbrink Eckart
Published: December 2013

Vibrational sum frequency generation spectroscopy is used to characterize octadecylsiloxane monolayers on glass substrates at ambient conditions with a focus on thermally induced conformational disorder. Different modes of the C–H stretching vibrations of the terminal methyl groups and the methylene groups are therefore monitored in the frequency range of 2850–3000 cm−1. We observe a progressive increase of conformational disorder of the alkyl chains due to gauche defects over the temperature range from 300 to 510 K. The conformational disorder is reversible over a temperature range from 300 to about 410 K. But after heating to temperatures above 410 K, order is not reestablished on the time scale of the experiment. These results suggest that the assumption of an all-trans configuration of the alkyl chains is an over-simplification which increasingly misrepresents the situation for elevated temperatures which are still well below the one at which decomposition starts.
High-power liquid-lithium jet target for neutron production
Authors: Halfon S. , Arenshtam A. , Kijel D. , Paul M. , Berkovits D. , Eliyahu I. , Feinberg G. , Friedman M. , Hazenshprung N. , Mardor I. , Nagler A. , Shimel G. , Tessler M. , Silverman I.
Published: December 2013

A compact liquid-lithium target (LiLiT) was built and tested with a high-power electron gun at the Soreq Nuclear Research Center. The lithium target, to be bombarded by the high-intensity proton beam of the Soreq Applied Research Accelerator Facility (SARAF), will constitute an intense source of neutrons produced by the 7Li(p,n)7Be reaction for nuclear astrophysics research and as a pilot setup for accelerator-based Boron Neutron Capture Therapy. The liquid-lithium jet target acts both as neutron-producing target and beam dump by removing the beam thermal power (>5 kW, >1 MW/cm3) with fast transport. The target was designed based on a thermal model, accompanied by a detailed calculation of the 7Li(p,n) neutron yield, energy distribution, and angular distribution. Liquid lithium is circulated through the target loop at ∼200 °C and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto a concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power areal densities of >4 kW/cm2 and volume power density of ∼2 MW/cm3 at a lithium flow of ∼4 m/s while maintaining stable temperature and vacuum conditions. The LiLiT setup is presently in online commissioning stage for high-intensity proton beam irradiation (1.91–2.5 MeV, 1–2 mA) at SARAF.
A revisitation of the Förster energy transfer near a metallic spherical nanoparticle: (1) Efficiency enhancement or reduction? (2) The control of the Förster radius of the unbounded medium. (3) The impact of the local density of states
Authors: Gonzaga-Galeana J. Alejandro , Zurita-Sánchez Jorge R.
Published: December 2013

The central motivation of this theoretical revisitation comes from the fact that some experimental works about Förster energy transfer report improvement of the Förster efficiency when the donor-acceptor molecular pair is in the vicinity of a metallic particle, while others found efficiency deterioration. In the presence of a nanoscale metallic sphere, we calculate contour plots of the Förster energy transfer rate KF and the Förster efficiency η as a function of the acceptor position rA for a fixed donor position. These contour plots clearly highlight the influence of the sphere on KF and η as the donor position, the orientations of donor and acceptor dipoles, and the particle size are varied; also the impact on KF(rA) and η due to the excitation of surface plasmons is easily noticeable from these contour plots. Moreover, we obtain the enhancement factor KF/KF0 (KF0 refers to the case without sphere) against the donor-surface separation for particular donor-acceptor spatial distributions, several particle sizes, and distinct molecular dipole orientations. Therefore, our calculations provide a systematic analysis of the Förster energy transfer in the presence of a metallic nanosphere. Based on these results, we formulate hypotheses for explaining the aforementioned contradictory experimental results about η. To complement our study, we examine the impact of the local density of states ρ on KF. KF is practically unperturbed by sphere when the intermolecular separation R is ≲ 3 nm, since the direct donor-acceptor electromagnetic interaction is dominant. On the contrary, when R ≳ 3 nm, the nanosphere perturbs KF and this perturbation is stronger if plasmonic resonances are excited. KF/KF0 can greatly be enhanced in certain regions, but these regions coincide with low-efficiency regions, compromising applications involving the Förster process. In the presence of the nanosphere, the high Förster efficiency region (η ⩾ 0.5) has the same shape as that for the case without sphere, but its extension (Förster radius Ro) is reduced; this effect is a consequence of the large increase of the donor direct decay rate and Ro depends strongly on donor position. Consequently, the sphere controls Ro that is associated with the efficiency pattern that corresponds to the unbounded medium; this effect can be exploited in the measuring technique of nanoscale displacements of proteins that is based on the fluorescence resonant energy transfer. The functional form of KF(ρ) is determined by the intermolecular separation R, the spatial configuration and the dipole orientations of the molecular pair, and the donor proximity to the nanoparticle.
Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films
Authors: Petrović Suzana M. , Gaković B. , Peruško D. , Stratakis E. , Bogdanović-Radović I. , Čekada M. , Fotakis C. , Jelenković B.
Published: December 2013

Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.
Coherent transfer of nuclear spin polarization in field-cycling NMR experiments
Authors: Pravdivtsev Andrey N. , Yurkovskaya Alexandra V. , Vieth Hans-Martin , Ivanov Konstantin L.
Published: December 2013

Coherent polarization transfer effects in a coupled spin network have been studied over a wide field range. The transfer mechanism is based on exciting zero-quantum coherences between the nuclear spin states by means of non-adiabatic field jump from high to low magnetic field. Subsequent evolution of these coherences enables conversion of spin order in the system, which is monitored after field jump back to high field. Such processes are most efficient when the spin system passes through an avoided level crossing during the field variation. The polarization transfer effects have been demonstrated for N-acetyl histidine, which has five scalar coupled protons; the initial spin order has been prepared by applying RF-pulses at high magnetic field. The observed oscillatory transfer kinetics is taken as a clear indication of a coherent mechanism; level crossing effects have also been demonstrated. The experimental data are in very good agreement with the theoretical model of coherent polarization transfer. The method suggested is also valid for other types of initial polarization in the spin system, most notably, for spin hyperpolarization.
Geometric solitons of Hamiltonian flows on manifolds
Authors: Song Chong , Sun Xiaowei , Wang Youde
Published: December 2013

It is well-known that the LIE (Locally Induction Equation) admit soliton-type solutions and same soliton solutions arise from different and apparently irrelevant physical models. By comparing the solitons of LIE and Killing magnetic geodesics, we observe that these solitons are essentially decided by two families of isometries of the domain and the target space, respectively. With this insight, we propose the new concept of geometric solitons of Hamiltonian flows on manifolds, such as geometric Schrödinger flows and KdV flows for maps. Moreover, we give several examples of geometric solitons of the Schrödinger flow and geometric KdV flow, including magnetic curves as geometric Schrödinger solitons and explicit geometric KdV solitons on surfaces of revolution.
Design, analysis and testing of a parallel-kinematic high-bandwidth XY nanopositioning stage
Authors: Li Chun-Xia , Gu Guo-Ying , Yang Mei-Ju , Zhu Li-Min
Published: December 2013

This paper presents the design, analysis, and testing of a parallel-kinematic high-bandwidth XY nanopositioning stage driven by piezoelectric stack actuators. The stage is designed with two kinematic chains. In each kinematic chain, the end-effector of the stage is connected to the base by two symmetrically distributed flexure modules, respectively. Each flexure module comprises a fixed-fixed beam and a parallelogram flexure serving as two orthogonal prismatic joints. With the purpose to achieve high resonance frequencies of the stage, a novel center-thickened beam which has large stiffness is proposed to act as the fixed-fixed beam. The center-thickened beam also contributes to reducing cross-coupling and restricting parasitic motion. To decouple the motion in two axes totally, a symmetric configuration is adopted for the parallelogram flexures. Based on the analytical models established in static and dynamic analysis, the dimensions of the stage are optimized in order to maximize the first resonance frequency. Then finite element analysis is utilized to validate the design and a prototype of the stage is fabricated for performance tests. According to the results of static and dynamic tests, the resonance frequencies of the developed stage are over 13.6 kHz and the workspace is 11.2 μm × 11.6 μm with the cross-coupling between two axes less than 0.52%. It is clearly demonstrated that the developed stage has high resonance frequencies, a relatively large travel range, and nearly decoupled performance between two axes. For high-speed tracking performance tests, an inversion-based feedforward controller is implemented for the stage to compensate for the positioning errors caused by mechanical vibration. The experimental results show that good tracking performance at high speed is achieved, which validates the effectiveness of the developed stage.
Adsorption of branched and dendritic polymers onto flat surfaces: A Monte Carlo study
Authors: Sommer J.-U. , Kłos J. S. , Mironova O. N.
Published: December 2013

Using Monte Carlo simulations based on the bond fluctuation model we study the adsorption of starburst dendrimers with flexible spacers onto a flat surface. The calculations are performed for various generation number G and spacer length S in a wide range of the reduced temperature τ as the measure of the interaction strength between the monomers and the surface. Our simulations indicate a two-step adsorption scenario. Below the critical point of adsorption, τc, a weakly adsorbed state of the dendrimer is found. Here, the dendrimer retains its shape but sticks to the surface by adsorbed spacers. By lowering the temperature below a spacer-length dependent value, τ*(S) < τc, a step-like transition into a strongly adsorbed state takes place. In the flatly adsorbed state the shape of the dendrimer is well described by a mean field model of a dendrimer in two dimensions. We also performed simulations of star-polymers which display a simple crossover-behavior in full analogy to linear chains. By analyzing the order parameter of the adsorption transition, we determine the critical point of adsorption of the dendrimers which is located close to the critical point of adsorption for star-polymers. While the order parameter for the adsorbed spacers displays a critical crossover scaling, the overall order parameter, which combines both critical and discontinuous transition effects, does not display simple scaling. The step-like transition from the weak into the strong adsorbed regime is confirmed by analyzing the shape-anisotropy of the dendrimers. We present a mean-field model based on the concept of spacer adsorption which predicts a discontinuous transition of dendrimers due to an excluded volume barrier. The latter results from an increased density of the dendrimer in the flatly adsorbed state which has to be overcome before this state is thermodynamically stable.
Elementary steps of the catalytic NOx reduction with NH3: Cluster studies on reaction paths and energetics at vanadium oxide substrate
Authors: Gruber M. , Hermann K.
Published: December 2013

We consider different reaction scenarios of the selective catalytic reduction (SCR) of NO in the presence of ammonia at perfect as well as reduced vanadium oxide surfaces modeled by V2O5(010) without and with oxygen vacancies. Geometric and energetic details as well as reaction paths are evaluated using extended cluster models together with density-functional theory. Based on earlier work of adsorption, diffusion, and reaction of the different surface species participating in the SCR we confirm that at Brønsted acid sites (i.e., OH groups) of the perfect oxide surface nitrosamide, NH2NO, forms a stable intermediate. Here adsorption of NH3 results in NH4 surface species which reacts with gas phase NO to produce the intermediate. Nitrosamide is also found as intermediate of the SCR near Lewis acid sites of the reduced oxide surface (i.e., near oxygen vacancies). However, here the adsorbed NH3 species is dehydrogenated to surface NH2 before it reacts with gas phase NO to produce the intermediate. The calculations suggest that reaction barriers for the SCR are overall higher near Brønsted acid sites of the perfect surface compared with Lewis acid sites of the reduced surface, examined for the first time in this work. The theoretical results are consistent with experimental findings and confirm the importance of surface reduction for the SCR process.
Multicomponent dynamics of coupled quantum subspaces and field-induced molecular ionizations
Authors: Nguyen-Dang Thanh-Tung , Viau-Trudel Jérémy
Published: December 2013

To describe successive ionization steps of a many-electron atom or molecule driven by an ultrashort, intense laser pulse, we introduce a hierarchy of successive two-subspace Feshbach partitions of the N-electron Hilbert space, and solve the partitioned time-dependent Schrödinger equation by a short-time unitary algorithm. The partitioning scheme allows one to use different level of theory to treat the many-electron dynamics in different subspaces. We illustrate the procedure on a simple two-active-electron model molecular system subjected to a few-cycle extreme Ultra-Violet (XUV) pulse to study channel-resolved photoelectron spectra as a function of the pulse's central frequency and duration. We observe how the momentum and kinetic-energy distributions of photoelectrons accompanying the formation of the molecular cation in a given electronic state (channel) change as the XUV few-cycle pulse's width is varied, from a form characteristic of an impulsive ionization regime, corresponding to the limit of a delta-function pulse, to a form characteristic of multiphoton above-threshold ionization, often associated with continuous-wave infinitely long pulse.
Influencing factors of private purchasing intentions of new energy vehicles in China
Authors: Wang Zhaohua , Wang Chen , Hao Yu
Published: December 2013

The new energy vehicles (NEVs) have gradually become the trend of the world automobile industry due to its energy-saving and environment-friendly features. The developed countries have increased the investment in R&D and the promotion of NEVs, and the sales of NEVs have already accounted for a considerable market share. In China, however, the market share of NEVs is still small; and the marketing promotion of NEVs is facing various difficulties. Then, a question arises naturally: What are the most important influencing factors for Chinese consumers to decide whether to buy a NEV or not? In order to answer this question, we conduct an empirical research on the basis of a large sample survey influencing factors. The results show that the five factors, namely, intrinsic essence of the products, government policy stimulation, cost, reference group, and symbolic factor of the products could notably affect the private purchase of NEVs, among which, intrinsic essence of the products and cost are the most important, while the effect of government policy stimulation is moderate and the other two factors have low impact on the purchase of NEVs. We have also analyzed the reasons and raised corresponding policy suggestions and proposals from the perspectives of both government and enterprises.
Life under flow: A novel microfluidic device for the assessment of anti-biofilm technologies
Authors: Salta Maria , Capretto Lorenzo , Carugo Dario , Wharton Julian A. , Stokes Keith R.
Published: December 2013

In the current study, we have developed and fabricated a novel lab-on-a-chip device for the investigation of biofilm responses, such as attachment kinetics and initial biofilm formation, to different hydrodynamic conditions. The microfluidic flow channels are designed using computational fluid dynamic simulations so as to have a pre-defined, homogeneous wall shear stress in the channels, ranging from 0.03 to 4.30 Pa, which are relevant to in-service conditions on a ship hull, as well as other man-made marine platforms. Temporal variations of biofilm formation in the microfluidic device were assessed using time-lapse microscopy, nucleic acid staining, and confocal laser scanning microscopy (CLSM). Differences in attachment kinetics were observed with increasing shear stress, i.e., with increasing shear stress there appeared to be a delay in bacterial attachment, i.e., at 55, 120, 150, and 155 min for 0.03, 0.60, 2.15, and 4.30 Pa, respectively. CLSM confirmed marked variations in colony architecture, i.e.,: (i) lower shear stresses resulted in biofilms with distinctive morphologies mainly characterised by mushroom-like structures, interstitial channels, and internal voids, and (ii) for the higher shear stresses compact clusters with large interspaces between them were formed. The key advantage of the developed microfluidic device is the combination of three architectural features in one device, i.e., an open-system design, channel replication, and multiple fully developed shear stresses.
Defects in paramagnetic Co-doped ZnO films studied by transmission electron microscopy
Authors: Kovács A. , Ney A. , Duchamp M. , Ney V. , Boothroyd C. B. , Galindo P. L. , Kaspar T. C. , Chambers S. A. , Dunin-Borkowski R. E.
Published: December 2013

We study planar defects in epitaxial Co:ZnO dilute magnetic semiconductor thin films deposited on c-plane sapphire (Al2O3), as well as the Co:ZnO/Al2O3 interface, using aberration-corrected transmission electron microscopy and electron energy-loss spectroscopy. Co:ZnO samples that were deposited using pulsed laser deposition and reactive magnetron sputtering are both found to contain extrinsic stacking faults, incoherent interface structures, and compositional variations within the first 3–4 Co:ZnO layers next to the Al2O3 substrate. The stacking fault density is in the range of 1017 cm−3. We also measure the local lattice distortions around the stacking faults. It is shown that despite the relatively high density of planar defects, lattice distortions, and small compositional variation, the Co:ZnO films retain paramagnetic properties.
Variation of lattice constant and cluster formation in GaAsBi
Authors: Puustinen J. , Wu M. , Luna E. , Schramm A. , Laukkanen P. , Laitinen M. , Sajavaara T. , Guina M.
Published: December 2013

We investigate the structural properties of GaAsBi layers grown by molecular beam epitaxy on GaAs at substrate temperatures between 220–315 °C. Irrespective of the growth temperature, the structures exhibited similar Bi compositions, and good overall crystal quality as deduced from X-Ray diffraction measurements. After thermal annealing at temperatures as low as 500 °C, the GaAsBi layers grown at the lowest temperatures exhibited a significant reduction of the lattice constant. The lattice variation was significantly larger for Bi-containing samples than for Bi-free low-temperature GaAs samples grown as a reference. Rutherford backscattering spectrometry gave no evidence of Bi diffusing out of the layer during annealing. However, dark-field and Z-contrast transmission electron microscopy analyses revealed the formation of GaAsBi clusters with a Bi content higher than in the surrounding matrix, as well as the presence of metallic As clusters. The apparent reduction of the lattice constant can be explained by a two-fold process: the diffusion of the excess As incorporated within AsGa antisites to As clusters, and the reduction of the Bi content in the GaAs matrix due to diffusion of Bi to GaAsBi clusters. Diffusion of both As and Bi are believed to be assisted by the native point defects, which are present in the low-temperature as-grown material.
Structural connectivity in schizophrenia and its impact on the dynamics of spontaneous functional networks
Authors: Cabral Joana , Fernandes Henrique M. , Van Hartevelt Tim J. , James Anthony C. , Kringelbach Morten L. , Deco Gustavo
Published: December 2013

The neuropathology of schizophrenia remains unclear. Some insight has come from modern neuroimaging techniques, which offer an unparalleled opportunity to explore in vivo the structure and function of the brain. Using functional magnetic resonance imaging, it has been found that the large-scale resting-state functional connectivity (rsFC) in schizophrenia — measured as the temporal correlations of the blood-oxygen-level-dependent (BOLD) signal — exhibit altered network topology, with lower small-world index. The origin of these rsFC alterations and link with the underlying structural connectivity remain unclear. In this work, we used a computational model of spontaneous large-scale brain activity to explore the role of the structural connectivity in the large-scale dynamics of the brain in health and schizophrenia. The structural connectomes from 15 adolescent patients with early-onset schizophrenia and 15 age- and gender-matched controls were built from diffusion tensor imaging data to detect the white matter tracts between 90 brain areas. Brain areas, simulated using a reduced dynamic mean-field model, receive excitatory input from other areas in proportion to the number of fibre tracts between them. The simulated mean field activity was transformed into BOLD signal, and the properties of the simulated functional networks were analyzed. Our results suggest that the functional alterations observed in schizophrenia are not directly linked to alterations in the structural topology. Instead, subtly randomized and less small-world functional networks appear when the brain operates with lower global coupling, which shifts the dynamics from the optimal healthy regime.
Coherency strain engineered decomposition of unstable multilayer alloys for improved thermal stability
Authors: Forsén R. , Ghafoor N. , Odén M.
Published: December 2013

A concept to improve hardness and thermal stability of unstable multilayer alloys is presented based on control of the coherency strain such that the driving force for decomposition is favorably altered. Cathodic arc evaporated cubic TiCrAlN/Ti1−xCrxN multilayer coatings are used as demonstrators. Upon annealing, the coatings undergo spinodal decomposition into nanometer-sized coherent Ti- and Al-rich cubic domains which is affected by the coherency strain. In addition, the growth of the domains is restricted by the surrounding TiCrN layer compared to a non-layered TiCrAlN coating which together results in an improved thermal stability of the cubic structure. A significant hardness increase is seen during decomposition for the case with high coherency strain while a low coherency strain results in a hardness decrease for high annealing temperatures. The metal diffusion paths during the domain coarsening are affected by strain which in turn is controlled by the Cr-content (x) in the Ti1−xCrxN layers. For x = 0 the diffusion occurs both parallel and perpendicular to the growth direction but for x > =0.9 the diffusion occurs predominantly parallel to the growth direction. Altogether this study shows a structural tool to alter and fine-tune high temperature properties of multicomponent materials.
Size-independent Young's modulus of inverted conical GaAs nanowire resonators
Authors: Paulitschke P. , Seltner N. , Lebedev A. , Lorenz H. , Weig E. M.
Published: December 2013

We explore mechanical properties of top down fabricated, singly clamped inverted conical GaAs nanowires. Combining nanowire lengths of 2–9 μm with foot diameters of 36–935 nm yields fundamental flexural eigenmodes spanning two orders of magnitude from 200 kHz to 42 MHz. We extract a size-independent value of Young's modulus of (45 ± 3) GPa. With foot diameters down to a few tens of nanometers, the investigated nanowires are promising candidates for ultra-flexible and ultra-sensitive nanomechanical devices.
Energy transfer characteristics of silicate glass doped with Er3+, Tm3+, and Ho3+ for ∼2 μm emission
Authors: Li Ming , Liu Xueqiang , Guo Yanyan , Hu Lili , Zhang Junjie
Published: December 2013

A Er3+/Tm3+/Ho3+ tri-doped silicate glass with good thermal stability is prepared by melt-quenching method. Efficient ∼2 μm emission is observed under 808 nm laser excitation. It is found that the 2.0 μm emission of Ho3+ can be enhanced under the excitation at 808 nm by incorporating Er3+ and Tm3+. Based on the measurement of absorption spectra, the Judd–Ofelt intensity parameters, radiation emission probability, and branching ratio are calculated to evaluate the spectroscopic properties simultaneously. The maximum value of emission cross section of Ho3+ is 3.54 × 10−21 cm2 at 2008 nm. Additionally, the phonon assistance and the micro-parameters in the energy transfer process are quantitatively analyzed by using Dexter model. The energy transfer coefficient from Tm3+ to Ho3+ can reach as high as 21.44 × 10−40 cm6/s, respectively. The emission property together with good thermal property indicates that Er3+/Tm3+/Ho3+ tri-doped silicate glass is a potential kind of laser glass for efficient 2 μm laser.
Efficiency limiting factors in Cu(In,Ga)Se2 thin film solar cells prepared by Se-free rapid thermal annealing of sputter-deposited Cu-In-Ga-Se precursors
Authors: Young Park Ha , Gwon Moon Dong , Ho Yun Jae , Ahn Seoung Kyu , Yoon Kyung Hoon , Ahn SeJin
Published: December 2013

We report an efficiency limiting factor of CuInGaSe2 (CIGS) thin film solar cells fabricated by rapid thermal annealing (RTA) of sputter-deposited Cu-In-Ga-Se films without an additional supply of Se vapor. The CIGS thin films show a single-phase chalcopyrite structure without Ga segregation, and there is no apparent Se deficiency in overall composition measured by routine compositional analysis. However, detailed investigation on properties of the CIGS films and devices reveals that the formation of Se vacancies on the CIGS film surface during Se-free RTA is a main limiting factor of the device efficiency.
Dependence of the mechanical behavior of alloys on their electron work function—An alternative parameter for materials design
Authors: Lu Hao , Hua Guomin , Li Dongyang
Published: December 2013

In this article, we demonstrate that the electron work function (EWF) as an intrinsic parameter can provide information or clues in a simple or straightforward way for material design, modification, and development. A higher work function of a material represents a more stable electronic state, which consequently generates a higher resistance to any attempt of changing the electronic state and other corresponding states, e.g., changes in structure or microstructure caused by mechanical and electrochemical actions. Using Cu-Ni alloy as an example, we demonstrate the correlation between the EWF and Young's modulus of the material as well as its hardness. The properties of a material can be modified using elements with appropriate work functions. This is also applicable for tailoring inter-phase boundaries or interfaces.
Dynamic tensile fracture of mortar at ultra-high strain-rates
Authors: Erzar B. , Buzaud E. , Chanal P.-Y.
Published: December 2013

During the lifetime of a structure, concrete and mortar may be exposed to highly dynamic loadings, such as impact or explosion. The dynamic fracture at high loading rates needs to be well understood to allow an accurate modeling of this kind of event. In this work, a pulsed-power generator has been employed to conduct spalling tests on mortar samples at strain-rates ranging from 2 × 104 to 4 × 104 s−1. The ramp loading allowed identifying the strain-rate anytime during the test. A power law has been proposed to fit properly the rate-sensitivity of tensile strength of this cementitious material over a wide range of strain-rate. Moreover, a specimen has been recovered damaged but unbroken. Micro-computed tomography has been employed to study the characteristics of the damage pattern provoked by the dynamic tensile loading.
Effects of Li doping on H-diffusion in MgH2: A first-principles study
Authors: Ming Wenmei , Zak Fang Zhigang , Liu Feng
Published: December 2013

The effects of Li doping in MgH2 on H-diffusion process are investigated, using first-principles calculations. We have identified two key effects: (1) The concentration of H vacancy in the +1 charge state (VH+1) can increase by several orders of magnitude upon Li doping, which significantly increases the vacancy mediated H diffusion rate. It is caused by the preferred charge states of substitutional Li in the −1 state (LiMg−1) and of interstitial Li in the +1 state (Lii+1), which indirectly reduce the formation energy of VH+1 by up to 0.39 eV depending on the position of Fermi energy. (2) The interaction between VH+1 and LiMg−1 is found to be attractive with a binding energy of 0.55 eV, which immobilizes the VH+1 next to LiMg−1 at high Li doping concentration. As a result, the competition between these two effects leads to large enhancement of H diffusion at low Li doping concentration due to the increased H-vacancy concentration, but only limited enhancement at high Li concentration due to the immobilization of H vacancies by too many Li.
Energy consumption and greenhouse gas emissions of biodiesel production from rapeseed in Iran
Authors: Ali Rajaeifar Mohammad , Ghobadian Barat , Davoud Heidari Mohammad , Fayyazi Ebrahim
Published: December 2013

The issue of searching alternatives for diesel fuel in transport sector that is one of the largest diesel fuel consuming sectors in each country has become more attractive nowadays. In this study, the energy consumption and CO2 emissions of biodiesel production from rapeseed as an alternative for diesel fuel in transport sector was assessed in terms of three main stages including agricultural crop production, transport, and industrial conversion. The results revealed that the total fossil energy input cost was calculated as 28 122.16 MJ ha−1 and the renewable energy output content (biodiesel as the final outcome) was estimated as 31 802.06 MJ ha−1. The net energy returns and the fossil energy ratio were calculated as 3679.9 MJ ha−1 and 1.13, respectively. It shows rapeseed could be a suitable energy crop for biodiesel production. CO2 emissions assessment showed that the total greenhouse gas emissions over biodiesel production life cycle were 1054.98 kg CO2 eq ha−1 and the agricultural crop production stage ranks the first. In order to establish energy crops cultivation such as rapeseed and achieve the sustainable development, meteorological and water source availability data collected and analyzed for all the 31 provinces in Iran to generate a map of regions capable of rapeseed cultivation. The results revealed that 24 provinces among 31 provinces have a great potential for rapeseed cultivation.
Polarization control of terahertz waves generated by circularly polarized few-cycle laser pulses
Authors: Song Liwei , Bai Ya , Xu Rongjie , Li Chuang , Liu Peng , Li Ruxin , Xu Zhizhan
Published: December 2013

We demonstrate the generation and control of elliptically polarized terahertz (THz) waves from air plasma produced by circularly polarized few-cycle laser pulses. Experimental and calculated results reveal that electric field asymmetry in rotating directions of the circularly polarized few-cycle laser pulses produces the enhanced broadband transient currents, and the phase difference of perpendicular laser field components is partially inherited in the generation process of THz emission. The ellipticity of the THz emission and its major axis direction are all-optically controlled by the duration and carrier-envelope phase of the laser pulses.
Three dimensional strain distribution of wrinkled silicon nanomembranes fabricated by rolling-transfer technique
Authors: Guo Qinglei , Zhang Miao , Xue Zhongying , Ye Lin , Wang Gang , Huang Gaoshan , Mei Yongfeng , Wang Xi , Di Zengfeng
Published: December 2013

This paper introduces a simple transfer technique named as rolling-transfer technology to transfer Si nanomembranes to pre-stressed elastomers with nearly 100% transfer efficiency. When transferred onto the elastomeric substrate, wave-like wrinkled Si nanomembranes with uniform periodicity and amplitude are formed. The three dimensional (3-D) strain distribution of the wrinkled Si nanomembranes has been investigated in detail through the micro-Raman mapping using two excited laser wavelengths. The sinusoidal bulking geometry of Si nanomembrane results in a periodical strain alternation along x direction, while a homogenous strain distribution in y direction. The inhomogeneous strain distribution along z direction can be interpreted with the physical model considering the shift of the neutral mechanical plane, which is qualitatively determined by the Von Karman elastic nonlinear plate theory, including the bending effect and the shear forces existing at the Si nanomembrane/elastomeric substrate interface.
Precise lattice location of substitutional and interstitial Mg in AlN
Authors: Amorim L. M. , Wahl U. , Pereira L. M. C. , Decoster S. , Silva D. J. , da Silva M. R. , Gottberg A. , Correia J. G. , Temst K. , Vantomme A.
Published: December 2013

The lattice site location of radioactive 27Mg implanted in AlN was determined by means of emission channeling. The majority of the 27Mg was found to substitute for Al, yet significant fractions (up to 33%) were also identified close to the octahedral interstitial site. The activation energy for interstitial Mg diffusion is estimated to be between 1.1 eV and 1.7 eV. Substitutional Mg is shown to occupy ideal Al sites within a 0.1 Å experimental uncertainty. We discuss the absence of significant displacements from ideal Al sites, in the context of the current debate, on Mg doped nitride semiconductors.
Common polymorphism in the oxytocin receptor gene (
OXTR
) is associated with human social recognition skills
Authors: Skuse David H. , Lori Adriana , Cubells Joseph F. , Lee Irene , Conneely Karen N. , Puura Kaija , Lehtimäki Terho , Binder Elisabeth B. , Young Larry J.
Published: December 2013

Significance

The capacity to remember faces previously seen is strikingly variable between individuals, and differences in that skill are also highly heritable, implying that genetic variation exerts an important influence. Research with rodents has shown the oxytocin receptor (
OXTR
) plays a critical role in conspecific recognition. We examined whether genetic variants of the
OXTR
affect face recognition memory in families with an autistic child. We discovered that a single
OXTR
polymorphism accounted for up to 10% of variation in their test performance, in both UK and Finnish populations. Approximately 35% of family members were homozygous for the risk genotype. Our findings imply that oxytocin’s role in facilitating social recognition has been conserved across perceptual boundaries through evolution, from rodents to humans.