The effects of electronic field on the atomic structure of the graphene/α-SiO(2) interface

The atomic structure of the graphene/α-SiO(2)(0001) interface under electric field F with different intensities is studied using the density functional theory method. Simulation results indicate that the atomic structure of the graphene/α-SiO(2)(0001) interface has only a slight change under the condition of F≤0.02?au. However, the distance between substrate and graphene d(0) changes evidently. Moreover, as F reaches 0.03?au, the formation of a C-O covalent bond on the interface is present, which would destroy the excellent electronic properties of graphene. Thus, there exists a maximum for F in application of the graphene.     

Commentary on the paper by Heimrich Kanis entitled ‘Reliability and validity of findings in ergonomics research’: where is the methodology in ergonomics methods?

This paper is a commentary on Kanis’ target paper in this issue. Kanis raised deficiencies in the reporting of reliability and validity of ergonomics methods in the literature and proposes a framework for the future. This paper applauds the approach and extends it. Despite the proliferation of ergonomics methods, there is a paucity of data on reliability and validity. There are many other aspects of the methods’ performance that could be reported as well, including the utility of the method. The structure of method reporting would benefit from some standardisation to enable comparison of approaches and usability of the method itself. It is also understood that the gathering of data on reliability and validity will be ongoing, as methods evolve and domain boundaries are crossed.     

Effect of electric field on the microstructure and electrical properties of (In + Ta) co-doped TiO2 colossal dielectric ceramics

Journal of Materials Science: Materials in Electronics - Flash-sintering is a promising method for shorting the processing time, reducing the sintering temperature, and refining grain. Here, we...     

Comments on ‘Higher order squeezing of the electromagnetic field in spontaneous and in stimulated Raman processes’

Of late, Giri and Gupta [J. Mod. Opt. 52 1769 (2005)] discussed the possibility of getting higher order (fourth and fifth orders) squeezing of the fundamental mode in spontaneous Raman and in stimulated Raman processes. These investigations are based on the earlier works of Kumar and Gupta [Quantum Semiclass. Opt. 7 835 (1995)]. We reinvestigate the model and we found that the entire calculations and hence the conclusion of Giri and Gupta and Kumar and Gupta are not only baseless but also misleading. There will be no squeezing of the fundamental mode in spontaneous and in Raman processes.     

Alternatives to the journal impact factor: I3 and the top-10% (or top-25%?) of the most-highly cited papers

Journal impact factors (IFs) can be considered historically as the first attempt to normalize citation distributions by using averages over 2?years. However, it has been recognized that citation distributions vary among fields of science and that one needs to normalize for this. Furthermore, the mean-or any central-tendency statistics-is not a good representation of the citation distribution because these distributions are skewed. Important steps have been taken to solve these two problems during the last few years. First, one can normalize at the article level using the citing audience as the reference set. Second, one can use non-parametric statistics for testing the significance of differences among ratings. A proportion of most-highly cited papers (the top-10% or top-quartile) on the basis of fractional counting of the citations may provide an alternative to the current IF. This indicator is intuitively simple, allows for statistical testing, and accords with the state of the art.     

The surface of liquid 4He,based on the idea that π i<j f(r ij) describes a droplet

We argue that the wave function f(r _ij) describes the ground state of a droplet of liquid ⁴ He. With this wave function, expressions for the surface energy and the surface tension of liquid ⁴ He at T = 0 are derived. Choosing particular f(r) and density profile, and the simplest pair correlation function, we plot the variation of and with surface thickness t. For slow variation of density at the surface, becomes proportional to t. The surface thickness is found to be about 4 ». The inclusion of phonon zero-point motion correlations in the wave function leads (at T = 0) to a –R ² log R term in the energy of a droplet of radius R, implying a logarithmic divergence in both and . At T > 0 the phonon correlations give a log T dependence of and and a negative bulk specific heat. Suggestions as to the reason for these problems are explored, but no definite conclusions are reached.     

Effects of a high-gradient magnetic field on the migratory behavior of primary crystal silicon in hypereutectic Al–Si alloy

Abstract

The migration of primary Si grains during the solidification of Al–18 wt%Si alloy under a high-gradient magnetic field has been investigated experimentally. It was found that under a gradient magnetic field, the primary Si grains migrated toward one end of the specimen, forming a Si-rich layer, and the thickness of the Si-rich layer increased with increasing magnetic flux density. No movement of Si grains was apparent under a magnetic field below 2.3 T. For magnetic fields above 6.6 T, however, the thickness of the Si-rich layer was almost constant. It was shown that the static field also played a role in impeding the movement of the grains. The primary Si grains were refined in the Si layer, even though the primary silicon grains were very dense. The effect of the magnetic flux density on the migratory behavior is discussed.     

Effect of the growth mode on the two- to three-dimensional transition of InAs grown on vicinal GaAs(001) substrates

Some differences were observed between conventional molecular-beam epitaxy (MBE) and mobility enhanced epitaxy (MEE) of InAs on a vicinal GaAs(001) substrate in the variation of the number density N of the InAs islands, with additional InAs coverage (θ-θ(c)) after the critical InAs coverage θ(c) during the two-?to three-dimensional (2D-3D) transition. For MBE the variation was consistent with the power law N(θ)～(θ-θ(c))(α); while for MEE, the linear relation [Formula: see text] was observed. The difference is discussed in terms of the randomness in the nucleation of the InAs islands.     

Characteristics of the research on reverse logistics (1995–2005)

This paper aims to describe and analyse the main characteristics of articles on reverse logistics published in the production and operations management field, in order to determine the evolution of this current research over recent years and improve our understanding of this issue. We built up a database with the articles on reverse logistics published in the most relevant journals within the period 1995–2005, and we have explored the topic, the methodology and the techniques of analysis, as well as other relevant aspects of the research. We have evaluated the first decade of research on reverse logistics, observing what has been done and how, where and by whom it has been carried out. The result is an extensive review of the research works that have created and developed the reverse logistics concept, outlining some directions of research for the near future and offering practical help to those who begin to research on this topic.     

Ultrasonic investigations on the flux state of the organic superconductor κ-(BEDT-TTF)2Cu(NCS)2

The flux state of the organic superconductor -(BEDT-TTF)₂Cu(NCS)₂ has been investigated by ultrasonic measurements. The magnetic field dependence in the longitudinal sound velocity, shows a remarkable dip. The amount of the dip is proportional to cos, where is the angle between the propagation direction of the sound and the magnetic field. The magnetoresistance anomaly in this salt, which is seen in the same magnetic field range as for the sound velocity, has been interpreted by the thermal fluctuation of the Josephson coupling between the superconducting layers. The sound velocity anomaly is interpreted by this mechanism. It would be concluded that such anomaly is caused by a large Grüneisen parameter in this salt.     

Standards,the Field that Can''''t Be Ignored on Your Road to Chinese Market China Standardization(English Version)—to help you know China and the newest trend and policy of China''''s standardization

China Standardization (English Version), supervised by the General Administration of Quality Supervision, Inspection and Quarantine of P.R. China (AQSIQ), jointly compiled by the Standardization Administration of China (SAC) and China Association for Standardization (CAS), is an exclusive high-class English magazine that is distributed world-     

Comprehensive metrological and content analysis of the public–private partnerships (PPPs) research field: a new bibliometric journey

Scientometrics - Studies around public–private partnerships (PPPs) have shaped a complex and colorful research field. A series of review studies have been performed to explore the knowledge...