Thermodynamic properties of Reissner–Nordström–de Sitter quintessence black holes

Mass, electric charge, and temperature of black holes in the Reissner-Nordström-de Sitter quintessence (RN-dSQ) spacetime are obtained. The heat capacities of the RN-dSQ black hole for certain electric charge and mass are analyzed. The electrostatic energy and the dark energy in the RN-dSQ black hole are also calculated.     

Magnetotransport properties of two-dimensional electron gas in AlGaN/AlN/GaN heterostructures

Magnetotransport measurements are carried out on the AlGaN/AlN/GaN in an SiC heterostructure, which demonstrates the existence of the high-quality two-dimensional electron gas (2DGE) at the AlN/GaN interface. While the carrier concentration reaches 1.32 × 10¹³ cm ^{- 2} and stays relatively unchanged with the decreasing temperature, the mobility of the 2DEG increases to 1.21 × 10⁴ cm²/(V·s) at 2 K. The Shubnikov—de Haas (SdH) oscillations are observed in a magnetic field as low as 2.5 T at 2 K. By the measurements and the analyses of the temperature-dependent SdH oscillations, the effective mass of the 2DEG is determined. The ratio of the transport lifetime to the quantum scattering time is 9 in our sample, indicating that small-angle scattering is predominant.     

B值行独立随机元阵列的完全收敛性

本文研究了B值行独立的随机元阵列完全收敛性，在对Banach空间B没有p型的要求下，根据Banach空间上的A．de Acosta．不等式与Hoffman-JФrgensen不等式，得到了几个有意义的结果．     

Ab initio study on elastic and thermodynamical properties of Ti<Subscript>1-x</Subscript>Zr<Subscript>x</Subscript>C

Elastic and Thermodynamical properties of Ti_1-xZr_xC have been investigated using LAPW + lo within the density-functional theory with the generalized gradient approximation. We have studied the stability of the alloy Ti_1-xZr_xC as a function of Zr composition in rocksalt (B1) structure by calculating the elastic constants C₁₁, C₁₂ and C₄₄ using the tetragonal and trigonal distortions. Mechanical properties such as Poisson ratio, bulk, shear and Young’s modulii of Ti_1-xZr_xC are calculated. The Debye temperature and hardness are also computed for the first time to our knowledge for Ti_1-xZr_xC in various compositions.     

Organisation of carbon nanotubes and semiconductor nanowires using lateral alumina templates

Carbon nanotubes and semiconductor nanowires have been thoroughly studied for the future replacement of silicon-based complementary metal oxide semiconductor (CMOS) devices and circuits. However, the organisation of these nanomaterials in dense transistor arrays, where each device is capable of delivering drive currents comparable with those of their silicon counterparts is still a big challenge. Here, we present a novel approach to the organisation of carbon nanotubes and semiconductor nanowires, based on the use of porous lateral alumina templates obtained by the controlled anodic oxidation of aluminium thin films. We discuss the growth of nanomaterials inside the pores of such templates and show the feasibility of our approach. Our first results point to further work on controlling the synthesis of catalyst nanoparticles at the bottom of the pores, these particles being necessary to nucleate and sustain the growth of carbon nanotubes or semiconductor nanowires. To cite this article: D. Pribat et al., C. R. Physique 10 (2009).     

Negative bending mode curvature via Robin boundary conditions

We examine the band spectrum, and associated Floquet–Bloch eigensolutions, arising in straight walled acoustic waveguides that have periodic structure along the guide. Homogeneous impedance (Robin) conditions are imposed along the guide walls and we find that in certain circumstances, negative curvature of the lowest (bending) mode can be achieved. This is unexpected, and has not been observed in a variety of physical situations examined by other authors. Further unexpected properties include the existence of the bending mode only on a subset of the Brillouin zone, as well as permitting otherwise unobtainable velocities of energy transmission. We conclude with a discussion of how such boundary conditions might be physically reproduced using effective conditions and homogenization theory, although the methodology to achieve these effective conditions is an open problem. To cite this article: S.D.M. Adams et al., C. R. Physique 10 (2009).     

System of generalized variational inclusions with -accretive operators in uniformly smooth Banach spaces

In this paper, we consider and study a system of generalized variational inclusions with H-accretive operators in uniformly smooth Banach spaces. We prove the convergence of iterative algorithm for this system of generalized variational inclusions. A new definition of H-resolvent operator as a retraction is introduced, and in support of the definition, we have constructed an example and a numerical example through Matlab programming. Some special cases are also discussed.     

Evaluating environmental regulation in Spain using process control and preventive techniques

Because environmental regulations may be adjusted over time to reflect updated understanding or new circumstances, there may be scope for strategic behaviour too. Regulations affect not only current emission levels, but also the effect on investment in R&D or new plant and equipment and, consequently, on competitive priorities. Although most of the literature devoted to the environmental regulation highlights the effects that legislation has on the adoption of decisions related to the environment as a competitive opportunity, there is actually no strong empirical evidence which supports that argument. This is why the present paper has as its aim to identify (1) how the regulation concerning the natural environment differs across sectors and (2) how it can influence managerial perceptions of the role to be played by the natural environment as a competitive opportunity. The research work has been carried out in two phases. The first phase involved comparative case studies of eight Spanish firms; during the second, the propositions emerging from the first phase were tested through a structural equation model of 239 hotels and 208 firms affected by the IPPC law in Spain. This paper has made a contribution to the existing research literature through the examination of the similarities and differences concerning managerial decision-making in the field of natural environment regulations. Moreover, a contact point between the Porter hypothesis and its criticism is offered. In relation to practical implications, updated information about the European, National and Community environmental legislation is presented that affects firms from eight sectors. In this context, legal environmental requirements are identified so as to make easier the adoption of managerial decisions which guarantee compliance with the law and avoidance of fines.     

N-way modelling of sediment monitoring data from Mar Menor lagoon, Spain

The present paper deals with the application of Tucker3 modelling to a sediment monitoring data set from the area of Mar Menor coastal lagoon (Spain). The aim of the study is to model and interpret the fractionation of heavy metals in the suspended particulate matter and sediment fractions resulting by sedimentation processes. Since the lagoon is seriously influenced by anthropogenic activities the modelling aims an assessment of the environmental hazard, too. After application of various scaling and centering procedures and estimation of the model dimensionality, an optimal (3, 3, 3) Tucker3 model was chosen for data interpretation. Using the model output (factor loadings connected to the four main core elements) it could be concluded that the heavy metal concentrations in the suspended particulate matter and sediment fractions increase in order Cu > Mn > Zn ≈ Pb > Cd and could be examined as estimation of basic levels for all heavy metals caused by different sedimentation processes. The second important core element summarizes the anthropogenic influence of the mining activity in the region. The third important core element shows the different mobility of the heavy metals. The fourth important core element should be related to the specific sediment formation at one of the sampling location.     

6-regular Cayley graphs on abelian groups of odd order are hamiltonian decomposable

Alspach conjectured that any 2k-regular connected Cayley graph on a finite abelian group A has a hamiltonian decomposition. In this paper, the conjecture is shown true if k=3, and the order of A is odd.