HDPE/CB导电复合材料电-热平衡态电学行为

研究了ＨＤＰＥ／ＣＢ导电复合材料在不同环境温度下电－热平衡态的电学行为,发现其电流密度－电场强度－电导率（Ｊ－Ｅ－σ）关系曲线经临界点参量约化后可有效地重叠。根据自发热临界电流密度、电场强度以及电导率与材料线性电导率之间的标度关系,揭示了复合材料在不同温度下的导电机理的一致性及宏观电学行为与微观导电网络结构的相互关联性。     

An investigation of basis set effects in the characterization of electron – atom scattering resonances using the dilated electron propagator method

 The effects of basis set variations on resonance attributes are investigated using systematically augmented basis sets by correlating the resulting changes in resonance energy and width with the alterations induced in the radial probability density profile of the resonant orbital. Applications to ²P Be⁻ and ²P Mg⁻ shape resonances reveal that basis sets capable of describing both electron density accumulation near the target nucleus to facilitate resonance formation and sufficiently large electron density away from the target nucleus to provide for its decay are necessary for effective characterization of these resonances. A comparison of radial probability density profiles from the bivariational self-consistent field, the second-order, the diagonal two particle–one hole Tamm–Dancoff approximation and quasiparticle decouplings reveals that relaxation effects dominate in resonance formation. Received: 3 January 2000 / Accepted: 5 March 2000 / Published online: 21 June 2000     

Uncertainty products of local periodic wavelets

This paper is on the angle–frequency localization of periodic scaling functions and wavelets. It is shown that the uncertainty products of uniformly local, uniformly regular and uniformly stable scaling functions and wavelets are uniformly bounded from above by a constant. Results for the construction of such scaling functions and wavelets are also obtained. As an illustration, scaling functions and wavelets associated with a family of generalized periodic splines are studied. This family is generated by periodic weighted convolutions, and it includes the well‐known periodic B‐splines and trigonometric B‐splines. This revised version was published online in June 2006 with corrections to the Cover Date.     

Microcanonical Finite-Size Scaling

In the microcanonical ensemble, suitably defined observables show nonanalyticities and power-law behavior even for finite systems. For these observables, a microcanonical finite-size scaling theory is established and combined with the experimentally observed power-law behavior. Scaling laws are obtained which relate exponents of the finite system and critical exponents of the infinite system to the system-size dependence of the affiliated microcanonical observables.     

New solid-state lasers and their application potentials

In recent years, Nd:YAG-lasers have found increasing interest in many fields of high-power applications that formerly had been the domain of CO₂-lasers. This was mainly due to several consequences of their wavelength, such as a higher absorptivity, lower sensitivity against laser-induced plasmas and, in particular, the use of flexible glass fibres for beam handling. Disadvantages like poor beam quality and low efficiency are being effectively reduced by recent developments of diode-pumped systems. Some promising concepts based on different pumping techniques and crystal geometries — rods, discs, fibres — will be discussed in view of attainable beam quality and means of power scaling. The second part of the paper will deal with investigations aimed at utilizing the beneficial properties of Nd:YAG-lasers, especially for welding. In particular, the advantages of the twin-focus technique are discussed in some detail with regard to power scaling, process improvements and flexibility increase. Based upon experience, the extension to a multi-focus technique is proposed by presenting experimental data obtained with lamp-pumped high-power lasers and results of numerical modelling. This evidence demonstrates the potential for industrial applications and provides an idea of what can be expected from the new generation of diode-pumped solid-state lasers with high beam quality.     

Rigorous Bounds for the Föppl—von Kármán Theory of Isotropically Compressed Plates

Summary. We study the F?ppl—von Kármán theory for isotropically compressed thin plates in a geometrically linear setting, which is commonly used to model weak buckling of thin films. We consider generic smooth domains with clamped boundary conditions, and obtain rigorous upper and lower bounds on the minimum energy linear in the plate thickness σ . This energy is much lower than previous estimates based on certain dimensional reductions of the problem, which had lead to energies of order 1+σ (scalar approximation) or σ ^2/3 (two-component approximation). Received August 7, 2000; accepted September 8, 2000 %%%Online publication November 15, 2000 Communicated by Robert V. Kohn     

湍流基础问题研究进展:能量传递,相互作用尺度,各向同性衰减的自保持性

为了更深入地了解湍流的物理过程,本文综述了各向同性湍流的基础问题．在评述了Ｋｏｌｍｏｇｏｒｏｖ能谱及能量级串过程后,深入讨论了Ｋｏｌｍｏｇｏｒｏｖ局部各向同性假设．接着综述了涉及能量传递的以及包括三元组相互作用的各向同性湍流相互作用尺度的详细物理过程．还讨论了惯性区、自相似性以及小尺度对大尺度各向异性的响应和末期衰减过程．之后为了举例说明这些论点,详细讨论了根据各向同性湍流直接模拟及大涡模拟得到的结果（包括对亚格子模型的讨论）.最后,综述了各向同性湍流的自保持性,并展望了今后的研究方向．文末列出了１５５篇参考文献     

小波伽辽金有限元法在梁板结构中的应用

本文给出了基于小波尺度函数展开的高阶导数及其在伽辽金有限元法中有关联的导数乘积积分的计算格式，从而实现了将小波伽辽金法用于求解高于二阶导数微分方程边值问题的数值计算，使其在结构力学问题求解中成为可能·数值算例表明：本方法具有良好的计算精度·     

一类非单调线性互补问题的高阶仿射尺度算法

In this paper, a new interior point algorithm-high-order atone scaling for a class of nonmonotonic linear complementary problems is developed. On the basis of idea of primal-dual affine scaling method for linear programming , the search direction of our algorithm is obtained by a linear system of equation at each step . We show that, by appropriately choosing the step size, the algorithm has polynomial time complexity. We also give the numberical results of the algorithm for two test problems.     

Influence of Inhomogeneity on Critical Behavior of Earthquake Model on Random Graph

We consider the earthquake model on a random graph. A detailed analysis of the probability distribution of the size of the avalanches will be given. The model with different inhomogeneities is studied in order to compare the critical behavior of different systems. The results indicate that with the increase of the inhomogeneities, the avalanche exponents reduce, i.e., the different numbers of defects cause different critical behaviors of the system. This is virtually ascribed to the dynamical perturbation.