Intergranular stresses in ZIRCALOY-2

The development of the understanding of the intergranular stresses in ZIRCALOY-2 is reviewed. Neutron diffraction measurements of the intergranular strains were made on rod-textured material and highly textured plate. The elastoplastic self-consistent (EPSC) model provides a sound theoretical foundation for our understanding of the behavior. The strain response of ZIRCALOY-2 to applied tensile stress is well described for two very different textures with the same slip and hardening parameters. It is almost certain that tensile twinning is the explanation for the response to compressive stress and rolling that is, as yet, incompletely understood. This article is based on a presentation made in the symposium entitled “Defect Properties and Mechanical Behavior of HCP Metals and Alloys” at the TMS Annual Meeting, February 11–15, 2001, in New Orleans, Louisiana, under the auspices of the following ASM committees: Materials Science Critical Technology Sector, Structural Materials Division, Electronic, Magnetic & Photonic Materials Division, Chemistry & Physics of Materials Committee, Joint Nuclear Materials Committee, and Titanium Committee.     

The complex backpropagation algorithm

The backpropagation (BP) algorithm that provides a popular method for the design of a multilayer neural network to include complex coefficients and complex signals so that it can be applied to general radar signal processing and communications problems. It is shown that the network can classify complex signals. The generalization of the BP to deal with complex signals should make it possible to expand the line of applications of this powerful nonlinear signal processing algorithm     

Efficient calculation of self/mutual impedances in MoM analysis ofa monopole in free space

This paper presents an analysis of a monopole in free space. The result is given in a concise form that facilitates numerical programming. Moreover, the calculation involves no numerical integration and, thus, the computation is extremely fast     

Fractals by Multigenerators

Abstract: Non-classical fractals generated by many generators are of interest. Random fractals caused by the random action of given generators and by random generrrtors are discussed The generators may have different scales. The fractal spectral function, the generalized fractal dimensions and scaling index are derived explicitly. Examples include the cracking patterns of concrete mix.     

浅论水电规划工作思路

在水电的前期设计阶段，规划专业的重要性显而易见。由于水电规划工作涉及专业很多，如果仅停留于规划专业本身，未必能解决问题。在规划工作中，既有定量的计算，也有定性的分析；既要站在国家的角度进行评价，也要进行企业的财务效益分析；既要考虑目前的现实情况，也要对未来的发展做出预测；既有企业的主观意志，也有自然、社会历史的限制。总之，规划专业是涉及多目标、多量纲的综合判断，若以局部来通观全体，则一定要流于片面的谬误。因此，水电规划工作须进行辩证的综合研究。     

SED88: a Pascal program for the analysis of sedimentation equilibrium data

Analytical ultracentrifugation is commonly used for the determination of molecular weights (sedimentation equilibrium) and sedimentation coefficients (sedimentation rate) of biological macromolecules in solution. A Turbo Pascal program for the analysis of sedimentation equilibrium centrifugation data produced by absorbance optical systems is described. The user may enter data from a scan of absorbance versus distance from the centre of rotation, via a graphics tablet (or ASCII file). This is subsequently manipulated to yield an apparent weight average molecular weight for the given sample. Plots of ln (absorbance) versus (radius2) may also be produced. The method described uses readily available computational equipment requiring only a graphics tablet in addition to an IBM PC compatible computer. This technique and the software developed have been used to investigate the molecular weight range of two International Humic Substances Society (IHSS) reference samples from the Suwannee River.     

A kinetic investigation into the removal of carbobenzyloxy group from protected amines via hydrogenolysis reaction

Hydrogenolysis of a carbobenzyloxy group (CBz) was studied utilizing molecular hydrogen in the presence of carbon-supported palladium catalyst. It was demonstrated that the kinetics of the reaction are greatly influenced by the presence of the CO₂ by-product. It was found out that the presence of CO₂ determines whether the reaction is first or zero order since it causes deactivation of the catalyst via inhibition. The effect of potassium carbonate (K₂CO₃) and triethylamine (TEA) as additives was investigated. A considerable solvent effect was also observed that may be explained by the variation of dispersion of the catalyst from one solvent to another.     

复合聚合物微粒乳液的制备与应用

对种子乳液聚合中加料方式、单体亲水性、引发剂等因素对复合微粒聚合物形成的影响作了介绍 ,总结了聚合物微粒形态预测的热力学和动力学方法。同时 ,讨论了复合聚合物微粒设计的原理并评述了其应用情况     

Inversion of confluent Vandermonde matrices

This paper is concerned with the inversion of confluent Vandermonde matrices. A novel and simple recursive algorithm for inverting confluent Vandermonde matrices is presented. The algorithm is suitable for classroom use in both numerical as well as symbolic computation. Examples are included to illustrate the proposed algorithm.