Homogenization of hardness distribution and distortion in high pressure gas quenching

Quenching with gases rather than oil or other liquid media has the advantages of reducing the risks concerning health and environment, while simultaneously homogenizing the quenching results and minimizing distortion due to a wide range of possible process parameter variations and the pure convective heat transfer. In this contribution, a coupled solution for increasing homogenization of quenching results within high pressure gas quenching will be presented. In the first stage, an experimental test facility was set up for flow investigations and in the second stage a numerical simulation model was generated. The numerical and experimental results of the flow through the chamber were compared for several boundary conditions. Finally, after complete verification of the simulation, the model may be used to assist in parameter variation for optimization of homogeneous high pressure gas quenching.     

对高校图书馆参考咨询服务的探讨

面对现代信息时代的挑战，高校图书馆参考咨询服务进行着深刻的变革，其系统化、网络化、合作化、社会化、高效化是这种变革的集中体现。     

ON THE ROBUST GLOBAL STABILIZATION OF nth-ORDER REACTIONS

In this paper, we employ a nonlinear adaptive mechanism to globally stabilize n^th-order reactions.     

锥形凸台成形的一种叠加滑移线场力学模型

分析了锥形凸台在不同体积成形工艺中的成形机理，基于模块化思想将锥形凸台的成形过程划分为挤压成形与角部充满两个特征时段；将上述两个特征时段的滑移线场力学模型有机联结，构建了锥形凸台成形过程的一种叠加滑移线场力学模型；介绍了叠加滑移线场力学模型的应力场与变形力的求解方法。该模型丰富了金属体积成形过程的特征单元库，可套用于局部成形的应力场与变形力求解，实现局部成形的模具优化设计。     

轮式工程机械轮边减速器优化模型与方法

论述了重构轮式工程机械轮边减速器优化设计数学模型的必要性,给出了精确化的目标函数,全面化和准确化的设计变量、基于并行设计的约束条件;介绍了对优化解适用性评价的方法和手段。巧妙地解决了优化解中离散变量的圆整问题,提供了基于MATLAB的求解反渐开线函数的M文件。     

钢纤维聚合物混凝土抗压本构关系

钢纤维聚合物混凝土是由聚合物混凝土基体和钢纤维共同组成的纤维增强复合材料，它的力学行为不仅依赖于聚合物混凝土基体的行为，而且与钢纤维的掺量、分散特征以及钢纤维的几何尺寸有关，本文将基于损伤力学原理研究在不同纤维掺量下的钢纤维聚合物混凝土的全程压力-应变曲线及其本构模型。     

Accurate and simple synthesis formulas for coplanar waveguides

Simple and accurate closed‐form formulas obtained by using a differential evolution algorithm are presented for the synthesis of coplanar waveguides (CPW). The results of the synthesis formulas proposed in this article are compared with those of the quasi‐static analysis, the synthesis formulas reported by the other researchers and also the experimental works available in the literature. The accuracy of the proposed synthesis formulas is found to be better than 0.75% for 9256 CPWs samples. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

A probabilistic simulator for population dynamics of quasispecies

We constructed a probabilistic simulator that allows all the events in population dynamics such as death, birth, mutation, and suppression/stimulation to be described by probabilistic rules. The simulator also facilitates a lattice used for expressing distribution and diversity (number of distinct strains) of quasispecies. The simulator is used to investigate the diversity threshold in HIV and T-cell interaction. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Investigation on interior moisture distribution inducing dielectric anisotropy of coals

Dielectric anisotropy phenomenon of coal was detectable by many dielectric measurements. The paper presented that it was attributed to coal interior moisture distribution. A new model describing interior moisture distribution was developed basing on microstructure observation of coal. In the model, coal interior moisture distribution was analyzed and simulated numerically, the relationship between interior moisture distribution and coal dielectric property was constructed, the character of the permittivity varying with moisture content had also been studied and coal dielectric anisotropy was deduced. Corresponding experiment results were well satisfied with the model analysis, demonstrating that the interior moisture content could cause coal dielectric anisotropy.