Atomistic Simulation of He Clustering and Defects Produced in Ni

Using the molecular dynamics method, the stability of small He-vacancy clusters is studied under the condition of the high He and low vacancy densities. The result shows that there is a competition between He atoms detrapped and self-interstitial atoms （SIAs） emitted during the clustering of He atoms. When the He number is above a critical value of 9, the SIA emission is predominant. The SIA emission can result in deep capture of He atoms since the binding energy of He to a He-vacancy cluster is increased with the number of SIAs created. The cluster thus grows up. In addition, more SIAs are created when the temperature is elevated. The average volume of a He atom is increased. The cluster expansion takes place at high temperature.     

基于顾客满意的渠道合作机制研究

将零售商的服务分为短期性服务和基于顾客满意的长期性服务,由于长期性服务对销售量的影响具有滞后性,因此本文建立了多时期渠道动态决策模型.在此基础上分析了三种情况:①制造商对零售商的长期性服务不激励、②制造商对零售商的长期性服务激励和③渠道整合结果表明:如果制造商不对零售商激励,零售商也有长期性服务偏好;如果对零售商激励,那么零售商付出的长期性服务更多,他们的努力程度由零售商利润的贴现系数决定.同时渠道整合时,渠道总利润要优于其余两种情况.制造商对零售商激励时双方的利润都要大于不激励时的利润,渠道整合时双方的利润与他们的分配比例有关.     

手性2—（2—吡啶基）—4—甲酯基—1,3—噻唑烷的合成及应用

不对称氢化硅烷化可实现由含碳碳或碳杂双键的化合物合成手性醇和手性腹，在石油化工、药物合成、生物碱等生物活性物质的合成等领域具有潜在的应用价值．90年代以来，不断有高活性、高选择性的手性催化剂的开发研究报道［‘－‘］，使不对称硅氢化研究成为催化科学的一个研究方向．我们开展了带有毗吹取代基的座隆烷类手性络合催化剂的研究工作D·‘’．a一毗院甲醛、L一半就氨酸甲酯盐酸盐、氯化环辛M烯合＃［Rh（COD）CI」。以及Ph2SIH。按文献［7j制备，苯乙酮为分析纯试剂．所用仪器有SP－－2305型气相色谱仪，170SX－FTIR型…     

稀土PMMA包裹硅铝氧烷凝胶填充天然橡胶的抗疲劳作用

用聚甲基丙烯酸甲酯（PMMA）对水玻璃、硝酸铝和α－甲基丙烯酸形成的硅铝氧烷溶胶进行包裹，得到PMMA包裹的硅铝氧烷凝胶，同时在反应过程中用稀土离子进行掺杂，得到的稀土掺杂PMMA微囊粉末填充到天然橡胶之中，经力学性能分析发现杨氏模量普遍提高，抗疲劳效果显著，一万次伸张疲劳后，拉伸强度的保持率比参照样品提高两倍以上。     

Syntheses and Crystal Structures of 4-Amino-3- （3-hyd roxyp ropyl）- 1H-1,2,4-triazole-5（4H）-thione and 6-（4-Biphenylyl）-3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine

1INTRODUCTION It has been reported that3,6-disubstituted-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines have a broad spec-trum of bioactivities,such as antimicrobial[1],antibac-terial,antifungal[2],anti-inflammatory[3],diuretic[4],an-thelmintic and analgesic[5].They can also be used as plant-growth regulating agents[6],photographic coup-lers,dyes for improved preservability and absorption characteristics,and inhibitors of malignant cellularZOU K.H.et al.:Syntheses and Crystal Structures o…     

Periodic electron oscillation in coupled two-dimensional lattices

We study the time evolution of electron wavepacket in the coupled two-dimensional(2D) lattices with mirror symmetry, utilizing the tight-binding Hamiltonian framework. We show analytically that the wavepacket of an electron initially located on one atomic layer in the coupled 2D square lattices exhibits a periodic oscillation in both the transverse and longitudinal directions. The frequency of this oscillation is determined by the strength of the interlayer hopping. Additionally, we provide nume...     

高分子支载的手性催化剂在不对称有机反应中的应用进展

本文评述了近年来高分子支载的手性催化剂在不对称氢化、不对称还原、不对称烷基化、不对称Ｄｉｅｌｓ－Ａｌｄｅｒ加成以及不对称二羟基化等有机反应中的应用进展。