作者: WANG, JQ;LIAO, ZY;WU, WH;FEND, DM
出处: SCIENCE IN CHINA SERIES B-CHEMISTRY 1991 Vol.34 No.2 P141-151
摘要: Ten benzoturoxans and their derivatives have been systematically investigated by XPS technique. A fairly good correlation between E(b)* and q(N) on th ...
作者: LUO, AQ;GE, BH;FU, RN;NI, JH;CHEN, JQ;DENG, L;HE, Q
出处: JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 1991 Vol.21 No.3 P327-334
摘要: Poly(methyl methacrylate) (PMMA), poly(diallyl phthalate) (PDAP) and nine poly(MMA-DAP) standard samples whose compositions were known were investigat ...
作者: WANG, JQ;FENG, DM;WU, WH;ZENG, MX;LI, Y
出处: POLYMER DEGRADATION AND STABILITY 1991 Vol.31 No.2 P129-140
摘要: The flame-retarding mechanism of polypropylene containing a chlorine system has been explored by XPS(ESCA). A wealth of information, such as chemical ...
作者: 周立伟,金伟其,倪国强 (北京理工大学工程光学系)
出处: 北京理工大学学报 1991 第2期 P33-41
关键词: 电子光学;电子透镜;电子聚焦/阴极透镜
摘要: 假定空间静电电位φ的磁感应强度矢量(?)在实验室坐标系中的分布是已知的,利用变分方法研究了正交和非正交两种曲线局部坐标基下宽电子束聚焦的普遍理论.将变分原理下的细电子束聚焦推广到宽电子束聚焦,证明了其结果与用电动力学方法研究宽电子束聚焦的一致性。
作者: Liu Duan,Luo Yong
出处: Acta Mechanica Sinica 1991 第2期 P178-185
关键词: integral;invariant;nonconservative;system
摘要: In this paper,we prove that for holonomic nonconservative dynamical system the Poincareand Poincaré-Cartan integral invariants do not exist.Instead of ...
作者: Luo Xuefu,Hwang Kehchih
出处: Acta Mechanica Sinica 1991 第2期 P140-146
关键词: growing;crack;near-tip;fields;elastic;perfectly-plastic;medium
摘要: Some possible alternative solutions of near-tip fields are studied for plane-strain Mode-I qua-si-static steady crack growth in incompressible(v=1/2)e ...
作者: 马星国,赵国珊 (北京理工大学机械工程系)
出处: 北京理工大学学报 1991 第2期 P60-67
关键词: 齿轮;齿面;激光淬火;热处理
摘要: 采用2kW连续式CO_2激光器探讨了激光淬火用于齿面强化的可行性、特点及其意义.分析了齿面激光淬火后淬硬层的硬度分布、组织变化及变形问题。采用Locati快速疲劳试验法测定了激光淬火后的齿面接触疲劳极限。并与齿面高频淬火及未经表面处理的调质齿轮作了对比性研究。结果表明,激光淬火亦适用于齿轮的表面硬化 ...
作者: ZHONG Jiaxiang,QI Yan,ZHANG Xiumu,GUO Yunyi
出处: 金属学报(英文版) 1991 第2期 P86-90
关键词: martensite;morphology;substructure
摘要: A new “mid-relief” plate martensite was observed together with lenticular plate and thinplate martensites in Fe-29.37Ni-0.34C alloy after twice steppe ...
作者: G.M.L.Gladwell,Fan Tianyou
出处: Acta Mechanica Sinica 1991 第1期 P82-87
关键词: three-dimensional;moving;contact;Lame;potentials;double;Fourier;transform;influence;functions;Galin’s;theorem
摘要: This paper presents a formulation for solving three-dimensional moving punch problem. It proves thatGalin’s theorem holds for the punch. As an example ...
作者: 杜志明,曾庆轩,冯长根 (北京理工大学)
出处: 兵工学报 1991 第2期 P63-70
关键词: 热爆炸理论;热点火理论;热爆炸判据;非线性计算方法;非线性传热学
摘要: 本文从定态临界性及转变性的一般定义出发,给出了临界条件及转交条件;结合非线性数值积分的特殊方法及牛顿迭代法,构造了一种新的求解普适热传递条件下热爆炸系统(Thomas系统)转变点的方法;给出了平板、圆柱和球形热爆炸系统转变值的计算结果。本文的计算方法在Biot教Bi→0时(接近于Semenov系统) ...
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