关于排列与置换的奇偶性

对于n次对称群Sn中的任意一个置换σ,证明n级排列σ(1)σ(2)---σ(n)与n次置换σ有相同的奇偶性.     

拓扑半共轭映射的周期点

研究了与具有周期为n的周期点的映射半共轭的映射的周期点的性质,给出了其周期值的确切估计。     

一种有限非交换环的构造方法

先分别对高斯整环Z(i)=｛a bi｜a,b∈Z｝的元素a bi的实、虚部a,b按模n同余分类得到Zn(i)=｛[a] [b]i｜a,b∈Z｝,再利用两个的直积构造了一类有限非交换环。     

稀土电解槽温度场有限元应用模拟研究

运用傅立叶方程建立了氟化体系稀土电解槽的温度场的有限元模型,采用VC6.0编程制作了相应的软件,并对导热系数、密度、比热等相关参数进行了运行计算研究.结果表明,建立的数学模型和编制的软件对稳态温度场的数学模拟计算结果与实际测试的结果基本吻合.可为新一代稀土电解槽体的开发设计提供参考.     

Study on effect of segments erection tolerance and wedge-shaped segment on segment ring in shield tunnel

INTRODUCTION Shield tunnel method has become the most pre- ferred method in city tunnel construction because of its excellent attributes: little effect on surrounding environment, fast and safe construction, outstanding performance in earthquake resistance, etc. (Zhang et al., 2004). In different shield tunnels, the arrangement and number of segments are different, but the whole assembling process is generally the same. The as- sembling process begins with A2P, then A1P, A3P, BP, CP, …     

Simulation of Fragment Impact on Multi-Layer Targets Using Contact Method

Cased explosives generate highly energetic fragments as their casing breaks up. Due to the complexity of casing fragment related behavior such as embedment, perforation and ricochet, it may be insufficient to use equivalent triangular pressure loading in fragment impact simulations. This simplified method may over- or under-predict the target response. Recently, a procedure using contact techniques has been proposed to overcome such difficulties. It has been shown that the new method has the inherent capability in modeling the multi-piece and multi-hit fragment impact problems in a more realistic way. To investigate the applicability of the proposed method to simulations involving multi-layer penetration, the selected problems of fragment impact on multi-layer targets are described in this paper. It is demonstrated that this method is capable of predicting the complicated multi-layer structural response caused by fragment impact and penetration. Modeling procedures and some technical issues are also discussed.     

排列组合与映射的关系

本给出了排列组合与映射之间的各种关系，揭示了它们之间的本质上的联系。     

用计算机进行卷材排样

本文阐述毛坯种数、卷材宽度、卷材种数对下料利用率的影响，结合生产实际进行分析，说明如何综合考虑各种因素，以提高硅钢片卷材的下料利用率。     

0—1数列与超限组合

本文给出了0-1数列若干性质.设a,c分别表示自然数集和实数集的基数,我们有下列结果:(1)C_a~a=c,(2)C_a~0+C_a~1+C_a~2+…+C_a~n+…+C_a~a=2~a     

自适应有限元方法在凹角域椭圆问题上最佳误差估计

完整给出由‖·‖ L∞(Ω) 范数最佳误差估计推出的一种关于线性椭圆问题近似解的自适应有限元方法 .本方法对给定误差能自动剖分 ,且不需要关于精确解的先验信息 ,通过在凹角域详细分析此过程 ,证明该方法是有效的 .在实例中也得到了所期望的结果 .