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41.
42.
复合材料层合板面内压阻效应层合理论研究 总被引:1,自引:0,他引:1
应用经典层合板理论和静电学理论,研究了正交异性介质的电导率,压导系数和压阻系数的特性,导出了Cauchy应变空间中压阻系数与压导系之间的关系;建立了平面应力状态下层合板面内压阻效应的层合理论。 相似文献
43.
设半参数回归模型Y(n)i=β·x(n)i+g(t(n)i)+E(n)i,i=1,2,…,n,本文由最小二乘法和一般加权方法定义的β、g(t)的估计量βn,gn(t),在误差为鞅差序列下获得了βn,gn(t)的r(≥2)阶平均相合性. 相似文献
44.
The finite generators of Abelian integral are obtained, where Γh is a family of closed ovals defined by H(x,y)=x2+y2+ax4+bx2y2+cy4=h, h∈Σ, ac(4ac−b2)≠0, Σ=(0,h1) is the open interval on which Γh is defined, f(x,y), g(x,y) are real polynomials in x and y with degree 2n+1 (n?2). And an upper bound of the number of zeros of Abelian integral I(h) is given by its algebraic structure for a special case a>0, b=0, c=1. 相似文献
45.
The stability and boundedness of the solution for stochastic functional differential equation with finite delay have been studied by several authors, but there is almost no work on the stability of the solutions for stochastic functional differential equations with infinite delay. The main aim of this paper is to close this gap. We establish criteria of pth moment ψγ(t)-bounded for neutral stochastic functional differential equations with infinite delay and exponentially stable criteria for stochastic functional differential equations with infinite delay, and we also illustrate the result with an example. 相似文献
46.
Svetlana Jankovi? 《Journal of Mathematical Analysis and Applications》2009,355(2):811-6134
The paper discusses both pth moment and almost sure exponential stability of solutions to neutral stochastic functional differential equations and neutral stochastic differential delay equations, by using the Razumikhin-type technique. The main goal is to find sufficient stability conditions that could be verified more easily then by using the usual method with Lyapunov functionals. The analysis is based on paper [X. Mao, Razumikhin-type theorems on exponential stability of neutral stochastic functional differential equations, SIAM J. Math. Anal. 28 (2) (1997) 389-401], referring to mean square and almost sure exponential stability. 相似文献
47.
纤维增强复合材料层合板的弹性性质依赖于单层板的纤维含量(体分比)以及铺层方式(总层数、各单层的厚度与铺设方向)。本文研究在给定材料用量条件下层合板的最大刚度设计问题,采用铺层参数作为铺层方式的描述参数、以铺层参数和单层板纤维含量体分比在层合板面内的分布的描述参数为设计变量,以层合板的柔顺性最小为目标,建立了铺层方式和纤维分布协同优化的层合板最大刚度设计问题的提法和求解方法,给出了具有最大刚度的层合板最优铺层方式和纤维含量的分布规律的设计实例。 相似文献
48.
李志兰 《浙江大学学报(理学版)》2011,38(5):606-610
熵值法是一种科学、简单、实用的综合评价方法.由于熵值法是一种客观赋权法,因此可以避免人为因素带来的偏差.以浙江省“十一五”期间6个基础研究学科领域获得浙江省自然科学基金资助项目的情况作为数据源,采用熵值法对这些数据进行分析总结,揭示了浙江省在基础学科领域的研究热点,并据此对浙江省“十二五”期间基础学科领域的研究发展趋势进行了预测和思考. 相似文献
49.
J. Kravčák 《Physica B: Condensed Matter》2012,407(19):3992-3995
The influence of variable conductivity and thickness of two outer non-ferromagnetic layers on magnetization reversal of one central ferromagnetic layer is theoretically investigated. The model of a thin rigid 180° domain wall moving transversely through the axially magnetized ferromagnetic layer is used to calculate induced eddy currents in lamination from which the domain wall mobility is determined. The effect of asymmetric distribution of eddy currents around moving domain wall results in acceleration of the wall near the edge of the lamination. The known domain wall mobility in ferromagnetic lamination can then be used to determine either the conductivity or the thickness of deposited outer non-ferromagnetic layers as proposed in discussion. 相似文献
50.
The effect of externally injected radiation on the two-photon laser-induced amplified spontaneous emission (TP-LIASE) is reported.
The wave generated via the same LIASE process in a seeder cell acts as a seeder field for the inverted medium created in a
main cell. A nearly tenfold gain is achieved in the B1
Σ
+
?A1
Π (0, 3) transition of the CO molecule. We demonstrate that the single rotational transition in the B1
Σ
+
?A1
Π (0, 4) band is selectively amplified by injection of laser radiation. This pump and seed arrangement facilitates detection
of molecular spectra by simply tuning the seed-laser frequency. The polarization effect of the input laser radiation is briefly
discussed.
Received: 9 June 2000 / Revised version: 2 October 2000 / Published online: 21 February 2001 相似文献