非比例加载下两相介质弹塑性特性的有限元分析

在Ｉｌｙｕｓｈｉｎ五维应变空间下,利用弹塑性有限变形的有限元法。研究了两相介质在非比例加载下的弹塑性特性,提出了应力模、延迟角随应变路径、转折角变化的近似计算公式,计算结果还表明,工程材料的许多复杂本构特性都是由第二相介质引起的．     

平面刻槽离子阱的热噪声引起的离子加热研究

研究了和平面刻槽离子阱中的电压热涨落噪声引起的离子加热和离子加热的直接计算模型,给出了离子加热的加热尺度,并利用有限元分析方法计算了当刻槽宽度和射频电极宽度比例α发生变化时加热尺度的变化。同时,还利用涨落耗散原理计算了控制电极的阻抗热涨落对离子产生的加热效应,并给出了x和y方向电场涨落的谱密度表达式,通过计算给出了较好的α值。     

思维很灵活 解法需斟酌

读了《中学生数学》2011年4月（上）期《中学生习作》栏中的李中培同学的《我是这样思考的》一文（后称文[1]），深深地为李同学的求新求简的思维、灵活的创新能力感到欣喜，     

Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors

We choose 8-hydroxyquinoline derivative-metal complexes(Beq,Mgq,and Znq) as the acceptors(A) and 4,4',4"-tri-(2-methylphenyl phenylamino) triphenylaine(m-MTDATA) as the donor(D) respectively to study the existing energy transfer process in the organic ultraviolet(UV) photodetector(PD),which has an important influence on the sensitivity of PDs.The energy transfer process from D to A without exciplex formation is discussed,differing from the working mechanism of previous PDs with Gaq[Zisheng Su,Wenlian Li,Bei Chu,Tianle Li,Jianzhuo Zhu,Guang Zhang,Fei Yan,Xiao Li,Yiren Chen and Chun-Sing Lee 2008 Appl.Phys.Lett.93 103309)]and REq[J.B.Wang,W.L.Li,B.Chu,L.L.Chen,G.Zhang,Z.S.Su,Y.R.Chen,D.F.Yang,J.Z.Zhu,S.H.Wu,F.Yan,H.H.Liu,C.S.Lee 2010 Org.Electron.111301]used as an A material.Under 365-nm UV irradiation with an intensity of 1.2 mW/cm~2,the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mAAV with a detectivity of 6.5 × 10~(11) Jones,which exceeds those of PDs based on Mgq(146 mA/W) and Znq(182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay.More photophysics processes of the PDs involved are discussed in detail.     

解数列问题的几种模式

读过《优美的级数公式》(《中学生数学》2 0 0 0年 1 2月上 )和《用组合数巧解数列题》(《中学生数学》2 0 0 1年 1 2月上 )等文后很受启发 ,进而归纳出几种讨论数列问题的模式 :模式一　欲证∑ｎｉ=1 ａｉ=Ｂｎ 成立 .若假设其成立的话 ,则Ａｎ =∑ｎｉ=1 ａｉ-Ｂｎ =0 ,对新数列{Ａｎ} ,Ａｎ=∑ｎｉ=1 ａｉ-Ｂｎ.若能证出Ａｎ +1 -Ａｎ=0 ,对一切ｎ成立 ,且Ａ1 =0 ,则Ａｎ =Ａｎ-1 =Ａｎ -2 =… =Ａ1 =0 ,从而∑ｎｉ=1 ａｉ=Ｂｎ 成立 .例 1　求证 :1·2·3…ｋ + 2·3… (ｋ + 1 ) +… +ｎ(ｎ + 1 )… (ｎ +ｋ -1 ) =1ｋ + 1 ｎ(ｎ + 1 )…     

对一道习题的再思考

对一道习题的再思考刘和邦（湖南炎陵一中４１２５００）初中代数第三册Ｐ１３５，第６题第６小题是：解方程（ｘ－１）（ｘ－２）＋（ｘ－３）（ｘ－４）＝２，文［１］给出了一种有异于常规思路的解法：解（ｘ－１）（ｘ－２）＋（ｘ－３）（ｘ－４）＝２（１）［（ｘ－...     

风沙两相流中的跃移运动

从单个跃移沙粒在气流中的运动方程出发 ,导出了风沙两相流中沙粒相速度分布函数的Boltzmann方程 ;并以此将单相颗粒流理论中的广义平衡方程推广到气固两相流的情形 .提出用Grad方法将粒子相速度分布函数展成无穷级数 ,并引入Gauss分布取代单相颗粒流理论中传统的Maxwell分布 .在保留到 3次项的情况下 ,建立了气体 颗粒两相湍流边界层三阶矩封闭理论的动力学方程组 .并在风洞频闪摄影实验的基础上 ,对理论进行简化 ,得到便于工程应用的简化方程     

重视课本知识,灵活解决问题

陈令深老师发表在《中学生数学》2005年2月(上)的《代换法解题》一文,介绍的代换思想方法,思路简捷且解法独到,富有新意,读后很受教益.但文中有的观点不敢苟同.下面仅以该文中例1、例3(本文作例1、例2)分析之.     

Solutions of the modification heating conduction equations of a kind of laser thermal effect

This paper has solved the Chester modified heat conduction equation of the different relaxation time Υ value under different temperature conditions, different boundary conditions and the different initial conditions by different means of methods. These solutions can help to obtain temperature field of laser thermal effects.     

Derivation of the modification heating conduction equation of a kind of laser thermal effect by quantum mechanics

The Fourier equation of heat conduction predicts a paradox that the effect of a thermal impulse (e.g. the thermal effect in pulse laser) in an infinite medium; i.e., a thermal impulse is propagated in an infinite velocity. In order to solve the thermal transport paradox, C. W. Ulbrich and M. Chester have proposed the modification heat conduction equation respectively from different macroscopic viewpoint. This paper derived the modification heat conduction equation according to phonon model and quantum mechanics from microscopic viewpoint.