双周期裂纹压电材料反平面剪切问题断裂力学分析

研究压电材料双周期裂纹反平面剪切与平面电场作用的问题．运用复变函数方法，获得了该问题严格的闭合解，并由此给出了裂纹尖端应力强度因子和电位移强度因子的精确公式．数值算例显示了裂纹分布特征对材料断裂行为的重要影响．叠间小裂纹能够对主裂纹的应力和电位移场起着屏蔽作用，相反行间小裂纹却起着放大作用，至于钻石形分布裂纹的影响规律则更为复杂．对于某些特殊情形给予了解答并导出一系列有意义的结果。     

追捕与逃跑策略

<正>首先讨论的是单个捕食者的几种捕食策略及相应的被捕食者的几种逃跑策略.捕食策略包括直追(SF).全预测(FF)和不完全预测(PF)策略.相应的逃跑策略有直线逃跑(sLE).先直线跑后转弯(FSTD)和反预测策略. 我们按照捕食策略和逃跑策略的一物降一物原则来发展这些策略,分别如下: 逃跑策略SLE FSTD AF; 追捕策略SF FF PF. 通过比较,我们认为对于THes采用AF策略最有利,而且Velo采用PF策略最有利. 对于上述策略,用我们对某些参数的估计值代入计算,得到Thes初始转弯距离的最佳值为1.6m,相应的Thes存活概率为0.656.     

Exponentially Expanded Grid Network Approach （EEGNA） ： An Efficient Way for the Simulation of Stiff Electrochemical Problems

The exponentially expanded space grid was incorporated into the network approach to overcome the problem of low simulation efficiency during the simulations of electrochemical problems with stiff kinetics or wide dlsperslon of diffusion coefficients, resulting in an effective electrochemical simulation method: exponentially expanded grid network approach (EEG-NA). The stability and accuracy of the EEGNA for the simulation of various electrode processes .coupled with different types of homogeneous reactions were investigated.     

指数扩展格网络方法：模拟球、柱和旋转圆盘电极体系电化学问题的有效方法

An exponentially expanded space grid technique has been employed in the network simulation of chronoamperometric and voltammetric problems in spherical, cylindrical and rotating-disk electrode systems, leading to an effective simulation strategy for electrochemical problems: exponentially expanded grid network approach (EEGNA). The success of this method is largely due to the improved ability in processing the boundary singularities existing for non-planar diffusions and the enhanced simulation speed and accuracy in contrast to the uniform or quasi-uniform grid network approach.     

Universal Electrochemical／Chemical Simulator Based on an Exponentially Expanding Grid Network Approach

A universal simulator capable of simulating virtually any user-defined electrochemical/chemical problems in one-dimensional diffusion geometry was developed based on an exponentially expanding grid modification of the existing network approach. Some generalized reaction-diffusion governing equations of an arbitrary electrochemical/chemical process were derived, and program controlled automatic generation of the corresponding PSPICE netlist file was realized. On the basis of the above techniques, a universal simulator package was realized, which is capable of dealing with arbitrarily complex electrochemical/chemical problems with one-dimensional diffusion geometry such as planar diffusion, spherical diffusion, cylindrical diffusion and rotational disk diffusion-convection processes. The building of such a simulator is easy and thus it would be very convenient to have it updated for simulations of newly raised electrochemical problems.     

一种判断电化学/化学反应体系热力学自洽性的新方法

介绍了一种判断电化学/化学反应体系热力学自洽性的新方法-“秩法”。结合 实际例子描述了该方法的原理、计算步骤。该方法充分利用矩阵“秩”的概念,由 反应系数矩阵的“秩”直接判断出其中的独立组分数,并且仅当寻找到依赖反应时 才需对有关方程进行求解。因此,“秩法”概念上清晰、直观,且由于可以直接调 用矩阵变换的子程序,程序实现也极为容易。该方法对于电化学、化学及化工反应 过程的模拟将非常有意义。