Generalized shear deformation theory for bending analysis of functionally graded plates

In this study, the static response is presented for a simply supported functionally graded rectangular plate subjected to a transverse uniform load. The generalized shear deformation theory obtained by the author in other recent papers is used. This theory is simplified by enforcing traction-free boundary conditions at the plate faces. No transversal shear correction factors are needed because a correct representation of the transversal shearing strain is given. Material properties of the plate are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The equilibrium equations of a functionally graded plate are given based on a generalized shear deformation plate theory. The numerical illustrations concern bending response of functionally graded rectangular plates with two constituent materials. The influences played by transversal shear deformation, plate aspect ratio, side-to-thickness ratio, and volume fraction distributions are studied. The results are verified with the known results in the literature.     

On the Cauchy problem for thermoelastic plates

The Cauchy problem for an infinite thermoelastic plate with a non‐homogeneous governing system and homogeneous initial conditions is solved by means of an area potential. This is the first step in the construction of a potential theory for time‐dependent problems for thermoelastic plates, enabling the reduction of various initial‐boundary value problems to their versions for the homogeneous system of equations with homogeneous initial conditions, which, in turn, may then be solved by means of dynamic potentials. Copyright © 2006 John Wiley & Sons, Ltd.     

Variational statement of deformation problems for a composite latticed plate with various types of lattices

The variational statement of various boundary value problems for tangential displacements and forces in a latticed plate with an arbitrary piecewise smooth contour is investigated. The lattice consists of several families of bars made of a homogeneous composite material with a matrix of relatively low shear stiffness. The energy method reduces the problem to the variational problem of minimizing the energy functional. The conditions on the plate contour are established under which the functional is minimal and positive definite, which ensures that the problem is well posed.     

测量微观不平度的90°相移激光干涉仪

叙述了测量微观不平度的90°相移激光干涉仪的原理和构成。对这种新型干涉仪的性能及有关问题作了讨论。测量结果的计算和样品扫描的控制，由个人计算机完成。垂直分辨率达1um，横向分辨率达10μm。实验结果证明了系统的稳定性。     

一种新颖的表面光波导型原子(或分子)分束器

提出了一种采用二元π位相板与柱面透镜组合而构成表面光波导型原子（或分子）分束器及其Mach-Zehnder干涉仪与X-分束器列阵的新方案，介绍了本方案的物理思想与基本原理，导出了光强分布、强度梯度、分束距离和分束路径的宽度与光学系统参数间的解析关系，并分析和讨论了本方案的潜在应用及其可行性. 研究表明，本方案设计新颖、光路简单，便于与其他元件组合构成具有表面微结构的集成原子（或分子）光学元器件及其全光型原子（或分子）芯片. 关键词： 原子（或分子）光波导 原子（或分子）分束器 原子（或分子）芯片 二元π位相板     

关于受冲击编织复合板的一个例子(实验特征及模型)

本文对厚编织复合材料板由硬的钢圆柱弹丸穿孔问题进行了研究．实验研究表明连续穿孔时在侵彻弹丸附近发生材料的横向剪切以及面内中间层分层的传播，而面内中间层分层的传播将导致纤维的拉伸断裂?由于冲击加载并不是瞬时的，这导致了横向剪切．在接近穿孔极限速度的入射速度(V50)范围内，这一机制依赖于复合材料板的厚度和中间层剪切强度．中间层分层的传播则由弹丸与靶接触时引起的弯曲波所致．由弯曲波所致的面内分层传播这一现象分别引起了面内圆形损伤和沿厚度内的锥形损伤．同时分层传播由弯曲波速所控制，其依赖于纤维的弹性特征、编织层的失效时间(其直接由编织层的弯曲刚度决定)及材料一些特定的失效参数．另外由于增加了拉伸破坏吸收的能量，分层传播还改进了材料的冲击强度．本文提出了一个分析模型来确定分层区域和靶的穿孔极限速度．采用这一模型对穿孔极限速度的计算结果表明其与实验值符合良好．     

板式蒸发器非共沸工质换热与压降研究

目前,针对单工质或近共沸工质的板式蒸发器研究已有开展,但对于非共沸工质的尚未见报道;本文结合实验 数据,欲将已有实验关联式推广到非共沸混合工质,经过比较发现,Hsieh的应用近共沸工质R410a的换热系数关联式 能很好的适应大温度滑移的混合工质,另外本文对摩擦压降关联式的系数经过适当的修正后也能应用于该工质。     

Finite deflection analysis of elastic plate by the boundary element method

An integral equation formulation for finite deflection analysis of thin elastic plates is presented, based on general nonlinear differential equations which are equivalent to the von Kármán equations and by virtue of generalized Green identities. Boundary element discretization is applied and a relaxation iterative approach is employed to solve the nonlinear plate bending problems. A number of numerical examples are given; the results of computation are compared with the analytical solutions and good agreement is observed. It appears that the approach developed in this paper is effective.     

国外图像光子计数系统的现状及发展

本文重点叙述国外图像光子计数探测系统的发展现状和未来趋势，以及高增益微通道板（ＭＣＰ）的最新进展。     

Tilting and shearing determination in the alignment of a Mach-Zehnder interferometer by zone plates

An easy and accurate method to detect the kind of disarrangement and its magnitude in the adjustment process of a Mach-Zehnder interfermeter by means of an equilateral hyperbolic zone plate is explained.