A free rectangular plate on elastic foundation

This article will discuss the bending problems of the rectangular plates with free boundaries on elastic foundations. We talk over the two cases, that is, the plate acted on its center by a concentrated force and the plate subjected to by a concentrated force equally at four corner points respectively. We select a fiexural function which satisfies not only all the geometric boundary conditions on free edges wholly but also the boundary conditions of the total internal forces. We apply the variational method meanwhile and then obtain better approximate solutions.     

弹性地基上的自由边矩形板

本文讨论了在弹性地基上的自由边矩形板的弯曲问题.我们讨论了两种情形,诸如在板的中心受到一集中力作用和在板的四个角点上各受到一相等的集中力作用.文中选择了一个挠曲函数,它不但能满足所有自由边上的全部几何边界条件,而且也满足所有的内力边界条件.同时,我们应用了变分法,从而得到了较好的近似解答.     

光敏感核不育水稻W6184s花药和花粉发育的细胞形态学观察

光敏感核不育水稻W6184s细胞形态学观察结果;花粉败育主要发生在小孢子发育后期,具大液泡的小孢子不能进入配子体发育阶段;小孢子发育的早期,少数小孢子母细胞就表现异常而导致花粉败育。在小孢子发育的同时,绒毡层出现各种异常现象。     

韧性断裂裂纹尖端的物理特征和力学行为

本文综述了金属材料发生韧性断裂的裂尖钝化,孔洞成核和长大,孔洞-孔洞或孔洞-裂尖汇合导致裂纹扩展的物理特征,和描述这些特征的本构理论及物理模型。      

闭合圆柱壳在轴向冲击荷载下的某些动力计算问题

本文讨论了闭合圆柱形壳体在轴向冲击荷载作用下的某些动力计算问题,其中包括动应力的计算和稳定性问题.文中分析了冲击过程中动量及能量的变化,并计入冲击物和被冲击的闭合圆柱壳系统质量的影响;用相当质量法将整个圆柱形壳体的分布质量转化为只集中在壳体一端的“相当质量”,从而导出闭合圆柱形壳体在轴向冲击荷载作用下的动力因数,因而解决了在上述受力情况下计算动应力的问题和求出临界荷重的问题.     

Combined longitudinal with lateral bending of rectangular plates supported at points of corners

This paper discusses the problems of combined longitudinal with lateral bending of rectangular plates which are supported at four points of corners by means of the variational calculus. In the text the lateral bending and the stability of thin plates are also treated respectively.     

弹性地基板由运动载荷引起的动力反应

本文用变分法讨论在弹性地基上的薄板由运动载荷所引起的动力反应.文中计及运动载荷的质量,讨论了关于强迫振动,挠度的影响面及内力的影响面,共振条件及临界速度等问题.     

生长促进剂康健重(Nitrovin)的液相色谱分析

康健重化学名称为1,5-双(5-硝基-2-呋喃基)1,4-戊二烯-3-酮脒基腙盐酸盐[1,5-bis(5-Nitro-2-furyl)-1,4-Pentadien-3-one Amidinohydrazone hydrochloride]是一种对鸡、鸭、猪、鱼等十分有效的生长促进剂。国外已有商品大量供应,国内已由北京市营养源研究所研制投产。其原药及在饲料中的含量测定多用极谱、示差脉冲     

CALCULATION OF ORTHOTROPIC SHALLOW CONOIDAL SHELL ROOFS

The present paper is to introduce the method for the calculation of the roof withorthotropic shallow conoidal shells which are always used in the industrial buildings. Sincethe middle surface of the shallow conoidal shell having the variable curvatures and twists,therefore the system of fundamental equations, which are obtained by us, are beingpossessed of the variable coefficients.If we want to find the exact analytical sohutions, it will be involved in greatmathematical difficulties. This paper gives the approximate solutions of the orthotropicshallow conoidal shell roof which is simply supported at all edges and under the uniformlydistributed load.In this paper the method of small parameter is used.     

正交异性劈锥面扁壳屋盖的计算

本文介绍工业建筑中常用的正交各向异性劈锥面扁壳屋盖的计算.由于该劈锥面扁壳的中曲面存在变曲率和扭率,故所得的基本方程组是变系数的,欲得到精确的解析解在数学上有很大的困难.本文用小参数法求出在均布载荷作用之下,四边简支的正交各向异性劈锥面扁壳屋盖的近似解答.