单箱三室连续-刚构箱梁桥的剪力滞效应

根据一座单箱三室连续-刚构组合桥梁,考虑桩-土相互作用分别建立了变截面三维梁单元和三维实体、板壳单元组合两种有限元模型,分析了桥梁在均布荷载和集中荷载作用下的剪力滞效应,并讨论了两种计算模型对动力特性的影响.结果表明,在均布荷载与集中荷载作用下箱梁的剪力滞效应明显不同,对于地震时程反应分析而言,采用变截面三维梁单元模型计算效率较高.所得的分析结果对指导这类桥梁的设计具有重要的工程实用价值.图7,表2,参8.     

泵站簸箕型进水流道水力特性试验及数值模拟

对一经优化设计的泵站簸箕型进水流道制作了水力模型,测试其水力损失;采用雷诺平均纳维斯托克斯方程(RAN S)和标准k-ε湍流模型,运用S IM PLEC算法,对流道内部流场进行了三维湍流数值模拟,揭示了流道内水流的流态和特征断面的速度分布规律.试验和数值分析结果表明,所设计的簸箕型进水流道内无漩涡,流态良好,水力损失小,水泵进口速度分布均匀,加权平均入流角接近90.°     

Cellular automata pedestrian movement model considering human behavior

The pedestrian movement is more complex than vehicular flow for the reason that people are more flexible and intelligent than car. Without the limit of 搇anes?pedestrian movement is loose and free. Furthermore, they are easily affected by other walkers as well as the environ-ment around. In this paper some special technique is intro-duced considering human behavior to make the rules more reasonable. By simulating the two-dimension pedestrian movement, the phase transition phenomena of pedestrian movement, including the up walkers moving from the bottom to the upper boundary and the right walkers moving from the left to the right boundary, are presented. Studying on the effect of the system size on the critical density shows that the critical density is independent of the system size in the scope studied in this paper.     

多跨弯曲连续箱梁有限条法分析中凝聚矩阵应用的探讨

探讨了多跨弯曲连续箱梁有限条法分析中凝聚矩阵的应用,给出对称结构在对称荷载作用下的赘余力凝聚矩阵．实例及有机玻璃模型测试结果表明,本文提供的凝聚矩阵是正确的．     

Phenomenon of multiple field-induced phase transition in PLZST antiferroelectric ceramics

The multiple field-induced phase transition in 4 at.% La modified Pb(Zr,Sn,Ti)O 3 family with temperature from -40℃ to 45℃ in reported. Two electric field-induced transitions from a metastable antiferroelectric phase to two ferroelectric phases are observed is polarization at the applied field of 4 MV/m. The critical field of phase transition between two ferroelectric phases is not larger than 2.5 MV/m, about ten to twenty percent of that ever found in PZT based ceramics. Lattice structure is shown to be orthorhombic by X-ray diffraction. Dielectric investigation reveals a relaxor-like ferroelectric behavior. Temperature-electric field phase diagram is also presented. An appreciate kind of materials is provided to investigate multiple field-induced phase transition with PZT-based ceramics.     

强磁场中氢原子束缚态能级之间的跃迁强度

在已求得强磁场中氢原子基态、低激发态能级和波函数的基础上,进一步得到了强磁场（Ｂ＝１０５～１０８Ｔ）中氢原子有关束缚能级之间的电偶极辐射跃迁强度．文中求得的跃迁强度与Ｆｏｒｓｔｅｒ及Ｇｒｅｎｅ等人用其他理论方法得到的结果相一致．文章提供的跃迁强度数据对研究天体物理和半导体中一些问题具有重要意义．     

基于随机Petri网可修控制系统的可用度计算

提出了一种基于随机Ｐｅｔｒｉ网的可修控制系统的稳态可用度的计算方法。该方法利用随机Ｐｅｔｒｉ网作工具来分析系统的状态变化关系，从而得出相应的Ｍａｒｋｏｖ链状态转移图，再利用由此得来的状态概率矩阵方程求解，计算较为简单。     

高层建筑桩箱（筏）基础沉降机理分析

充实、完善文献［１］的高层建筑桩箱（筏）基础的沉降计算简易理论，以考虑桩箱（筏）基础与地基的共同作用，并编制高层建筑桩箱（筏）基础沉降计算程序－－ＤＺ程序，通过微机计算分析，对桩箱（筏）基础的一些影响因素进行探讨，得到一些设计人员感兴趣的结果，例如荷载与沉降、桩数与沉降等关系。该法简单、方便、能手算，有利于设计人员的应用。     

箱形梁桥横向内力计算的计算机方法

针对箱形梁桥设计中桥面板横向内力计算问题进行分析，探讨了考虑桥梁纵向挠曲作用对横向内力计算的影响，以及在横向框构中考虑材料在应力─应变的线性与非线性关系两种不同状况下内力分布的变化，提出了箱形梁桥横向内力在工程设计中的计算机分析方法，编制了计算程序，并对实例进行计算比较。     

无机物的颜色及其变化规律探讨

本文从物质的内部结构出发，讨论了水溶液中金属离子，无机化合物的颜色与离子的电子层结构，离子的极化作用，配离子的形成，温度，晶格类型及分散度等的关系，说明了某些无机物的显色机理及变化规律。