嵌岩变截面桩的应用与计算

简要论述嵌岩变截面桩的应用条件及优点。分别采用各民支地基竖向、横向反力系数为常数,建立轴向、横向位移函数通解及导数的矩阵式。引入桩顶、桩端边界条件,桩的连续条件,求解积分常数。该方法全部可采用电算完成,并经论证及验算,对于具有超固结粘土和硬壳层的土质情况,。该方法比其它方法更接近于实际。     

紫外光大气传输特性的模拟研究

为进一步了解紫外光信号在的不同大气条件中的传输特性, 基于紫外光非视线传输的Monte Carlo方法的算法模型, 模拟分析了不同情况下紫外光信号在大气中的传输特性。实验结果表明, 单脉冲信号随距离的增加, 脉冲展宽和脉冲延迟效应更加明显; 在晴、 阴、 雨、 雾不同天气条件下, 雨天对传输信号的能量的衰减影响最大。     

彩色图象倒色现象的理论分析

本文介绍了彩色图象的倒色现象,并通过电路原理和混色理论分析了形成原因。     

论城市化的水文效应

城市化是人类发展的必然趋势,也是一个国家走向现代化的必经阶段,近数十年来,城市化过程迅猛,由此出现了一系列严重的城市生态环境问题,如水资源危机、水质恶化,针对城市化对水循环、水文过程、城市水资源和水环境的影响作了详细分析,并提出了相应的对策。     

杂交棉不去雄人工制种技术研究

选用具有叶基无红斑这个隐性指示性状的棉花品种作母本,用具有相对显性性状的常规品种作父本,结合"柱头套管法"进行杂交棉不去雄人工制种,以人工去雄制种作对照,对两种制种方法的成铃率和异交率及杂交种子的部分农艺性状作了比较研究. 试验结果表明,用不去雄"柱头套管法"制种的异交率比人工去雄法的低8.4%,但前者的成铃率比后者的高6.6%,单铃种子重和单铃种子数分别比后者的重0.37 g,多3.16粒.     

Modulation of low-frequencyoscillations in GaAs MESFETs’ channel current by sidegating bias

The demand for higher speed and better functionality incircuits using GaAs metal-semiconductor field-effect tran-sistor (MESFET’s) has led to higher density. Higher den-sity has caused increasing sensitivity to interaction amongFET’s. When we place an electrode nearby the MESFETand set the voltage across the electrode beyond a criticalvalue, the drain current ID will decrease abruptly and thesidegate current ISG will increase rapidly. This is calledsidegating effect[1,2]. The sidega…     

Geomorphology visualization modeling and tidal current virtual reality for coastal ocean

The new technology of geomorphology visualization modeling and virtual reality for tidal current numerical simulation are the important methods utilized in coastal ocean research. In the project of studying the evolutionary trend of radial sand ridges in South Yellow Sea of China, this method becomes the key to reveal the correlation between the seabed topography and the hydrodynamic factor—— tidal current. It is proved that using the geomorphology visualization and tidal virtual reality techniques, oceanog-raphers might be able to intuitively discover the interaction pattern of sand ridges and tidal current, predicting the development of sand ridge stability in the future. Furthermore, a prolotypic software system——VROcean was designed and implemented to examine the performance of the new visualization technology on the contrast to traditional methods.     

一种具有异轨星间链路的Walker星座网络拓扑与路由生成方案

Walker星座网络能否建立异轨星间链路是提升其通信能力的关键所在.研究了一种24/3/1 Walker星座,通过对卫星间的能见分析及星间链路特性分析,探索了建立异轨道星间链路的可行性.然后,按照时段接续的异轨星间链路方案,进行了24/3/1 Walker星座网络的拓扑仿真与生成,并在此基础上对星座网络采用K短路径和最短路径路由选择策略进行了对比仿真分析.结果表明,按照时间段接续建立异轨星间链路的方案是可行的,所生成的网络拓扑的切换时间间隔最小为30 s,最大为115 s,K短路径策略在总体上要优于最短路径策略.