Study on early warning index of spatial deformation for high concrete dam

Owing to the deficiency in early warning for high concrete dam,a formula was established to characterize the deformation behavior of high concrete dam as a whole.The early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula proposed.The steps were as follows.Firstly,the probability method was utilized to define the degree of order and degree of chaos for each survey point.Secondly,the weight distribution among the survey points was...     

基于粒子群优化BP神经网络的超声波缺陷位置预测

海洋设备的无损检测对于保障设备安全使用至关重要,由于设备所处的海洋环境特殊,要实现对海洋设备缺陷位置的准确估计难度较大.论文提出了一种基于粒子群优化BP神经网络(PSO-BP)预测设备缺陷位置的方法.通过模拟了海洋检测环境,用钢板作为实验对象,用超声波探伤仪对缺陷钢板进行了数据采集,获取了水下钢板的实时数据.通过粒子群算法对BP网络进行优化后对数据进行分析,对比缺陷出现的实际位置和预测位置,证明了粒子群优化的BP神经网络对于超声波检测的缺陷出现位置具有较好的预测效果.     

水电黑启动的实现方法

以水电黑启动在重庆彭水电站的实现方法为例,对彭水电站黑启动初始状态、总体思路及其步骤进行详细论述,总结出彭水电站黑启动的重要性,同时提出实施过程中的注意事项。     

关于虚功原理及用其求解约束反力的分析

从虚功原理的定义入手,分析了在理想约束下以及在光滑约束下的虚功原理的运用,并且运用虚功原理对解决有非理想约束存在时约束反力的求法问题进行了探讨分析。     

Influence of static pre-loading on the dynamic bending strength of concrete with particle element modeling

Experimental tests show that static pre-loading has a significant effect on the dynamic strength of concrete.Based on meso-scale particle element model,numerical simulations of dynamic bending tests with pre-loading are performed.Complete stress–strain relationships are then obtained.Significant increase in dynamic strength is found when the pre-loadings are imposed within the elastic limit of concrete.However,when the imposition of pre-loadings reaches the plastic or softening range,dynamic strengths may gradually decrease along with the increase in pre-loadings.The distribution of energy components and the failure modes are discussed to explain the mechanisms of the phenomena.     

消泡剂在发酵工业中的应用

泡沫问题是发酵工业中一个棘手的问题,几乎所用的液体深层发酵都会用到天然或者化学消泡剂。在过去的发酵过程中,泡沫控制一般是依靠经验,关于消泡剂的系统知识较少。本文综述了发酵工业中消泡剂的种类和作用机制,以及消泡剂的应用进展。     

基于FPGA的TDM over IP的设计

设计一种TDM over IP的技术系统。该系统用FPGA将E1数据包通过串并转换到千兆以太网数据包,经IP网传输到终端设备,再通过并串转换将以太网数据包转换成E1数据包完成传输。经过软件和硬件测试验证了此系统在千兆以太网上传输的可行性,系统没有出现误码,固有输出抖动是0.55UI,最大峰值抖动指标均满足ITU-G.823标准要求。