非一致地震激励下大跨斜拉桥非线性响应计算

基于随机过程理论关于幅值、相位与功率谱的关系式,采用二维相干非一致激励功率谱模型,根据场地地震动参数合成人工地震波,考虑波动传播效应和多点激励效应,分析了某座跨长江的大跨度斜拉桥在地震激励下的空间非线性响应特性,计算了桥梁结构关键部位在地震力作用下的响应特性,并与一致激励下对应响应量进行了比较。认为非一致激励下大跨斜拉桥关键部位的某些响应量大幅增加,反应了进行非一致响应分析的必要性。     

编组站阶段计划IDSS的车流推算方法研究

针对编组站阶段计划IDSS的设计,运用聚类分析与逻辑推理的研究成果,提出了一种有效的车流推算实现方法.     

高含水期油田地面工程现状及发展趋势

随着油田开采时间的不断增长,国内外很多油田都进入了产能后期,都面临着相同的问题:采出油含水率高,以及由此带来的一系列问题(脱水能力不足、原油集输与处理系统运行效率和设备利用效率下降及生产成本过高等).在解决高含水期油田集输问题上,国内外都积累了一些成功的经验,文中对脱水能力不足,原油集输与处理及设备利用率等方面进行了详...     

Untangling process complexity in logistics delivery services with unpredictable service sequences: a mixed-method study of chemical tanker port calls

We explore the complexity issue relevant to a logistics service process characterized by unpredictable service stages and service sequences in the context of chemical tankers’ call in the Port of Houston. The operational dimensions of uncertainty and conflict surrounding process complexity are examined through a mixed-methods approach using both qualitative and quantitative data collected from the Port of Houston. We propose a taxonomy to classify several uncertainty and conflict factors emerged from our qualitative analysis, including structural conflict, structural uncertainty, infrastructural conflict, and infrastructural uncertainty. The case study findings are validated and triangulated by a quantitative analysis which quantifies the time and cost impacts of unproductive chemical tanker movement on port-call service performance. We contribute to the complexity theory by introducing four dimensions of process complexity to the stream of process-oriented logistics service research. These four complexity dimensions can be used by managers to untangle their process complexity. Our pseudo-service-stage based mapping technique will also be valuable for managers to visualize their service processes with unpredictable service sequences. Finally, we call for future research on synchronization across operational processes between service stages.     

浅谈特殊阶段工程质量管理

本文主要讲述在工程施工中，对于雨季、交叉作业期，收尾阶段等特殊时间的工程质量管理，强调管理的系统性及一致性，目的在于服务于工程的总体目标。     

某河堤在搅拌桩施工中出现滑动的原因分析

某河堤在水泥搅拌桩施工工程中出现了旧、新堤先后滑动的稳定性事故,本文对造成这种滑动的原因进行了深入的分析,以供大家商榷。     

长区间轨道电路及信号机点灯方案的探讨

根据京九线信号自动闭塞改造工程中站间距离长的特点，提出长大区间轨道电路及信号机点灯的解决方案。     

对确定航道设计最低通航水位中河段划分标准的设想

从径、潮动力作用结合日水位变幅对通航标准的影响出发,确立河段特性对样本标准的要求,提出将河段类型划分为三类的设想。     

一种具有宽带隔振性能控制器的理论设计

本文对双层事振主动控制系统进行了理论分析，通过对系统力传递率的推导，采用上层质量响应变量作为控制器输入参数的方法来构造具有宽带隔振性能的控制器，理论分析表明采用该控制器的系统具有无条件的稳定性，对采用本文构造的控制器的双层隔振系统进行了主动隔振仿真研究，仿真结果表明采用该控制器的主动隔振系统对各种激扰力都具有理想的隔振性能。     

A review of the effect of a/ W ratio on fracture toughness （Ⅲ） ——theoretical analysis

In part I and II of this series, experimental investigation in both EPFM and LEFM had been discussed. In this part, further theoretical analysis is given. The theoretical development of Two Parameter Fracture Mechanics by Hancock etc, has rationalized our experimental results. This method can be applied to engineering practice, and will allow the advantage of enhanced toughness for specimens with low levels of constraint to be taken into account for defect assessment.