A Hemodynamic Study of the Effect of Neuromuscular Electrical Stimulation on Enhancing Popliteal Venous Flow

Neuromuscular electrical stimulation has been studied to be a method of prophylaxis for deep venous thrombosis by activating the calf muscle pump. However, there is little evidence of the effects of different stimulating parameters on hemodynamics and comfort levels. The objective of this paper is to compare the effects of different stimulating parameters(current amplitude, pulse-width) on hemodynamic alterations of the popliteal vein and the comfort levels in a group of fourteen healthy subjects. Doppler ultrasound detection of peak venous velocity and blood volume were taken from baseline, twelve sequential electrical stimulations and foot dorsiflexion for each subject. A visual analogue scale was used to assess the subjects' pain perception of neuromuscular electrical stimulation. The results showed that peak venous velocity and blood volume augmented as current amplitude and pulse-width increased while pain level also increased. A compromise was reached that parameters consisting of an amplitude of 10 m A and a pulse-width of 500 μs would obtain a high-peak venous velocity and blood flow volume with a relatively comfortable perception. In addition, parameters consisting of an amplitude of 20 m A and a pulse-width of 300 μs were also shown to be a promising choice. However, further studies need to be done to validate and enrich these findings.     

桥梁工程高墩施工技术研究

针对桥梁工程高墩施工,分别在模板施工、混凝土工程施工以及墩身施工监测等几方面详细介绍了桥梁工程薄壁空心高墩施工技术,可以为桥梁工程高墩建设施工项目作业管理提供合理的技术参考。     

交流系统短路电流上升率特性分析及其应用*

论文从船舶交流电力系统短路电流主要馈送来源着手,建立系统模型并对短路电流上升率进行数学公式推导,然后从船舶电力系统角度对决定短路电流上升率的因素进行分析,并讨论了不同短路角时短路电流的变化趋势对电流上升率的影响。通过对比仿真,给出一定船舶电力系统下具体短路点故障诊断时参考电流上升率的选取方法和条件。参考电流上升率的选取方法为船舶电力系统电流上升率作为故障诊断整定设定提供参考。     

张唐铁路（64＋64）m T型刚构设计分析

该文以新建张家口至唐山铁路工程T型刚构为工程背景,介绍（64＋64）m T型刚构的结构特点及设计思路,并着重对T型刚构的桥型优势,梁体钢束布置,转体施工球铰局部效应,曲线T型刚构转动中心计算等进行了详细分析.所得结论可为同类工程的设计提供参考.     

4—氯—N—（4‘—氯亚苯基）苯甲酰胺的合成与表征

以对氯苯甲酸和对氯苯胺为主要原料，高产率获得了４－氯－Ｎ－（４＇－氯亚苯基）苯甲酰胺（简称ＤＣＢＡ）。通过元素分析、红外光谱、核磁共振氢谱及热分析对其结构和热性能作了表征。     

高速公路建设BOT与TOT融资方式探讨

BOT(建设→经营→转让)、TOT(转让→经营→转让)是国际性的融资方式.本文分析其运作特点和优点,同时分析二者的关系.     

浅析物资经营中的风险及其对策

侧重对物资经营中的常见风险类型进行分析、估计，并对防范物资经营风险提出了可行实用的措施。