快速压缩(膨胀)机的湍流问题和光学诊断优化方法

回顾了典型快速压缩(膨胀)机的基本原理和结构特征,并阐述了快速压缩(膨胀)机运行时缸内存在的湍流问题。此外,结合各研究实例中的典型测试方法,重点介绍了在快速压缩(膨胀)机研究中用于速度场、温度和浓度测量的光学诊断技术,并阐述了目前光学诊断技术应用于快速压缩(膨胀)机的测试能力及其局限性。     

浅嵌岩承台双壁钢围堰环形封底施工技术

结合呼准铁路黄河特大桥28^#墩圆形双壁钢围堰内环形封底施工,介绍钢围堰的设计、环形封底施工工艺、施工技术及简易内模的设计和加工,为今后类似工程提供参考。     

基于GPS技术的儿童定位和报警电路的设计与制作

利用 GPS 技术、单片机和射频通信技术,完成了儿童定位和报警电路的设计与制作.本电路解析 GPS数据获得儿童的位置、速度信息,SD 卡存储轨迹信息,8位 ATmega 单片机完成距离的计算和逻辑判断,射频收发芯片完成儿童与监护人之间的数据传送,实现两者之间应答式的实时定位监护.     

The effect of prostaglandin E1 on recovery of early renal graft functions after transplantation

Objective To investigate the effect of prostaglandin E: (PGE1) on recovery of early renal graft functions after transplantation. Methods One hundred and seven patients after renal transplantation were allocated in the treated group, and treated by conventional treatment with injection of 10 μg prostaglandin E1 additionally twice a day for 14 days. And eighty-eight patients who received conventional treatment alone after renal transplantation at the corresponding period were allocated in the control group. Indexes of the two groups, including incidence of delayed graft function and acute rejection reaction, volume of urine, serum certaintie (SCr), endogenous certainties clearance rate (CCr), the blood flow resistance in graft as well as blood viscosity (BV), and platelet aggregation rate (PAR), were determined. Results The urinary volume and endogenous certainties clearance rate of the treated group were significantly higher, but the level of SCr, incidence of renal function recovery retardation, BV, PAR and blood flow resistance in graft were significantly lower than these of the control group (P<0.05). The difference of incidence of acute rejection reaction between the two groups was insignificant (P>0.05). Conclusion Prostaglandin E1 can improve blood microcirculation and decrease the incidence of renal function recovery retardation. These effects are helpful for recovery of renal function after renal transplantation.     

Construction and identification of recombination expression vector Ksp-Cadherin-Gpx1-Kik1

Objective To construct and identify the Gpx1-Klk1 vector which contains kidney-specific promoter (Ksp-cadherin). Methods Through PCR amplification, the human Gpx1, Klk1, and Ksp-cadherin eDNA were obtained by taking Gpx1 cDNA, Klk1 eDNA, and Ksp-cadherin BAC as templates. After being testified, the PCR products were inserted into the expressive vector pIRES-EGFP step-by-step to produce a recombinant vector Ksp-cadherin-Gpx1-Klk1. This vector was examined by restriction enzyme digestion and sequence analysis. Results The recombinant expressive vector Ksp-cadherin-Gpx1-Klk1 was successfully constructed. Conclusion The construction of the recombinant vector Ksp-cadherin-Gpx1-Kik1 laid foundations for investigations in establishing transgenic animal models, the over-expression of Gpx1 and Kikl in mammal kidney, and gene therapy for ischemia-reperfnsion injury during kidney transplantation.     

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在分析实测数据的基础上,针对地铁车站内乘客疏散时间计算问题建立了考虑人群密度、空间环境变化的数学模型。文中分别对乘客下车过程、站台、通道和楼梯的行走过程、使用自动扶梯过程以及通过出口过程进行分析研究,以乘客疏散过程为依据建立基于统计学与排队理论的综合计算模型,给出了适合计算地铁车站内容乘客出站所需疏散时间的方法。本文以西直门地铁站乘客疏散为案例验证了所建立计算模型的有效性及实用性,模型计算结果与观测数据的总体误差约为2.25%,其中仅楼梯阶段与出口的通行时间计算误差超过10%。案例研究结果还表明地铁车站疏散能力存在上限,在进行地铁车站设计与列车运行计划制定的过程中应充分考虑这一限制因素。     

冰天雪地安全行车攻略

攻略一:行车要慢 在积雪结冰的道路上行车,附着系数的减小不仅使制动距离加大,而且易发生溜滑.     

现代有轨电车主要特征与国内外发展研究

从运能、速度、定制的灵活性及使用的舒适性4个方面,将现代有轨电车与传统有轨电车进行对比,分析了现代有轨电车的主要特征。以法国阿尔斯通公司的Citadis系列有轨电车和劳尔公司的Translohr系列有轨电车为例,从尺寸、运能、技术性能、噪音等方面,研究对比了钢轮钢轨和胶轮＋导轨两种制式的有轨电车,介绍了这两种制式的有轨电车尤其是Citadis系列有轨电车的使用情况。针对当前国内现代有轨电车的使用状况,提出了相关建议。     

无线电测向与定位技术助力海洋运输安全

介绍无线电测向与定位技术的功能、相关设备和使用情况,阐述这项技术在保障海洋运输安全方面的重要作用。     

公路桥梁的桥面防水

简述了防水混凝土和各种防水层的应用,并指出了目前使用中存在的问题。并提出建议,桥面的防水设施不应"一刀切",而应因地制宜地采用不同的设防标准。