复杂环境下石方控制爆破施工技术

文中结合通灌铁路路堑石方控制爆破施工,根据当地环境条件和地质条件,采用深孔台阶控制爆破施工技术,并根据试验和爆破效果分析,总结了符合现场条件的爆破参数、操作要点及安全防护措施。在通灌铁路复杂环境下石方路堑施工中,高效快速地完成了爆破施工作业,且路堑边坡平整稳定,取得了良好的安全爆破效果,经济、环境效益显著。     

Microfluidics-based assay on the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors

Abstract A new microfluidic system with four different microchambers （a circle and three equilateral concave polygons） was designed and fabricated using poly（dimethylsiloxane） （PDMS） and the soft lithography method. Using this microfluidic device at six flow rates （5, 10, 20, 30, 40, and 50 μL/h）, the effects of microenvironmental geometry and aqueous flow on bacterial adhesion behaviors were investigated. Escherichia coli HB101 pGLO, which could produce a green fluorescent protein induced by L-arabinose, was utilized as the model bacteria. The results demonstrated that bacterial adhesion was significantly related to culture time, microenvironment geometry, and aqueous flow rates. Adhered bacterial density increased with the culture time. Initially, the adhesion occurred at the microchamber sides, and then the entire chamber was gradually covered with increased culture time. Adhesion densities in the side zones were larger than those in the center zones because of the lower shearing force in the side zone. Also, the adhesion densities in the complex chambers were larger than those in the simple chambers. At low flow rates, the orientation of adhered bacteria was random and disorderly. At high flow rates, bacterial orientation became close to the streamline and oriented toward the flow direction; All these results implied that bacterial adhesion tended to occur in complicated aqueous flow areas.The present study provided an on-chip flow system for physiological behavior of biological cells, as well as provided a strategic cue for the prevention of bacterial infection and biofilm formation.     

社会力模型在行人运动建模中的应用综述

为研究社会力模型在行人运动建模中的应用状况与存在的问题,系统分析了相关文献,跟踪研究了模型的基本原理、表达式的改进、参数的取值、可行性和模拟结果的真实性.研究显示,社会力行人交通流模型能较好地反映行人流在正常和逃生情况下的状态,模拟结果与实测的行人现象符合,具有很好的适应性和真实性,可为交通设施设计和行人流管理提供参考...     

浮运转体法架设钢桁梁施工技术

在青阜铁路增建二线茨淮新河特大桥钢桁梁架设施工中,根据现场施工条件,合理利用六七式铁路舟桥器材、六四式铁路军用梁等战备器材,拼组成浮运船,使钢桁梁在岸边预拼装,然后利用浮体转体法、浮运法将钢桁梁整体架设到位,大大降低了施工难度,减少了占用航道时间,创造了良好的经济效益,可供同类施工参考.     

沙漠地区涵洞轻型井点降水施工技术

S313线兰嘎段LJ-11标位于内蒙占南部毛乌素沙漠腹地.地层为粉细砂.为完成涵洞基坑开挖任务.经方案比选采取轻型井点降水措施.主要介绍轻型井点降水的施工设计、井点管安设、降水、施工注意事项等内容,并分析了影响降水的各种因素.提出了改进降水效果的有效途径和措施,对类似工程有借鉴意义.     

Dynamic response of the non-contact underwater explosions on naval equipment

Shock resistance capacity of the shipboard equipment especially for large ones, has been a strong concern of navies all over the world for a long time. The shipboard equipment have previously generally been studied separate from hull structure before. In this paper the coupling elastic effect between equipment and hull structure is taken into account. With the ABAQUS software, the integrated model of the equipment coupled with the hull structure is established to study the dynamic response of the shipboard equipment to the shock wave load as well as the bubble pulsation load. In order to verify the numerical method, the simulated results are compared to the experimental data, which are from a specific underwater explosion on an actual ship. On this basis, by changing the charge location, attack angle, equipment installation location and other parameters, the characteristics of dynamic response under different conditions can be obtained. In addition, the results of the integrated calculation and the non-integrated one are compared and the characteristic parameters which affect the equipment shock response are analyzed. Some curves and conclusions are obtained for engineering applications, which provides some insights into the shock resistance of shipboard equipment.     

基于人工涡旋流的船舶堵漏新方法

分析了船舶传统堵漏方法存在的问题,突破单纯“堵”的思想框架.提出基于人工涡旋流的船舶堵漏新方法,并设计制作了验证性实验装置,进而分别研究了用于产生人工涡旋流的柔性、刚性桨叶对破口进水量的影响规律.实验结果表明:该方法通过在破口外侧合适位置人工形成局部高速涡旋流场,能够大幅减小海水对破口处的压力,也就可大幅减小破口处单位时间的进水量,从而为破口的舱内封堵创造有利条件.研究结论可为船舶堵漏理论的进一步丰富完善以及相应堵漏器材的研制提供必要的基础和依据.     

大型LNG船推进型式研究

介绍了大型LNG船船型的特点,对适合于大型LNG船的推进型式进行了分析研究和模型试验研究,对用于LNG船舶的不同类型的推进装置进行了比较分析。得出了一些结论,并指出在当前低排放绿色船舶的要求下,采用双燃料电力推进方式更有发展前景,但若要在大型LNG船上采用此推进方式,尚有待一些问题的解决。     

有限深度均匀流中圆柱桩群绕流对流速的影响*

通过有限深度均匀流水槽试验研究不同圆柱桩群对均匀水流的绕流影响程度.通过多组试验研究数据对比分析得到圆柱桩群对均匀水流的影响规律;不同圆柱桩群对同样水流影响性质与程度的差别;不同圆柱桩群对水流流场影响范围的规律;圆柱桩群的阻流率、排架密度、桩群长度对水流流场的影响规律;不同流速的水流对圆柱桩群影响的反应规律;水流绕流圆柱桩群时,横向断面流速的变化规律等.研究分析还发现:桩群阻力是桩群影响水流的一个因素但非唯一因素,桩群的排列方式和桩群迎流角对水流流速的变化有不同程度的影响,且其影响程度大于阻力影响.     

船舶电气自动化设备产业发展研究

船舶电气自动化设备是船舶配套设备的重要组成部分。本文论述了我国乃至我省船舶配套产品,特别是船舶电气及自动化产品的现状,总结了船舶电气自动化设备组成和分类;指出船舶电气及自动化系统发展趋势;最后针对船舶电气自动化设备的技术引进、消化吸收与开发创新提出一些想法与具体建议。