结构动力学基于摄动法的高阶非线性随机有限元方法研究(英文)

Several algorithms were proposed relating to the development of a framework of the perturbation-based stochastic finite element method (PSFEM) for large variation nonlinear dynamic problems. For this purpose, algorithms and a framework related to SFEM based on the stochastic virtual work principle were studied. To prove the validity and practicality of the algorithms and framework, numerical examples for nonlinear dynamic problems with large variations were calculated and compared with the Monte-Carlo Simulation method. This comparison shows that the proposed approaches are accurate and effective for the nonlinear dynamic analysis of structures with random parameters.     

Pan-electronic Vehicle System

提出了全电子汽车系统的汽车车身电气系统设计方案,它以骨干网和局域网两级网络为数字信号网络、以电源网络提供电源并以中央协调器进行整车的协调控制.通过骨干网/局域网实现电器互联,并以分布式电源网实现整车弱电和强电的供电,以标准化电器接口实现了整车线束的简化,从而构建了一个智能型、标准化、一致性强、扩展性好、可靠性高的电器系统.最后开发了实验样车,验证了系统的可行性.     

城市错位交叉口信号控制方案优化研究

针对城市中心地区较为常见的错位交叉口带来的交通问题,结合南京市中航科技城开发建设项目,对错位交叉口的交通信号联动控制方法进行研究,以保证错位交叉口运行的顺畅性和安全性.基于错位交叉口信号联动控制模型的建立,以南京市航空路一瑞金路一尚书巷形成的错位交叉口为研究对象,利用Vissim建立错位交叉口的仿真环境,对城市错位交叉口的运行状态进行了评价.研究结果表明通过优化错位交叉口信号控制策略,可以提高错位交叉口的通行能力,减少交叉口车辆的延误,达到改善交叉口运行环境的目的.     

航标部门参与溢油清污应急的经验与思考

文中从我国航标管理机构参与海上溢油应急反应实践入手,总结了在该工作中的经验和启示,并对比发展需要和发达国家实践提出了加强航标机构溢油应急反应能力建设的建议。     

越南某电厂新建煤码头排水系统设计方案优化

越南某燃煤电厂为满足当地电力的发展需求,拟对电厂进行扩建,并新建煤码头及输煤系统。针对外方提供的新建煤码头排水系统设计方案,从技术和经济角度展开全面分析,指出外方设计的排水系统存在的不足。结合国内煤码头排水系统的习惯做法,通过对比分析,对外方设计的排水系统进行优化,以满足码头区域雨水和冲洗废水“零排放”的环保要求。     

Improving the coexistence of offshore wind farms and shipping: an international comparison of navigational risk assessment processes

The continued growth and evolution of the offshore wind industry, and the emergence of other novel marine uses such as wave and tidal generators, have upped the ante for spatial planners, as well as consenting and approval authorities in various coastal states. These stakeholders rely on processes such as navigational risk assessments (NRAs) to balance safety and efficiency requirements and to make optimal decisions over use of space. Given the increasingly complex and crowded seascape, however, there are some apprehensions about potential shortcomings in these NRA processes. There is also some concern that these inadequacies may lead to unsafe or inefficient marine spatial use. To understand how NRA processes can be improved further, a literature review is conducted, followed by a survey of respondents who are involved in the planning, consenting and/or approval of offshore wind farms across seven different countries. A summary of the NRA processes in these seven countries is presented, and several shortcomings are identified. Based on the findings of the survey, a list of recommendations is presented to enhance existing NRA processes—and to improve the coexistence of shipping and offshore wind farms (OWFs).     

Five-axis interpolation of continuous short linear trajectories for 3[PP]S-<Emphasis Type="Italic">XY</Emphasis> hybrid mechanism by dual Bezier blending

A novel five-axis real-time interpolation algorithm for 3[PP]S-XY hybrid mechanism is proposed in this paper. In the algorithm, the five-axis tool path for controlling this hybrid mechanism is separated into two sub-paths. One sub-path describes the movement of 3[PP]S parallel kinematic mechanism module, and the other one describes the movement of XY platform. A pair of cubic Bezier curves is employed to smooth the corners in those two sub-paths. Based on the homogenous Jacobian matrix of 3[PP]S mechanism, a relationship between the position errors of every driving joint in hybrid mechanism and the position deviation of the tool tip center point at the moving platform is established. This relationship is used to estimate the approximation error for the corners smoothing according to the accuracy requirement of tool tip center in interpolation. Due to the high computational efficiency of this corner smoothing method, it is integrated into the look-ahead module of computer numerical control (CNC) system to perform online tool path smoothing. By performing the speed planning based on a floating window scheme, a jerk limited S-shape speed profile can be generated efficiently. On this basis, a realtime look-ahead scheme, which is comprised of path-smoothing and feedrate scheduling, is developed to acquire a speed profile with smooth acceleration. A monotonic cubic spline is employed for synchronization between those two smoothed sub-paths in tool path interpolation. This interpolation algorithm has been integrated into our own developed CNC system to control a 3PRS-XY experimental instrument (P, R and S standing for prismatic, revolute and spherical, respectively). A club shaped trajectory is adopted to verify the smoothness and efficiency of the five-axis interpolator for hybrid mechanism control.     

轮轨噪声的产生机理及其治理措施

根据国外对轮轨噪声机理研究和实验成果及技术应用实例,分别从轮轨粗糙度激励、车轮振动、钢轨振动、轨枕振动和声辐射等五个主要方面对轮轨噪声的产生机理进行分析和讨论,注重研究轨道交通的噪声源———轮轨噪声,找到轮轨噪声的产生根源,为轮轨噪声的治理提供可靠的理论依据,然后以此机理为着眼点,再结合国外对机理的研究和试验成果及其技术和产品的应用实践,分别从以上提到的轮轨噪声产生机理的五个主要方面,并结合我国轨道交通轮轨噪声的实际情况,提出控制轮轨噪声的治理措施,为我国城市轨道交通轮轨噪声治理提出参考性建议。     

先天性长QT综合征相关人类HERG基因真核表达载体的构建及其功能表达

目的构建先天性长QT综合征相关HERG基因的真核表达载体,观察其在真核细胞中的表达,建立稳定的细胞系,探讨基因的功能。方法原核克隆载体pGEM-HERG经限制性内切酶获得HERG cDNA,将HERG cDNA亚克隆到真核表达载体pcDNA3中,用Lipofectamin2000转染试剂介导将pcDNA3-HERG及荧光真核表达载体pRK5-GFP共转染至HEK-293细胞,利用G-418进行细胞筛选,并用稀释法建立稳定的HEK-HERG细胞系。用全细胞膜片钳技术检测HERG基因的功能表达情况。结果在原核克隆载体pGEM-HERG的基础上构建了HERG的真核表达载体pcDNA3-HERG,并使其在HEK-293细胞中成功表达,建立的HEK-HERG细胞系稳定传代。膜片钳技术检测到了HERG通道电流的表达。结论该方法可成功构建及表达HERG的真核表达载体,为今后突变型HERG的研究奠定了基础。