In this paper, the design of a virtual experiment system based on Flex and XML is described. The system adopts threelayer architecture and it is composed of four modules. Flex is used to design user interface, and XML...In this paper, the design of a virtual experiment system based on Flex and XML is described. The system adopts threelayer architecture and it is composed of four modules. Flex is used to design user interface, and XML is used as data format between layers or modules. Data services are used to store or retrieve the information of experiment components or experiment scenes. Principles for the design of simulation engine and simulation scheduler are discussed. The design of the simulation engine for ＂Digital Logic＂ course is described in detail. The system has been implemented in the experiment teaching of Digital Logic. Teaching results and the feedback from students demonstrate that the virtual experiment system can improve the effects of experiment teaching and arouse the learning interests of students.展开更多
The main factors that influence the temperature field of frozen subgrade were analyzed.The experimental equipment for simulating frozen subgrade was built up,and the declining regulating tubes were placed at the foot ...The main factors that influence the temperature field of frozen subgrade were analyzed.The experimental equipment for simulating frozen subgrade was built up,and the declining regulating tubes were placed at the foot of the embankment. By means of this equipment two simulating experiments of controlling temperature filed of frozen sub- grade were carried out in the laboratory.One method is to collect natural cold energy,and the other one is to collect natural cold energy ccompanied by artificial refrigeration simultaneously.The result indicates that the latter is an ef- fective method for maintaining the stability of the frozen subgrade.展开更多
为了提高压电振动能量采集器的转换输出效率,提出了一种新型自供电的去整流桥同步电感开关(Self-Powered and Rectifier-Free Synchronized Switching and Discharging to a storage Capacitor through an Inductor,RF-SSDCI)功率提取...为了提高压电振动能量采集器的转换输出效率,提出了一种新型自供电的去整流桥同步电感开关(Self-Powered and Rectifier-Free Synchronized Switching and Discharging to a storage Capacitor through an Inductor,RF-SSDCI)功率提取接口电路。电路由电容与三极管组成的自供电开关模块和由电感电容串联组成的功率提取模块组成。由于省去了传统的二极管整流桥结构,电路更有利于小型化与集成化。另外,电感电容串联组成的功率提取模块保证电感为储能电容充能时无需开关控制,降低了开关导通时间对电路功率提取的影响,从而减少了功率损耗。利用电路分析理论详细阐述了电路的工作原理和提取输出功率,仿真和实验结果验证了RF-SSDCI电路的有效性。RF-SSDCI的最大提取功率达到63.6μW,比SEH(Standard Energy Harvesting)电路和SP-OSCE(Self-Powered Optimized Synchronous Charge Extraction Circuit)电路提高近109.2%和135.5%。展开更多
文章依据具体工程,介绍了转体结构的组成,分别从下转盘施工、球铰制造及安装、滑道安装、支撑脚安装、转体牵引计算、称重实验等方面着手,研究了转体结构施工流程和技术要点。项目应用建筑信息模型(building information modeling, BIM...文章依据具体工程,介绍了转体结构的组成,分别从下转盘施工、球铰制造及安装、滑道安装、支撑脚安装、转体牵引计算、称重实验等方面着手,研究了转体结构施工流程和技术要点。项目应用建筑信息模型(building information modeling, BIM)技术,对转体桥梁的转体系统进行碰撞检测及施工流程模拟,验证了施工方案的可行性,并对高风险作业步骤进行了改良,为转体桥梁施工方案的有效执行提供了支持,旨在为类似工程提供参考和借鉴。展开更多
基金Supported by the Key Project of the National Science and Technology Pillar Programs (2008BAH29B05, 2008BAH29B06)Education Reform Project in Hubei Province(2009052)
文摘In this paper, the design of a virtual experiment system based on Flex and XML is described. The system adopts threelayer architecture and it is composed of four modules. Flex is used to design user interface, and XML is used as data format between layers or modules. Data services are used to store or retrieve the information of experiment components or experiment scenes. Principles for the design of simulation engine and simulation scheduler are discussed. The design of the simulation engine for ＂Digital Logic＂ course is described in detail. The system has been implemented in the experiment teaching of Digital Logic. Teaching results and the feedback from students demonstrate that the virtual experiment system can improve the effects of experiment teaching and arouse the learning interests of students.
基金Projects 2002CB412704 supported by the National Key Basic Research and Development Foundation of the Ministry of Sciences and Technology of China KZCX1-SW-04 supported by the Knowledge Innovation Program of the Chinese Academy of SciencesSKLFSE200304
文摘The main factors that influence the temperature field of frozen subgrade were analyzed.The experimental equipment for simulating frozen subgrade was built up,and the declining regulating tubes were placed at the foot of the embankment. By means of this equipment two simulating experiments of controlling temperature filed of frozen sub- grade were carried out in the laboratory.One method is to collect natural cold energy,and the other one is to collect natural cold energy ccompanied by artificial refrigeration simultaneously.The result indicates that the latter is an ef- fective method for maintaining the stability of the frozen subgrade.
文摘为了提高压电振动能量采集器的转换输出效率,提出了一种新型自供电的去整流桥同步电感开关(Self-Powered and Rectifier-Free Synchronized Switching and Discharging to a storage Capacitor through an Inductor,RF-SSDCI)功率提取接口电路。电路由电容与三极管组成的自供电开关模块和由电感电容串联组成的功率提取模块组成。由于省去了传统的二极管整流桥结构,电路更有利于小型化与集成化。另外,电感电容串联组成的功率提取模块保证电感为储能电容充能时无需开关控制,降低了开关导通时间对电路功率提取的影响,从而减少了功率损耗。利用电路分析理论详细阐述了电路的工作原理和提取输出功率,仿真和实验结果验证了RF-SSDCI电路的有效性。RF-SSDCI的最大提取功率达到63.6μW,比SEH(Standard Energy Harvesting)电路和SP-OSCE(Self-Powered Optimized Synchronous Charge Extraction Circuit)电路提高近109.2%和135.5%。
文摘文章依据具体工程,介绍了转体结构的组成,分别从下转盘施工、球铰制造及安装、滑道安装、支撑脚安装、转体牵引计算、称重实验等方面着手,研究了转体结构施工流程和技术要点。项目应用建筑信息模型(building information modeling, BIM)技术,对转体桥梁的转体系统进行碰撞检测及施工流程模拟,验证了施工方案的可行性,并对高风险作业步骤进行了改良,为转体桥梁施工方案的有效执行提供了支持,旨在为类似工程提供参考和借鉴。
