EWB在模拟电子技术教学中的应用

EWB是应用广泛的仿真软件,可以进行工程意义上的仿真,在电路设计方面很受电子设计者的欢迎.还可以将其用于电路原理、电工学、电子技术等课程的辅助教学,帮助学生将实践与理论知识相结合,提高课堂教学效果.本文以基本放大电路为例说明EWB在模拟电子技术教学中的辅助作用.应用EWB对基本放大电路从静态到动态以及工程方面做了全面的仿真.     

Role of Alloying Elements P, Cu in Liquid Phase Sintering of Short Cast Iron Fiber

The effects of alloying elements P and Cu on the sintering process and mechanical properties of short cast iron fiber compact have been studied. The experimental results show that the sintering can be enhanced obviously by addition of phosphorus. The radial crush strength of sintered compacts increases with P content up to 0.15%, but when P content is over 0.15%,eutectics formed at the interfaces of fibers cause the decrease in strength and quasi-cleavage fracture of the sintered compact. Addition of Cu could not only reduce the volume shrinkage effectively, but also increase the strength and hardness of the sintered compact.     

Study on Interface between Sub-micron Particles and Matrix n Al2O3p/Al Composites

The microstructural characteristic of 1070Al matrix composites reinforced by 0.15 μm Al2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and Al2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.     

Application of mass spectrometry in the analysis of polybrominated diphenyl ethers

This review summarized the applications of mass spectrometric techniques for the analysis of the important flame retardants polybrominated diphenyl ethers (PBDEs) to understand the environmental sources, fate and toxicity of PBDEs that were briefly discussed to give a general idea for the need of analytical methodologies. Specific performance of various mass spectrometers hyphenated with, for example, gas chromatograph, liquid chromatograph, and inductively coupled plasma (GC/MS, LC/MS, and ICP/MS, respectively) for the analysis of PBDEs was compared with an objective to present the information on the evolution of MS techniques for determining PBDEs in environmental and human samples. GC/electron capture negative ionization quadrupole MS (GC/NCI qMS), GC/high resolution MS (GC/HRMS) and GC ion trap MS (GC/ITMS) are most commonly used MS techniques for the determination of PBDEs. New analytical technologies such as fast tandem GC/MS and LC/MS become available to improve analyses of higher PBDEs. The development and application of the tandem MS techniques have helped to understand environmental fate and transformations of PBDEs of which abiotic and biotic degradation of decaBDE is thought to be one major source of Br_1‐9BDEs present in the environment in addition to direct loading from commercial mixtures. MS‐based proteomics will offer an insight into the molecular mechanisms of toxicity and potential developmental and neurotoxicity of PBDEs. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:737–775, 2010     

灵敏度追踪软件及其应用

在市场经济条件下，企业的重要原料，产品及生产能力等因素直接影响经济效益，因此，需经常进行经济分析，以便作出好的生产经营决策。灵敏度追踪是进行上述分析的先进方法，例了对外购自营原油量进行灵敏度追踪的应用实例。     

面向半稠密三维重建的改进单目ORB-SLAM

构建更详细的地图以及估计更精准的相机位姿一直都是同时定位与地图构建（Simultaneous Localization And Mapping,SLAM）技术所追求的目标,但是以上目标与实时性要求、较低的计算代价和受限的计算资源条件是相矛盾的。提出一种在单目ORB-SLAM（Oriented FAST and Rotated BRIEF-SLAM）方法的基础上利用关键帧中提取到的直线特征进行半稠密三维重建的方法。由ORB-SLAM实时提供一组关键帧及其对应的相机位姿信息和一系列地图点,提出一种关键帧再剔除算法进一步减少冗余帧数目,使用直线段提取方法提取各帧中的直线段,使用纯几何约束方法对以上检测得到的直线段进行匹配,生成一个由直线段构成的半稠密三维场景模型。实验结果表明新方法持续稳定的运行,能在低计算代价条件下快速地在线三维重建。     

联邦卡尔曼滤波器在无人机导航系统中的应用

针对无人机GPS／RP／DR组合导航系统的特点，设计了用于该系统的联邦卡尔曼滤波器。该滤波器具有全局最优性，其结构遵循信息分配原则，其算法改善了数值计算的稳定性和系统的容错性，并减少了信息传输量与计算量。理论分析及仿真结果表明，该联邦卡尔曼滤波器能够满足无人机在GPS或RP信号无效或两信号均短期无效情况下定位导航的精度要求。     

某型无人机开切伞控制方法研究

针对某型无人机开切伞控制电路要求结构简单,可靠性高的特点,提出了一种基于双积分电路和GAL的设计方法;首先研究了开切伞电路的硬件结构,重点介绍了手摇方式下的开切伞电路模块,主要包括:双积分电路,比较单元,GAL译码三部分,阐明了双积分电路判断PWM波占空比变化的原理,然后使用WinCupl环境完成对GAL的编程,仿真;实际飞行试验表明,该方法实现了开切伞电路的逻辑功能,可以完成任务要求。     

Vega开发无人机模拟飞行视景系统

"某型无人机模拟飞行系统"是一个用于模拟无人机飞行的全任务试飞仿真系统,而视景系统作为整个仿真系统的终端显示平台,其开发的优劣直接影响到整个系统的综合性能;针对传统视景系统建模周期慢、仿真效果差等特点,提出了一种利用仿真软件Vega开发视景系统的方法,使用Creator中的"贯通面"、LOD、DOF技术建立了逼真的无人机和地景模型,Lynx搭建底层模型文件,基于MFC的Vega编程控制无人机位姿、视点、舵面偏转等,至此完成无人机视景系统的驱动;无人机试飞实验证明,该视景系统取得了比传统视景系统更好的效果。     

大型公共建筑运行阶段节能管理研究

针对大型公共建筑存在较为严重的能源浪费,并且在新建建筑中该类建筑的比例呈增长趋势的问题,从节能管理角度探讨推进大型公共建筑运行阶段的节能工作。首先分析大型公共建筑的能耗特点,识别出运行阶段的节能制约因素,然后根据节能管理主体的不同,分别从政府、业主、物业公司和使用者4个方面制定节能管理策略,从而实现大型公共建筑的节能运行,提高运行管理效率。