有机电致发光的研究及其进展

介绍了有机电致发光器件的优点,器件的几种结构,有机电致发光的机理,以及评价有机电致发光器件的一些主要参数.阐述了有机发光二极管是一种很有前途的显示技术.     

Buck变换器在Matlab/Simulink下的仿真研究

本文首先分析了Buck变换器的工作原理,推导出Buck变换器电路参数的计算公式;然后介绍了Buck变换器的控制技术及其特点;最后在Matlab/Simulink下建立仿真模型。仿真结果验证了提高开关管的频率,可使得输出电压更平稳。     

Amplification of a Few Cycle Optical Pulses in Graphene

This paper focuses on the propagation of a few cycle optical pulses in graphene in a case of electromagnetic field.Electrons in the quantum formalism were considered and a change of dispersion law with Coulomb repulsion was taken into account.The effective equation was numerically analyzed and an influence of Coulomb repulsion was found.The amplification of few cycle optical pulses in graphene with applying of electromagnetic field to our system was discovered.Results about the amplification of pulse in g r...     

基于数字证书的自有APP签名保护方案

为应对移动应用(APP)盗版、仿冒、篡改风险,保证自有APP来源可信、内容完 整,本文提出了一套基于数字证书的APP签名保护与安全控制技术方案,实现了对 自有应用进行签名认证和全流程安全管控。该方案规范了自有APP的签名证书,明 确了正版标识;采用可信副署签名技术,加强代码保护,实现被篡改应用可识别可 追溯;通过中央监控平台,及时发现并限制异常应用,实现了APP的全流程实时安全管控。     

一种汽车防撞雷达多目标识别方法

针对汽车防撞雷达在多目标环境下遇到的虚假目标问题,基于各种多目标识别方法给出一种改进型变周期线性调频连续波(LFMCW)雷达多目标识别方法。该方法将改进型变周期三角波作为调频信号,通过对回波信号进行动目标检测、恒虚警检测等处理后进行容差函数的判断,最终达到去除虚假目标的目的。仿真结果表明,与传统LFMCW雷达相比,该方法在复杂多目标环境下能去除虚假目标,从而更为准确地识别目标。在实际应用中为驾驶员提供正确的目标距离和相对速度信息,从而起到主动防御的作用。     

增压流化床燃烧联合循环发电技术及其在中国的发展

概述了增压流化床燃烧联合循环(PFBC—CC)发电技术的基本原理和该技术在国外的发展情况,阐述了在中国发展PFBC—CC的意义,对该技术在中国的研究开发作了历史回顾和现状介绍,并对其发展目标作了展望。     

基于MCU的权控智能节水系统设计

为了节约水资源,营造环保、舒适的人居环境,针对现有卫生间冲水器实时性差,误检率高,节水效果不明显等问题,提出一种基于AT89C2051单片机的嵌入式智能型节水系统设计方案。该系统采用主注水控制技术及加权控制辅注水技术,极大地缩短了冲水迟滞时间。采用基于3min检测周期的冲水机理能实时、有效地检测判断出高峰期、低峰期和无人期;采用改进的红外监测技术使红外监测的误检率降低到0.2%。现场试验结果表明,系统各项性能指标均达到设计指标要求,节水率提高到88%。     

被动元器件在电子镇流器上的应用

电子镇流器在使用上有一些特殊的要求,来抵抗严酷的应用条件,这些包括高湿度、高电压、高频率、高温度、高纹波电流和长寿命。本文针对上述问题,运用详细的解释、分析和数据对比,给出了一些有效的对策措施和试验方法。最后,得出结论,解决这些关键点可以保证镇流器处于高质量水平。     

Physics-of-failure models of erosion wear in electrohydraulic servovalve,and erosion wear life prediction method

A series of Physics-of-Failure (PoF) models for particle erosion wear of electrohydraulic servovalves (EHSV), and the PoF based erosion wear service life prediction models, are established. Because there are only few correlative quantitative researches on the effect of erosion wear to EHSV, establishing the PoF models is of great significance to solve the problem. These models can also help to design a high-reliability and long-life EHSV, to establish relevant specifications, or to carry out accelerate life tests of EHSV. Before modeling, this paper analyzed the failure mechanism; and deduced mathematical models of servovalve’s critical performance parameters (CPP) that involved in the Slide Valve’s pressure gain, null leakage flow, and the Flapper nozzle Valve’s null bias, which may be affected by particle erosion wear. The factors that influence servovalves lifetime are the hardness, shape and size, velocity, concentration of particle, the design and assembling parameters, and the application method. With erosion wear equations, we connect the factors to mathematical models of CPP to establish the PoF models. The methods to ascertain parameters in the models are proposed. Contaminant erosion wear experiments are carried out at fluid cleanliness level 7. The results show the PoF models can be utilized to precisely describe the degradation process and accurately estimate the erosion wear life of various servovalves.     

方波调制误差对光纤陀螺的影响分析与实验

根据数字闭环光纤陀螺的方波调制、解调原理,指出调制方波的频率、相位和占空比不理想是造成方波调制误差的原因。讨论了周期脉冲干扰的频率和相位特征,利用周期脉冲干扰的傅里叶级数推导出了方波调制误差的数学模型。建立了带有方波调制误差的闭环光纤陀螺简化模型,推导出了方波调制误差和陀螺输出偏置误差的关系。通过仿真和测试分析了调制方波的周期、相位、占空比、光纤环的群延时以及放大电路的增益带宽对陀螺输出偏置的影响。最后,给出了一种利用周期脉冲干扰波形检测方波调制误差的简易方法。