AlGaAs／AlAs体系DBR的MOCVD生长及表征

设计并利用MOCVD在（311）GaAs衬底上生长了12．5个周期的Al0．6Ga0．4As／AlAs黄绿光分布式Bragg反射（DBR）体系，测量了白光反光谱及其外延片峰值波长分布，反射率90％以上，波长不均匀性在1．0％以下；利用了X射线双晶衍射对其进行结构表征，580nm波长DBR结构周期为84．5nm。     

APPLICATION OF THE PML ABSORBING BOUNDARY CONDITION TO FD-TD SIMULATION

The key problem of finite-difference time-domain (FD-TD) method is the skillful application of special conditions on the boundaries of the computational domain. A new technique named Perfectly Matched Layer(PML) yields a robust Absorbing Boundary Condition(ABC) independent of the angle of incidence and the frequency of outgoing waves. In this paper, the principle of the PML technique is briefly presented. Then some problems in the application and their settlements are discussed emphatically. Finally three numerical tests and a measured result are devoted to examine the accuracy and effectiveness of this approach.     

Measurement of circumferential viscosity profile in stationary journal bearing by shear ultrasonic reflection

Viscosity is the most important property of a lubricant that can affect bearing performance. It controls the film thickness that is established during an operation. In this study, the ultrasonic method was used to measure the static viscosity profile around a journal bearing by using shear reflection coefficients at several locations around the journal bearing. This enables the viscosity profile to be established. The technique introduced was found to be successful and acceptable results were obtained from certain regions of the journal bearing flow. This study serves as a preliminary work for developing viscosity measurement in a rotating journal bearing.     

Reflection and absorption characteristics of electromagnetic waves for PV modules

In this paper, the authors investigated the reflection and absorption characteristics of a general photovoltaic (PV) module. As a result, the electromagnetic waves could be attenuated only 6 dB in typical PV module. However, if the PV module is installed in the outer wall of buildings, electromagnetic interference is caused by the surroundings. To reduce this electromagnetic interference, the authors suggested a method to absorb electromagnetic wave using multiple PV modules that have deference impedance, and simulation was performed. As a result, it was confirmed that using a typical PV module and the PV module including electronic device, the reflection waves of those PV modules could be attenuated up to 12 dB.     

The effect of growth parameters on CrN thin films grown by molecular beam epitaxy

In this paper, we report on the controlling of the effect of growth parameters such as substrate temperature and the ratio of Cr and N atoms on phase formation, surface morphology and crystallization of CrN(001) thin films grown by plasma-assisted molecular beam epitaxy on the MgO(001) substrate. The reflection high energy electron diffraction, atomic force microscopy, X-ray diffraction and scanning tunneling microscopy are used to characterize the thin films grown under various conditions. High-quality CrN(001) thin films are achieved at a substrate temperature 430 °C with a low Cr deposition rate.     

对国内规划和建筑设计方案招标、征集工作的思考——以上海外滩滨水区城市设计方案国际征集为例

简要介绍了国内近些年来开展规划和建筑设计招标、征集工作以来所带来的相关影响,并以上海外滩滨水区城市设计方案国际征集工作为例,作了简要的回顾和评述,以期为今后相关工作的开展提供一定的借鉴意义.     

村庄规划可实施性的反思与对策

当前村庄规划普遍存在实施效果不理想的问题,主要原因是村庄规划缺少地域性、科学性、协调性.应不断更新规划观念,丰富规划设计手段,通过增加产业规划、把握特色规划、制定建设计划、实施阳光规划和完善跟踪机制等措施提高村庄规划的可实施性.     

反射式可调移相器

针对现代通信中线性功率放大器的补偿要求,介绍一种利用反射理论设计可调移相器,实现大范围移相,同时幅度波动很小,并详细讨论了它的工作原理和实验结果。     

一种用于色识别的反射谱快速采集系统

本文设计并建立了一种用于色识别的反射谱快速采集系统,该系统采用光电倍增管作为光电探测器,并通过Apple-Ⅱ计算机自动控制色谱的采集和处理过程,性能稳定。     

新型波导缝隙天线反射特性的研究

本文根据等效源原理的分析了一种新型裂缝天线的反射特性，一个或两个横缝位于馈电矩形波导终端的短路面上。