Effects of vacancy structural defects on the thermal conductivity of silicon thin films

Vacancy structural defect effects on the lattice thermal conductivity of silicon thin films have been investigated with non-equilibrium molecular dynamics simulation.The lattice thermal conductivities decrease with increasing vacancy concentration at all temperatures from 300 to 700 K.Vacancy defects decrease the sample thermal conductivity,and the temperature dependence of thermal conductivity becomes less significant as the temperature increases.The molecular dynamics result is in good agreement with the theoretical analysis values obtained based on the Boltzmann equation.In addition,theoretical analysis indicates that the reduction in the lattice thermal conductivity with vacancy defects can be explained by the enhanced point-defect scattering due to lattice strain.     

新型Sb基二类超晶格红外探测器

InAs/Ga(In)SbⅡ类超晶格材料由于特殊的二型能带结构,可以通过人造低维结构获得类似于体材料的带间吸收,从而获得较高的量子效率;另外,通过调节材料参数调节能带结构,器件响应波段可调;通过能带结构设计抑制俄歇复合,获得较小的暗电流和较高的器件性能。因为以上特有的材料性能和器件特性,Sb基二类超晶格在国际上被认为是第三代红外焦平面探测器的优选材料。对二类超晶格材料的设计和器件特性进行了研究,设计了峰值波长4μm的nBn结构的中波红外探测器,在没有蒸镀抗反膜的条件下,77 K温度下测试得到的峰值探测率为2.4×1011cm Hz1/2W-1,计算得到的量子效率为47.8%,峰值探测率已经接近目前的碲镉汞中波红外探测器器件性能。研究结果充分显示了二类超晶格优越的材料和器件性能。     

基于Visual C#的OPC客户端实现

OPC是连接数据源(OPC服务器)和数据的使用者(OPC应用程序)之间的软件接口标准.这里乙C#为开发工具,按照OPC技术的规范标准,将OPC技术应用到虚拟仪器显示组件中.具体实现了OPC客户端数据访问服务器的过程,接口步骤及其读写数据的方法,并根据OPC服务器提供的数据,最终在虚拟仪器显示组件中生成了虚拟的正弦波、方波、锯齿波、三角波等.     

BER Performance of Frequency Domain Differential Demodulation OFDM in Flat Fading Channel

A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performance is evaluated by computer simulation and compared with the timedomain differential demodulation(TDDD).The results indicate that the performance of FDDD is betterthan that of TDDD,and the lower band of BER in the former is lower than that of the latter.     

A Theoretical Investigation of Slot Waveguide Bragg Gratings

Bragg grating, structures based on dielectric slot waveguide, are investigated theoretically for potential applications as optical resonators and filters. Important device performance parameters, such as the reflection spectrum, the peak reflectivity, and the field confinement factor, are examined as functions of key waveguide and grating design parameters.     

Receiver IQ Imbalance Estimation via Pure Noise for 60 GHz Systems

This paper proposes to estimate receiver (RX) IQ imbalance via pure noise for 60 GHz millimeter-wave systems. We study the impact of RX IQ imbalance on noise, and derive the maximum-likelihood algorithm to acquire the imbalance parameters, which is decoupled from transmitter IQ imbalance, channel response, and carrier offset. Also, the proposed method has low computational complexity and meets the low-power and low-cost requirements of 60 GHz systems. Moreover, the jitter performance of the estimation reaches the corresponding Cramer–Rao lower bound under a wide range of imbalance parameters.     

地方师范院校物联网工程专业学生创新能力培养研究

地方师范院校工科专业普遍存在师资薄弱,资源投入不足的问题,导致工科专业学生的动手实践与创新能力不足,无法达到“新工科”专业建设的培养目标。针对此问题,结合内江师范院物联网工程专业在办学过程中遇到的问题,分别从优化师资配置、校企合作共建课程、采用项目学习法教学、建立以解决问题为核心的评价标准等几方面进行改革。通过方案实施,学生的动手实践能力与创新能力得到了明显提升。     

中兴通讯IP over WDM解决方案

介绍了IP网络的发展趋势,承载电信级业务的IP承载网的3种组网方式,着重介绍了IP over WDM解决方案的优势和特点。     

一种无人机扩频遥控系统的性能分析

在剖析无人机扩频遥控系统组成的基础上,对无人机扩频遥控系统的处理增益、抗干扰容限及保密性能做了具体的分析,对无人机扩频遥控系统的雷达截获概率做了深入的探讨。