振动对星间相干激光通信的影响

针对星间相干激光通信中卫星平台的振动造成发射天线和接收天线的瞄准角误差，使系统信号信噪比下降，误码率 (BER)增加，该文以瑞利分布作为振动造成的瞄准角误差模型，结合高斯本振光和艾里信号光外差检测模型，以PSK零差通信体制为例分析卫星振动对系统的瞬时误码率和平均误码率的影响，给出误码率仿真计算结果。指出接收天线瞄准角误差对星间光通信质量影响很大，在瞄准角误差的标准偏差σ小于1μrad范围内，系统误码率小于10^-6。     

An analytic model for gate-all-around silicon nanowire tunneling field effect transistors

An analytical model of gate-all-around(GAA) silicon nanowire tunneling field effect transistors(NW-TFETs) is developted based on the surface potential solutions in the channel direction and considering the band to band tunneling(BTBT) efficiency. The three-dimensional Poisson equation is solved to obtain the surface potential distributions in the partition regions along the channel direction for the NW-TFET, and a tunneling current model using Kane’s expression is developed. The validity of the developed model is shown by the good agreement between the model predictions and the TCAD simulation results.     

A unified charge-based model for SOI MOSFETs applicable from intrinsic to heavily doped channel

A unified charge-based model for fully depleted silicon-on-insulator (SOI) metal–oxide semiconductor field-effect transistors (MOSFETs) is presented. The proposed model is accurate and applicable from intrinsic to heavily doped channels with various structure parameters. The framework starts from the one-dimensional Poisson–Boltzmann equa- tion, and based on the full depletion approximation, an accurate inversion charge density equation is obtained. With the inversion charge density solution, the unified drain current expression is derived, and a unified terminal charge and intrinsic capacitance model is also derived in the quasi-static case. The validity and accuracy of the presented analytic model is proved by numerical simulations.     

微波法制备纳米TiO2

国内外合成纳米TiO2的方法很多。微波加热法与常规方法相比反应速率快、效率高，并适合推广到大规模的工业生产中。本研究工作以Ti(SO4)2为主要原料，在Ti(SO4)2的水解反应中引入微波加热技术，系统地研究了其制备工艺条件，为纳米TiO2微粒的制备开辟一条新路。     

LaNi5系贮氢合金的软化学合成及其电化学性能研究

应用燃烧法制出了约20nm的混合金属氧化物前躯体,用它和CaH₂进行还原扩散反应,在850℃反应2h就可制得10μm以下的单相合金粉,如加少量助熔剂,在650℃即可完成还原扩散反应,得到的合金微粒大小只有2μm。这种方法制备的合金比熔炼合金的活化性能更好,850℃温度下反应得到的合金具有比熔炼合金更高的高倍率充放电容量。     

光学星间链路技术

通过卫星间直接通信实现数据中继是空间通信技术发展的一个重要方面。光学星间链路与传统的微波链路相比具有重量轻、体积小、功耗低等诸多优点,但在捕获和跟踪等方面也存在着巨大的困难。描述了光学星间链路的系统结构极其关键技术,包括通信收发机、捕获与跟踪、光源与探测器以及空间应用的一些特殊问题。介绍了国际上几个主要研究计划的进展情况,并对光学星间链路的发展前景进行了综述。     

ICP-AES测定车用无铅汽油中的铅

ICP-AES测定车用无铅汽油中的铅含量，与标准中规定的测定方法(AAS)相对照，结果显示，ICP-AES测定的铅含量与AAS法测定值基本相同。RSD(n=11)小于4.37%。本方法操作简便、分析速度快、结果准确。     

Silicon-on-nothing MOSFETs fabricated with hydrogen and helium co-implantation

In this paper, a method to fabricate Silicon-on-Nothing （SON） MOSFETs using H^＋ and He^＋ co-implantation is presented. The technique is compatible with conventional CMOS technology and its feasibility has been experimentally demonstrated. SON MOSFETs with 50nm gate length have been fabricated. Compared with the corresponding bulk MOSFETs, the SON MOSFETs show higher on current, reduced leakage current and lower subthreshold slope.