OFDM系统信道盲估计的一种新算法

利用循环前缀（CP）引入的信息冗余，在利用接受信号的二阶统计特性实现正交频分复用（OFDM）系统信道盲估计的子空间算法基础上，采用矩阵变换的方法，改善信息序列的非周期相关函数，推导出信道估计的新算法。     

适于复杂信息融合系统的近似联合概率数据关联算法

文中在B.Zhou提出的直接概率计算(DC)和近似概率计算(AC)算法基础上提出了一种新的近似多传感器多目标联合概率数据关联算法。近似概率法是以一个目标为中心的近似聚为构造互联事件的起点，并在计算中将DC和AC结合得到的一种全邻的点迹—航迹关联算法，它能有效地提高目标点迹—航迹的关联正确率，在计算时耗上较完全联合概率法快得多，能满足工程中实时性的要求。将其在杂波下目标密集、航迹复杂的数据融合系统中进行实验，对关联正确率，关联耗时等与最近邻法进行了比较，效果较好。     

Rare-earth-enabled universal solders for microelectromechanical systems and optical packaging

In packaging of microelectromechanical systems (MEMS), optical, and electronic devices, there is a need to directly bond a wide variety of inorganic materials, such as oxides, nitrides, and semiconductors. Such applications involve hermetic-sealing components, three-dimensional MEMS assembly components as well as active semiconductor or optical components, dielectric layers, diffusion barriers, waveguides, and heat sinks. These materials are known to be very difficult to wet and bond with low melting-point solders. New Sn-Ag- or Au-Sn-based universal solders doped with a small amount of rare-earth (RE) elements have been developed, which now allow direct and powerful bonding onto the surfaces of various MEMS, optical, or electronic device materials. The microstructure, interface properties, and mechanical behavior of the bonds as well as the potential packaging applications of these new solder materials for MEMS and optical fiber devices are described. Various packaging-related structural, thermal, or electrical issues in MEMS are also discussed.     

Experience with Siberian Centralized Dispatch Regulation regarding location determination of damages sustained by intersystem high-voltage transmission lines

A set of measures that can be implemented by the Relay-Protection and Automated-Equipment Service for Centralized Dispatch Regulation (CDR) in Siberia to determine the location of damage sustained by inter-system 550-and 220-kV transmission lines maintained by the United Power System (UPS) of Siberia, and the methodology and technology of damage-location determination (DLD) are described. The damage sustained by the 500-kV high-voltage lines (HL), and the accuracy of DLD relative to zero-sequence emergency parameters are analyzed statically. __________ Translated from élektricheskie Stantsii, No. 5, pp. 59–62, May, 2006.     

基于AlAs氧化法研制的垂直腔面发射激光器

结合垂直腔面发射激光器的制备,研究了AlAs选择性氧化工艺中氧化炉温、氮气流量、水温等条件和AlAs层的横向氧化速率之间的关系,并得到了可精确控制氧化过程的工艺条件,在优化的工艺条件下运用湿氮氧化制备出InGaAs/GaAs垂直腔面发射激光器,实现了器件的室温脉冲激射.     

Examination of the role of oxygen in the photografting of methacrylic acid on a polyethylene film with a mixed solvent consisting of water and organic solvents

The photografting of methacrylic acid (MAA) on a linear low‐density polyethylene film (thickness = 30 μm) under air and nitrogen atmospheres was investigated at 60°C in mixed solvents consisting of water and an organic solvent, with xanthone as a photoinitiator. The organic solvents used were acetone, methanol, tetrahydrofuran, and dioxane. A maximum percentage of grafting occurred at a certain concentration of the organic solvent in the mixed solvent. This was observed for the systems under both air and nitrogen. The grafting reaction under air exhibited an induction period, but the rate of grafting after the period was greater than that under nitrogen. The formation of poly(ethylene peroxide)s by photoirradiation seemed to be a factor for the accelerated photografting under air. On the basis of attenuated total reflection infrared spectroscopy and scanning electron microscopy of the grafted film, the MAA‐grafted chains of the sample prepared under air tended to penetrate more deeply inside the film than those of the sample prepared under nitrogen. The resulting grafted films exhibited a pH‐responsive character: the grafted films shrank in an acidic medium but swelled in alkaline medium. This was evaluated from measurements of dimensional changes in the grafted films. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 992–998, 2003     

苯和甲苯差分吸收光谱方法的实验室测量研究

本文介绍了差分光学吸收光谱法(DOAS)测量大气污染气体浓度的基本原理。DOAS方法就是利用氙灯发出的紫外—可见光，经望远镜准直后再经过一段距离的传输，由望远镜来接收．在传输中，由于各种不同的分子在不同的波段对光有不同的吸收特征，使光谱具有了污染物的特征，再通过与光源发出的光进行比较，反演这些气体在大气中浓度．我们将DOAS方法应用在监测有机物上，在分析光谱的过程中，应用多项式拟合和最小二乘法，从而精确地从测量光谱中来反演出大气中污染气体的浓度．文中用DOAS方法测量了苯和甲苯的样品，并分析了结果，结果和理论吻合．可为环境中有机污染物监测提供可靠的方法。     

EPON:下一代接入网的最佳选择

EPON技术具有大带宽、高性价比、结构简单和一定服务质量保证等特点,被业界普遍看好,成为 下一代接入网的最佳候选技术.本文主要介绍了EPON的工作原理、分层结构、接入控制和组帧方式,最后给出 了实现EPON的关键技术和难点以及EPON的发展近况.     

Effects of cononsolvency on gelation of poly(vinyl alcohol) in mixed solvents of dimethyl sulfoxide and water

We studied the rates of gelation and phase separation of poly(vinyl alcohol) (PVA) solutions in mixtures of dimethyl sulfoxide (DMSO) and water at 25 °C and found that both the rates show a maximum at a volume fraction of DMSO φ_DMSO=0.60 while gelation was not observed either in pure DMSO or pure water, suggesting that water-DMSO is a cononsolvent system for PVA. On the basis of the data by Cowie [Can J Chem 36 (1961) 2240] we concluded that the 1:2 stable complex between one DMSO molecule and two water molecules is the main cause of this cononsolvency.     

溶胶–凝胶法制备ATO-SiO_2抗静电复合薄膜的特性研究

采用两步溶胶–凝胶法制备出 ATO(掺锑氧化锡)-SiO_2复合抗静电薄膜。通过 DTA-TG、XRD、SEM 对 薄膜的结构和形貌进行了表征,结果表明:抗静电复合薄膜表面均匀致密。薄膜中 SiO_2为无定形结构,ATO 的衍射峰 与 SnO_2一致。研究了 SnO_2的含量对薄膜导电性能、结合强度和透过率的影响,发现随 SnO_2含量增加 ?(SnO_2/ SiO_2)从 5 至 12.5,薄膜的表面电阻降低(从 1010ù/□降低到 108ù/□),薄膜的结合强度下降,薄膜的透过率降低(从 89.0%降至 84.2%),结合三方面性能,得出最佳 SnO_2的配比为:?(SnO_2/ SiO_2)=10。