Effect of gravity on InGaSb crystal growth

The effect of gravity on dissolution of GaSb in InSb melt and growth of InGaSb was experimentally investigated. Experiments were carried out in a GaSb(seed)/InSb/GaSb(feed) sandwich system under an imposed temperature gradient. In the experiments, the GaSb feed crystal dissolved into the InSb melt to supply the required GaSb component for the growth of In_0.1Ga_0.9Sb crystal. Two parameters were considered: (1) the inclination angle (θ) of the sample for gravity as 0° and 53°, and (2) the sample diameter (D) as 9 mm and 5mm. When θ was 0°, the interface was almost flat, indicating that convection was axisymmetric and stable. Whereas the interface was distorted towards gravitational direction when θ was 53°, indicating that solutal convection was dominant. The decrease of growth temperature and sample diameter reduced the distortion of interface and the dissolution amount of GaSb feed. The homogeneous crystals were grown at the initial growth stage by supplying the GaSb component during growth.     

曲面小孔精密测量系统软件结构及其实现

曲面小孔测量系统是为解决球面小孔孔位测量而研制的一套专用测量设备。分析了该测量系统的软件系统结构及其用VC 6．0的实现方法，配合相应的硬件该软件可以较好地解决曲面小孔孔位测量问题，极大地提高了测试效率。     

超大偏移距地震资料处理方法

超大偏移距地震资料处理中，保护好各种有效信息是处理好该类资料的关键，而超大偏移距采集到的远偏移距反射信息不符合双曲线规律，用常规动校正方法后出现过动校正和拉伸等问题，难以完成地质要求。针对超大偏移距地震资料动校正出现的问题进行了剖析，为解决该类资料的处理，分析了各向同性介质中非双曲线动校正的方法原理，结合超大偏移距地震资料的特点，对超大偏移距资料广角反射信息的应用和沙漠地区资料处理方法进行了探讨。经实际资料处理后，取得了较为满意的效果。     

基于蚁群聚类算法的离群挖掘方法

离群挖掘是数据挖掘研究的重要内容,在实际生活中获得广泛应用。该文首先给出了离群数据的量化定义,并用基于蚁群的聚类学习方法,产生了状态空间的整体特征。然后结合具体的设备对象,提出了离群数据的挖掘方法。最后进行了实验验证,结果表明该文提出的方法是有效的。     

自适应模糊PID控制在烧结过程中的应用

烧结过程具有大时滞、参数不确定性等特性，仅利用常规PID控制很难使烧结过程中的各项性能指标满足工艺要求．针对这一情况，本文提出了一种参数白适应的模糊PID控制器．该控制器的参数调整采用确定性的模糊调整规则，不但使控制器的设计易于实现而且具有很强的适应性和鲁棒性．仿真结果表明，该控制器能够对烧结过程进行有效控制．     

二氧化锡气敏基材的制备方法

对四氯化锡加氨水中和制备二氧化锡气敏材料的方法进行了考察。二氧化锡经５００℃灼烧３ｈ，再于３００℃下老化，其ＸＲＤ谱图与７００℃的烧所得二氧化锡的ＸＲＤ谱图基本相同，但其比表面比后者大１０ｍ２／ｇ，两者比表面之比为０．６９；而在２５０℃下两种材料在清洁空气中的稳定电阻值（Ｒ０）之比为０．６６；在５００×１０－６（体积比）乙醇气中的稳定电阻值（Ｒｇ）之比为０．６８５．前者对乙醇气的灵敏度稍优于后者。更适于用作气体传感器的基材。     

Managing deadline miss ratio and sensor data freshness in real-time databases

The demand for real-time data services is increasing in many applications including e-commerce, agile manufacturing, and telecommunications network management. In these applications, it is desirable to execute transactions within their deadlines, i.e., before the real-world status changes, using fresh (temporally consistent) data. However, meeting these fundamental requirements is challenging due to dynamic workloads and data access patterns in these applications. Further, transaction timeliness and data freshness requirements may conflict. We define average/transient deadline miss ratio and new data freshness metrics to let a database administrator specify the desired quality of real-time data services for a specific application. We also present a novel QoS management architecture for real-time databases to support the desired QoS even in the presence of unpredictable workloads and access patterns. To prevent overload and support the desired QoS, the presented architecture applies feedback control, admission control, and flexible freshness management schemes. A simulation study shows that our QoS-aware approach can achieve a near zero miss ratio and perfect freshness, meeting basic requirements for real-time transaction processing. In contrast, baseline approaches fail to support the desired miss ratio and/or freshness in the presence of unpredictable workloads and data access patterns.     

基于MAS的化工过程故障诊断原型系统

在充分研究了大型化工生产过程的特点和故障产生机制的基础上,将MAS技术引入到化工过程的故障诊断中,构建了一个基于MAS的化工过程故障诊断原型系统.该系统把化工过程划分为一些相对独立的组件,分派特定的诊断智能体对其进行故障的诊断.通过智能体之间的协作,系统具有良好的准确性和实时性.     

Preparation of an exponentially rising optical pulse for efficient excitation of single atoms in free space

We report on a simple method to prepare optical pulses with exponentially rising envelope on the time scale of a few ns. The scheme is based on the exponential transfer function of a fast transistor, which generates an exponentially rising envelope that is transferred first on a radio frequency carrier, and then on a coherent cw laser beam with an electro-optical phase modulator. The temporally shaped sideband is then extracted with an optical resonator and can be used to efficiently excite a single (87)Rb atom.     

高灵敏光度法测定粉煤灰中痕量汞

研究了在 pH 10 5氢氧化铵 -氯化铵缓冲溶液中痕量汞 与三氮烯类试剂 6 硝基苯并噻唑重氮氨基 4 硝基苯(NBTDNB)的显色反应 ,基于此 ,建立了一种测定痕量汞 的高灵敏新光度法。在弱碱介质中 ,汞 与该试剂形成 1∶2的黄色络合物 ,用双波长法测定 ,表观摩尔吸光系数为 2.2 0× 10 5,汞 量在 0.0～ 13.0 μg/2 5mL范围内符合比尔定律 ,方法的检出限为 2 .8× 10 - 9g/L ,相对标准偏差为 2 . 1%～ 3. 2 %。本法应用于粉煤灰中痕