The Influence of Annealing Temperature on the Structure and Properties of TiO2 Films Prepared by Sputtering

The TiO₂ films were prepared on slides by dc reactive magnetron sputtering, then the samples were annealed at 300°C, 350°C, 400°C, 450°C, 500°C and 550°C, respectively. X-ray diffraction (XRD) was used to obtain the TiO₂ film crystalline structure; X-ray photoelectron spectroscopy (XPS) was used to study the film surface stoichiometries; surface morphologies were studied by scanning electron microscopy (SEM); the contact angle was tested to indicate the TiO₂ film wettability; and the photocatalytic activity testing was conducted to evaluate the photocatalysis properties. The photocatalytic activity and contact angle testing results were correlated with the crystallinity, surface morphologies and surface ·OH concentration of TiO₂ films. The samples with a higher polycrystalline anatase structure, rough surface and high ·OH concentration displayed a better photoinduced hydrophilicity and a stronger photocatalysis. Funded by the National “863” Project Foundation (No. 2003LG0034)     

Evolutionary Topology Optimization for Heat Conduction Fields

An effective evolutionary method for solving the structural topology design problems of heat conductive fields is presented in this paper. The topology optimization model based on minimizing the heat transport potential capacity dissipation of heat conductive field is then established and the corresponding sensitivity of objective function is derived to determine which elements would be removed of the heat conductive field for having the increment of the objective heat transport potential capacity dissipation minimized. A Filtering technique is employed in sensitivity field to eliminate numerical instabilities in the evolutionary procedure. Numerical examples are presented to demonstrate the validity and the engineering applicability of the evolutionary method by contrast with SIMP method, meanwhile we can come to a conclusion that higher speed of convergence and clearer optimal topology distribution without intermediate elements can be attained by using evolutionary strategy, with the results laying a reliable foundation for the subsequent shape and size optimizations in thermal engineering.     

大功率LD封装技术的研究

提出一种新的LD列阵封装方法。把热沉形状改为台阶式，使稳态工作条件下的芯片前腔面散热速度提高，前后腔面温差大幅度降低，因此可以提高COD阈值，降低腔面退化率，且更方便于光纤耦合封装。利用Ansys软件对大功率LD稳态工作的温度分布进行模拟。结果发现：改进前的芯片前、后腔面温差为9．0K，改进后温差降为3．5K，降低了60%；热沉前、后端面的温差由原来的18．2K降为8．0K，降低了56％。     

板坯连铸凝固传热过程的有限元模拟

在建立板坯连铸凝固传热数学模型的基础上,采用有限元软件MSC Marc对国内某板坯连铸机的凝固过程进行模拟,并对其仿真结果进行分析.     

基于数据库和可视化技术的翅片管换热器仿真

构建了翅片管换热器的性能仿真系统的整体框架，通过引入数据库技术和可视化技术，结合换热器分布参数仿真模型，实现了该仿真系统。该系统具有分工明晰的输入、仿真和输出模块，能方便用户输入仿真参数，准确快捷地对翅片管换热器性能进行仿真，并以各种形象直观的方式输出仿真结果。     

人工神经网络在棒束临界热流密度预测中的应用

基于已有的棒束临界热流密度数据库，采用COBRA-Ⅳ程序计算得到子通道局部临界热流密度数据库。用人工神经网络（ANN）理论对数据库进行训练，得到基于ANN理论的棒束临界热流密度预测模型。预测模型的预测精度显著高于常用经验关系式的预测精度，其预测值的均方差为5.63%。     

国际热核聚变实验堆磁体线圈终端盒的设计

线圈终端盒（CTB）是国际热核聚变实验堆超导磁体系统的重要组成部分，其内部组件的漏热常常是整个磁体系统的主要漏热源之一，在很大程度上决定着低温系统的液氦消耗量。本文从降低热负荷的角度对CTB内部冷屏、超导电流传输线、电流引线、阀及冷却管路、外部盒体的设计进行了详细阐述，为最终结构的确定提供了理论依据。     

放射性核废料自埋过程中的热量阈值

针对恒释热率热源接触熔化，提出了热量阈值的概念。分析计算了典型反应堆核废料自埋接触熔化过程中的热量阈值和达到阈值的时间以及相应的熔化深度，并与相关文献结果进行比较，指出了相关文献中的一些错误，得出了一些有意义的结论。     

逆热传导方程的一类正则化算法

考虑了标准的一维逆热传导方程,问题是不适定的,即解不连续地依赖于数据.通过Fourier逼近的方法进行正则化处理,提出了一类新的算法并且与已有的正则化算法进行了比较,理论分析和数值实验均表明该算法是稳定的,且具有相同的精度和计算复杂性,同时也具有灵活性和广泛性.     

平板热管的研究现状与最新进展

平板热管由于质量轻、良好的启动性和均温性的优势,而成为目前电子元件散热方面的热点研究,在国外已经得到应用。目前国内的研究成果很少。综述了平板热管目前国外的主要研究趋势、结构和加工方法的改进、参数优化、内部流动与传热的研究、毛细限和沸腾限及对多个热源冷却的研究等,并对这些前沿的研究结论进行概述,指出了下一步的研究趋势和面临的主要挑战。