FORMATION OF AIN WHISKERS BY NITRIDATION OF AI/AIN POWDERS

The aluminum nitride whiskers were synthe-sized by the nitridation of Al/AlN powders in a flowing ni-trogen atmosphere. The whiskers were about 0. 5μm in diame-ter and 10～20μm in length, and they were straight and hadsmooth surfaces. The morphology of the whiskers were stud-ied by means of SEM and TEM. The AlN whiskers weregrown via vapor-solid (VS) mechanism.     

不同自旋量子相干的密度矩阵计算

本文利用密度矩阵的对称共轭性,提出一个在弱相互作用下,方便地计算量子相干的方法。首先推导出纯体系的各种公式,然后计算不同自旋四种混合体系的各种量子相干。获得了它们的数目的比值以及它们的总和。推导出混合体系的各种公式。除理论计算外,还扼要地讨论这一研究结果的意义。     

TRANSIENT FLOW DRAINAGE EQUATIONS CONSIDERING BOTH DELAYED GRAVITY RESPONSE AND EVAPORATION FROM WATER TABLE

The drainable porosity is one of the important parameters in the unsteady drainage formulas. Due to delayed gravity response the drainable porosity is a function of the rate of drawdown and the depth of water table. The evaporation from groundwater plays an important role in lowering water table, in drainage design formulas it should be taken into account. Drainage equations considering evaporation from groundwater varying with water table depth and evaporation from water surface and involving constant drain-able porosity have been proposed by many authors. In this paper new formulas considering both delayed gravity yield and evaporation as a function of water table depth are developed and verified by experimental data.     

三峡二期工程施工及关键性技术

本文重点介绍了混凝土生产与温度控制、金属结构及机电设备等施工情况和关键性技术。三峡工期工程需浇筑混凝土1846万m~3,安装金属结构及机电设备埋件19.2万t,施工工期6年。     

THE DYNAMIC EQUATION FOR A SPHERICAL BUBBLE IN UNIFORM SIZED SOLID PARTICLE-LIQUID HOMOGENEOUS SUSPENSION

The momentum equation for solid-liquid two-phase flow proposed by Elghobashi and Abou-Arab is taken as the governing equations for the liquid phase,and the Lagrangian dynamic equation for a spherical particle moving in the liquid flow as the basic equation for the relative motion of the particle in the liquid phase in the paper.The dynamics equation for a bubble in solid-liquid twophase flow is proposed,as well as the simplified equations under two extreme conditions with the relationship between the bubble collapse characteristic time τ_C~* and particle response time τ_(rel)~* being τ_C~*>> τ_(rel)~* and τ_C~* <<τ_(rel)~*.     

新颖的波长可选择调谐外腔激光器研究

采用增益芯片与取样光纤光栅双端耦合、双端可调的新颖外腔调谐方式,得到了36 nm的准连续调谐范围、约35 dB的边模抑制比、模式稳定性良好的实验结果。讨论了取样光纤光栅参量对可调谐激光器性能的影响,检验了取样光纤光栅波长漂移的应力响应。提出了一种新颖的、简单的调谐方案,详细地阐明了其调谐机理。     

质子交换膜燃料电池组水管理研究

介绍了水管理对质子交换膜燃料电池组的重要性，对当前主要采用的外增湿、内增湿、自增湿技术进行综述，认为内增湿能为电池提供有效供水、减轻了电池组的体积和重量，具有良好的实用性。分析了双极板不同流场排水能力和动态排水技术，并对质子交换膜燃料电池水管理提出一些建议。     

垃圾焚烧炉炉温控制模糊神经网络模型研究

对垃圾焚烧过程进行了分析,并采用模糊神经网络方法建立了垃圾焚烧炉炉温控制模型,获得了用以控制垃圾焚烧过程的控制查询表,并在模型建立的基础上进行了仿真实验.仿真和现场应用结果表明该模糊神经网络模型能够适应复杂多变的焚烧过程的控制要求.     

基于GIS的LL-Ⅱ分布式降雨径流模型的结构

主要讨论了LILAN—Ⅱ分布水文模型的结构。该模型结构是为水文过程模拟和预报而设计的，它提出了变动生态产流模式，耦舍了一维坡面流、一维壤中流、一维地下水流、一维河川径流和二维土壤含水量方程组。通过实际检验，该模型能够明显改善模拟预报精度、增强数值计算稳定性、提高参数优选的运行速度和减少存储空间，能够适合不同水文特征地区的产汇流计算，可以提供流域内任意空间网格的水文计算过程。     

偏转二次风对炉内结渣的影响

从四角切向燃烧炉内空气动力工况及运行参数方面分析炉膛结渣的原因,并具体结合125MW、660MW锅炉燃烧器的设计特点,利用数值模拟计算及现场试验方法,研究了偏转二次风对炉内结渣的影响。研究结果说明:偏转二次风的角度应控制在15°以内。图5参9