激光熔覆层陶瓷颗粒界面力学行为的数值分析

研究了激光涂覆时因陶瓷颗粒与金属之间物理性能差异而在其界面处形成的残余应力特征。在一定假设条件下，通过有限元计算和界面应力场分析，得出熔覆层由陶瓷颗垃的数量及其形状对陶瓷／金属界面应力状态的影响。

铁基合金激光熔覆组织及高温时效转变的TEM研究

利用ATEM研究了铁基多元合金Fe-Cr-W-Ni-C激光熔覆层的微观组织、亚稳相结构特征以及高温时效时的亚稳相转变机制。结果表明组织为亚共晶组织，即γ+(γ+M_7C_3)，γ-奥氏体为具有较高合金度的过饱和亚稳相，M_7C_3(M为Cr,Fe,W)为六方结构的Cr基亚稳合金碳化物。熔覆组织在高温时效时存在两类碳化物形成机制，即亚稳γ中析出M_(23)C_6、M_2C与MC碳化物以及M_7C_3→M_(23)C_6与M_7C_3→M_6C的碳化物原位转变机制。熔覆组织具有较高的显微硬度并存在显著的二次硬化特征。

高超声速喷管非平衡尺度效应的数值分析

采用轴对称热化学非平衡全N-S方程,数值分析了高超声速喷管流场中非平衡引起的尺度效应.并给出计算条件下喷管轴线上的物理量和化学组元分布.计算结果表明,在喉部下游不远处流动趋近于化学冻结和热力冻结状态.流场(特别是核心无粘流区)的特性不仅取决于流动尺度的相对值,也取决于其绝对值.

半浮区热毛细对汉的不稳定性与转捩

近十年来，微重力流体开展了半浮区液桥热毛细对流的不稳定性与转捩的研究。文中给出了热毛细振荡对流发生的临界参数。报导了有关的地面模拟实验，微重力实验以及本问题的线性稳定性分析、能量分析和数值模拟结果，并介绍了定常轴对称热毛细对流通过非定常轴对称荡热毛细对流到湍流的转捩过程和三种热毛细振荡对流的产生机理。

海洋工程中的弹性支持梁

油气输送管线是海洋工程中的重要装备,对其进行安全评估是工程设计和检测的必要组成部分和主要目标.由于海底不平、挖沟作业、海流冲刷等情况会使管线在海底起伏弯曲,因此需要对这种变形状态下的管线进行强度分析.考虑海底土壤对管线的弹性支持作用,将管线模型化为支撑在弹性地基上的长梁,给出这种弹性支持梁在起伏弯曲情况下的强度分析方法.该问题的特点是:由起伏引起的弹性梁的两段悬空长度、一段与地基接触的长度均是待求量.与通常的弹性地基梁问题不同,这是一个动边界问题.

城市生活垃圾中微量金属元素含量的特性分析

城市生活垃圾中含有多种微量金属元素,可能会对环境和人们的健康造成危害.分析这些元素随着产地及时间的差别,了解它们在垃圾中的富集量,对于垃圾的处理和综合利用是非常重要的.在此通过连续监测1年内某沿海城市若干地区生活垃圾的组成成分,得到了垃圾中微量金属元素的原始数据,探讨了微量金属元素随来源和季节的分布规律,并进行了较为详尽的讨论.

有限厚度非均质海床对非线性波浪响应的有限元模拟

在Biot 多孔介质动力固结理论的基础上，对有限厚度砂质海床与非线性波浪的相互作用进行了有限元数值模拟。进行参量研究，分析了波浪非线性、海床非均质性和相对厚度等因素对海床土层内超孔隙水压力分布的影响。

功能梯度材料裂纹能量释放率

提出一个评价功能梯度材料裂扩展能量释放率的简单方法，用双悬臂梁柔度法推导了典型梯度材料理解纹沿梯度方向扩展的能量释放率解析表达式，用算例分析了裂纹扩展方向不同能量释放率的差别.

Interactions of CO, HCl, and Sox in Pulverised Coal Flames

The effect of HCl and SO_2 on CO oxidation in pulverised coal flames was investigated experimentally and kinetically in an entrained flow combustion reactor. Two bituminous coals (German 'Goettelborn' and a Polish coal) were used as fuels with a feeding rate of 1 or 1.5 kg/h. HCl or SO_2 is introduced into the reactor premixed with the primary air. Experimental results indicate that HCl addition may inhibit CO oxidation in coal flames and increases CO emission. Reducing temperature in the reactor will enhance the inhibitory effect of HCl on CO oxidation. The measured CO profiles along the reactor height clearly show that the addition of HCl may inhibit CO oxidation. In the experimental range of SO_2 addition. The inhibiting effect of SO_2 on CO oxidation is less significant than HCl. A detailed kinetic mechanism is used to model the reactions. And the controlling reactions are analysed.

Deformation Defects in Nanocrystalline Nickel

Defects induced by plastic deformation in electrodeposited, fully dense nanocrystalline (nc) Ni with an average grain size of 25 nm have been characterized by means of high resolution transmission electron microscopy. The nc Ni was deformed under uniaxial tension at liquid-nitrogen temperature. Trapped full dislocations were observed in the grain interior and near the grain boundaries. In particular, these dislocations preferred to exist in the form of dipoles. Deformation twinning was confirmed in nc grains and the most proficient mechanism is the heterogeneous nucleation via emission of partial dislocations from the grain boundaries.

色散效应对GaAs太阳电池双层减反射膜的影响

考虑双层减反射膜材料的折射率色散效应,采用光学干涉矩阵法计算了SiO2/ZnSe和SiO2/ZnS两种GaAs太阳电池双层减反射膜的反射率与波长的函数曲线,以及加权平均反射率随着顶层减反射膜SiO2厚度变化的函数曲线,并与未考虑色散效应的情况进行了对比.计算结果表明,色散效应对双层减反射膜的反射率有较大的影响,特别是对300～500nm波长范围的影响更大,且对不同材料的减反射膜的影响也是不同的.与未考虑色散效应的情况相比,考虑色散效应后,SiO2/ZnSe双层减反射膜的最小加权平均反射率从1.14％增加到

Concentration distribution in solution crystal growth: effect of moving interface conditions

The linear diffusion-reaction theory with finite interface kinetics is employed to describe the dissolution and the growth processes. The results show that it is imperative to consider the effect of the moving interfaces on the concentration distribution at the growth interface for some cases. For small aspect ratio and small gravity magnitude, the dissolution and the growth interfaces must be treated as the moving boundaries within an angle range of 0 degrees < gamma < 50 degrees in this work. For large aspect ratio or large gravity magnitude, the effect of the moving interfaces on the concentration distribution at the growth interface can be neglected except for gamma < - 50 degrees.

Study of Gliding Arc Discharge Plasma

本文研究了滑动弧放电过程中电参数的变化，并对滑动弧等离子体中的非平衡度和各参数之间关系进行了讨论。应用了双通道电弧模型 ，对电弧在气流作用下的运动规律进行了数值模拟。模拟的结果有助于分析滑动弧非平衡等离子体的产生机理。 The elelctric parameters change during discharge is studied and the relationship between non-equilibrium degree and parameters is discussed for gliding arc discharge.Using two-channel model, the rules of arc moving due to effect of the airflow is simulated.The numerical simulation results can help analyzing the generation mechanism of gliding arc non-equilibrium plasma.