激光法合成SiC超细粉末物理化学过程的研究——Ⅰ.实验规律及粉末特性

用50W连续波CO_2激光器为热源,诱发SiH_4和C_2H_4反应,合成SiC超细粉末。实验确定了反应腔体内压力p、气源中的C/Si原子比、喷嘴内径2r以及激光功率密度与粉末特性之间的关系,并对合成的产物进行物理、化学表征。     

加脂的化学柔软作用机理

加脂是软革制造过程中最重要的工序。本文建立了一个加脂过程和加脂机理的模型。在该模型中，传统的完全依赖ＰＨ值的观察被扩展，结合了加脂剂与浴液间的相互作用的性能和传送提供润滑作用的中性油组分的乳化剂的作用，并扩展了乳化剂的角色。以这种方式引入的化学柔软作用对革的强度有积极的效果，而相比效应力柔软作用会降低革的强度。     

Finite Element Analysis of a Moving Boundary Value Problem

A finite element formulation and the solution of a set of nonlinear coupled heat and mass transfer equations for a two-phase system with a moving evaporation interface is presented. The interface condition takes into account the moisture transfer balance at the moving boundary. The finite element results were compared with existing results for a single phase system for model validation. In the two-phase system, the movement of evaporation front has an appreciable effect on the temperature and moisture distribution inside the porous medium during drying. The effect of the nondimensional heat of vapourization parameter γ on the evaporation front, temperature and moisture distribution in porous medium was studied. The higher the value of γ, the slower is the movement of the evaporation front. The temperature decreased and the moisture content increased as the nondimensional vapourization parameter γ increased. This model has potential applications in studying the heat and mass transfer characteristics in food and biomaterials.     

锻热淬火工艺对工具钢碳化物粒度的影响

研究了锻热淬火工艺对Ｔ１０钢和ＧＣｒ１５钢碳化物技度的影响。结果表明，碳化物粒度随变形量的增大而细化；终锻温度在高于碳化物析出的温度范围内变化，其碳化物粒度都同样细小；终锻温度不宜过低，否则将使碳化物变粗。     

添加剂及硫元素对ZL108合金中铁相形态的影响

在含铁为１２％的ＺＬ１０８合金中，加入５％的以锰、铬、稀土为基本成分的添加剂时，合金中针状、片状的铁相变为团球状、块状及梅花状。单独加硫时，铁相呈短杆状。先加入３％的添加剂再加硫，则铁相变为非常细小的团球状、块状，根据ＧＢ３５０８－８３的规定，铁相形态可达一级     

Petri net based scheduling

Timed Petri nets can be used to model and analyse scheduling problems. To support the modelling of scheduling problems, we provide a method to map tasks, resources and constraints onto a timed Petri net. By mapping scheduling problems onto Petri nets, we are able to use standard Petri net theory. In this paper we will show that we can use Petri net based tools and techniques to find conflicting and redundant precedences, upper- and lower-bounds for the makespan, etc. This is illustrated by a Petri net based analysis of the notorious 10×10 problem due to Fisher & Thompson (1963)     

钠化焙烧钒渣时氯化挥发镓的热力学分析

本文讨论了６００～１２００Ｋ范围内使用ＮａＣｌ作为添加剂焙烧钒渣时氯化发镓的热力可靠性。结论是：氯氧比的大小与溶性钒酸钠生成有直接联系，ＮａＣｌ和Ｎａ２Ｏ。Ｖ２Ｏ５平衡时的氯氧比最大；在氯化钠作用下，镓主要生成ＧａＣｌ３挥发，计算得到的ＧａＣｌ３的生成压相当大。     

抗盐降滤失剂SDX的研究与应用

介绍了抗盐降滤失剂SDX的合成方法与现场应用简况,评价了SDX的抗温、抗盐、防塌及配伍性能。试验结果表明,SDX能耐150℃以上的高温,可抗盐至饱和,具有良好的降滤失和抑制性能,与其它处理剂的配伍性好,适用于各种水基泥浆。     

Study on Factors Affecting the Structure of High SpeedSteel Ingot Produced by ESR

ＳｔｕｄｙｏｎＦａｃｔｏｒｓＡｆｆｅｃｔｉｎｇｔｈｅＳｔｒｕｃｔｕｒｅｏｆＨｉｇｈＳｐｅｅｄＳｔｅｅｌＩｎｇｏｔＰｒｏｄｕｃｅｄｂｙＥＳＲＬｉＺｈｅｎｇｂａｎｇ；ＣｈｅＸｉａｎｇｑｉａｎＡｂｓｔｒａｃｔ：Ｔｈｅｉｎｆｌｕｅｎｃｅｏｆｔｈｅｍｅｔａｌｐ...     

中小型变压器供电电机起动方式的选择

通过分析和计算及实例，从允许电压降范围和电动机母线电压校验两方面叙述了电动机起动时如何合理地选择起动的方式。