THE STICKY ISSUES OF DRYING

Unconrolled agglomeration of particles and adhesion of the particulate mass to wall surfaces are common severe problems in many drying operations. This paper reviews the mechanisms of interparticle and particle-surface attraction as well as the theory and the existing tests for characterising powders in terms of internal strength, wall friction and adhesion. The usefulness of the information obtained from these tests in dryer design and operation is critically reviewed. The importance of powder stickiness in various types of dryers is discussed and established methods of combating the problem are presented Recommendations an made for further research in the area of powder cohesion and adhesion.     

圆筒形铸件缩松缩孔的产生原因及解决方法

针对圆筒形铸铁辊体冒口端面产生的缩松、缩孔缺陷，进行了举例说明、系统分析，找到了缺陷产生的原因及影响因素。通过解决措施的应用与实施，有效地克服了圆筒形辊体铸件冒口端面产生的缩松、缩孔缺陷，同时应用到其它大型圆筒形铸件中，都得到了良好效果。     

Time‐dependent heat transfer coefficient of a wall

A time‐dependent coefficient of heat transfer is proposed for the computation of thermal power required, so that a room temperature reaches a desired value within a given time. A mathematical formulation of the room heating transient phenomenon is constructed in a dimensionless form. Using an integral approximate solution an analytical expression for this coefficient is provided and it is verified by diagrams adopted by DIN 4701. Copyright © 2003 John Wiley & Sons, Ltd.     

Matrix mediated alignment of single wall carbon nanotubes in polymer composite films

Alignment of single wall carbon nanotubes (SWNT) in liquid crystalline (LC) polymer matrix imparting orientation to the nanotubes along the nematic director was studied by atomic force microscopy, measurements of electrical conductivity and Raman spectroscopy of the composite in the directions parallel and perpendicular to the nematic director. The composites were prepared through dispersion of SWNT with LC monomer in a common solvent, their alignment in nematic monomer and consequent UV polymerization of the monomer. The anisotropy of electrical and optical properties of the system depends strongly on the concentration of the nanotubes in the range of 1-10% SWNT being especially strong for smaller concentrations and negligible at higher loads. A simple semi-quantitative model is suggested to account for the orientational behavior of nanotubes in nematic matrices. It successfully describes the observed anisotropy of physical properties at microscale (up to 200 μm) in terms of anchoring of the polymer chains to the nanotubes surface and adjustment of the nanotubes orientation to the nematic direction due to such coupling. The increasing disorientation of the nematic domains at higher nanotubes loads is explained as a development of larger number of LC defects induced by the nanotubes in the nematic matrix due to their intrinsic nature of aggregation. The anisotropy of physical properties at macro scale (several millimeters) is much smaller and less dependable on SWNT concentration because differently oriented LC domains effectively wash out the anisotropy.     

铝合金穿孔板吸声墙面施工技术

以教育部综合办公楼工程的机房铝合金穿孔板吸声墙面施工为例,介绍其固定件及吸声墙面的做法。     

土体中毛细水压力的研究

该文从毛细水产生负孔隙水压力概念入手 ,对较难确定的孔隙水压力系数以及较抽象的地下连续墙时效稳定分析等问题进行了定量计算 ,以期对工程实践有一定的指导作用     

阿曼Daleel油田分支井钻井液技术研究

对Daleel油田作业5区三分支水平井DL-59井井下复杂情况分析,室内测定了引起复杂情况的Nahr Umr泥页岩地层的矿物组分和粘土矿物含量,优选了适应在该泥页岩地层215.9 mm造斜井段的钻井液配方中的各种处理剂,最后研制出钻井液配方,通过DL-73井应用后,取得了良好的防塌效果.     

格栅式水泥搅拌桩支护在西涌泵站的应用

简介水泥搅拌桩的支护机理,以西涌泵站为例介绍采用格栅式水泥搅拌桩作支护结构的设计及计算方法,指出该技术能较好地解决软湿粘性土地区枢纽深基础开挖问题.     

多层住宅砖混房屋设计中两点问题的探讨

浅议多层住宅砖混房屋中构造柱的作用及设置方法；探讨了砖混结构墙下条形基础底面积重复利用问题及其解决方法。