一种自动布线方法：多级线探索法

本文介绍了一种在微机上实现的印制板自动布线方法──多级线探索法及其编程方法。这种方法是基于完备布线算法的概念，通过分析李氏算法和传统线探索法的不足之处而得到的。虽然它也是一种线探索法，但有较传统线探索法更强的探索能力，不需要结合李氏算法而能单独完成布线任务，是一种较理想的算法，通过实验获得了较为满意的效果。     

60m高度处单片露天超高混凝土悬臂墙的设计与施工

通过采用竖向预应力技术 ,解决了 60m高度处单片 8m高悬臂钢筋混凝土墙根部裂缝宽度超过规范限值的问题 ;采用将预应力钢绞线顶端锚固于墙高中段等结构和施工措施 ,控制墙体长细比不超过 3 0 ,减少了由于长细比过大对墙体承载力的不利影响     

Performance of a non‐load‐bearing steel stud gypsum board wall assembly: Experiments and modelling

A gypsum wall assembly was exposed to an intense real‐scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both visual and infrared, were used to image the unexposed face of the wall assembly during the fire exposure. The behaviour of the wall assembly under the fire load is discussed as are current model results for a simulation of the fire test. Copyright © 2006 John Wiley & Sons, Ltd.     

柘林电站第二溢洪道砼鼻坎截水墙施工

柘林水电站第二溢洪道,在鼻坎先于下部截墙施工中,为了满足当年泄洪,施工先沿截墙自上而下挖掘交通竖井,支撑牢固,安设好提升设备并打通墙底导洞后,再自下而上分层扩挖及浇筑砼.开挖采用登渣作业,出渣用可伸缩手柄架子车经吊篮提升.墙顶砼浇筑,通过预留在鼻坎内的下料小井进料.     

Cyclic variations in the permeability of the cell wall of Saccharomyces cerevisiae.

To study cell-cycle-related variations in wall permeability of Saccharomyces cerevisiae, two approaches were used. First, an asynchronous culture was fractionated by centrifugal elutriation into subpopulations containing cells of increasing size. The subpopulations represented different stages of the cell cycle as judged by light microscopy. Cell wall porosity increased when these subpopulations became enriched with budded cells. Secondly, synchronous cultures were obtained by releasing MATa cells from alpha-factor induced G1-arrest. These cultures grew synchronously for at least two generations. The cell wall porosity increased sharply in these cultures, shortly before buds became visible and was maximal during the initial stages of bud growth. It decreased in cells which had completed nuclear migration and before abscission of the bud had occurred. The porosity reached its lowest value during abscission and in unbudded cells. We examined the incorporation of mannoproteins into the wall during the cell cycle. SDS-extractable mannoproteins were incorporated continuously. However, the incorporation of glucanase-extractable mannoproteins, which are known to affect cell wall porosity, showed cyclic oscillations and reached its maximum after nuclear migration. This coincided with a rapid decrease in cell wall porosity, indicating that glucanase-extractable mannoproteins might contribute to this decrease.     

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.     

紧凑 Tokamak(球形环)聚变堆第一壁及中心导体柱上中子负荷及核热计算与分析

采用通用蒙特卡罗粒子输运程序ＭＣＮＰ／３８计算低环径比Ｔｏｋａｍａｋ（紧凑环或球形环）聚变堆第一壁及中心导体上的中子壁负荷分布和核热沉积分布，并与常规Ｔｏｋａｍａｋ堆第一壁上中子壁负荷分布和核热沉积分布进行比较、分析。结果表明，在中子壁负荷归一化为１ＭＷ／ｍ２时，与常规Ｔｏｋａｍａｋ相比，在低环径比Ｔｏｋａｍａｋ堆第一壁及中心柱表面上中子壁负荷分布峰值并不比常规Ｔｏｋａｍａｋ堆第一壁上的峰值高，而且低于低环径比Ｔｏｋａｍａｋ堆整个第一壁上的平均值，而中心柱上的核热沉积峰值稍高于常规Ｔｏｋａｍａｋ堆第一壁上的核热沉积峰值，但对较高中子壁负荷情况，中心导体柱上的核热沉积和辐照损伤仍可能是比较严重和值得特别研究的问题。