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.     

复合脱氧剂对纯净钢生产的影响

论述复合脱氧剂的一般化学特性，并以碳化硅和硅铝铁两种复合脱氧剂为例，讨论其对改善钢的质量，进行纯净钢生产的影响。     

Photo-reversible Reaction in Polymer Langmuir-Blodgett Films

Preparation of photoreactive Langmuir-Blodgett (LB) films was carried out using polymers/oligomers prepared from long-chain dialkyl esters of di-and tetra-olefins and having cyclobutane rings in the main chain. These polymers/oligomers formed stable monolayers on a water surface when mixed with arachidic acid. These monolayers could be deposited onto a substrate successfully forming Y-type films. The oligomer LB films were polymerized on irradiation. The polymer LB films showed a photo-reversible process between polymers and oligomers, depending on wavelength of the irradiating light. On the basis of spectral data and molecular weight change, this behaviour was found to be caused by cleavage and formation of cyclobutane rings.     

The design of experiments when there are errors in all the variables

The Error-in-Variables Model (EVM) applies to a large class of problems in parameter estimation in which there is error in all the variables. This property makes it of more general applicability than the widely used technique of ordinary Least Squares. While there is a voluminous literature on EVM there is nothing on a general method for designing experiments when EVM applies. In this paper we present an extension of the concept of D-optimality to provide such a general method. It is illustrated by applying it to the estimation of copolymer reactivity ratios and to fitting an ellipse.     

门式脚手架在已建高层建筑外装修中的应用

介绍门式脚手架在已建高层建筑外排栅中的整体搭设和应用实例。     

化工企业环境因素的评价

化工企业环境因素评价是建立环境管理体系的核心任务，化工企业生产过程的特点决定了其环境因素数量多、环境影响大、识别评价难、控制难度大。本文介绍了化工企业环境因素评价的技术方法和过程，可以为提高环境因素评价的科学性、客观性和充分性提供参考。     

乌江渡水电站扩建工程开挖爆破对原水电站建筑物震动影响的控制研究

为确保原有的乌江渡水电站水工建筑物和发电设备以及扩建工程建筑物的施工安全,加快扩建工程施工进度,本扩建工程施工中对关键部位开挖所产生的爆破震动影响实施全面而有效的实时爆破监控,并根据监控成果的研究指导开挖爆破作业,以确定符合实际的安全爆破震动参数。     

Wear resistance of plasma coatings for a constant work of friction

We analyze the wear resistance of plasma coatings for a constant work of friction. The dependences of the wear resistance of the coatings are obtained for a broad range of loading conditions. It is shown that the minimum sensitivity to loading conditions is exhibited by the molybdenum coatings. It is also established that the wear resistance of the coatings decreases as the amplitude of displacements increases and the cyclic frequency of the tests decreases due to the intensification of fatigue processes on the surfaces. The comparative characteristics of coatings are presented. __________ Translated from Problemy Prochnosti, No. 5, pp. 94–100, September–October, 2007.     

Drying Characteristics of Barley Grain Dried in a Spouted-Bed and Combined IR-Convection Dryers

A study was performed to determine the drying characteristics and quality of barley grain dried in a laboratory scale spouted-bed dryer at 30, 35, 40, and 45°C and an inlet air velocity of 23 m/s^-1, and in an IR-convection dryer under an infrared radiation intensity of 0.048, 0.061, 0.073, and 0.107 W cm^-2 at an air velocity of 0.5 m/s^-1. The results show that the first, relatively short, phase of a sharp decrease in the drying rate was followed by the phase of a slow decrease. The time of barley drying depended on temperature of inlet air in a spouted-bed dryer and on radiation intensities in an IR-convection dryer. Barley drying at 45°C in a spouted-bed dryer was accompanied by the lowest total energy consumption. The average specific energy consumption was lower and the average efficiency of drying was higher for drying in a spouted-bed dryer. The effective diffusivities were in the range 2.20-4.52 × 10^-11 m² s^-1 and 3.04-4.79 × 10^-11 m²/s^-1 for barley dried in a spouted-bed and in an IR-convection dryer, respectively. There were no significant differences in kernel germination energy and capacity between the two drying methods tested.     

β放射性气体浓度计的新分度方法

本文介绍β放射性气体浓度计的一种新的分度方法——泄漏元件排气法。其特点是一只元件可分度放射性气体浓度计的许多读出数(甚至是几个量程),操作方便。