马来酸酐接枝聚丙烯的进展

马来酸酐接枝聚丙烯是拓宽聚丙烯应用领域的重要手段之一,本文综述了马来酸酐接枝聚丙烯的接枝方法和原理,接枝物的性能以及接枝物在聚丙烯合金和共混物、复合材料、粘合剂和涂料领域的广泛应用。     

我公司进行热电联产的可行性分析

大压差减温减压是能的严重贬值。根据公司供热现状，分析了热电联产的可行性，利用蒸汽余压发电后，再供生产系统各热用户，这样既节约了能源又缓解了集团公司用电紧张的局面，而且有相当可观的经济效益。     

Practical Design Model for Calculating Bubble Diffuser Contactor Ozone Transfer Efficiency

Ozone transfer to water or wastewater is necessary before desirable, effective ozone reactions occur. Several factors affect ozone transfer efficiency, including water quality characteristics, contactor configuration, and applied ozone characteristics. The design model presented in this paper addresses all factors affecting ozone transfer. The model was used to compare measured transfer efficiency with predicted transfer efficiency at four full-scale wastewater ozone disinfection facilities. A relatively good prediction was obtained at each plant.

The paper presents an example calculation of ozone transfer efficiency. Also, the effect of changes to some of the factors affecting transfer efficiency is presented, such as changes in diffuser depth, plant elevation, ozone concentration, water quality (i.e., ozone demand), pH, detention time, temperature, and acombination of factors. The design model may be used to evaluate the effect of changes in plant design on transfer efficiency, but cannot provide an absolute value for transfer efficiency until difficult-to-measure parameters, such as bubble diameter, are known.     

On the examination of recycle on heat (and mass) transfer in concentric tubes

The effect of recycle on heat (and mass) transfer in concentric circular tubes has been investigated by finite difference methods. Theoretical results show that recycle can enhance the heat transfer rate for large Graetz numbers compared with that in an open tube (without an inner tube inserted and without recycle). Competition between a preheating effect and a residence-time effect can be used to explain the heat transfer behavior. The heat transfer rate can be further augmented, with nearly no increase in total pressure drop, by employing flow pattern B instead of flow pattern A.     

医用高分子材料的现状与应用

概述了医用高分子材料的发展现状及其用途,并介绍了医用高分子材料的发展动向。     

Pore structure of bulk tungsten carbide powder catalysts

Bulk tungsten carbide catalysts are prepared by direct carburization/reduction of tungsten trioxide in methane-hydrogen mixtures. The catalytic properties of such catalysts have been studied by several authors. The porous structure of these catalysts is studied by adsorption of N₂, Kr, CF₄ and neohexane. Adsorption isotherms and hysteresis loops for the catalysts suggest the presence of a microporous structure made of parallel plates distant approximately by 20 Å. These results are compared to those obtained using such catalysts for hydrogen oxidation and where condensation in the porous structure was observed.     

火焰原子吸收光谱法测定硅粉中的铜

介绍了用火焰原子吸收法测定工业硅粉中微量铜的具体方法和过程，同时也给出了最佳实验条件。实验中采用新的样品处理方法，得到了令人满意的结果。其中样品回收率为99．8％—104．0%，相对标准偏差为0．31％—0.38％。本方法在实际应用过程中，简单、快速、     

大型常压锥顶贮罐的设计

以工程实例为依据，论述国内以往较少采用的大型梁柱式支承锥顶贮罐的结构，介绍了国内外相关设计标准，给出了贮罐的典型结构－斜椽，横梁和立柱的计算公式，并用Excel电子表格编制了计算书。     

Mass transfer between solid particles and liquid in a three phase fluidized bed

Particle-liquid mass transfer in a co-current three-phase fluidized bed of glass beads, water and air was studied with two measurement techniques. Both techniques measured the weight loss of a few particles coated with benzoic acid in a bed of inert glass beads. The effects of liquid and gas velocities, gas distribution and surface active agents on particle-liquid mass transfer in a three-phase fluidized bed were thus determined. In the absence of surface active agents in the liquid, particle-liquid mass transfer rates in a three-phase fluidized bed were up to 30% higher than in the corresponding liquid fluidized bed. When surface active agents were added to the liquid, the particle-liquid mass transfer rate was increased by up to about 100% in the three-phase fluidized bed, relative to the liquid fluidized bed. The particle-liquid mass transfer coefficient was found to be inversely proportional to the liquid hold-up in the three-phase fluidized bed.     

双向搜索多约束路由启发式计算方法

为提高大型通信网络中搜索满足多约束条件路由的速度,提出一种双向搜索路由的计算方法.首先从源和目的节点同时出发,计算到达各中间节点的可达路径.然后在各可达路径中进行路径的筛选.可达路径是采用邻接矩阵变换方式获得的,筛选路径是根据非线性开销函数,采用启发方式择优选取.当两方向搜索的节点数累计达到n-2后,对接合并两方向到达中间节点的路径,从中再选择最佳路径作为路由输出.通过算例详细介绍了可达路径计算及启发式选优方法.阐述了算法的正确性及特点,分析了最大时间杂性.通过仿真实验评估,不仅更进一步验证了新算法的正确性,而且表明新算法在搜索路由速度上要优于其他算法.