平面壁附近高分子链的尺寸和形状

The size and the shape of non-reversai random-walking polymer chains near an impenetrable, noninteracting fiat surface are investigated by means of Monte Carlo simulation on the simple cubic lattice. It was found that both size and shape are dependent on the normaLto-surface distance z0 of the first segment of chain. We find that the size and shape of chains, characterized by mean square radius of gyration (S^2) and mean asphericityparameter (A) respectively, show similax dependence on distance z0. Both (S2) and (A) reach the maximum at z0 = 0, then decrease with the increase of z0 and soon reach the minimum values, afterwards they go up continuously and approach to the limit values of free chain. The similar dependence of (S^2) and (A) on z0 can be explained by a positive correlation between A and S^2. However, the dependence of the correlation coefficient CA,S2 on z0 is very complicated and deserves further study. The overall density probability of segments is also investigated. Results show that segments near the surface are relatively less, and the symmetrical distribution disappears when the chain locates near the surface.     

保持医用管材的形状和尺寸

随着新型医用多腔管结构的日趋复杂，对挤出成型工艺也提出了越来越高的要求。利用电力调压控制系统可快捷、准确地控制内径空气和冷却槽压力，使管材在成型过程中能够保持严格的形状和尺寸。[编者按]     

生物大分子行为及其相互作用的单分子荧光技术研究

通常所进行的大部分实验都是测量集体分子的系宗平均值，只能给出整个体系中所有分子的平均行为，而无法直接跟踪单个分子的运动或解释其运动规律。使我们失去了很多的研究机会。利用单分子研究方法可以弥补这一缺憾，我们可以研究单个分子在复杂体系中的行为，而且能够揭示分子随时间变化的特性。     

分压注入工具对溶液分子线团尺寸的影响研究

为了研究分压注入工具对不同组分溶液的剪切作用,采用动态光散射(DLS)方法,研究了不同流量下,分压注入工具对不同组分聚合物溶液和三元复合溶液分子线团尺寸的影响。结果表明,初始溶液中聚合物的分子量越高、浓度越大或流经分压注入工具的流量越大时,分压注入工具对溶液的剪切作用越大,分子线团尺寸改变越明显。实验结果可为油田分层开采时分压注入工具型号的选择提供理论支持。     

容器封头筒体形状尺寸偏差的标准化

前言众所周知,容器的封头和圆筒体是石化设备常用的主要零件,其形状偏差过大,势必会引起很大的应力集中,而尺寸偏差太大,强行组装亦会产生不应有的附加应力,均对容器的使用带来一定的危险。因此,国家有关部门制     

倾斜下表面上形成的气泡形状及尺寸

本文研究了在倾斜下表面上，经小直径导管引入液相的气体所形成的气泡形状和尺寸及其受倾斜角度、导管直径及气体流量大小的影响。并获得了预测气泡脱离容积的关系式。     

《炼钢转炉用耐火砖形状尺寸》标准的制订与应用

为起草《炼钢转炉用耐火砖形状尺寸》冶金行业标准（YB／Th60－94）（下简称本标准），导出了大小端差距比为基础的转炉炉衬特殊尺寸参数计算式。用这些计算式定量地比较了当今国际标准、国外先进标准及国内外转炉炉衬结构中各种形状及尺寸砖的优缺点。本标准除体现了国际标准《氧气炼钢转炉用碱性砖》（ISO5019／6）单环等中间尺寸坚宽楔形砖、双楔形砖砌砖优点外，还有以下创新：（1）砖的尺寸系列更趋合理，并拓宽了应用范围；（2）国内外首次列入本标准的尺寸参数及基于尺寸参数的双楔形砖砖环、转量简化计算式，为本标准的设计计算提供精确数据，为其推广实施提供了方便条件；（3）采用本标准的武钢三座90t转炉的三年实践表明，它具有易于成型、制砖、砖的内在质量均一、砌筑操作方便、用后残砖剩余尺寸小且不掉砖及寿命延长30％以上等优点，使武钢转炉炉龄达到国内领先水平并进入国际先进行列，且经济效益显著。本标准由冶金部于1994年9月发布，1995年5月实施，标准水平等级为国际先进水平（Y）。     

初始冷凝液滴尺寸分布的分子团聚模型

Initial dropwise condensation of moist air on a hydrophobic self-assembled monolayer（SAM）surface was investigated with a high speed camera and a microscope.The transient initial droplet size distribution and the growth of micro-droplets by direct condensation on the surface without coalescence were analyzed from the concept of molecular clustering.Based on the general characteristics of nucleation of dropwise condensation,a molecular clustering physical model was proposed to describe the state of steam molecules in the bulk steam phase before condensing on the cooled surface.     

有机物在超临界CO_2中无限稀释扩散系数的分子动力学模拟

根据物质的实验临界常数或与物质最基本分子结构相关的Joback或Lydersen临界常数估算法得到物质的临界常数,结合Lennard-Joned流体的对比状态方程,按照对应态原理得到了38种有机物分子的新的Lennard-Jones位能参数.由这些位能参数结合简单的组合规则,首次对一些高附加值的复杂实用有机物在313.15 K、16 MPa的超临界CO_2中的无限稀释扩散系数采用分子动力学模拟的方法进行了研究.模拟结果表明,采用这种新思路可以有效地预测超临界体系的扩散性质,满足超临界萃取工艺开发和设计的需要.     

有机物在超临界CO2中无限稀释扩散系数的分子动力学模拟

根据物质的实验临界常数或与物质最基本分子结构相关的Joback或Lydersen临界常数估算法得到物质的临界常数,结合Lennard-Jones流体的对比状态方程,按照对应态原理得到了38种有机物分子的新的Lennard-Jones位能参数。由这些位能参数结合简单的组合规则,首次对一些高附加值的复杂实用有机物在313.15　K、16MPa的超临界CO     

EFFECTS OF SOLUTE ADSORPTION ON HINDERED DIFFUSION UPTAKE RATES IN FINITE BATH EXPERIMENTS

This work investigates the effects of solute adsorption on hindered diffusion behavior in porous catalysts. A mathematical model describing the adsorptive diffusion process is developed. The model, termed the shrinking pore model, incorporates the local reduction in catalyst pore diameter due to the adsorption of solute molecules on the pore walls. The influence of the adsorbed solute layer is found to depend on two additional parameters, reflecting the relative degree of adsorption and molecule/pore size ratio. Hindered diffusion experiments are performed for diffusion controlled adsorptive uptakes of two solute molecules, quinoline and polystyrene, from cyclohexane on a porous catalyst. Comparison of the experimental data and model simulation results shows that for the larger polystyrene solute the shrinking pore model better represents the uptake behavior than the conventional model which assumes constant catalyst properties, e.g. pore diameter, during the uptake process. Experimental measurements were found to be in good agreement with model simulations after accounting for additional hindered diffusional effects due to an adsorbed solute layer on the pore walls. The additional hindrance due to the adsorbed solute was found to be very significant for the uptake of the larger polystyrene solute, whereas it was not significant for the smaller quinoline solute.     

SOLUBILITY OF CO2 AND H2S IN A HINDERED AMINE SOLUTION

The solubility of H₂S and CO₂ in aqueous solutions of the sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), was determined at 40 and 100°C. Partial pressures of C)₂ ranged from approximately 2 to 6000 kPa and of H₂S from 2 to 2200 kPa. The solubility results were compared with previously reported acid gas solubilities in aqueous monoethanolamine (MEA) solutions.     

非对称受阻酚类抗氧剂及其应用

非对称受阻酚类抗氧剂是当今世界聚合物抗氧剂研究领域的一大趋势,介绍了非对称受阻酚类抗氧剂的结构、性能及其代表性品种,同时指出了该类抗氧剂的应用前景,对生产加工有一定的参考价值。     

聚烯烃分子量及分子量分布对其物理机械性能的影响

综述了分子量及分子量分布与聚烯烃物理机械性能的关系,其中包括应力-应变、冲击、蠕变、应力松驰、疲劳、结晶和流变学性质。通常,聚合物的机械性能随分子量增大而提高,而当分子量高于某一定值时保持恒定。本文对聚烯烃的生产和加工都具有实际意义。     

双功能受阻胺光稳定剂GW-540与紫外线吸收剂并用效应的研究

本文用IR、UV、SEM等方法,研究了双功能基受阻胺光稳定剂——三(1,2,2,6,6-五甲基-4-哌啶基)亚磷酸酯(GW-540),与紫外线吸收剂UV-531、UV-327并用时对聚丙烯的防光作用,结果表明:GW-540-UV-531并用体系有良好的防光作用,呈强的协同效应;GW-540-UV-327并用体系呈弱的对抗作用。结果还表明:GW-540对531和327的光分解均有保护作用.电镜研究表明,加入GW-540后,使UV-327在聚丙烯中分散更不均匀,从而影响其效率的发挥。文中提出了两个体系的协同和对抗作用机理。     

三维电极电化学水处理技术研究现状及方向

综合近十几年国内外有关三维电极电化学水处理技术研究文献,概述了三维电极的特点,分类,理论与应用研究状况,并提出了三维电极目前研究存在的问题及今后的方向。     

分子吸附对聚乙烯醇在氧化铝粉末压缩体中扩散系数的影响

利用氧化铝粉末压缩球状体和Ｆｉｃｋ第二扩散定律,系统地研究了聚乙烯醇在多孔介质和实验系统ｐＨ值为８．４０±０．２条件下的扩散行为,以及聚乙烯醇在球体外表面吸附对扩散系数的影响．实验结果和相应计算得到的扩散系数表明：发生在氧化铝表面的分子吸附,不仅导致扩散平衡状态时的Ｍｔ（聚乙烯醇在时间ｔ的扩散量）高于理论计算值Ｍ∞,而且使实验初始阶段计算的扩散系数远大于其它过程扩散系数．由分子吸附产生的实验误差和扩散系数计算误差,可通过修正浓度分配系数Ｋ,或者直接从Ｍｔ中去除可能存在的吸附量得到解决．