镍硫化物阳极溶解的电化学研究

研究了合成镍硫化物的阳极过程。Ni_3S_2,Ni_7S_6和NiS的活性溶解伴随着生成表面产物层,其反应机理与电极电位有关。根据三种不同类型产物层生成规律的电化学研究,Ni溶出表观电子数的测定,以及产物层相组成分析和相的元素分析,认为存在三组平行反应:直接生成HSO_4~-或SO_(4-)~2的反应,生成中间硫化物的反应及生成元素硫的反应,每组反应具有不同的优势发展电位区。NiS_2阳极溶解时,基本上为生成HSO_(4-)或SO_(4-)~2的反应。     

A METHOD FOR CALCULATING THE EXTENT OF REACTION OF SOLID PARTICLES WITH FLUID IN COMPLETELY MIXED REACTORS CONNECTED IN SERIES

When solid particles react with a fluid,the overall rate is influened by the fraction of the solidunconverted as well as by the operating conditions such as temperature and pressure.Calculation of solidsconversion in the individual reactor of a multi-stage reactor system has therefore to be based upon thesolids residence time distribution (RTD) in the respective stages.By using either the Dirac function δ(0) or the probability density function of the sum of independentrandom variables,the solids RTD in any stage of completely mixed reactors connected in series with nointerstage backflow has been obtained.The latter method has also been used in deriving general formu-las for the calculation of solids conversion when the order of chemical reaction is simple.For complexchemical reaction rate equations a stagewise procedure for numerical computation is proposed,and twocases are discussed according to whether the rate equation is expressed in its integral or differential formrespectively.     

混合溶剂抽提甲基环己烷的溶剂性能

采用浊点法测定了甲基环己烷-庚烷-单-溶剂（N-甲基-吡咯烷酮,NMP）或混合溶剂（N-甲基-吡咯烷酮＋环西砜、苯甲醇＋环丁砜）的三元或四元体系在（25±0．1）℃下的液液分层曲线．结合体系的物性（如折光指数或比重）测定了各体系的结线数据．由实验数据计算得到的选择性系数、溶解度和容量等数据,可以初步评价单一溶剂以及混合溶剂体系萃取分离烷烃与环烷烃的基本性能．研究发现单一纯溶剂的选择性系数较小,但与环丁砜组成混合溶剂体系能在一定范围内提高选择性系数．苯甲醇与环丁砜混合溶剂体系的选择性系数、溶解度和容量优于相同质量组成的N-甲基-吡咯烷酮与环丁砜混合溶剂体系．     

Numerical solution of viscous flow past a solid sphere with the control volume formulation

The control volume formulation with the QUICK finite difference scheme is used to solveincompressible liquid flow past a solid sphere in terms of stream function and vorticity.Several tech-nical points are addressed on improving the accuracy and efficiency of numerical simulation of similarproblems of fluid flow.In particular,the importance of suitable specification of the distortion func-tion to enforcing the far field boundarv conditions is emphasized.     

NONUNIFORMITY OF TWO PHASE FLOW IN CAPILLARY SYSTEMS

Gas-liquid flow in simple systems consisting of capillaries is analyzed by theory of irreversible thermodynamics so as to shed light on induction of nonuniformity of multiphase flow. By the Prigogine's theorem of minimum entropy production, stability of uniform two-phase flow and possible transition to nonuniform distribution are discussed. The analysis of model systems suggests potential application of irreversible thermodynamics to research of multiphase hydrodynamics in chemical reactors.     

有机相中酶的活性、对映体选择性和稳定性

有机相中的酶能催化许多在水中不能发生的反应,这些反应正越来越多地用于制备其它方法难于获得的化合物,如手性化合物。本文综述了有机相中酶的活性、对映体选择性和稳定性的影响因素与可能的改进方法。     

滚筒式填料筛板萃取器反胶团法萃取蛋白质

设计出滚筒式填料筛板萃取器,并应用该萃取器反胶团法萃取蛋白质。萃取溶菌酶和牛血清白蛋白（ＢＳＡ）的实验结果表明,该萃取器萃取效果良好,分相迅速,可澄清分相的水相ＫＣＬ最低浓度为０．０２ｍｏｌ／Ｌ,可有效解决反胶团法萃取蛋白质过程分相困难的问题。报道使用石油醚为溶剂反胶团法萃取蛋白质。石油醚为混合烷烃,价格低廉,易于纯化,萃取效果良好,不会引起酶的失活。     

粗糙固体平面上液滴的接触角滞后的简单流体静力学模型

The phenomenon of hysteresis of contact angle is an important topic subject to a long time of argument.A simple hydrostatic model of sessile drops under the gravity in combination with an ideal surface roughness model is used to interpret the process of drop volume increase or decrease of a planar sessile drop and to shed light on the contact angle hysteresis and its relationship with the solid surface roughness. With this model, the advancing and receding contact angles are conceptually explained in terms of equilibrium contact angle and surface roughness only,without invoking the thermodynamic multiplicity. The model is found to be qualitatively consistent to experimental observations on contact angle hysteresis and it suggests a possible way to approach the hysteresis of three-dimensional sessile drops.     

STUDIES ON FLOODING POINT AND HOLD-UP IN A SOLVENT EXTRACTION COLUMN WITH RECIPROCATING SIEVE PLATES

The flooding point and hold-up of the dispersed phase in an extraction column with reciprocating-sieve plates of 32 mm inside diameter and 1960 mm effective column height have been investigated under thefollowing conditions:Percent perforation of the plates 40%,53.5% and 63.7%,diameters of perforatedholes 7.8,9.0 and 9.8 mm,and distances between plates 20 and 40 mm respectively.Experiments werecarried out with three different liquid-liquid systems covering a rather wide range of physical properties.The relative velocity of the two phases passing through the perforations of the plates is consideredin the present work to be related to the work done by the oscillating plates in the column on unit massof liquid in unit time.Therefore the flooding velocity and hold-up in extraction column with reci-procating sieve plates should be related to A~2F~3 instead of AF as reported before.Equations weredeveloped to correlate the experimental data of flooding point and hold-up respectively.     

湿法炼铅的简况及开展湿法炼铅工作的一点意见

一、前言炼铅的主要原料为硫化铅精矿,矿物主要为方铅矿。世界上目前生产铅主要采用火法。将铅精矿先在烧结机上进行焙烧烧结,烧结块送鼓风炉熔炼,产出粗铅。粗铅再经火法或火法加电解进行精炼得精铅产品。这个过程效率比较高,能适应不同的原料,消