无限长圆管中任意轴对称体绕中心轴旋转的小Re数问题

本文以Sampson旋转子在圆管中反演得到的无穷级数作为基本奇点,对分布函数采用离散奇点线分布法和分段二次抛物分布法,解决了任意轴对称体在无限长圆管中绕中心轴旋转的Stokes流动问題。通过对长球的数值计算,比较了两种方法,结果表明分段二次抛物分布法各方面都优于离散法。此外,本文还研究球串在无穷长圆管中绕中心轴旋转的小Re数问题,第一次给出了每个球所受的阻力矩系数。     

软嵌式薄层粉末电极 I: 薄层粉末旋转电极和光电化学电极

研究粉末电催化剂目前多采用多孔电极(如气体扩散电极)方法, 也用糊状电极或粉末悬浮液方法, 但均不适于研究电极过程动力学.为了研究粉末催化剂, 我们制备了软嵌式超薄层粉末旋转盘环电极和光电化学电极. 这种电极制备简单, 实验数据重现性良好, 能广泛用于各种电极过程动力学研究.     

The effect of the vasomotion on the mass transfer in microcirculation

Detailed structure of the attracting set of the piecewise linear Henon mapping(x, y)→(1- a|x|+by,x)with a=8/5 and b=9/25 is described in this paper using the method of dual line mapping. Let A and B denote the fixed saddles in the first quadrant, and in the third quadrant, respectively. It is claimed that(1)the attracting set is the closure of the unstable manifold of saddle B, which includes the unstable manifold of A as its subset, and(2)the basin of attraction is the closure of the stable manifold of A, bounded by the stable manifold of B, which is in the limiting set of the stable manifold of A.Relations of the manifolds of the periodic saddles with the manifolds of the fixed point are given. Symbolic dynamics notations are adopted which renders possible the study of the dynamical behavior of every piece of the manifolds and of every homoclinic or heteroclinic point.     

IRREDUCIBLE VERTEX OPERATOR FOR TEMPERATURE 2τ AND REAL TIME GREEN's FUNCTIONS 1. GENERAL FORMALISM

A method is proposed for the derivation of the irreducible vertex operator for the temperatune 2t as well as the real time 2t Green function. Rigorous}expressions are obtained and their usefulness is discussed. Furthermore, a preferable choice.of single particle basis is suggested.     

高效液相色谱法测定血液中冬凌草甲素的含量

冬凌草甲素(Rubescensin A,以下简称甲素),是从植物冬凌草中经提取分离出的一种抗癌有效成分。它具有多方面的药理作用,目前临床上用于治疗食管癌、肝癌和胰腺癌等。为给临床合理用药提供理论依据,研究甲素的动力学特性,准确测出服药后血液中甲素浓度随时间变化的规律显得十分重要。对药物和生理体液中微量成分的分离和测定,目前大部分都采用高效液相色谱法。但血液中甲素的高效液相色谱测定,国     

The inlet effect on the drag factor of a sphere in a tube

The creeping motion Ground a sphere situated axisymmetrically near the entrance of asemi-infinite circular cylindrical tube is analyzed using infinite series solutions for thevelocity components. pressure and the stream function. Truncating the infinite series. thecorresponding coefficients in the series are determined by a collocation technique. The dragfactor and the stress distribution on the surface of the sphere are calculated for the sphere inmotion in quiescent fluid and for the flow with uniform velocity at the entrance past a rigidlyheld sphere. The results indicate that a sphere near the entrance which has a uniformentrance velocity profile will suffer larger drag than that in infinite tube.Theconvergence of the collocation technique is tested by numerical calculation. It is shown thatthe technique has good convergence properties.     

THE METHOD OF CONTINUOUS DISTRIBUTION OF SINGULARITIES TO TREAT THE STOKES FLOW OF THE ARBITRARY OBLATE AXISYMWETRICAL BODY

This paper deals with the Stokes flow of the arbitrary oblate axisymmetrical body by means of constant density and quadratic distribution function approximation for the method of continuous distribution of singularities. The Sampson spherical infinite series arc chosen as fundamental singularities. The convergence, accuracy and range of application of both two approximations are examined by the unbounded Stokes flow past the oblate spheroid. It is demonstrated that the drag factor and pressure distribution both conform with the exact solution very well. Besides, the properties, accuracy and the range of application are getting belter with the improving of the approximation of the distribution function. As an example of the arbitrary oblate axisymmetrical bodies, the Stokes flow of the oblate Cassini oval are calculated by these two methods and the results are convergent and consistent. Finally, with the quadratic distribution approximation the red blood cell, which has physiologic meaning, is considered and for the first time the (orresponding drag factor and pressure distribution on the surface of the cell are obtained.     

卟啉化合物的电催化行为IV.载在石墨上经热处理的四(对甲氧基苯基)卟啉钴对胱氨酸还原的电催化作用

应用循环伏安法及带环的旋转圆盘电极(RRDE)在2mol.dm^-^3HCl溶液中研究了经热处理的四(对甲氧基苯基)卟啉钴(Co-TMPP)对胱氨酸还原反应的电催化作用.在循环伏安曲线上出现明显的氧化还原电流峰,表明Co-TMPP对胱氨酸还原有很好的电催化活性.在Co-TMPP/石墨电极上的还原反应为不可逆的简单电荷传递反应,其控制步骤的电子数为1.在极化电位较正时(-0.35~-0.45V)为电化学控制,在电位较负时(<-0.45V)为电化学及扩散混合控制.根据实验结果计算了动力学参数并初步讨论了反应机理.应用薄层盘环电极及聚四氟己烯粘结膜电极分别测定了胱氨酸还原反应的电流效率.实验结果表明,经热处理的Co-TMPP能提高胱氨酸还原反应的电流效率.     

静电场描绘装置的改进

阐述了利用水作导电介质对静电场描绘装置的改进结果． 测试情况表明, 使用改进后的装置, 操作更简便直观, 测试结果较精确．     

二氧化碳氧化丙烷制丙烯催化反应的研究铬镁铝复合氧化物催化剂的制备、表面微量吸附量热及催化性能

以共沉淀法合成的铬镁铝类水滑石为前体,制备了一系列不同原子比的铬镁铝复合氧化物,研究了其对二氧化碳氧化丙烷制丙烯反应的催化性能.采用微量吸附量热技术,以CO2和NH3为探针分子定量地表征了样品表面酸碱中心的强度和数量,并与其催化性能进行了关联.结果表明,Cr:Mg:Al原子比为1:1:1的催化剂具有较大的比表面积(94.5m2/g),样品中Mg(Al1.5Cr05)O4物相的含量最多.样品表面存在数量较多强度较强的酸性中心和数量最少强度较弱的碱性中心,对NH3吸附,它的吸附热为145 kJ/mol,吸附覆盖度为3.55μmol/m2;对CO2吸附,它的吸附热为115kJ/mol,吸附覆盖度为0.063μmol/m2.该样品的催化活性最高,在温度为650℃,CO2/C3H8摩尔比为3.6,GHSV(C3H8)为3000 h-1时,C3H8的转化率为22.8%,C3H6的选择性为83.5%,收率为19.1%.