AsCl_3在9mol·L~(-1)盐酸一苯和水一苯相中分配比的测定

本文介绍了笔者设计的测定AsCL_3在9mol·L~(-1)盐酸—苯相的分配比(D_1)和在水—苯相中的分配比(D_2)的简便方法。试验测知,在19℃时,D_1为10.82,D2为0.0180。苯对9mol·L~(-1)盐酸中的As(Ⅲ)的萃取率为91.5％,水对苯相的As(Ⅲ)的反萃取率为98.2％(等体积一次萃取)。     

试论电视公益广告的社会特征

电视已成为大众文化传播的重要渠道,也是受众认识社会和改造自我的最直接的信息来源;并且电视公益广告作为一种特殊的电视节目样式,已在受众心中形成了一定的影响力,成为各家树立品牌形象的重要手段;从社会文化承载、传播和构建的角度,研究电视公益广告的社会特征,并对电视公益广告目前存在的问题与未来发展做了相应探讨,以倡导、推介社会风尚及道德观念,规范社会行为为基本内容和目的的电视公益广告。     

楚官玺杂识

壹《玺汇》0003着录一方官玺，白文六字：■ 坪君■（图　1）该玺与《玺汇》0002“（弋）易（阳）君”风格酷似，“弋阳”属楚境①，“坪”无疑亦应属楚境。     

怎样发挥师专图书馆的教育职能

作者从五个方面分别论述了师专图书馆教育职能的含义、师专图书馆在师生读者中怎样发挥教育职能等问题,同时提出:一定的物质基础和科学的管理手段是师专图书馆教育职能得以充分发挥的有力保障。     

关于Sikkema—Bernstein多项式导数的迭代极限

本首先给出了Sikkema-Bernstein多项式的迭代极限及误差估计；然后构造一个整系数Sikkema-Bernstein型多项式，并给出了该多项式的导数逼近导函数是有界变差时的收敛阶估计式。     

三角形packing问题中零自由度动作的分类

三角形packing问题中三角形可以进行连续平移和旋转,如果不对三角形放置动作进行限制,则计算将无法实现。本文提出了零自由度动作概念,并对它进行了详细的分类,为求解三角形Packing问题建立了一个接近客观情况的模型。     

微孔膜内大分子有效扩散系数的计算

报道一种计算分子尺寸与构型对微孔内大分子有效扩散系数影响的理论方法。基于刚性圆球分子在圆柱型孔内的扩散理论，定义分子平均投影半径和水力学球半径，分别用于估算孔内外浓度分配系数和孔内水力学拖曳力。对不同构型的大分子，使用该法计算的有效扩散系数与已发表的实验数据吻合良好。     

基于消息的单片机编程方法

在单片机MCS-51的开发运用中，通常要使用各种中断。如中断服务程序执行时间过长，当有另外的中断发生时，单片机就不能及时地进行处理，特别是对MCS-51这样的只有两级中断优先级的单片机更是这样。借鉴Windows编程的原理，在单片机编程中引入消息的概念，将中断产生的标志作为消息，而数据处理则放在消息循环中进行，这样一方面减少了中断服务程序的长度，提高了响应中断的速度；另一方面又不影响数据的处理。     

走向校本的素质教育——天津市中小学实施素质教育的研究

一、走向校本———素质教育深化发展的必然从20世纪80年代开始,我国就在不同层面出现了素质教育的实践探索,而且涌现了一批成功的素质教育模式,如“成功教育”、“和谐教育”、“愉快教育”等,并且在不同层面进行了宣传和推介。从1996年起,原国家教委还从区域性层面对实施素质     

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=l 7). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF Of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P＜0.05)].Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17±0.21 cm and 0.74±0.13 cm, and remarkably lower than those of the model group, which were 1.64±0.14 cm and 1.19±0.12 cm (P＜0.05); the LVEF of the MSCs group after operation was 63±6%, and remarkably higher than that of the model group,which was 53±6% (P＜0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%),the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. Conclusion: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.