1,1,1-三氯乙烷的稳定剂配方研究

通过试验提出了2组有使用价值的稳定剂配方组成。结果表明,研究取得了预期效果,特别配方(Ⅱ)使用后,产品各方面特性和旭化成产品的指标相似,稳定后产品能被用户广泛接受。     

Lee's指数用于评价成年大鼠肥胖程度的探讨

目的 研究Lee's 指数在评价成年大鼠肥胖程度方面的可行性与准确性。方法 将成年肥胖大鼠Lee's 指数与体重增加率、腹腔脂肪湿重、脂肪细胞大小以及血脂等指标同步测量。结果 肥胖模型大鼠较其它各组大鼠Lee's 指数明显增加, 且与上述其它观察指标变化一致, 高度相关。结论 Lee's 指数可作为评价成年肥胖模型大鼠肥胖程度的指标。     

地震不连续点成像

地震不连续点成像类似于反射波勘探中的共中心点叠加技术.它是根据绕射波的运动学和运力学两方面特征,在共炮间距道集上,将绕射波聚焦成像,形成绕射点剖面。该绕射点在其剖面上以亮点的形式显示出来,它有可能与断点相对应。应用该绕射点剖面与原地震剖面进行叠合,有助于解释人员对断点进行定位解释。     

新型树脂复鞣剂的研究进展

介绍了新型树脂复鞣剂的品种如含烷氧基团复鞣剂、含氨基和羧基的两性复鞣剂、长链烯基加脂性复鞣剂、含氟硅的复鞣剂等及其相关领域的发展;指出今后树脂复鞣剂将会向着多功能化、系列化方向方展。     

微处理机在炉温、油压自动控制中的应用

本文应用DDC装置实现了单机自动化的设想。并对某厂钢锭加热炉炉温、油压系统中采用GE—80型双板微处理机构成DDC装置,使炉温、油压的控制实现了自动控制,对改造老企业提高了劳动生产率,具有较好的效果。     

一位微处理机控制真空远红外木材干燥炉的探讨

本文主要介绍如何用一位微处理机检测和控制温度、湿度等模拟量。     

基于数据仓库的税务地理信息系统构建

地理信息系统是空间数据和属性数据的统一体,面对越来越庞大和复杂的数据管理和分析要求,它需要更有力的信息技术——数据仓库技术的支持。本文通过实例阐述了数据仓库技术在税务地理信息系统构建中的基础地位,对数据仓库与地理信息系统的结合进行初步的探索。     

cAMP mediates transepithelial K+ and Na+ transport in a strial marginal cell line

The recently described gastrointestinal glutathione peroxidase (GI-GPx) is the fourth member of the family of the selenoenzymes glutathione peroxidases (GPx). In contrast to the more uniform distribution of, for example, the classical glutathione peroxidase (cGPx), it is expressed exclusively in the gastrointestinal tract and has, therefore, been suggested to function as a primary barrier against alimentary hydroperoxides. In order to get an idea of its relative importance we investigated its position in the hierarchy of selenoprotein expression. The selenium-dependent expression of GI-GPx was analyzed in comparison with that of other GPx types at the level of mRNA and protein in HepG2 and CaCo-2 cells. Furthermore, the selenocysteine insertion sequence (SECIS) efficiencies of GI-GPx, phospholipid hydroperoxide glutathione peroxidase (PHGPx) and cGPx in response to selenium were determined by a reporter-gene assay in human hepatoma cells and baby hamster kidney cells. GI-GPx mRNA levels increased during selenium deficiency, whereas cGPx mRNA levels decreased and PHGPx mRNA levels remained almost unaffected. In cells grown in selenium-poor media, all GPx-types were low in both activity and immunochemical reactivity. Upon selenium repletion immunoreactive GI-GPx protein reached a plateau after 10 h, whereas cGPx started to be expressed at 24 h and did not reach its maximum level before 3 days. SECIS efficiencies decreased in the order PHGPx > cGPx > GI-GPx. The augmentation of SECIS efficiencies by selenium was highest for cGPx and intermediate for PHGPx, whereas it was marginal for GI-GPx. The high mRNA stability under selenium restriction, the speed of biosynthesis upon selenium repletion and the marginal effect of selenium on the SECIS efficiency indicate that of the GPx isotypes, GI-GPx ranks highest in the hierarchy of selenoproteins and point to a vital role of GI-GPx in the gastrointestinal tract.     

Study of the powder/membrane interface by using the powder microelectrode technique I. The Pt-black/Nafion® interfaces

The polarization behavior of a Pt microdisk electrode, a platinized Pt microdisk electrode and a Pt-black powder microelectrode immersed in sulfuric acid solution, in contact with a moist Nafion® membrane were studied by cyclic voltammetry. The experimental results reveal that the surface diffusion of the adsorbed species plays an important role in determining the kinetics of interfacial reactions taking place at the powder/Nafion® membrane interface. The weakly adsorbed hydrogen atoms diffuse significantly faster than the strongly adsorbed hydrogen and the oxygen-containing surface species. Surface active sites in the range of tens of microns from the powder/Nafion® interface can be involved in interfacial reactions. The apparent coefficients of diffusion of various surface species were estimated from the variation of peak current with scan rate of potential. The apparently higher irreversibility of electrode reaction observed at the powder/membrane composite electrode is explained by considering mechanism of current generation of this type of electrode.     

辛烷—水二元部分互溶体系的相平衡

采用改进的Ｐａｒｔ釜测定了在０．１０１３ＭＰａ下,辛烷－水二元部分互溶体系的汽液相平衡数据,经热力学一致性检验表明,所测的数据是可靠的。采用等温法制定了５～７５℃范围内的液液相平衡数据。实验结果表明,辛烷在水中的溶解度仅为７．３×１０－５～７．５×１０－４,水在辛烷中的溶解度为３．８×１０－３～１．０×１０－１,该体系是互溶度极小的体系。