表面活性剂增敏原子吸收分光光度法测定铜的研究

研究了17种试剂对铜的FAAS增敏作用,发现CTMAB,SDBS,TritonX-100.ED-TA,O-Phen,CO(NH_2)2,N(CH_2CH_2OH)_3具有不同程度负增敏作用;CH_3COCH_3无增敏作用;(Na)_2WO_4,柠檬酸钠略具增敏作用;C_2H_5OH.NH_2OH·HCl,SSA,CAS,H_2O_2,乙二胺,OP具有明显的增敏作用,而其中尤以OP最为显著。基于OP对Cu增敏作用建立了新的测定铜FAAS法;本法用于发样分析获得了满意的结果。此外,尚对样品预处理进一步研究并探讨了Sur(OP)对Cu增敏作用的机理。     

The amplified fluorescence quenching of heteroatomic conjugated polymers based on the “molecular wire”effects

One of the most important components of chemicalsensor is sensing material, which selectively binds ananalyte and signals the binding. In conventional sensorresearch, the sensitivity and reversibility of sensor arelargely determined by the association constant of thebinding. An approach to enhancing the association con-stant can be benefit for sensitivity, but disadvantageous to reversible response. Therefore, the search for new sensing materials with the high sensitivity, good selectivity and…     

Humanin peptide suppresses apoptosis by interfering with Bax activation

Bax (Bcl2-associated X protein) is an apoptosis-inducing protein that participates in cell death during normal development and in various diseases. Bax resides in an inactive state in the cytosol of many cells. In response to death stimuli, Bax protein undergoes conformational changes that expose membrane-targeting domains, resulting in its translocation to mitochondrial membranes, where Bax inserts and causes release of cytochrome c and other apoptogenic proteins. It is unknown what controls conversion of Bax from the inactive to active conformation. Here we show that Bax interacts with humanin (HN), an anti-apoptotic peptide of 24 amino acids encoded in mammalian genomes. HN prevents the translocation of Bax from cytosol to mitochondria. Conversely, reducing HN expression by small interfering RNAs sensitizes cells to Bax and increases Bax translocation to membranes. HN peptides also block Bax association with isolated mitochondria, and suppress cytochrome c release in vitro. Notably, the mitochondrial genome contains an identical open reading frame, and the mitochondrial version of HN can also bind and suppress Bax. We speculate therefore that HN arose from mitochondria and transferred to the nuclear genome, providing a mechanism for protecting these organelles from Bax.     

Primary observations of the existence of Fas-like cytoplasmic death factor in plant cells

The main activity of Fas is to trigger cytoplasm death program in animal cells. In G2 pea, vacuole plays a pivotal role in inducing cell death in the cytoplasm of longday (LD) grown apical meristem cells. Expression patterns of the Fas in G2 pea cells revealed that the Fas is mainly localized in the vacuole of cells undergoing programmed cell death (PCD). The Fas expression is corresponding to the initiation of menadione-induced PCD in tobacco protoplasts.The results suggest the existence of the Fas-like mediated cytoplasmic death pathway in plant cells.``     

石油钻机刹车块材料筛选的原理与试验方法

本文根据石油钻机刹车工作理论和摩擦学的基本原理,用系统分析的方法,在大量试验的基础上,结合我国实际情况,提出了一套石油钻机刹车块材料筛选的原理与实验方法。筛选原理包括刹车块材料特性指标和刹车块材料的摩擦学系统特性。根据筛选原理所建立的试验方法体系由三级试验组成,即基本摩擦学特性试验、热冲击制动摩擦学特性试验和缩尺刹车副模拟工况制动摩擦学特性试验。用本实验方法,可以科学地筛选出适合不同条件下工作的各种刹车块,从而可充分利用刹车块的性能,延长其使用寿命。几年来,已为国内几家刹车块生产厂家所采用,提高了产品质量,开发出多种新产品,其中有两种产品获得国家优质产品奖。     

一种绘制双代号网络图的新方法

本文从几个方面分析了工序关系, 然后在此基础上提出一种绘制双代号网络图的新方法。该方法简单易行, 从而为计算机自动绘图创造了一些条件。     

聚乙烯醇缩丁醛—接枝丙烯酰胺的合成及生物医学性能

聚乙烯醇缩丁醛—接枝—丙烯酰胺共聚物已采用硝酸铈铵/硝酸引发体系于水悬浮液中在30℃合成,接枝长度和每个聚乙烯醇缩丁醛分子上支链的数几分别确定为(?)n3-6×10~4和0.1-0.3。测定了反应时间和铈离子浓度对接枝率,接枝长度和支链数目的影响。亦讨论了其他反应参数的影响,并研究了此聚合物的吸水率,对牛血清白蛋白的粘附及血液相容悱。结果表明此共聚物当接枝率为15—25%而平均接枝链长度((?)n)大于4×10~4其血液相容性良好。     

ZQ高压功率二极管的玻璃钝化研究

本文研究报导了ZQ高压功率二极管的玻璃钝化方法,采用适当的腐蚀技术、玻璃粉涂敷技术和玻璃微晶化技术,获得了良好的内层玻璃钝化膜。实验结果表明,用该膜钝化的ZQ器件具有优良的可靠性和高温工作特性。     

试论饭店业员工培训

随着饭店业的发展，越来越多的饭店企业开始重视员工培训，注重员工整体素质的提高，但是由于在培训认识、体制、教学方法以及评估等方面存在种种问题，使得培训效果与预期目标相距甚远。文章分析了当前饭店业培训工作中存在的问题，并尝试提出了解决问题的途径及方法。     

1.10—菲萝啉及荧光桃红萃取光度法测铝中的微量锰

本文研究了锰-1.10菲箩啉-荧光桃红萃取光度法测定锰的条件.在弱酸性及中性条件下锰(Ⅱ)与1.10-菲萝啉及荧光桃红形成可被氯仿萃取的[Mn(Phen)_2]Phlo络合物,最大吸收波长λ_(man)=562.8nm,s=1.073×10~6L mol~(-1)·cm~(-1),其含量在0～10μg/10ml氯仿呈线性关系.