煤的ESR波谱研究

利用JES—FEIXG型电子自旋共振波谱仪,系统地研究了褐煤与烟煤的ESR波谱,这些波谱可在室温下得到。褐煤与风化烟煤中存在大量稳定的自由基,从褐煤到烟煤,随着煤化作用的加强,ESR波谱的吸收峰变窄。风化使烟煤的自旋浓度明显下降,这将为判断煤是否风化提出又一定量判据,其原因可能是由于风化使煤的局部大分子遭到破坏,从而影响π电子自由基的稳定性。     

Reaction of CH radical with O<Subscript>2</Subscript> by time-resolved FTIR spectroscopy

The Methylidyne radical, CH, plays a crucial role in several complex environments such as planetary atmos- pheres and interstellar clouds, and is one of the most im- portant and active intermediate in hydrocarbon flames[1]. The CH involving reactions, including chemiionization, oxidation of hydrocarbons, the soot formation[2—5], and especially the formation of prompt NO[6], are of funda- mental interest in combustion chemistry, owing to the high reactivity and the large enthalpy of formatio…     

Ginkgo biloba extract inhibits oxygen species production generated by phorbol myristate acetate stimulated human leukocytes

Summary A Ginkgo biloba extract (Gbe) containing flavonoids, among other compounds, was tested for the release of activated oxygen species ( , H₂O₂, OH^.) during the stimulation of human neutrophils (PMNs) by a soluble agonist. The extract slows down O₂-consumption (respiratory burst) of stimulated cells by its inhibitory action on NADPH-oxidase, the enzyme responsible for the reduction of O₂ to . Consequently, superoxide anion ( ) and hydrogen peroxide (H₂O₂) production is significantly decreased when the PMNs stimulation is done in the presence of the extract at concentrations of 500, 250 and 125 g/ml. Moreover, the hydroxyl radical generation (OH^.) is very much decreased at concentrations as low as 15.6 g Gbe/ml, which indicates that the extract also has free radical scavenging activity. Gbe is able at least to reduce very severel the activity of myeloperoxidase contained in neutrophils. This enzyme, secreted into the intra and extracellular medium, catalyzes the oxidation of chloride (Cl^–) by H₂O₂ to yield strong oxidants (HOCl, chloramines) which are implicated in inflammatory processes     

一种用小型计算机实现的机器人视觉系统

本文介绍了一种机器人视觉系统.它以析象管摄象机构成图象轮廓传感器,用PDP-11/23小型计算机对图象信息进行处理,以实现图象轮廓的识别. 用于图象分析和分类的重要信息,主要包含在图象轮廓中.析象管摄象机适于实现随机控制的光学信号的扫描.由计算机控制的扫描发生器形成一种径向放射状的“星形扫描”,它用来探测轮廓,并实现基于卡尔曼-布什-滤波器的自动轮廓跟随.这样可大大压缩计算机处理的数据量,并可形成基于“结点—位置关系—结点”基元的句法图形结构,实现联想的句法模式识别.文中叙述了系统的硬件结构.工作原理及计算机应用软件的概况.     

关于多项式的模

刻划了多项式模Ｍ「ｘ１,ｘ２,…,ｘｎ」的分次子模,分次Ｊａｃｏｂｓｏｎ根,分次底座,并证明了当Ｒ是左Ｎｏｅｔｈｅｒ环时,Ｍ是内射左Ｒ－模当且仅当Ｍ「ｘ,１,ｘ２,…,ｘｎ」是分次内射左Ｒ「ｘ１,…,ｘｎ」模,进而得到多项式的相应理论。     

银杏叶黄酮抗氧化作用的研究

利用化学发光法和分光光度法研究了银杏叶黄酮Ｗ和Ｈ抗氧化作用。结果表明,水溶性的黄酮Ｗ和醇溶性的黄酮Ｈ不仅能有效地消除Ｏ２＾－、Ｈ２Ｏ２,而且能抑制脂质过氧化,并提示两者都有可能清除ＬＯ,ＬＯＯ和＾１Ｏ２。然而,两者清除这些活性氧能力差异显著,且都无清除ＯＨ能力。     

苯乙烯原子转移自由基聚合及其嵌段共聚物合成

分别采用氯乙酸甲酯,氯乙腈,氯化苄和三氯乙酸甲酯作引发剂,氯化亚铜／２,２′－联吡啶配位化合物作催化剂,进行了苯乙烯（Ｓｔ）和甲基丙烯酸甲酯（ＭＭＡ）的原子转移自由基聚合,研究了引发剂种类对聚合速率及所得聚合物的相对分子质量及其分布的影响,并考察了各种引发剂的引发效率,实验结果表明,只有当引发剂Ｃ－Ｃｌ键断裂能低于聚合物末端Ｃ－Ｃｌ键断裂能时,才能得到较好的引发效率,聚合物的相对分子质量分布也较窄     

里查孙公式的量子统计导出

用量子统计规律对金属里的自由电子进行了分析,并导出了里查孙公式．     

语言幺半群中子幺半群的自由性

证明了强左奇异且右奇异语言及｛１｝之集是语言幺半群的自由子幺半群;由此给出了强双侧奇异语言幺半群自由性的一个简化证明．进而讨论了极大前（后、双）缀码子幺半群的自由性问题．     

自由基的检测与应用

正常生理状态下,生物体内会产生自由基。如自由基反应失衡,多余的活性自由基就会损伤膜指质、蛋白、核酸等,甚至导致各种疾病。实验中用自旋捕集技术或化学生光法来检测自由基。