酶催化乙酰基转移反应的密度泛函研究(Ⅱ)

用密度泛函方法的B3LYP在6-31 g(d,p)基组水平上,研究了底物对-氨基苯甲酸与芳基胺-N-乙酰基转移酶之间的乙酰化反应.该反应共有两种可能的反应机理:协同反应和分步反应.计算结果表明,协同反应机制在竞争中占优势,是势能面上的最低能量反应通道.     

二十世纪七十年代联邦德国“新主体性”文学管窥

上个世纪七十年代在联邦德国文坛出现的“新主体性”文学,是一个有其历史特殊性的文学现象。它强调作家的自我、主观、经验、亲历、亲身或参与性,是对60年代文学“政治化”潮流的一定层面反拨,是理想失落后对关注、反映、表现、寻求自我的“饥渴”的弥补,但也并非自动就是一个根本性的思想放弃,而是带有新的信息、内涵与特征。反思或认同,人生或历史,体验或追求,感知或希冀,“新主体性”文学的边界是模糊和流动的。所撷取的代表性作品表明,个人与社会,文学与政治,自我语言与公共语言,知识分子精神困惑与知识分子精神守望,牵牵连连,难分难解。     

‘Wallbanking’, innovativeness and computer attitudes: 25–40-year-old ATM-users on the spot

Attitudes towards ‘wallbanking’ (making use of banking services through an Automated Teller Machine (ATM)) and self-reported frequency of wallbanking have been related to attitudes towards innovations and towards computers. The investigation also included the perception of advantages as well as disadvantages of wallbanking, factors that determine one's choice of a bank, man-machine problems related to the use of an ATM, and demographic factors. Using a sample of 201 respondents in the age range of 25 to 40 years, structural equation modeling revealed that wallbanking attitudes have a major influence on the frequency of using ATMs. The innovativeness attitude ‘New is wasteful’ also showed a clear negative link with the frequency of wallbanking. On the other hand, the relationship between computer attitudes and the frequency of using ATMs had to be rejected. Income and education proved to have an indirect link with the frequency of wallbanking, which refines other research findings. These results may reflect specific financial management characteristics of the age group under investigation.     

BX型中变催化剂还原性能的研究

铁铬系中温变换催化剂在使用前需经还原活化才具有催化活性。而还原条件的选取，又对催化剂还原后的性能有直接的影响。本文用透射电子显微技术研究了ＢＸ型催化剂还原前后的差异，分析了造成这一差异的原因，并计算了还原后催化剂颗粒的平均直径。用程序升温还原技术研究了催化剂的还原过程，用红外光谱技术研究了不同温度下催化剂的还原速率。综合研究结果讨论了还原过程中催化剂对还原条件的具体要求。并结合上述结果讨论了工业生产中现采用的还原程序，认为现采用的还原程序比较理想。     

HCONMe_2对[Co(N_3)(NH_3)_5]~(2+)与 Fe(Ⅱ)反应动力学性质的影响

H_2O—HCONMe_2混合溶剂中,[Co(N_3)(NH_3)_5]~(2+)被Fe(Ⅱ)还原的反应,X_(HCONM)<0.3时,反应的二级速度常数 k 随 X_(HCONMe2)增大而增大;X_>0.3后,k 随 X_2增大而减小.在 H_2O—HCONMe_2混合溶剂中,Fe(Ⅱ)的吸收光谱显示:近紫外区,溶液的吸光度随 X_(HCONMe2)增大而增大;Fe(Ⅱ)的电极电势与 X_的依存灶:随 X_增大,Fe(Ⅱ)的下降,但在X_>0.3后,趋于一定值.因此,反应速度的变化,可认为是由于 Fe(Ⅱ)配位圈中水分子的被取代和 Fe(Ⅱ)电极电势的变化.     

Small Parts Aspiration, Ingestion, and Choking in Small Children: Findings of the Small Parts Research Project

Obtaining information on current child injury trends and their associated issues is an important factor in developing products that meet or surpass acceptable toy safety boundaries. Understanding these boundaries helps determine safe product design characteristics that reduce the risk of product-related injury. Inchcape Testing Services developed a Small Parts Aspiration, Ingestion, and Choking Hazards Research Project, independent of an ongoing consumer Product Safety Commission (CPSC) project. The project's purpose was to determine, independent of CPSC, whether a more stringent small parts regulatory standard was necessary and, if so, to ensure that the standard was determined objectively. This article reports on the project's findings relating to critical characteristics (size, shape, and consistency) relative to the victim's age, of objects responsible for child choking injuries and fatalities.     

羊毛染色新方法

本文探讨了羊毛偶合反应染色新方法,即重氮化羊毛与色酚的偶合染色以及预处理羊毛与重氮化色基的偶合染色。研究了羊毛预处理及偶合染色工艺对染色效果和物理机械性能的影响,指出该方法在降低染色成本和提高染色牢度方面具有显著优势。     

金属与型壳界面作用对精铸件表面质量的影响

讨论金属与型壳界面作用对精铸件表面粗糙度和粘砂缺陷的影响。面层涂料中加入少量氧化铁，可有效地防止钢铁精铸件的表面粘砂缺陷。