MANNICH反应及其在生物碱合成中的应用

本文详细讨论了 Mannich 反应、机理及其在生物碱合成中的应用,并利用 Mannich 反应合成了两种生物碱.     

Nonlinear predator-prey singularly perturbed Robin Problems for reaction diffusion systems

The nonlinear predator-prey reaction diffusion systems for singularly perturbed Robin Problems are considered. Under suitable conditions, the theory of differential inequalities can be used to study the asymptotic behavior of the solution for initial boundary value problems. Project supported by the National Natural Science Foundation of China (No. 10071048), and by the “Hundred Talents Project” of the Chinese Academy of Sciences     

C-[L-Ser-L-Ser]催化的不对称Reformatsky反应

利用液相法合成了侧链带双羟基且具有C2 对称性的环二肽C_[L_Ser_L_Ser]并将其作手性配体催化不对称的Reformatsky反应。考察了反应底物结构以及反应条件等因素对反应产物e.e.值的影响。产物的e.e.值最高达 64%。提出了可能的反应机理     

稀土农用技术及作用机理研究进展(综述)

本文对近年来稀土农用的文献进行了综述,总结了稀土农用的效果和施用技术,从6个方面概括了稀土增产提质的生物效应本质,提出了当前稀土农用研究中存在的问题及今后努力的方向．     

A distributional analysis of the effect of physical exercise on a choice reaction time task

Abstract

The aim of this study was to examine the facilitating effects of physical exercise on the reaction process. Eleven participants with specific expertise in decision-making sports performed a choice reaction time task during moderate sub-maximal exercise (90% of their ventilatory threshold power). Participants were tested at rest and while cycling. During exercise, the participants were faster, without being more variable. We suggest that the effect of exercise on cognitive performance was due to a major generalized improvement of the whole distribution of response time and, although the benefit effect was small, it was consistent throughout the entire range of reaction times.     

关于柳宗元被贬后对待挫折的心理分析

通过对柳宗元被贬后的复杂心态及行为反应的分析，认为被贬谪后的柳宗元对待挫折是采取了积极进取的建设性反应。他根据实际情况调整了行为方式，致力于总结历史经验和文学创作，绕过难于在官场上有所作为的障碍，继续为国家的统一和社会的进步而呼唤呐喊，最终实现了“取贵于后”的人生价值。因而，他不是一受挫折即一蹶不振的懦夫，而是在失败后依然坚持斗争的成功者。     

中学化学中的离子反应与高考中的离子反应方程式

This thesis discusses the judgment of the ionic reaction and ionic reaction representation.     

Metal hydride work pair development and its application on automobile air conditioning systems

INTRODUCTION Metal hydrides are special alloys which absorb and desorb hydrogen reversibly. At room temperature, metal hydrides could absorb as much hydrogen as liquid hydrogen of the same volume under much lower pressure and much higher temperature (Güther and Otto, 1999). Massive reaction heat is generated accompanying this reaction, which could be used for waste heat recovery, solar energy utilization and re-frigeration with no side effect to environment (Izhvanov et al., 1996). Con…     

The Persistence of Solid and Liquid Naive Conceptions: A Reaction Time Study

The study explores whether the naive concepts of solid and liquid persist in adolescence. Accuracy of responses and reaction times where measured while 41 ninth graders classified different solids (rigid, non-rigid and powders) and different liquids (runny, dense) into solid or liquid. The results show that these naive conceptions affect adolescences’ classifications in terms of both accuracy and reaction time. The rate of correct classifications of non-rigid solids and powders was significantly lower than of rigid solids. Lower rate of success was also found for classification of dense liquids compared with runny liquids. In addition, the reaction time results of correct classifications for non-rigid solids and powders were longer than those for rigid solids and, likewise, reaction times for dense liquids were longer than for runny ones. These results suggest that reasoning processes associated with correct classification of objects that are not consistent with the naive conceptions are more demanding.