甲烷水合物(H_2O)_(20)…CH_4稳定性的量子化学研究

采用密度泛函理论PBE方法和二级微扰(MP2)理论,对甲烷水合物(H2O)20…CH4两种不同构型512(H2O)20…CH4和435663(H2O)20…CH4进行了理论研究。在PBE/6-31++G(d,p)水平下进行结构优化,得到了它们的平衡稳定结构;在MP2/aug-cc-pVTZ水平下,结合基函数重叠误差(BSSE)完全均衡校正法,对其复合物进行能量计算。通过计算得出:512(H2O)20…CH4和435663(H2O)20…CH4的结合能分别为-4.75 kcal/mol和-4.44 kcal/mol,大约是相同水平下单一H2O…CH4结合能的8~9倍;512(H2O)20…CH4构型较435663(H2O)20…CH4稳定。     

语言输入与输出的认识—基于克拉申输入假说的评析

本文从二语习得，儿童母语刁得和外语教学的不同角度探讨了克拉申“输入假说”的部分理论依据，指出该学说存在的一些不足之处；得到其对外语学习的指导作用，但是也指出在语言习得中语言输出和输入一样的重要。     

唐代社会阶层结构变革：由贵贱到贫富

唐代中叶，一个新兴的阶层——富民阶层崛起。由此，中国古代社会的阶层结构出现转型，由身份等级制向以财富为标准的贫富转化。富民作为“民”无权将佃农沦为自己的依附民，而只能依靠财富的力量。以契约形式利用佃农的劳动力。这样，在法律身份平等基础上的一种新型的契约关系成为主导。唐代社会阶层结构的变革对国家政策、制度产生了深远影响，标志着中国古代社会由前期向后期转型。     

一种二维表通用程序的设计方法

本文讨论一个通用的二维表程序的设计。它具有热键、全屏幕编辑、操作简便及定义简单等特点。用户可通过该程序进行简单的定义就能完成不同项目的计算机管理。特别适用于用户自己根据需要随时修改和增加的管理系统。这对专业人员缺乏的基层单位能加快计算机管理的推广和应用。     

Was Newtonian cosmology really inconsistent?

This paper follows up a debate as to the consistency of Newtonian cosmology. Whereas Malament [(1995). Is Newtonian cosmology really inconsistent? Philosophy of Science 62, 489–510] has shown that Newtonian cosmology is not inconsistent, to date there has been no analysis of Norton's claim [(1995). The force of Newtonian cosmology: Acceleration is relative. Philosophy of Science 62, 511–522.] that Newtonian cosmology was inconsistent prior to certain advances in the 1930s, and in particular prior to Seeliger's seminal paper of Seeliger [(1895). Über das Newton'sche Gravitationsgesetz. Astronomische Nachrichten 137 (3273), 129–136.] In this paper I agree that there are assumptions, Newtonian and cosmological in character, and relevant to the real history of science, which are inconsistent. But there are some important corrections to make to Norton's account. Here I display for the first time the inconsistencies—four in total—in all their detail. Although this extra detail shows there to be several different inconsistencies, it also goes some way towards explaining why they went unnoticed for 200 years.     

一类二阶积微分方程的必要条件

本文讨论了二阶非线性积微分方程所决定的一类Lagranga问题的必要条件.引进系统合理的温和解,证明了系统温和解的存在性.进一步用直接方法导出了最优化的必要条件.     

对称四甲基六元瓜环、钠离子、对硝基苯酚三元配合物的晶体结构

在有机分子存在条件下,制备得到对称四甲基六元瓜环(TMeQ[6])与Na离子的晶体,并利用单晶X-射线衍射分析方法对其结构进行了测定.结果表明,在对硝基苯酚存在条件下,两个Na离子分别与TMeQ[6]两个端口的两个羰基氧原子直接配位,形成典型的“分子胶囊”结构.“分子胶囊”间通过共用水分子而形成了一维超分子链.而NO2-Ph-OH通过与TMeQ[6]的π-π堆砌和C-H…π相互作用有序地排列在超分子链的周围.     

How to (properly) strengthen Bell's theorem using counterfactuals

Bell's theorem in its standard version demonstrates that the joint assumptions of the hidden-variable hypothesis and the principle of local causation lead to a conflict with quantum-mechanical predictions. In his latest counterfactual strengthening of Bell's theorem, Stapp attempts to prove that the locality assumption itself contradicts the quantum-mechanical predictions in the Hardy case. His method relies on constructing a complex, non-truth functional formula which consists of statements about measurements and outcomes in some region R, and whose truth value depends on the selection of a measurement setting in a space-like separated location L. Stapp argues that this fact shows that the information about the measurement selection made in L has to be present in R. I give detailed reasons why this conclusion can and should be resisted. Next I correct and formalize an informal argument by Shimony and Stein showing that the locality condition coupled with Einstein's criterion of reality is inconsistent with quantum-mechanical predictions. I discuss the possibility of avoiding the inconsistency by rejecting Einstein's criterion rather than the locality assumption.     

一致度量拓扑意义下参数最优化问题解的稳定性

在一致度量拓扑意义下，研究了参数最优化问题解的通有稳定性。针对目标函数空间，引进了函数的一致度量拓扑，结合上图拓扑意义下该问题解的稳定性结果，通过巧妙构造辅助映射，得到了参数最优化问题的解具有通有稳定性。     

相转移条件下钯催化合成邻氯苯乙酸

报道在相转移催化剂存在下，以Ｐｄ（ＰＰｈ３）２Ｃｌ２作羰基催化剂，用邻氯氯苄、一氧化碳为原料在常压下羰基化合成邻氯苯乙酸，收率６２．２％，并考察了该反应的影响因素。