用多极矩展开方法计算H2分子间的相互作用对势

分子间相互作用对势是利用分子动力学研究物态性质的重要基础．作者利用多极矩展开方法，获得了H2-H2的从头算相互作用对势．采用从头算分子结构程序，先计算了3种不同数目特定构型下的相互作用势，再由此荻取多极矩的展开系数，构造相互作用对势，并对不同的展开方法下荻取的H2-H2的相互作用对势进行了分析比较．     

CLASSICAL TIME DEPENDENT SOLUTION FORNEUTRON TRANSPORT IN A SLAB WITHGENERALIZED BOUNDARY CONDITIONS

1.IntroductionSincethepioneeringworkofLehner,WingandJorgens['3],thetimedependentneutrontransportproblemhasbeentreatedbymanyinvestigators,andtheliteratureonthissubjectisconsiderable.Variousmethods,theCO-semigroupmethodin[2,3],theNeumannseriesexpansionmetho…     

Sources of cumulus expansion enabling factor (CEEF) in porcine follicles

It was shown that expansion of porcine cumulus did not depend on oocyte-secreted factor(s), and it is therefore presumed that porcine CEEF may not be produced exclusively by the oocyte. In this experiment, we used mouse oocytectomized complexes (OOX), which were incapable of CEEF production, to assess the secretion of CEEF by evacuated zona, oocytes of different quality and somatic cells in the porcine follicles. The results showed that: (ⅰ) Evacuated zonae from both porcine and mouse oocytes did not produce CEEF. (ⅱ) Porcine oocytes of A, B and C types from 3—6 mm follicles were not significantly different in both production and activity of CEEF. (ⅲ) Both porcine OOX from 3—6 mm follicles and granulose cells from < 1 mm follicles secreted CEEF in a large quantity, independent of gonadotropins; mural granulose cells from 3—6 mm follicles, however, produced neglectable amount of CEEF. (ⅳ) The follicular fluid from 3—6 mm porcine follicles contained CEEF activity that was concentration-dependent, and thus it enabled cumulus expansion in 60% mouse OOX when used at 10% of concentration, but the expansion rate of mouse OOX decreased to 9% when the concentration was increased to 50%. (ⅴ) Mouse OOX cultured in porcine CEEF-containing M199 expanded only in the presence of gonadotropins, suggesting that the activity of porcine CEEF is hormone-dependent.     

Novel Web Query Automatic Expansion Based on Rough Set

One of important reasons caused low precision was presented, which was due to inaccurate express of the query. So a new method of automatic query expansion based on tolerance rough was put forward. In the algorithm, the uncertain connection between query terms and retrial documents was described as term tolerance class. The upper approximation set of query sentence was considered as query expansion. The new additional terms were also given weight numbers. The results of experiment on collection of Google 5 000 Web pages showed that the approach was effective on query expansion and high search precision was gained.     

高温下氯化钠的P-V-T关系与热力学性质

在假设α(0,TR)BTR(0,TR)=常数的前提下,讨论了氯化钠的P-V-T关系和热力学性质.结果表明,所得到的理论值和实验值吻合很好.     

Properties of the Environmental-Friendly Si/Al Composite for Electronic Packages Fabricated by Squeeze Casting Technology

Introduction The electronic packaging materials were main-ly used to providing mechanical support,airproofprotect and electronic apparatus thermal dissipa-ting[1-3].With the development of computer,theaeronautics and astronautics and the military com-muni…     

电影元素与产业战略的双赢——评影片《地球上的星星》

《地球上的星星》是印度2008年放映的一部关于孩子、关于教育、关于爱的影片，一经放映便引起了巨大的轰动。影片在电影元素应用与商业运作两个方面都获得了成功，值得人们进行深入探讨。     

扩展Jacobi椭圆函数展开法及其应用

对 Jacobi椭圆函数展开法进行了研究, 指出了选择展开函数时需满足的2 个条件. 这 2 个条件可视为选择展开函数的1个简单原则. 在此原则指导下, 构造了新的展开函数, 且得到了 KdV方程、mKdV方程、Boussinesq方程更多的准确周期解. 该方法可用来求解一大批非线性演化方程(组).     

ON THE TRANSIENT DEPARTURE PROCESS OF M^x/G/1 QUEUEING SYSTEM WITH SINGLE SERVER VACATION

This paper studies the transient departure process of M^x/G/1 queueing system with single server vacation. We present a simple probability decomposition method to derive the expected number of departures occurring in finite time interval from any initial state and the asymptotic expansion of the expected number. Especially, we derive some more practical results for some special cases.     

信息技术对会计工作的影响

信息技术的高速发展对会计业务产生很大冲击,会计工作面临新的变革,会计学理论体系的变革、会计语言的变化、会计工作内容的更新等,拓展了会计业务的范围,对会计人员的素质提出了新的要求。