一水甲酸锂晶体二阶非线性光学系数的理论计算

采用有限场方法和含时耦合微扰方法,在6-31+G*基组水平上并考虑了电子相关效应和色散效应的影响,计算了一水甲酸锂晶体的宏观二阶非线性光学极化率和二阶非线性光学系数。其中非线性光学系数d31和d32与Roberts报道的相符,而另一个系数d33则比文献值大。计算结果还表明,在非共振情况下,电子相关效应对非线性光学极化率的影响远远超过了色散效应,同时表明Roberts报道的非线性光学系数比Singh等人报道的更为合理。     

Characteristics of lubrication at nanoscale in two-phase fluid system

Thin film lubrication (TFL) is a condition in which the lubricating features between two surfaces in relative motion are determined by the combination of the properties of the surfaces and the lubricant and viscosity of the lubricant. The effects imposed by couple stress on lubrication characteristics cannot be disregarded in this regime where the ordered molecules dominate the fluid field. There are different tensor measures and constitutive equations in this case other than Newtonian case. The lubrication of two-phase (solid phase and liquid phase) fluid is investigated in this paper. The existence of couple stress will enhance the lubricant viscosity and hence increase the film thickness and improve the load-carrying capability. Size-dependent effects can be seen in the lubrication with couple stress, and the thinner the lubricating film is, the more obvious the effect will be.     

基体改进剂石墨炉原子吸收光谱直接测定饮料中的砷、铅、铜的研究

饮料是食品卫生监督检验的常测样品,饮料中的砷、铅、铜的含量是必测的指标。长期以来样品均采用酸式湿消化或碱式干灰化处理,分别用化学法测定,分析速度慢,方法的灵敏度也较低。近年来出现的基体改进剂石墨炉原子吸收光谱直接测定食品中铅和铜的方法,使分析速度和灵敏度都有了很大提高。但在食品中直接测砷却遇到很大的困难,砷是允许灰化温度最低的元素,在食品样品中,由于有大量有机物的作用,使它更容易损     

过渡金属类立方烷原子簇化合物电子结构和二阶非线性光学性质的密度泛函理论研究

采用基于第一原理的含时密度泛函理论(TDDFT)对一系列具有类立方烷簇芯结构的过渡金属簇合物二阶非线性光学性质进行了研究。结果证明, 由于簇芯结构的对称性的影响, 这一类簇分子的二阶非线性光学系数的数值要小于三核欠完整类立方烷体系。通过对电子结构的分析, 发现二阶非线性光学性质主要是由簇芯内电荷的迁移造成的。轨道分析显示, -S原子对于电荷的迁移起主要的传递作用。定域化轨道分析证明簇分子中存在的多中心键有利于簇芯内电荷的迁移。分子模拟的研究表明:虽然类立方烷结构簇分子的值比较小, 但是通过合理的配体设计, 获得具有较大值非线性光学晶体是可能的。     

N-(1, 3, 4-噻二唑-2-基)-N′-芳酰基脲的合成及其生物活性

N-(1;3;4-噻二唑-2-基)-N′-芳酰基脲的合成及其生物活性;噻二唑;芳酰基脲;合成;生物活性;植物生长调节剂     

二（1N-苄基-苯并咪唑）二氯合钴配合物的晶体结构、电化学和热稳定性能研究(英)

0IntroductionBenzimidazoleisaninterestingheterocyclicringbecauseitispresentinvariousnaturallyoccurringdrugs,suchasomeprazole,astemizoleandemedastinedifumarate[1].Theefficacyofsubstitutedbenzimida鄄zolesinthetreatmentofparasiticinfectionsiswellknown[2,3].B…     

Structure of Hexakis(imidazole)nickel(II) Nitrate Water Solvate:[Ni(Im)_6] (NO_3)_2·4H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＩｍｉｄａｚｏｌｅｈａｓａｔｔｒａｃｔｅｄｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒｅｓｔａｓａｌｉｇ ａｎｄｉｎｍａｎｙｂｉｏｌｏｇｉｃａｌｓｙｓｔｅｍｓｉｎｗｈｉｃｈｉｔｐｒｏｖｉｄｅｓａｐｏ ｔｅｎｔｉａｌｂｉｎｄｉｎｇｓｉｔｅｆｏｒｍｅｔａｌｉｏｎｓ .1Ｉｍｉｄａｚｏｌｅｉｔｓｅｌｆｉｓａｎｕｎｉｄｅｎｔａｔｅｌｉｇａｎｄａｎｄｆｏｒｍｓｃｏｍｐｌｅｘｅｓｗｉｔｈｍｅｔａｌｉｏｎｓｔｈｒｏｕｇｈｉｔｓｔｅｒｔｉａｒｙｎｉｔｒｏｇｅｎａｔｏｍ .Ｓｏｍｅｃｏｍｐｌｅｘｅｓｏｆｉ…     

一维链状配位聚合物[Cd(N-MeIM)_2(SCN)_2]_n的结构表征和电化学性能研究(英文)

0 IntroductionThe rapid development in the area of polymericmetalorganic frameworks (MOFs) continues to producevarious structures with interesting compositions andtopologies[1￣5] , along with potential applications asfunctional solid materials for molecular selection, ionexchange, and catalysis[6￣10]. By the careful selectionand design of organic ligands, such as linear isothio-cyanate-based building blocks, a wide variety of solid-state supramolecular architectures have been con-structed[1…     

石墨炉AAS法直接测定食品中铅、镉、锰、铜和铬

食品中铅、镉、锰、钢和铬的测定是食品卫生监测的常作项目。目前主要采用酸消化或高温灰化样品,化学法测定,比较耗时。本文介绍以磷酸为基体改进剂,用石墨炉原子吸收(AAS)直接进样测定食品样品中上述五个元素,对于能与水互溶的液体样品,易溶于水的固体样品以及用水制成悬     

Dawson结构钼磷酸的合成与表征

合成了H_6P_2Mo_(18)O_(62)杂多酸及其四丁基铵盐和四丁基鏻盐,用IR、~(31)P NMR、GV等手段核查其纯度并研究了热稳定性、酸性和氧化还原性。结果表明,Dawson结构钼磷酸较Keggin结构钼磷酸有更强的氧化性。