一个新的夹心型杂多钨酸盐Na6(C5N2H7){[Na(H2O)2]3Co(H2O)5-[Co(H2O)]3(AsW9O33)2}•27H2O的晶体结构及性质

在pH＝7.5的水溶液中, Na₂WO₄•2H₂O, NaAsO₂, CoCl₂•6H₂O与对氨基吡啶反应, 得到了一种新的夹心型杂多钨酸盐Na₆(C₅H₇N₂){[Na(H₂O)₂]₃Co(H₂O)₅[Co(H₂O)]₃(AsW₉O₃₃)₂}•27H₂O单晶, 用X射线单晶衍射法及元素分析确定了其结构, 晶体属三斜晶系, P 空间群, 其晶胞参数为: a＝1.3276(8) nm, b＝1.7581(10) nm, c＝2.4381(14) nm, α＝70.954(9)°, β＝86.663(9)°, γ＝72.885(9)°, V＝5.136(5) nm³, Z＝2, R₁＝0.0608, wR₂＝0.0848 [I＞2σ(I)]. 在{[Na(H₂O)₂]₃Co(H₂O)₅[Co(H₂O)]₃(AsW₉O₃₃)₂}^7－阴离子中, 一个Co^2＋与聚阴离子{[Na(H₂O)₂]₃[Co(H₂O)]₃(AsW₉O₃₃)₂}^9－的一个端基氧共价连接, Co^2＋呈现出5和6两种配位数, 质子化的氨基吡啶正离子作为抗衡离子存在于晶体之中. 对标题化合物进行了IR, UV-Vis, TG-DSC表征. 对该化合物、Na₂WO₄•2H₂O及CoCl₂•6H₂O催化H₂O₂氧化乙醛的活性进行了比较研究, 该化合物的催化活性远优于简单化合物Na₂WO₄•2H₂O和CoCl₂•6H₂O.     

应用Monte Carlo方法计算He原子包含电子相关作用的基态能量

应用Monte Carlo方法计算He原子包含电子相关波函数的基态能量,获得了与精确值非常接近的结果．实践表明,应用Monte Carlo方法有可能在多电子体系中直接采用包含任意2个电子间距离ry的函数作为变分函数来考虑电子相关作用．     

Optical behaviors of conjugated-chain compounds containing benzene and furan units

Thirteen conjugated-chain compounds which contain benzene and furan units were prepared, their optical behaviors, including UV-vis absorption coefficient (varepsilon), absorption wavelengths (lambdaa), fluorescence emission wavelengths (lambdae), and quantum yields (Phi) were measured. Meanwhile, their LUMO and HOMO energy were determined by cyclic voltammetry and their second-order polarizations (betaxxx) values were determined by solvatochromic method, respectively. The results showed that this kind of compounds possess a shorter lambdaa (320-365 nm) and performance a higher Phi values, especially for 2aa, 2ab, 2ac and 2bb, their Phi values are all more than 90%. These compounds, except 2db, showed a higher betaxxx values in DMSO, especially for 2dc (75.77x10(-30) m5 C-1) and 2dd (83.32x10(-30) m5 C-1), than that 10-methyl-acridone (6.578x10(-30) m5 C-1) or 10-benzylacridone (6.845x10(-30) m5 C-1) in DMSO did, and second harmonic generation value of 10-methylacridone and 10-benzylacridone in powder are, respectively, 1.381 and 1.861 times of that value of urea. The betaxxx values and Phi values determined for these compounds in this work were lower than these values which were desired in the original work, this phenomena was explained from their molecular structures. This work confirmed that as these compounds performance shorter lambdaa and higher Phi values, they could be good blue-color optical materials for some fields, such as OLED materials, two-photo absorption materials, fluorescent dyes.     

液氦温区La2/3Ca1/3Mn1-xCuxO3(x=0.15)体系的磁电阻弛豫效应

实验上研究了液氦温区La2/3Ca1/3Mn1-xCuxO3(x=0.15)单相多晶样品给定磁场下的电阻随时间的变化,发现磁电阻随时间变化并非遵从对数规律而是呈指数型变化行为.对这一指数型磁电阻弛豫行为的可能起因进行了讨论,指出这是与Mn位上Cu掺杂将额外磁性杂质引入到样品中有关.     

n-Hg_(0.80)Mg_(0.20)Te界面积累层中二维电子气的输运特性研究

通过变磁场霍耳测量研究了MBE生长的Hg0 .80 Mg0 .2 0 Te薄膜在 1 5— 2 5 0K温度范围内的输运特性 .采用迁移率谱 (MS)和多载流子拟合过程 (MCF)相结合的方法对实验数据进行了分析 ,由该方法获得的结果和ShubnikovdeHass(SdH)振荡测量的结果都证明材料中存在二维 (2D)电子和三维 (3D)电子 .其中 2D电子主要来自于Hg1-xMgxTe CdTe的界面积累层或Hg1-xMgxTe与真空界面附近的积累层 .3D电子迁移率随温度的变化关系表明了Hg1-xMgxTe中的电子散射机理与Hg1-xCdxTe中的非常相似 :在低温下电离杂质散射 (考虑了屏蔽效应 )起主导地位 ,而温度在 10 0K以上时 ,晶格散射占主导地位 .     

Fresnel波带板编码成像技术

 介绍了Fresnel波带板编码成像原理,并设计出高空间分辨率的Fresnel波带板编码相机,用双孔可见光源对编码相机的成像进行了实验研究,表明该编码相机可以真实地还原源区的空间大小和形状。     

Population of Unstable Nuclides and Nuclear Temperature Extraction in 46.7MeV/u 12C Induced Reaction

The experiment results of unstable nucliaes decay by using the light charged particle correlation function obtained in ¹²C 46.7MeV/u+⁵⁸Ni experiment are reported.Under the assumption of statistical equilibrium,the nuclear temperatures are extracted,and the influence of the reaction mechanism on the nuclear temperature are also investigated.     

The Effect of the Neutron Skin and the Neutron Distribution Diffusion on Nuclear Potential

The interaction potentials between two heavy ions are calculated by using the energy density formalism and the nuclear Fermi density distributions,the factor of the neutron skin and the surface diffusion of the neutron distribution increasing with the increases of the neutron excess is considered.In this calculation,the experimental fusion barriers are well reproduced,and improved for the intermediate heavier nuclear systems.It is found that the neutron skin and the neutron distribution diffusion can explain the influence of the neutron excess degree of freedom on the proximity scaling.     

10-烃基吖啶酮的非线性光学活性研究

随着激光技术应用的发展,非线性光学材料的研究不断深人［'j,目前倍频效应和短的截止波长的倍频材料是二阶非线性光学有机材料研究的热点之一L'．现有的非线性光学有机材料,如偶氮苯、共轭烯烃与SChiff碱等类化合物,因分子具有较大的共轭长度使其吸收多处于可见光区,不适合于半导体激光等向蓝紫激光倍频"·"．0'（暖酮含有大。共轭结构,分子两端同时连有吸电子基团。X一0）和推电子基团（＞N-R）而发生分子内的电荷转移,使分子具有非线性光学活性"－·这类化合物结构简单,并有很好的光稳定性,且该类化合物最大紫外吸收在385～40…     

一个实用的合成甾烯-3-羧酸Epristeride的方法

甾烯-3-溴化合物通过钯催化的一氧化碳插入反应被转化成为相应的甾烯-3-羧酸类化合物。从而为甾烯-3-羧酸Epristeride提供了一个实用的合成方法。