Hydrothermal Synthesis and Crystal Structure of a Novel Isophthalate-bridged Copper(II) Polymer with Two-dimensional Network Structure: [Cu_2(phen)(ipt)_2]_(2n)·nH_2O (ipt = isophthalate, phen = 1,10-phenanthroline)

1 INTRODUCTION donor due to the presence of the protonated carboxyl group; (d) it can form short bridges via one car- Coordination polymers are of great interest due to boxylato end or long bridges via the benzene ring[7]. their physical properties and potential applications in We believe that coordination functionality of isoph- functional materials[1~3]. Aromatic polycarboxylic acids thalate can lead to interesting structures. In this com- such as 1,2,4,5-benzenetetracarboxylic acid[4],…     

Synthesis,Characterization and DFT Calculation of a New Silver(I) Iodid Templated by Conjugated Cation:(ipq)_4Ag_4I_8

1 INTRODUCTION The construction and characterizations of low dimensional inorganic/organic hybrid materials have increasingly attracted the interest of chemists duo to their unusual topologies and relevance in a wide range of applications in materials science including transport, magnetic materials, catalysts, and lumi- nescent materials[1]. Among the various families of hybrid functional materials, the family of metal halides is an important one. As a branch of the metal halides, silver(…     

Synthesis and Crystal Structure of a New Organic-inorganic Hybrid One-dimensional Polymer： [Zn（C8H23N5）]2（Pb3I10）

1 INTRODUCTION Recently, the organic-inorganic hybrid Ⅳa groupmetal halides with low-dimensional structure haveattracted much attention of chemists and physicistsdue to their particular properties and applications.For example, they are akin to “natural quantum-well”architectures and have tunable excitonic propertiesusually governed by the inorganic substructure andorganic component[1]; they have been applied assome technologically important materials, such assemiconductor materials in …     

Crystal Structure and Characterization of 2-N-(2-Hydroxy-benzylidene) Furanmethanoamine Nickel(II) Complex

1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1～3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4～7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate…     

Synthesis and Crystal Structure of Copper(II) Complex with N-Acetoxyl-picolinamide

1 INTRODUCTION The picoloylhydrazide compounds are close to thebiologic environment and can react with microele-ments in organism so as to have antitubercular andantineoplastic activities. However, owing to the exis-tence of amino group, this kind of compounds aretoxic to some extent[1]. In order to decrease theirtoxicity, hydrazone or hydrazide compounds synthe-sized by the condensation reaction of amino and car-bonyl groups have been well studied in recentyears[1～7]. Herein we report t…     

Ab Initio Study on the Anti-HIV Activities of Hydroxyflavones

1 INTRODUCTION AIDS, in other words, Acquired Immunodefici-encysyndrome, is a viral contagious disease withhigh death rate. However, effective treatment againstit has not appeared so far. At present, about 100kinds of natural compounds that could be extractedfrom natural products or artificially synthesized havebeen found to have anti-HIV activities to some ex-tent. They belong to flavonoid, terpenoid, steroid, cou-marin, peptide, alkaloid etc., respectively. Previousstudies show that…     

Correlation Study on Sweetness of Amino Acid with Different Configurations and Quantum Chemical Parameters

1 INTRODUCTION Since the introduction of QSAR by Hansch and Fujita in 1964, Deutsch and Hansch have quickly used it in the study of nitrophenylamine sweet reagents. They found good correlation between their distribution coefficients in octanol/water system and sweetness degree. Subsequently, they detected that vibration of aroma-substituent compounds has so- mething to do with sweetness. Henceforth, statistic correlations between structure and sweetness ofseries compounds have been inv…     

Investigation on Electronic Structures and Spectra for the Substituted Fullerene C77B-

1 INTRODUCTION After Guo[1] synthesized and detected C60-nBn and C70-nBn by mass spectra, investigations on fullerenes doped by other atoms became more and more interesting. Andreoni[2] studied the impurity states of the doped fullerenes C59B; Dong[3] calculated the structural and electronic properties of C59B; Wang[4] assessed the stability of heterohedral fullerenes C60-xBx. Lamparth[5] prepared C59N and C69N , and put forward the possible structures for C59N . Sahoo[6] obtained…     

Synthesis,Crystal Structure and Antimicrobial Property of 4-Bromo- 2- [（3-methypyridin-2-ylimino）methyl]phenol

The title Schiff base compound 4-bromo-2-[（3-methylpyridin-2-ylimino）methyl]phenol was prepared and structurally characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P2 1/n, with a = 4.4870（9）, b = 19.953（4）, c = 13.860（3）A, β = 93.13（3）°, V = 1239.0（4）A3 Z = 4, Dc = 1.561 g/cm3, C13H11BrN2O2 , Mr = 291.15, p = 3.302 mm-1 and F（000） = 584. The final refinement gave R = 0.0608 and wR = 0.1377 for 1329 observed reflections with I 〉 2σ（I）. X-ray diffraction reveals that the non-hydrogen atoms in the compound are nearly coplanar, with the mean deviation of 0.0197A from the plane. The molecule adopts an E configuration about the central C=N functional bond. The compound possesses moderate antimicrobial property.     

基于加权方差估计的降维

提出一种新的降维方法, 加权方差估计(WVE), 它包含了切片平均方差估计(SAVE)作为特例. 并且利用Bootstrap方法从WVE中 选择出最优估计, 给出了维数的选择方法. 该最优估计通常远好于已有方法, 比如切片逆回归(SIR)等. 已有的许多方法, 如SIR, SAVE等, 通常对每个 观测给予相同的权来估计中心子空间(CS). 通过引入权函数, WVE根据观测样本距中心子空间的距离, 对不同观测给予不同权重. 权函数使得WVE在很 一般或复杂的情形下有很好的表现, 比如, 回归变量的分布严重偏离椭圆对称分布. 而椭圆对称分布假设是许多方法 的基本假定, 如SIR, SAVE等. 和已有方法相比, WVE对自变量的分布不敏感. 本文建立了WVE的相合 性. 与其他方法的模拟比较表明了WVE的优点.