Tb~(3+):LaBr_3能级分析

本文对Ln~(3+):LaCl_3和Ln~(3+):LaBr_3体系进行晶场能级分析,其主要目的有二:(一)对已测得的实验能级进行理论计算和归宿;(二)探讨能级间的相互作用及等价算符方法和不可约张量方法对该体系的适合程度。理论计算采用投影算符方法构成J=6,5,4,3,2,1,0的D_(3h)不可约表示基矢。在整个计算过程中,晶场矩阵由相同不可约表示的基矢构成。对~7F(J=6,5,4,3,2,1,0)本文分别应用等价算符方法(略去晶场J相互作用即略去所谓的晶场J混合作用)和不可约张量方法(考虑晶     

SiH_3NO_2－SiH_3ONO异构化的量子化学研究

用ＭＮＤＯ法研究了ＳｉＨ_３ＮＯ_２和其异构体ＳｉＨ_３ＯＮＯ之间的转化。结果表明，Ｓｉ－Ｎ键的断裂和Ｓｉ－Ｏ键的生成有较小的能垒，反应为放热过程。     

Preparation and Luminescence Behavior of CaSiO3：Eu^3＋（Bi^3＋）

CaSiO3：Eu0.08^3＋Bi0.002^3＋ with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at 238,396,415,437 and 359 nm correspond to the charge-transfer band of Eu^3＋-O^2- , the absorption transitions of ^7F0.1→^3L6, ^7F0→^5D3, ^7F1→^5D3 of Eu^3＋ ions, and ^3P1→^1S0 of Bi^3＋ ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to ^5D0→^7F2 of Eu^3＋ ions was stronger than the magnetic dipole transition located at 587 nm corresponding to ^5D0→^7F1 of Eu^3＋ ions, which shows that more Eu^3＋ ions were located in nonreversion center lattices. The energy transfer from Bi^3＋ ions to Eu^3＋ ions in the phosphor was also discussed. The results show that Eu^3＋ ions could be well sensitized by ^3＋ions, and the energy-transfer pattern between Bi^3＋ ions and Eu^3＋ ions was resonance energy transfer.     

SiH3No2—SiH3ONO异构化的量子化学研究

用ＭＮＤＯ法研究了ＳｉＨ３ＮＯ２和其异构体ＳｉＨ３ＯＮＯ之间的转化，结果表明，Ｓｉ－Ｎ键的断裂和Ｓｉ－Ｏ键的生成有较小的能垒，反应为放热过程。．     

三核铁苯甲酸配合物［Fe_3O（OBz）_6（CH_3OH）_3］（NO_3）（

测定了三核苯甲酸铁配合物［Ｆｅ_３Ｏ（ＯＢｚ）_６（ＣＨ_３ＯＨ）_３］（ＮＯ_３）（ＣＨ_３ＯＨ）_２（ＯＢｚ~－＝苯甲酸根）的电子光谱，应用配体场理论和Ｔ－Ｓ图求得配体场参数１０Ｄｑ＝１２４５７ｃｍ~（－１）。用ＣＮＤＯ／２方法对其简化模型进行了计算。     

三核铁苯甲酸配合物[Fe3O(OBz)6(CH3OH)3](NO3)(CH3OH)2的电子光谱及其理论分析

测定了三核苯甲酸铁配合物[Fe₃O(OBz)₆(CH₃OH)₃](NO₃)(CH₃OH)₂(OBz^-=苯甲酸根)的电子光谱,应用配体场理论和T-S图求得配体场参数10Dq=12457cm^-1.用CNDO/2方法对其简化模型进行了计算。     

Synthesis and Crystal Structure of 1-（4-Chlorophenyl）-2-cyano-3-amino-3a-hydroxy-3a,3b ,6, 7-te trah y drobenzo[ 4,5]indene

1 INTRODUCTION dimerization of α,β-unsaturated ketones[10]. Herein we discuss the crystal structure of the title compound In the early seventies three groups of investiga- synthesized by the reaction of 2-cyano-3-(4-chloro- tors[1~3] have established that low-valent titanium phenyl)-3-(1-tetralon-2-yl) induced by TiCl4/Zn system. can abstract oxygen from ketones or aldehydes, lead- When 2-cyano-3-(4-chlorophenyl)-3-(1-tetra- lon-2-yl) ing to the formation of olefins. A variety of other…     

Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro[2,3-d]pyrimidin-4（3H）-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.     

Synthesis and Fungicidal Activities of 2-Alkylthio-5- （3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazoles

Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.     

Synthesis and Crystal Structure of （H3O）2[Cu3Cl3（H2O）3（NC9H12.5O6）2]

1 INTRODUCTION The polydentate ligand nitrilotripropionic acid, H3ntp[N(CH2CH2COOH)3], has attracted conside- rable research interest in constructing coordination polymers, designing organic-inorganic hybrid mate- rials[1], synthesizing supramolecular compounds[2], etc. due to its high degree of flexibility with three carboxylic acid moieties allowing for a variety of coordination through oxygen atoms[3]. It also pro- vides other versatile properties such as the possibili- ty of inter-…     

Syntheses and Crystal Structures of Two Complexes with 3-（3-Pyridyl）acrylic Acid

1 INTRODUCTION A recent feature in the development and progress of chemical research is the concern for molecular assemblies, ensembles, and all of structural aggre- gates[1]. The self-assembly of transition metal ions and N-containing organic ligands has been proven a popular approach for the construction of supramo- lecular architecture[2～7]. 3-(3-Pyridyl)acrylic acid is an excellent ligand, not only due to its prolific coor- dination sites but also to its potential hydrogen bon- ding…     

等电子系列XO-3及BF3的定量价键阐述

等电子系的理论和实验研究，可以揭示体系内部电子运动与其外在宏观性质之间的关系．由于等电子体BO33-、CO32-和NO3-均可稳定存在，可以推测该系列的下一个物种OO3也会短暂存在，尽管实验仅发现O4以O2双聚体，即vanderWaals分子（O2）2形式存在．最近Roeggen等［1］和Hotakka等［2］同时对OO3（D3h点群）进行了理论上的研究，前者采用EXGEM方法和（9s5p1d）／［6s4p1d］基组进行计算，表明OO3是一亚稳结构，且Ro－o＝1．330A；后者对BO33-、CO32-、NO3-及OO3系列进行了对比研究，发现采用6－31G基组作HF计算得到的键长和振…     

用直接动力学方法确定CF3CHFCF3与Cl原子反应的速率常数

采用直接动力学方法研究了CF3CHFCF3与氯原子反应的动力学特性,利用包含小曲率隧道效应的正则变分过渡态理论确定了200～2 000 K温度区间内反应的速率常数.     

GdAlO_3:Er~(3+),Yb~(3+)荧光粉的制备与上转换发光性能

采用共沉淀、溶胶-凝胶和固相反应法制备了GdAlO3:Er3+,Yb3+荧光粉.借助X射线衍射、扫描电子显微镜、傅里叶变换红外光谱、N2-吸附、吸收光谱和荧光光谱等手段研究了不同方法制备的GdAlO3:Er3+,Yb3+荧光粉结构、形貌、表面基团和光吸收及上转换发光性能.结果表明:用共沉淀法比固相反应法和溶胶-凝胶法可以在更温和的条件下制得纯相GdAlO3:Er3+,Yb3+荧光粉,用共沉淀法和溶胶-凝胶法制备的GdAlO3:Er3+,Yb3+荧光粉颗粒都在纳米尺寸,溶胶-凝胶法制得的样品存在相对严重的颗粒团聚现象,而用固相反应法制备的荧光粉为微米级颗粒.GdAlO3:Er3+,Yb3+荧光粉在980 nm激发的上转换发射光谱包含波长为524和546 nm的绿光与659 nm的红光,且三种方法制备的样品绿光发射强度都显著高于红光.不同方法制备的荧光粉上转换发光强度和红光/绿光强度比相差较大,共沉淀法制备的样品上转换发光强度要显著高于固相法以及溶胶-凝胶法制备的样品,而溶胶-凝胶法制备的样品发光中红光/绿光相对强度比最高.红外光谱显示,不同方法制备的GdAlO3:Er3+,Yb3+荧光粉表面OH-、CO32-及CO2官能团含量不同,溶胶-凝胶法制备的样品要明显高些.基于红外光谱、不同Er3+和Yb3+离子掺杂浓度及不同激光功率上转换发光的结果,对Er3+和Yb3+之间的能量传递过程及不同方法制备荧光粉的上转换发光性能进行了讨论.     

Storage-Reduction of NOx over Combined Catalysts of Pt/Ba/Al2O3-Mn/Ba/Al2O3： Carbon Monoxide as Reductant

Storage-reduction of NOx by carbon monoxide was investigated over combined catalysts of Mn/Ba/Al2O3-Pt/Ba/Al2O3. Combination of Mn/Ba/Al2O3 and Pt/Ba/Al2O3 catalysts in different ways showed excellent NOx storage-reduction performance and the content of Pt could be reduced by 50%. Not only the addition of 5Mn/15Ba/Al2O3 to lPt/15Ba/Al2O3 could improve its storage ability, but also enhance the NOx conversion consequently. NOx conversion over the combined catalysts (the combined catalysts I and II) was increased under dynamic lean-rich burn conditions, the maximum NOx conversion increased from 69.4% to respectively 78.8% and 75.7% over two combined catalysts.     

纳米级PbCO3制备方法的改进

对沉淀法制备的PbCO3 结构和形貌的表征发现PbCO3 晶体生长速度很快 ,沉淀法很难制备纳米级PbCO3 。采用 80 0 0r/min高速条件下的沉淀法 ,制备了纳米级PbCO3 。同时对原料和反应物浓度影响的实验表明 ,Pb(CH3 COO) 2 ·3H2 O取代Pb(NO3 ) 2 时 ,所制备PbCO3 的粒度分布集中 ,粒子尺寸为 10 30nm ,并且粒子粒径随着Pb(CH3 COO) 2 ·3H2 O浓度的增大而减小     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1, 2, 4]triazolo[3, 4-b； 4＇, 3＇-d][1, 3, 4] thiadiazines

To find new structural leading compounds for the research of the multidrug resistant of antibacterial agents, five novel 8-substituted phenyl-l-pyridin-3-yl-5H-bis[1, 2, 4] triazolo[3, 4-b;4‘,3‘-d] thiadiazines were prepared from the corresponding intermediates of 3-(5-substituted phenyl[1,3,4]oxadiazol-2-ylmethylsulfanyl)-5-pyridin-3-yl-[1,2,4]triazol-4-ylamines via intramolecular cyclization and the antibacterial activity in vitro against Gram-postive (G^ ) and Gramnegatiye (G) bacteria was primarily evaluated.     

g-C3N4纳米片制备方法研究

作为一种sp2共轭体系的非金属聚合物半导体,g-C3N4纳米片在光电化学、催化、光催化及生物医药等领域具有广泛的应用前景。本文综述了g-C3N4纳米片的制备方法,总结了各种不同方法制备g-C3N4纳米片的的优缺点,并对g-C3N4纳米片的发展进行了展望。     

Preparation of nanometer FeCuP alloy and its application in decomposition of PH3

A new ternary Fe-based alloy catalyst FeCuP applied to decompose PH_3 was prepared with low-cost material by chemical reduction deposition method.The properties of it were characterized by XRD,ICP and SEM.Its catalytic activity on the decomposition of PH_3 and the decomposition conditions were studied.FeCuP alloy exhibits high thermal stabilities and high catalytic activity.Using it as catalyst,the decomposition temperature of phosphine decreases from over 800℃to 400-500℃.The decomposition rate of phosphine achieved 100%.