黄曲霉素B2分子吸附在银团簇的表面增强拉曼散射机理

采用密度泛函理论（DFT）B3LYP方法,6-311G（d,p）（C,H,O）/LANL2DZ（Ag）基组,计算了黄曲霉素B₂（AFB₂）分子吸附在Ag₂团簇的表面增强拉曼散射（SERS）光谱和预共振拉曼光谱,并与实验结果比较. 结果显示：AFB₂分子在基态Ag₂团簇表面吸附时,增强因子最大达到10²,对应吡喃（pyrane）环C=O伸缩振动,主要是由AFB₂分子周围化学环境改变而引起的基态静极化率改变导致的化学增强. 不同激发波长下的AFB₂分子预共振拉曼光谱的增强强度不同：电荷转移态激发波长为1144 和544 nm时拉曼信号增强了10²倍,而选择电荷转移预共振波长432和410 nm作为入射光时,其拉曼信号增强了10⁴倍,增强机理为银团簇和黄曲霉素分子之间的电荷转移共振增强. 因此通过改变入射光波长,选择电荷转移共振激发波长,更有利于强致癌物AFB₂分子的痕量检测.     

草药中 11种元素的聚焦微波辅助萃取-等离子体质谱法测定

利用ICP－MS对青钱柳叶、龙胆草以及秦皮中的11种金属元素进行测定。应用CEM Star-Ⅱ聚焦微波萃取系统,采用正交设计实验研究了温度、时间、料液质量体积比对浸取效率的影响。结果表明,温度是影响提取效率的主要因素,提取时间对某些元素影响也比较明显,但料液比对几乎所有元素的影响都很小。钒元素在微波萃取条件下溶出率很低。     

N1923从碱性氰化液中萃取金(Ⅰ)的研究

采用放射性同位素１９８Ａｕ示踪法研究了伯胺Ｎ１９２３和ＴＢＰ从碱性氰化液中萃取金（Ⅰ）,考察了酸化率、水相ｐＨ值、萃取剂浓度等对萃取率的影响,以及ＮａＯＨ对载金有机相的反萃作用。结果表明,ＴＢＰ含量大于２０％,酸化的Ｎ１９２３与ＫＡｕ（ＣＮ）２摩尔比值在１：１时,金能够完全被萃取。载金有机相可采用０．ｌｍｏｌ·Ｌ－１的Ｎａ０Ｈ溶液定量反萃。机理研究表明,伯胺和ＴＢＰ萃取Ａｕ（ＣＮ）２－,符合ＢＣ类协同萃取机理。当金浓度大于１０ｇ·Ｌ－１时,在萃取有机相中形成纳米级的聚集体。     

C_(60)RuH_2(CO)(PPh_3)配合物的合成和氧化还原性能研究

自从１９８５年Ｋｒｏｔｏ等人１发现Ｃ６０等碳原子簇以来在化学、物理以及材料科学掀起了富勒烯的研究热潮２。目前富勒烯配合物的制备及其性质的研究是富勒烯化学最为活跃的研究领域之一３～５人们正致力于探索富勒烯各类衍生物的结构与性质之间的依赖关系以期合成出具有特殊性能的富勒烯配合物为富勒烯的实际开发应用奠定基础。本文合成表征了Ｃ６０ＲｕＨ２ＣＯＰＰｈ３配合物研究了其氧化还原特性。１实验部分１．１Ｃ６０ＲｕＨ２ＣＯＰＰｈ３的合成合成按下列反应进行ＲｕＣｌ３＋３ＰＰｈ３＋ＨＣＨＯＲｕＨ２ＣＯＰＰｈ３３ＲｕＨ…     

BaLaB_9O_(16)∶Eu,Tb的真空紫外光谱特性

采用高温固相反应法合成了BaLaB9O1 6 ∶RE (RE =Eu ,Tb)等离子荧光体 ,测量了它们的真空紫外激发光谱和 14 7nm激发下的发射光谱。结果表明 ,硼氧阴离子基团基质吸收带位于 15 0nm附近 ,Eu3 电荷迁移带位移 2 5 0nm附近 ,Tb3 的 4f 5d吸收位于 15 0～ 2 60nm的区域内 ,相关数据表明 ,基质与稀土离子之间存在能量传递。     

注射用生物可降解胰岛素纳米微球的制备

共聚物;药剂释放体系;注射用生物可降解胰岛素纳米微球的制备     

三维含时量子散射研究H+ClH体系

用三维含时量子散射理论模拟了H+GlH体系在BW2,mBW2,G3势能面上的动力学行为.其计算结果表明,振动量子态对反应几率影响很大;势能面的地形对转动量子态如何影响反应几率起重要作用;反应几率表现出"黄金规则".此外,BW2,mBW2势能面上的反应几率几乎相同,而G3势能面上的反应几率较前者低,大概由于G3的势垒高的缘故.     

General Formulations of Finite-field Method Classified by Symmetry for Molecular Linear and Nonlinear Polarizabilities

1 INTRODUCTIONWith the invention of lasers[1] and the observation of second-harmonic generation in quartz[2], nonlinear optics(NLO), as a cornerstone of photonics, has been booming since 1960's. And intense interest has been aroused to search materials exhibiting appropriate nonlinear optical properties suitable for the construction of practical optical devices for the important techniques such as frequency converting, signal processing and optical computing[3～6]. In order to determine …     

Synthesis and Structure of Dimolybdenum(I) Carbonyl Compound with Thiolate and Carboxylate Mixed-tri-bridging Ligands [Bu_4N][Mo_2(CO)_6(SC_6H_4Cl-p)_2(CF_3COO)]

1 INTRODUCTION Molybdenum(I) compounds, in particular Mo(I)-SR compounds, are rare amongst numerous Mo compounds. So far, only the following compounds [Mo2(CO)8-n(SR)2(CH_3CN)n] (R = C6H5, CH_2CO2Et, n = 0, 2)[1～5] have been reported in the literature. Recently, we make an effort to develop investigations on Mo(I) compounds on the basis of preparing new Mo(I) compounds by introducing different functional ligands into Mo2(SR)2(CO)8, then determining their structures and measur…     

Synthesis and Structure of Dimolybdenum Carbonyl Thiolate Compound [Et4N]2[Mo2（CO）8（SC6H4—CH3—m）2]

1 INTRODUCTION In 1984, thiolate ligand was successfully introduced into molybdenum carbonyl compound by the reaction of Mo(CO)6 with [Et4N]SR( R = C6H5, But) in a moderate condition[1]. From then on, a series of dinuclear molybdenum(0) carbonyl thiolate compounds have been synthesized and characterized by using a variety of thiolate ligands in our research group. It was found that a planar Mo2S2 unit is in the compound [Et4N]2[Mo2(CO)8(SC6H4-CH_3-p)2][2] (2) and a "butterfly" t…