流动注射氢化物发生-原子荧光光谱法测定土壤中有效态As(Ⅲ)和As(Ⅴ)

提出了一种流动注射氢化物发生 原子荧光光谱法测定土壤中有效态As(Ⅲ )和As(Ⅴ )的方法。在0 1mol·L-1柠檬酸介质 (pH =3 1)中选择性测定As(Ⅲ ) ,然后用L 半胱氨酸流动注射在线还原As(Ⅴ )后测定总砷 ,由二者之差求得As(Ⅴ )。设计了在线还原及氢化物发生流路和操作程序 ,选择了各项化学条件和流路参数。As(Ⅲ )和As(Ⅴ )的检出限 (3σ)分别为 0 11和 0 0 7ng·mL-1。对于 10ng·mL-1As(Ⅲ )溶液 ,连续7次测定得精密度 (RSD)为 1 43% ,应用于实际土壤样品的测定 ,加标回收率在 82 %～ 10 4%之间     

氢化物发生进样与ICP-MS检测方法的联用

本文以近十几年所发表的论文为主，同时也参考了早些年的研究文献，综合介绍了氢化物发生与电感耦合等离子体质谱联用的分析方法，主要比较了研究工作者们沿用的各类氢化物发生器的构造和性能，分析测试中主要存在的问题，以及这种方法的应用现状和前景。     

Synthesis, Characterization of Heterodinuclear Co-Cu Complex and Its Electrocatalytic Activity towards O_2 Reduction: Implications for Cytochrome c Oxidase Active Site Modeling

IntroductionMetalloenzymesplaymanyimportantrolesinnatureespeciallyinelectron transferbiologicalprocesses .Be causeoftheirimportanceandcomplexity ,manysimplifiedmodelsystemshavebeenconstructedforthestudyoftheirchemistry .Amongvariouspolymetallicmetalloenzymes ,cytochromecoxidase (CcO)istheoneofthemostspecialinterest.CcO ,theterminalenzymeoftherespiratorychain ,catalyzesthereductionofO2 by 4H+,4e- towaterwith outleakageofanypartiallyreducedintermediateswhicharetoxictocellsuchasH2 O2 .Thefree…     

PFT—NMR相位循环的计算机辅助设计

本文介绍了通过选择相干传递路径来计算相位循环的理论依据。在此基础上提出了一个计算机程序PHASE.BAS用于计算相位循环。使用此程序设计了一个128步的相循环用于一维和二维INADEQUATE实验。实验结果表明此相循环能很好地消除单量子信号、压制t_1噪声,其效果明显优于Bruker MSL脉冲序列库中的32次循环的结果。     

Ca3Co2O6及其掺镍体系的电子结构计算

用离散变分密度泛函方法(DFT-DVM)计算了钴酸盐Ca3Co2O6及其掺镍体系，讨论了电子结构，化学键等与热电性能之间的关系．结果表明，价带和导带主要由Co3d，Ni3d和O2p原子轨道贡献．价带和导带之间的能隙宽度表现出了半导体电子结构特征，且掺镍体系的能隙比不掺镍体系窄．掺镍体系的共价键和离子键都比不掺镍体系弱．由此得到，掺镍后体系的热电性能将有所改善．     

REMOVAL OF PHOSPHATES FROM WATER BY PILLARED RECTORITE

1. INTRODUCTION In recent years, water body eutrophication has become a serious problem. Eutrophication is caused mainly by growth of aquatic plants that are stimulated by dissolved nutrients such as phosphates. Concentrations of TN and TP over the level of cleaning-itself are major indicators for water body eutrophication [1,2]. The presence of trace amounts of phosphate (even less than one ppm) in treated waste water from municipalities and industries is often responsible for eutrophic…     

X射线光电子能谱研究低温氧等离子体对棉纤维表面改性

本文叙述了用X射线光电子能谱(XPS)表征棉纤维的表面特性,比较了不同方法处理的棉纤维的表面改性。还讨论了等离子体对棉纤维的润湿性和脱脂作用机理。实验表明:刻蚀、氧化、分裂和接枝含氧基团是低温氧等离子体对棉纤维表面的主要作用。     

铝基氧化铜干法烟气脱硫及再生研究

采用浸渍法制备了XP型和DS型两种铝基氧化铜脱硫剂，并利用制得的脱硫剂进行了烟气循环脱硫-再生实验，同时利用BET、XRD和EPMA等方法研究了载体性质对脱硫剂性能的影响以及脱硫剂的表面微观结构在脱硫和再生过程的变化。实验和分析表明，用于制备脱硫剂的载体应同时具备较大的比表面积和合适的孔结构，实验条件下制得的铝基氧化铜脱硫剂的脱硫效率可达90％，该脱硫剂在多次循环脱硫-再生过程中性能保持稳定。     

Preparation and characterization of highly photoactive nanocrystalline TiO_2 powders by solvent evaporation- induced crystallization method

Highly photoactive bi-phase nanocrystalline TiO2 photocatalyst was prepared by a solvent evaporation-induced crystallization (SEIC) method, and calcined at different temperatures. The obtained TiO2 photocatalyst was characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results show that solvent evaporation can promote the crystallization and phase transformation of TiO2 at 100℃. When calcination temperatures are below 600℃, the prepared TiO2 powders show bimodal pore size distributions in the mesoporous region. At 700℃, the pore size distributions exhibit monomodal distribution of the inter-aggregated pores due to the collapse of the intra-aggregated pores. At 100℃, the obtained TiO2 photocatalyst by this method shows good photocatalytic activity, and at 400℃, its photocatalytic activity exceeds that of Degussa P25. This may be attributed to the fact t     

微量法测定有机锡化合物中锡的含量

随着金属有机化学的不断发展,金属有机化合物中金属元素的分析显得日益重要。本微量法是用混合酸快速分解有机锡化合物,以EDTA络合剂和四价锡离子所生成的稳定的Sn~(+4)-EDTA络合物为依据,其过量的EDTA,用Pb(NO_3)_2、CuSO_4、ZnAc_2或La(NO_3)_3为滴定剂进行回滴,均得到准确的分析结果。此方法简单、快速、极易掌握操作技术;滴定