负载型贵金属纳米粒子作为光/超声催化剂在化学合成和降解污染物方面的应用

综述了Au/TiO2、Au/ZrO2、Ag/AgCl等负载型贵金属纳米粒子作为有效的光/超声催化剂在化学合成和降解污染物方面的应用.负载型贵金属纳米粒子能够有效地将太阳能转化为化学能.在紫外光或可见光的辐照下,负载型贵金属纳米粒子能够催化一系列的选择性化学转化,如醇类化合物氧化为醛/酮类化合物、硫醇氧化为二硫化合物、苯氧化为苯酚、硝基苯类化合物还原为偶氮化合物等.在超声波辐射下,负载型贵金属纳米粒子能够有效地催化分解水产氢.此外,在紫外光或可见光的辐照下,负载型贵金属纳米粒子能够有效地催化降解多种污染物,如醛类、醇类、酸类、酚类化合物和染料等.在超声波辐射下,负载型贵金属纳米粒子也能够有效地催化降解包括染料在内的有机污染物.     

反相高效液相色谱法测定肾复康胶囊中的野黄芩苷和芦丁

建立了肾复康胶囊中野黄芩苷和芦丁的反相高效液相色谱测定方法。以甲醇-水为提取溶剂,采用超声提取法对样品进行前处理。以0.02 mol/L磷酸二氢钾缓冲溶液(含1.0％（体积分数）冰醋酸)-甲醇（体积比为63∶37）为流动相,于330 nm波长下检测,肾复康提取液中野黄芩苷和芦丁可达基线分离,分析时间在20 min内。野黄芩苷和芦丁在10 ~300 mg/L内,其峰面积与浓度之间线性关系良好,目标物的加标回收率大于98％。该方法适用于肾复康胶囊及相关药材中野黄芩苷和芦丁黄酮类化合物的测定和质量控制。     

中英高中物理教材中关于电场内容的比较

针对学生在电场学习中的障碍,借鉴和比较中英两国在电场内容上的不同处理,从教学实践和教材编写方面提出意见.     

Deposition Behavior and Mechanism of Ni Nanoparticles on Surface of SiC Particles in Solution Systems

Ni-deposited SiC particles are prepared successfully by a facile chemical reaction approach. The structure and morphology analyses demonstrate the Ni nanoparticles have been deposited on the surface of SiC particles. The deposition behavior of Ni on the surface of SiC particles is investigated. Pd-Sn catalytic nuclei formed in the pretreatment process promote the redox reaction and lead to the reduction of Ni^2＋ to metal nickel. Moreover, the kinetic mechanism of the reaction process of Ni%2＋ and H2PO^-2 has also been discussed in detail. Kinetic models have been established.     

肝生素治疗40例重型乙型病毒性肝炎的疗效初探

应用肝生素治疗各种重型乙型病毒性肝炎,结果表明,４０例重型乙型病毒肝炎患者经肝生素治疗,治疗组死亡１５例,病死率３７．５％,对照组死亡２６例,病死率６５．０％,两组比较有显著差异。肝生素在重型肝炎的早中期治疗效果特别理想,可认为肝生素是目前治疗重型病毒性肝炎比较理想的护肝药物。     

Microwave Absorbing Materials： Solutions for Real Functions under Ideal Conditions of Microwave Absorption

We present general equations for metal-substrate single-layer microwave absorbing materials. The optimum electromagnetic parameters and matching thicknesses for electric-loss, magnetic-loss, and electromagnetic-loss materials are given, and possible solutions for the equations and the corresponding theoretic curves are discussed as well. The results may be helpful for designing high-performance microwave absorbing materials.     

杯［4］吡咯涂敷C18反相色谱柱分离阴离子及酚类化合物杯吡咯涂敷的HPLC固定相的初步研究

用meso-八甲基杯［4］吡咯静态涂敷MN-C18填料,制备了一种新型大环化合物涂敷固定相。以去离子水作为流动相,考察了有机阴离子(邻苯二甲酸氢根、水杨酸根、苯甲酸根离子)及酚类化合物(间苯三酚、对苯二酚、间氨基酚、间苯二酚、邻苯二酚、苯酚)的色谱分离。与未涂敷柱相比,新型涂敷固定相成功地实现了对3种阴离子的基线分离;对酚类化合物的保留显著增加,同时提高了分离度(尤其是间氨基酚与间苯二酚、间苯三酚与对苯二酚两对峰)。这可归因于杯吡咯与被分析物间存在的氢键相互作用,初步的实验结果也表明杯吡咯对阴离子及中性客     

Carbon materials with quasi-graphene layers: the dielectric, percolation properties and the electronic transport mechanism

We investigate the dielectric properties of multi-walled carbon nanotubes (MWCNTs) and graphite filling in SiO₂ with the filling concentration of 2-20 wt.% in the frequency range of 10²-10⁷ Hz. MWCNTs and graphite have general electrical properties and percolation phenomena owing to their quasi-structure made up of graphene layers. Both permittivity ε and conductivity σ exhibit jumps around the percolation threshold. Variations of dielectric properties of the composites are in agreement with the percolation theory. All the percolation phenomena are determined by hopping and migrating electrons, which are attributed to the special electronic transport mechanism of the fillers in the composites. However, the twin-percolation phenomenon exists when the concentration of MWCNTs is between 5-10 wt.% and 15-20 wt.% in the MWCNTs/SiO₂ composites, while in the graphite/SiO₂ composites, there is only one percolation phenomenon in the graphite concentration of 10-15 wt.%. The unique twin-percolation phenomenon of MWCNTs/SiO₂ is described and attributed to the electronic transfer mechanism, especially the network effect of MWCNTs in the composites. The formation of network plays an essential role in determining the second percolation threshold of MWCNTs/SiO₂.