SiO2包覆纳米CaCO3的透射电镜表征

在透射电子显微镜（TEM）电子衍射模式下，用适当孔径的物镜光阑选择非晶态SiO2的衍射区域，拍摄以溶胶一凝胶法制备的SiO2包覆纳米CaCO3的暗场像。与未经包覆SiO2的纳米CaCO3的暗场像作对比，可以看出经过SiO2包覆的纳米CaCO3粒子周围有一白色亮环，从而得到SiO3包覆层的暗场照片。用高分辨方法观察了包覆层与CaCO3粒子间的界面情况。     

电极条件对硫酸介质中电解还原提纯镱过程的影响

研究了以钌铱钛合金网和汞分别为阳、阴电极, 在无气氛保护条件下, 采用电解还原方法从铥、镱、镥硫酸盐溶液中分离提纯镱的过程. 讨论了在8 V恒电压时的电极间距、位置, 以及阴、阳极表面积对电解过程中的电流、还原率影响. 优化了电解还原过程, YbSO4产品的纯度稳定达到99.5%以上, 一次收率可达80%;提镱后母液中的铥和镥被富集4倍以上, 其中Lu含量高于50%, 十分有利于后续铥/镥分离.     

2-(4-氯苯基)-3-甲基丁酸的消旋

以酸酐及有机惰性溶剂作混合溶剂，少量叔胺等作催化剂，2-(4-氯苯基)-3-甲基丁酸能在比较温和的条件下基本完全消旋，收率接近90％。     

Direct synthesis, characterization of Cu-SBA-15 and its high catalytic activity in hydroxylation of phenol by H2O2

Transition metal copper substituted mesoporous silica (Cu-SBA-15) was synthesized using triblock copolymers surfactant as template agent under acidic condition. The result Cu-SBA-15 was characterized with XRD, ICP-AES, FT-IR and N₂ adsorption–desorption measurements, which prove that Cu(II) was mainly incorporated into the framework of Cu-SBA-15. Its catalytic activity was studied for phenol hydroxylation using H₂O₂ (30%). The substituting element (Cu²⁺) is incorporated into the framework position forming a new type of active site which raises the phenol conversion to 62.4% and the diphenol (the mixture of catechol (CAT) and hydroquinone (HQ)) selectivity to 97%. The Cu-SBA-15 has very high selectivity for catechol (about 71% selectivity), which is completely different from that of the microporous titanium silicalite zeolites (47.1% phenol conversion and about 50% selectivity to CAT under same reaction conditions). The results obtained indicate that the selective oxidation of phenol with H₂O₂ by a radical substitution mechanism.     

Photovoltaic Characteristics of a Naphthylamine Derivative

Organic photovoltaic （OPV） cells were fabricated via vacuum vapor deposition with {4-[2-（3-di-cyanomethylidene-5,5-dimethylcyclohexenyl）vinyl]phenyl}di（1-naphthyl）amine （DNP-2CN） as the electron donor, and fullerene （C60） as the electron acceptor. A thin film （10 nm） of tris（8-quinolinolato）aluminum （Alq3） was adopted as the buffer layer. A device based on this DNP-2CN exhibited an open circuit voltage （Voc） of 370 mV, a short-circuit current density （Jsc） of 0.61 mAocm 2, and a white-light power conversion efficiency （ η） of 0.09% （AM1.5, 75 mW.cm^- 2）.     

Determination of trace rhodium by supramolecular catalytic kinetic spectrofluorimetry of β-CD-rhodium-KBrO3-vanillin salicylhydrazone

A sensitive catalytic kinetic spectrofluorimetric approach for determining ng mL⁻¹ levels of rhodium is presented, and the possible mechanism of the catalytic reaction was investigated. The determination is based on the catalytic property of rhodium to enhance the reaction of o-vanillin salicylhydrazone (OVSH) with potassium bromate in a water-ethanol medium at pH 4.80 and 45 °C. The presence of β-cyclodextrin (β-CD) obviously sensitized the assay due to its high inclusion ability towards OVSH. Under optimized experimental conditions, fluorescence measurements of the β-CD-rhodium-KBrO₃-OVSH catalytic kinetic reaction system were carried out in its fluorescent band centered at λ_ex = 333 nm and λ_em = 476 nm, respectively. The calibration graph was linear over the concentration range of 0.47–100 ng mL⁻¹ with a detection limit of 0.14 ng mL⁻¹. The effect of interferences was discussed, and the results show that the extraction method can be used to separate rhodium from interference species such as iridium. The proposed method, applied to several synthetic mixtures containing rhodium mixed with varying amounts of metal salts, produced satisfactory results.     

Hybrid polymerization of iso-butyl vinyl ether

The radiation-induced hybrid polymerization in the presence of the N-alkoxypyridinium salt having relatively stable nonnucleophilic anion (PF₆⁻) has been investigated in the paper. Based on the analysis of experimental data and the GPC spectrum, the onium salts not only oxidize -alkoxyalkyl radicals, produced from IBVE in dichloromethane by irradiation, to the corresponding cations, but also give nonnucleophilic anions PF₆⁻ for the polymerization system. The experimental results clearly demonstrate that free radical and cationic polymerization mechanisms occurred simultaneously in IBVE/EMP⁺PF₆⁻/CH₂Cl₂ systems on irradiation with γ-ray.     

分析信号处理方法的比较研究

研究了高效液相色谱－火焰原子吸收光谱联用系统分析信号处理方法，比较了各种处理方法的优缺点，用积分与适应平滑法综合处理色谱峰分析信号，不仅能有效地消除噪声，而且能使分析信号得到加强，以测定镍为例，经积分与适应平滑法综合处理后，检出限改善了２．７倍。     

Synthesis and Characterization of Novel Polyimides Based on Pyridine-containing Diamine

A new aromatic diamine monomer containing pyridine unit, 2,6-bis （4-aminophenoxy- 4＇-benzoyl）pyridine（BABP）, was synthesized in three steps, starting from 2,6-pyridinedicarboxyl chloride. A series of novel pyridine-containing polyimides were prepared v/a the polycondensation of BABP with various aromatic dianhydrides through poly（amic acid） precursors, and thermal or chemical imidization of the precursors. The polyimides exhibit desirable properties, e.g., good solubility in N-methyl-2-pyrrolidone and m-cresol, excellent thermal stability and film-forming capability, as well as high inherent viscosity, indicating high molecular weight.     

高效液相色谱-质谱法测定水产品中孔雀石绿及其代谢物

在水产养殖过程中,人们经常使用各种药物进行水体消毒和防止鱼病害,孔雀石绿就是其中的一种染料类杀菌剂,近年来发现它特别是其代谢物在水产体内有明显的残留现象,且代谢物的残留时间较长,由于孔雀石绿化学官能团三苯甲烷是一种致癌物质,所以欧盟、美国等宣布禁止其在经济鱼类(观赏鱼除外)养殖过程中使用。经文献检索,国内虽有水产品中孔雀石绿残留量检验方法的报道,但未涉及代谢物残留量检测方法的报道。国外已建立的检测方法主要采用了气相色谱质谱联用法测定孔雀石绿代谢物、高效液相-色谱法同时测定孔雀石绿及其代谢物和高效液相色谱-质谱法同时测定孔雀石绿及其代谢物。我们利用HPLC-VIS和Q-TOFMS技术分别建立了高效液相色谱法(初筛法)和高效液相串联质谱法(确证法)两种检测方法。