顶空气相色谱法测定延生护宝液中甲醇残留量

本文用顶空气相色谱法，以ＧＤＸ－１０１为固定相，测定了延生护宝液中甲醇残留量，方法的回收率在８５．９％－１０１．６％之间，变异系数０．３％，最小检出量１．０ｍｇ／Ｌ。     

2,3-吡啶二羧酸铜(Ⅰ)配合物的合成与结构

铜配合物具有多变的配位结构,可活化小分子,可用于氧转移、氧化加成、新陈代谢、均相催化等许多领域。还可以用作金属酶的化学模拟和配合物结构及反应性能研究方面[1-3]。本文以2,3 二羧酸 吡啶为辅助配体及[(PPh3)2Cu(BH4)]作为起始原料,室温下,通过取代反应合成了单核铜(Ⅰ)配合物[(PPh3)2Cu(C7H4NO4)],经元素分析、电导、光电子能谱、红外光谱及单晶XRD方法对配合物进行了表征。1　实验部分1 1　仪器和试剂意大利ERBA 1106元素分析仪,JA96 970等离子光谱仪,Nicolet170SX分析仪(CsI压片),AV 300Bruker分析仪(CDCl3溶剂,8…     

Sonochemical Degradation of Polychlorinated Biphenyls in Aqueous Solution

Ultrasonic waves in a liquid induce the formation of cavitation bubbles. Submitted to an oscillating pressure field, cavities filled with vapor and dissolved gas pulsate, grow and implode violently when they reach a critical resonant size. According to the 慼ot spot?theory, extremely high temperature and pressure are produced during the collapse of cavitation bubbles1. Under these extreme conditions, the molecules vaporized in the bubbles as well as in the surrounding condensed layer could …     

Urokinase片断的二级、三级结构预测及构效关系研究

urokinase(简称UK)属于絲氨酸蛋白酶,其一级结构已经测定。去掉前135个残基后得到的低分子量UK(LUK)氨基酸残基的顺序与糜胰蛋白酶、胰蛋白酶等絲氨酸蛋白酶十分类似。从二硫桥的配置来看LUK与糜胰蛋白酶比较接近,而UK对Lys侧链处肽键的专一性则和胰蛋白酶相近。在这一类酶中,起到活性中心作用的氨基酸为Ser195,His57及Asp102.在UK中此三个氨基酸都保留了下来。蛋白水解酶中起专一性作用的残基主要是     

镍 钴 钯 铁2—（二苯基膦基）吡啶配合物的合成及其催化羰基化反应

众所周知,铑催化剂是醇类羰基化的有效催化剂,但是铑价格昂贵且对设备有腐蚀性,因此,寻找出对醇类羰基化催化活性好的非贵金属催化剂,对醇类羰化的工业化有十分重要的意义。 本文在温和条件下,合成了四种含有相同配体(Ph_2PPy)不同金属的有机配合物(金属基分别为Ni、Co、Pd、Fe),并探索了它们对乙醇羰基化反应的催化活性。     

Solvent-free Synthesis of Dihydrofuran-fused [60]Fullerene Derivatives by High-speed Vibration Milling

Solvent-free organic reactions have been attracting great interest of chemists due to the elimination of the usage of harmful organic solvents,low costs,and simplicity in the procedure1.Solvent-free mechanochemical reactions of fullerenes were explored and are significant for the reactions of fullerenes because the low solubility of fullerenes in common organic solvents requires large quantity of organic solvents and some novel fullerene reactions could only occur in the solid-state reaction2.…     

无相移滤波技术用于分析化学信号处理

把无相移滤波技术引入了分析化学信号处理领域。其方法为：先将输入序列按顺序滤波，然后将所得结果逆转后反向通过滤波器，再将所得结果逆转后输出。通过对色谱信号的实验研究表明，与普通的数字滤波方法相比较，无相移滤波不但具有普通数字滤波的优点，而且不会产生滤波前后的相位偏移，具有良好的应用前景，尤其对于需要准确计算保留时间的场合，用此预处理方法非常适合。     

Ultraviolet photolysis of CH2I2 in methanol: O-H insertion and HI elimination reactions to form a dimethoxymethane product

Ultraviolet photolysis of low concentrations of CH2I2 in methanol solution found that CH2I2 is converted into dimethoxymethane and some H+ and I- products. Picosecond time-resolved resonance Raman (ps-TR3) experiments observed that the isodiiodomethane (CH2I-I) photoproduct decayed faster as the concentration of methanol increases, suggesting that isodiiodomethane is reacting with methanol. Ab initio calculations indicate isodiiodomethane is able to react with methanol via an O-H insertion/HI elimination to form an iodoether (ICH2-O-CH3) and HI products. The iodoether can then further react via another O-H insertion/HI elimination reaction to form the dimethoxymethane (CH3-O-CH2-O-CH3) observed in the photochemistry experiments. A reaction mechanism consistent with these experimental and theoretical observations is proposed.     

Comparison of the dehalogenation of dihalomethanes (CH2XI, where X = Cl, Br, I) following ultraviolet photolysis in aqueous and NaCl saltwater environments

The ultraviolet photolysis of low concentrations of CH(2)XI (X = Cl, Br, I) were investigated in water and saltwater solutions by photochemistry and picosecond time-resolved resonance Raman spectroscopy. Photolysis in both kinds of solutions formed mostly CH(2)(OH)(2) and HI and HX products. However, photolysis of the CH(2)XI molecules in saltwater resulted in production of some CH(2)XCl products not observed in aqueous solutions without salt present. The appearance of these new products in saltwater solutions is accompanied by a decrease in the amount of CH(2)(OH)(2), HI, and HX products compared to photolysis in aqueous solutions without salt present. The possible implications for photolysis of CH(2)XI and other polyhalomethanes in seawater and other salt aqueous environments compared to nonsaltwater solvated environments is briefly discussed.     

LIGHT-SCATTERING STUDY OF POLYELECTROLYTE HOLLOW CAPSULES

Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in solution. The ratio of hydrodynamic radius (Rh) from dynamic LLS to the radius of gyration (Rg) from static LLS is almost unity, revealing that the entities are hollow in solution. The results suggest that the LLS method can be regarded as a good complement to the confocal laser scanning microscopy (CLSM) method for the characterization of small hollow capsules, and it possesses the advantage of not needing fluorescence labeling.