α－甲基苯乙烯对HIPS／SBS共混物流变行为及力学性能的影响

用锥板式流变仪研究了α－ＭＳ对ＨＩＰＳ／ＳＢＳ共混物流动行为的影响，结果表明：不同α－ＭＳ用量的共混物和如曲线相似．均随增加τ＿ｗ增大、η＿ａ下降。流动指数，ｎ均小于１为非牛顿假塑性流体。加入少量（约２．５％）α－ＭＳ使共混物熔融指数提高３倍，其总体力学性能变化不大。     

反相离子对高效液相色谱法测定母粉及母液中的杀鼠新

用反相离子对高效液相色谱法测定了杀鼠新母粉及母液中有效成份含量。采用Partisil-10ODS色谱柱，以甲醇：离子对溶液＝80：20（体积比）为流动相，离子对溶液为0.005mol/L四丁基铵磷酸盐（pH为7.5)的缓冲溶液，测定波长285nm。方法在0.025-0.15g/L范围内有很好的线性关系。杀鼠新母粉和母液的相对标准偏差分别为1.24%、0.77%(n=7)，回收率分别为：母粉,97.7%-99.8%；母液，98.5%-100.4%。     

The initial oxidation of magnesium: an in situ study with XPS,HERDA and ellipsometry

The initial oxidation of magnesium at oxygen partial pressures between 1.3 × 10^?8 and 1.3 × 10^?5 Pa and at temperatures ranging from 273 to 550 K has been investigated in situ with X‐ray photoelectron spectroscopy (XPS), ellipsometry and high resolution elastic recoil detection analysis (HERDA). Quantitative analysis of the XPS spectra showed a clear oxygen deficiency with respect to MgO for the initial oxide. HERDA measurements confirmed this relatively low oxygen content in the thin oxide layers formed. Ellipsometry measurements showed that the electronic structure of the initially formed oxide differs significantly from that of bulk MgO. The band gap values at room temperature for the oxide layers investigated are clearly smaller than the value for bulk MgO. Copyright © 2006 John Wiley & Sons, Ltd.     

高配位双环氮氧杂有机锡化合物在二甲亚砜溶剂中的酸性解离常数

本文报道了在DMSO溶剂中利用Bordwell指示剂重迭法测定六种高配位双环氮氧杂有机锡化合物的α-CH的酸性离解常数(pKa)的方法, 并对配合物的结构与其α-CH酸性的关系进行了讨论。     

消毒剂产品中三氯新的测定及其稳定性研究

 采用反相高效液相法测定消毒剂产品中的三氯新。在KromasilC18柱 (2 0 0mm× 4 6mmi d )上 ,以甲醇 乙腈 水 (含 0 0 2mol/LKH2 PO4,pH 2 7) (体积比为 4 0∶4 0∶2 0 )溶液为流动相 ,2 80nm波长下检测 ,样品用流动相超声溶解。三氯新的回收率为 94 2 %～ 10 2 2 % ,相对标准偏差 (RSD)为 2 2 %～ 3 0 %。方法操作简便 ,精密度和准确度高 ,适合三氯新的快速分析。在 5 4℃时保存 14d和 37℃时保存 90d后 ,标准品和样品的含量没有明显变化 ,证明三氯新具有良好的稳定性。     

反相高效液相色谱检测丹参药材中4种丹参酮的含量

建立了测定丹参药材中4种丹参酮含量的反相高效液相色谱法，色谱条件：流动相为水(含0．5％三乙胺)-甲醇-四氢呋喃(45／55／5，V／V／V)，流速为1mL/min；PDA检测波长254m；4种成分丹参酮Ⅰ、丹参酮ⅡA、隐丹参酮和二氢丹参酮的加样回收率在95．1％-101．2％之间，线性范围为0．08-2μg。该方法准确，稳定，重现性好。根据该色谱条件，测定了不同产地的丹参药材，结果表明：该色谱方法准确检测了生药中4种丹参酮的含量，适合于丹参药材的质量控制。     

氯氮平、去甲氯氮平及奥氮平的高效液相色谱电化学检测特性的研究

 采用高效液相色谱安培电化学检测法 ,考察了氯氮平、去甲氯氮平和奥氮平在不同 pH值流动相下的色谱分离情况及其色谱峰高与检测电压的关系。结果表明 ,氯氮平、去甲氯氮平和奥氮平的保留时间均随流动相 pH值的升高而延长 ;在pH值为 4 5 6和 5 5 6的流动相中 ,均可实现基线分离。 3种化合物的色谱峰高与检测电压之间呈典型的“S”型曲线 ,pH值升高时该曲线均左移。氯氮平、去甲氯氮平和奥氮平的检测电压必须大于产生最大氧化电流的最低电压才能得到稳定的检测电流。这种典型的“S”型伏安曲线对于化合物的定量和定性检测具有重要意义。     

Phase transfer catalytic system with the third liquid phase

Phase transfer catalysis, a technique to bring the reactants in two immiscible phases together by adding a phase transfer agent, has been employed in the production of fine chemicals and pharmaceuticals in the last few decades. The third liquid phase (catalytic phase) may be formed when phase transfer catalysts (PTC), cannot be dissolved in either organic or aqueous phase. The third phase catalytic systems have the following three advantages, that is, (1) high activity (2) repeated use and (3) separation between the organic phase and the aqueous phase. It is expected that simple new processes can be constructed by applying these three advantages.     

Determination of inorganic arsenic species As(III) and As(V) by high performance liquid chromatography with hydride generation atomic absorption spectrometry detection

The paper presents the principles and advantages of a technique combining high performance liquid chromatography and hydride generation atomic absorption spectrometry (HPLC-HGAAS) applied to speciation analysis of inorganic species of arsenic As(III) and As(V) in ground water samples. With separation of the arsenic species on an ion-exchange column in the chromatographic system and their detection by the hydride generation atomic absorption spectrometry, the separation of the analytical signals of the arsenic species was excellent at the limits of determination of 1.5 ng/ml As(III) and 2.2 ng/ml As(V) and RSD of 4.3% and 7.8% for the concentration of 25 ng/ml. The hyphenated technique has been applied for determination of arsenic in polluted ground water in the course of the study on migration of micropollutants. For total arsenic concentration two independent methods: HGICP-OES and HGAAS were used for comparison of results of real samples analysis.