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421.
422.
A computer-assisted method is described for optimization of multi-component,mobile phase selection for separation of five phosphoamidothioate enantiomers with a series of silica and chiral columns in normal phase HPLC.The method is based on the triangular solvent selection concept using a statistical scanning method.The optimization of the separation over the experimental region is based on a special polynomial estimation from seven experimental runs,and resolution (Rs) is used as the selection criterion.Excellent agreement was obtained between predicted and experimental data. 相似文献
423.
YuXinLI YouMingWANG XiaoPingYANG SuHuaWANG ZhengMingLI 《中国化学快报》2004,15(1):14-16
The synthesis of 2-alkyl(aryl)-3-methylthiopyrano[4,3-c]pyrazol-4(2H)-ones via 5, 6-dihydro-2H-pyran-2, 4-dione-3-dithioacetals with (un)substituted hydrazines is described and the mechanism of the formation of title compounds is discussed. Their structures were confirmed by ^1HNMR spectra and elemental analysis. 相似文献
424.
Xiu Feng LIU Hui Ming ZHU Tuan Wei ZHANG Bao Quan ZHANG? School of Chemical Engineering Technology Tianjin University Tianjin 《中国化学快报》2005,(1)
In a number of fermentation processes, organic solvents are often used due to the poorsolubility of many substrates and/or products in water. However, the interface betweenwater and organic phases may lead to the diffusion-limited bioconversion. Supercriticalfluid technology can be employed to eliminate the mass transfer resistance existed in thebiphasic system1-6. Hydrocortisone is an effective anti-inflammatory drug and an important precursor ofother steroid drugs. The C11β-hydroxylati… 相似文献
425.
PU Shou-cheng GUO Yuan-qiang GAO Wen-yuan ZHANG Tie-jun .School of Pharmaceutical Science Technology Tianjin University Tianjin P.R.China 《高等学校化学研究》2009,25(1)
1 Introduction Centipeda minima(Compositae) is an annual herbaceous plant found in moist places throughout the plains mainly in the southern regions of the People’s Republic of China, Eastern tropical Asia, Australia 相似文献
426.
LOU LanLan YU Yi YU Kai JIANG Shu DONG YanLing & LIU ShuangXi Institute of New Catalytic Materials Science College of Chemistry Nankai University Tianjin China College of Environmental Science Engineering 《中国科学B辑(英文版)》2009,(9)
An imidazole modified mesoporous material has been prepared through a co-condensation procedure and adopted to covalently anchor chiral Mn(Ⅲ) salen complex. The active centers in the as-synthesized catalyst were presented in the form of ionic species. The results of XRD, FTIR, DRUV-Vis, and N2 sorp-tion confirmed the successful immobilization of chiral Mn(Ⅲ) salen complex inside the channels of the modified support and the maintenance of the mesoporous structure of parent support in the immobi-lized catalys... 相似文献
427.
ZHANG Hong YU Yaoting PAN Jilun WANG lianyong Bioactive Materials Research laboratory Nankai University Tianjin 《Chinese Journal of Reactive Polymers》2001,(1)
1. INTRODUCTION Biological artificial liver support systems have been extensively studied in treatment of hepatic failure [1]. In the device, cells included primary hepatocytes [2] and liver cell lines (i.e. C3A, HepG2 [3]) with relatively high differentiations, which are all attachment dependent cells; the cell density is crucially important for its efficiency in clinical application. Microcarrier -attached hepatocytes have been applied in the device in an attempt to raise the cell dens… 相似文献
428.
Mamat Turson 《中国化学快报》2009,20(9):1136-1140
To make more homogenous organic monolithic structure,reversible addition-fragmentation chain transfer(RAFT) process was employed in the synthesis of the clenbuterol imprinted polymer.In the synthesis,the influence of synthetic conditions on the polymer structure and separation efficiency was studied.The result demonstrated that the imprinted columns prepared with RAFT process have higher column efficiency and selectivity than the columns prepared with conventional polymerization in the present study,whic... 相似文献
429.
近红外光谱的数据预处理研究 总被引:25,自引:5,他引:20
进行了小麦样品近红外光谱数据的预处理研究,一般仪器记录的样品近红外光谱数据中包含有一系列噪声和干扰信号,因此适当的预处理是进行后续光谱定标、建模及模型传递的基础,对可靠地获得准确分析结果具有很重要的作用。结合小麦样品蛋白质含量近红外光谱分析工作,对由近红外光栅光谱仪和傅里叶变换近红外光谱分别记录的66种小麦样品光谱数据,采用高斯一阶、二阶导数小波变换方法进行了预处理。对比常用的一阶差分预处理,证明高斯函数导数小波变换方法是十分有效、实用的,预处理后光谱曲线非常光滑、噪声消除效果明显,富含有用光谱分析信息的区域更加清晰显示,因而非常有助于后续的光谱定标、建模和模型传递工作。 相似文献
430.