CoMoK／γ—Al2O3水煤气变换催化剂的硫化及反硫化

以Ｈ２Ｓ和ＣＳ２作硫化剂，用ＰＰＳ和ＴＰＤＳ方法研究了水煤气变换催化剂ＣｏＭｏＫ／γ－Ａｌ２Ｏ３的硫化及反硫化过程。用Ｈ２Ｓ／Ｈ２硫化时，只发现Ｈ２Ｓ的消耗和Ｈ２Ｏ的生成，用ＣＳ２／Ｈ２硫化时，只发现Ｈ２Ｓ的消耗和Ｈ２Ｏ的生成。用ＣＳ２／Ｈ２硫化时，首先生成ＣＯ２，然后是ＣＨ４，Ｈ２Ｏ和Ｈ２Ｓ，ＴＰＧ实验表明催化剂表面上积炭，造成催化剂和活性降低，但积炭在水煤变换反应进行了逐渐除法。ＴＰＤＳ实验表     

Molecularly imprinted sol-gel nanotubes membrane for biochemical separations

In this study, we report a simple procedure for applying molecular imprinting functional groups to the inner surfaces of the template-synthesized sol-gel nanotubes for chemical separation of estrone. The silica nanotubes were synthesized within the pores of nanopore alumina template membranes using a sol-gel method by simultaneous hydrolysis of a silica monomer-imprinted molecule complex and tetraethoxysilane (TEOS). A covalent imprinting strategy was employed by generating a sacrificial spacer through the reaction of the isocyanate group of 3-(triethoxysilyl)propyl isocyanate and a phenol moiety of estrone to form a thermally cleavable urethane bond. This allowed us to remove the imprinted estrone by simple thermal reaction and to simultaneously introduce functional groups into the cavity formed by the silica nanotubes. Experiments indicated that estrone could be bound selectively by such an approach and have a binding affinity of 864 +/- 137 (n = 3).     

Studies on the determination of diacetyl guanfubase A concentration in rabbit plasma and pharmacokinetics

A gas chromatographic method for monitoring diacetyl guanfubase A in plasma is described. The procedure involved a single solvent extraction of drug from rabbit plasma into ethyl acetate with guanfubase A as an internal standard. The extract was analyzed subsequently on a gas chromatograph equipped with a hydrogen flame ionization detector. The recovery was 86.43% +/- 6.90% (+/- SD); the RSD of within-day and between-day was 2.81%-5.26% and 5.22%-8.24%, respectively; the regression line was linear over the concentration range of 25-200 micrograms/mL, the limit of detection was 10 micrograms/mL. No endogeneous interference was found in chromatograms of the biological samples. This method was applied to the pharmacokinetic study of diacetyl guanfubase A in rabbits.     

某些含二维液晶基元的热致液晶高分子的向列态纹影响构

发现某些含二维液晶基元的热致液晶高分子容易产生反向壁织构与含有高强度有错点（│Ｓ│大于１）的向列态纹影织构。这类液晶高分子的织构与形态学特点与含一维棒状液晶基元的其他液晶高分子不同。     

Solution dynamics and stability of lanthanide(III) (S)-2-(p-nitrobenzyl)DOTA complexes

Addition of a benzyl substituent to the macrocyclic ring of DOTA has a substantial impact on the conformational ring flipping motion of the macrocycle in the resulting LnDOTA complexes. The p-NO2-benzyl substituent in the Ln(p-NO2-Bn-DOTA)- complexes lies in an equatorial position and effectively "locks" the conformation of the ring into the deltadeltadeltadelta configuration. The presence of the p-NO2-benzyl group also increases the population of the square antiprismatic (SAP) coordination isomer for all Ln(p-NO2-Bn-DOTA)- complexes relative to that seen for the respective LnDOTA- complexes. Despite this increase in SAP isomer population, the rate of water exchange in these complexes remains comparatively fast. The kinetic and thermodynamic stabilities of the Ln(p-NO2-Bn-DOTA)- complexes are also slightly lower than the corresponding LnDOTA- complexes but appear to be sufficiently high for in vivo use.     

Characteristics of electroosmotic flow and migration of neutral solutes under stepwise gradient elution of capillary electrochromatography

A theoretical study on the velocity of electroosmotic flow (EOF) and the retention times of neutral solutes under multiple-step gradient of capillary electrochromatography (CEC) was carried out, focusing on that with three kinds of mobile phases. Through the model computations, the detaining time of the second kind of mobile phase in the column was proved to play an important role in affecting EOF. The variation speed of EOF was shown to be determined by the differences among dead times in different steps. In addition, the prediction of the retention times of 13 aromatic compounds under gradient mode was performed with the deduced equations. A relative error below 3.3% between the calculated and experimental values was obtained, which demonstrated the rationality of the theoretical deduction. Our study could not only improve the comprehension of stepwise gradient elution, but also be of significance for the further optimization of separation conditions in the analysis of complex samples.     

Stereoselective nitrenium ion cyclizations: asymmetric synthesis of the (+)-Kishi lactam and an intermediate for the preparation of fasicularin

The asymmetric synthesis of the (+)-Kishi lactam and an intermediate for the preparation of the marine natural product fasicularin is reported. The keystone of this divergent synthesis is the diastereoselective azaspirocyclization of an N-methoxy γ-arylbutanoamide, which is believed to proceed through the intermediacy of an N-acylnitrenium ion.     

Synthesis of 2,2＇-（Substituted Arylmethylene）bis（1,6,6-trimethyl 6,7,8,9-tetrahydrophenanthro[1,2-b]furan-10,11-dione） Derivatives

The reactions of tanshinone IIA with aromatic aldehydes have been investigated and several 2, T-（substituted arylmethylene） bis （1,6,6-trimethyl-6,7,8,9-tetrahydrophenanthro[1,2-b]- furan- 10, 11-dione） derivatives were obtained,     

应用反向传播神经网络预测化合物脑血分配系数

选用27种三维结构性质描述符对脑血分配系数预测建立神经网络模型.网络模型选用典型的适合函数逼近的两层结构神经网络对脑血分配系数(lgBB,BB为脑血浓度比)进行预测,计算中采用的模型具有一个双曲正切型激活函数的隐含层和一个线性激活函数的输出层.计算表明,使用小心选择的反向传播神经网络模型对化合物脑血分配系数具有较好的预测能力.     

Development of chromium-free iron-based catalysts for high-temperature water-gas shift reaction

Chromium-free iron-based catalysts were prepared and studied in regard to their performance in the high-temperature water-gas shift reaction (HTS). The effects of various catalyst preparation variables (i.e., Fe/promoter ratio, pH of precipitation medium, calcination and reduction temperatures) and preparation methods were investigated. Aluminum is a potential chromium replacement in HTS catalysts. Further improvement in WGS activity of Fe–Al catalysts can be achieved by the addition of small amounts of copper or cobalt. Catalysts were characterized using BET surface area measurements, temperature-programmed reduction (TPR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). As a textural promoter, aluminum and chromium prevent the sintering of iron oxides and stabilize magnetite phase by retarding its further reduction to FeO and metallic Fe. The promotional effect of Cu is found to be strongly dependent on the preparation method.