反相液相色谱结合型胆汁酸的选择性变化规律

本文报道了反相液相色谱(RP-HPLC)和离子对反相液相色谱甘氨型(G)和牛磺型(T)结合胆汁酸的选择性变化规律,首次发现在给定冲洗剂浓度下,G、T对结合型胆汁酸的选择性因子或结合型选择性为常数。本文同时还在反相液相色谱保留值基本方程的基础上讨论了G、T对选择性变化规律的理论依据。     

Enlarged Area A-type Zeolite Membranes Prepared by Vacuum Seeding Method

High quality A-type zeolite membranes, with enlarged area over 70 cm^2, were successfully synthesized on a tubular ~-A1203 support by applying the vacuum seeding method.     

Water/Oil Diphasic Hydroformylation of Higher Olefins over a TPPTS-Rh/SiO_2 Catalyst

A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous high-surface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of mass transfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performance for hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of the traditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersed Rh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation of higher olefins such as 1-dodecene.     

褐煤亚临界—超临界水萃取研究

在半连续实验装置上，采用非等温实验技术，以水为溶剂，对大雁、昌宁两种褐煤进行了萃取。结果表明，在适宜条件下可得到高的转化率和较高的萃取物产率；萃取物中 主要馏分为预沥青烯，为原煤中的富氢组分；过程中产生的气体主要分为CO2；萃取物和气体生成速率随温度而变，在400℃左右存在极大值；萃取后褐煤（即残渣）具有比原煤低的水分、低氧含量、高的碳含量及一定的挥发分。本文对对萃取过程进行了宏观动力学处理，结果表明，萃取过程要用一级反应方程式来描述；在萃取的主要温度区间，活化能约为120kJ/mol.     

A New Process for Synthesis of Dimethyl Carbonate from Ethylene Carbonate and Methanol without any Catalyst under Supercritical Conditions

Dimethyl carbonate was synthesized by transesterification reaction between ethylene carbonate and methanol under supercritical conditions without any catalyst. Experimental results showed that the residence time and the molar ratio of methanol to ethylene carbonate all can affect the conversion of ethylene carbonate. When the molar ratio of methanol to ethylene carbonate was 8:1, 81.2% conversion can be achieved at 9.0 MPa and 250℃ after 8 h.     

Synthesis and Spectral Properties of Novel Water-soluble Near-infrared Fluorescent Indocyanines

Two fluorescent pentamethine and a squarylium indocyanines containing at least one p-carboxybenzyl group on N atoms in the heterocyclic rings were synthesized. They had good water solubility and photostability. Their maximum absorption and maximum emission were 600-700 nm in water. When it was anchored onto nanostructured TiO2 electrode, compared with in water, the squaraine showed double absorption peaks (one blue shifted and another red shifted) and absorption intensity of the red shift peak increased with the increase of the time of irradiation. The intensity of the blue one decreased simultaneously. We proposed that the presence of two electronic charge forms of squaraine anchored on the TiO2 film might be the reason.     

Live retention database for identification of compounds in capillary gas chromatographic analysis --Principle and structure

A live retention database for compound identification in isothermal and any step temperature programmed capillary gas chromatography has been developed. The database utilizes the Kovats retention indices of compounds on a given stationary phase and the retention time of n-alkanes measured at isothermal conditions on the column to be used, together with the programming parameters. Identification is performed by search operation that compares the calculated results with the retention values of unknown peaks. Cross-reference of the search results of different operating conditions is performed automatically by the database in order to increase the reliability of the identification. The error of the database conversion is ≤± 0.5 index unit, or ≤± 1% on retention time. This paper describes the principle and the structure of the database in detail. The experimental results for different calsses of compounds tested at divers operating conditions will be presented in Part Ⅱ.     

膜亲和色谱用于胰蛋白酶抑制剂的分离

分别采用酰化-胺化和氯甲基化-胺化对聚砜进行化学修饰,用相转化法制成平均孔径为450nm的超滤膜,经重氮化反应,共价键合上具有活性的胰蛋白酶。其相对活力可达10200 u/g。每克化学改性聚砜膜上可固载化上15 mg胰蛋白酶。用此酶膜对胰蛋白酶抑制剂进行了亲和分离,一次可得6.5mg纯胰蛋白酶抑制剂。     

LOW-TEMPERATURE HEAT CAPACITY AND THERMODYNAMIC FUNCTIONS OF 2-CHLORO-6-(TRICHLOROMETHYL)PYRIDINE

The heat capacity of 2- chloro- 6- (trichloromethyl)pyridine has heen measured with anadiabatic calorimeter in the range from 13 to 316K. There is no indication of any phasetransition or thermal anomaly in this temperature region for the present compound. Theresults have been compared with those reported in [1] in the overlapping temperaturerange. The experimental heat capacity data have been fitted to a smoothed curve by the aidof the effective frequency distribution method, and the heat capacities below 13K have beenobtained by extrapolating the fitting curve down to 0K. The standard molar thermodynamicfunctions between 0 and 400 K have been derived by combining the present heat capacitymeasurements with the previous ones. The values of C_p~o (T), S~o(T) - S~o(0), [H~o(T) -H~o(0)]/T, and - [G~o(T) - H~o(0)]/T at T = 298.15 K are 189.35, 244.60, 112 .45 and 132.15J·K~(-1)·mol~(-1), respectively.     

GC/MS测定马面鲀鱼油中脂肪酸

本实验利用GC/MS电子轰击电离和化学电离两种方法对马面鲀鱼油中饱和、不饱和脂肪酸(经甲酯化后)进行了测定,用色谱法作了定量,共鉴定出16种脂肪酸。