Study on open tubular capillary affinity liquid chromatography

A novel mode of affinity chromatography (AC) based on an open tubular capillary column (OTAC) is demonstrated. The OTAC column is prepared by immobilizing Cibacron blue F3GA onto the inner surface of a 50-microm-i.d. capillary column. The AC experiment is performed on a capillary electrophoresis instrument by using its pressure system as the driving force. Bovine serum albumin and lysozyme (Lys) are successfully separated with stepwise gradient elution. The relative standard deviation (RSD) for the elution time of the retained Lys is 0.08%, and good repeatability of its peak area and peak height with an RSD value lower than 2.12% for 10 consecutive runs is observed. The loading capacity and detection limit for the retained Lys are approximately 36 ng and 8.6 ng, respectively. It is also found that the amount of protein adsorbed is unaffected by the flow rate of the loading buffer, and OTAC can be used for the fast determination of biopolymers. Some of the advantages of OTAC over conventional modes of open tubular capillary liquid chromatography are that the detection sensitivity and loading capacity of a sample can be greatly improved, because the relatively large inner diameter of the capillary can be adopted and the whole capillary column can be used to adsorb the solute in OTAC.     

Preparation of Y2Ba4Cu7O15-δ Superconductor without High Oxygen Pressure

The synthesis of bulk Y₂Ba₄Cu₇O_15-δ superconductor at atmospheric oxygen pressure via solid state sintering is reported. Temperature ranging from 860 to 890 °C as well as time interval over 2 to 15 days were used to investigate the formation of the Y₂Ba₄Cu₇O_15-δ phase. A time-temperature profile characterizing the conditions for the preparation of Y₂Ba₄Cu₇O_15-δ phase suggests the optimal condition to be sintering at 890 °C for over 10 days. Detailed results of X-ray diffraction, electrical resistivity, iodometric titration and magnetization measurements are described.     

Four new triterpene glycosides from Thalictrum squarrosum

Four new triterpene glycosides were isolated from the dried aerial parts of Thalictrum squarrosum (Ranunculaceae). They were designated as squarroside I, being a cycloartane-type glycoside, and squarrosides II, III and IV, being oleanene-type glycosides. Their structures were established by using two dimensional (2D) NMR techniques.     

仪器分析测试技术信息化教学探索与实践

针对高职学生的特点，以仪器分析测试技术课程实训教学为例，按照课前布置学习任务，学生翻转课堂学习，"教、学、做"一体化课堂教学，课后复习巩固的形式，开展信息化教学的探索与实践，并对信息化教学的效果和存在的问题进行了分析。通过信息化教学改革，仪器分析测试技术课程突破了传统教学时空的限制，激发了学生学习的兴趣，构建了"学生主体、教师主导"的教学新模式，提高了课堂教学效果，对推动高职课堂信息化教学的改革具有一定的借鉴意义。     

A new method for inversion of hydroxyl group of carbocyclic nucleosides

The hydroxyl group of carbocyclic nucleosides was inversed when the compounds were treated with Me_3SiCl,KCN and a catalytic amount of NaI in DMF/CH_3CN.     

甲基锍盐的合成

在四氟硼酸银存在下，分别以硫醚、硫醇、硫酚或过硫醚为原料与碘甲烷反应制备了相应的甲基锍盐。用１ＨＮＭＲ和１３ＣＮＭＲ表征产物的结构并提出了反应的机理。     

气相[（SiO2）nX]^—团簇产生机理

利用ＸｅＣｌ准分子激光烧蚀多种硅氧多孔结构材料，在负离子通道测得丰富的「（ＳｉＯ２）ｎＸ」＾－负离子团簇，并讨论了多孔网结构和表面活性基团的分布对激光能量的吸收，传输及团簇产生的重要作用。     

Extraction of thorium,uranium and cerium from fresh water using manganese dioxide coprecipitation

A manganese dioxide coprecipitation procedure is utilized to replace a time-consuming evaporation step for the extraction of thorium, uranium and cerium from freshwater samples. The average recovery for 20-liter samples is greater than 95% for²³⁴Th and¹⁴⁴Ce. The data indicate that the manganese dioxide coprecipitation process does not affect the recovery of thorium and uranium during our routine analytical procedure.     

Molecular and nanoscale materials and devices in electronics

Over the past several years, there have been many significant advances toward the realization of electronic computers integrated on the molecular scale and a much greater understanding of the types of materials that will be useful in molecular devices and their properties. It was demonstrated that individual molecules could serve as incomprehensibly tiny switch and wire one million times smaller than those on conventional silicon microchip. This has resulted very recently in the assembly and demonstration of tiny computer logic circuits built from such molecular scale devices. The purpose of this review is to provide a general introduction to molecular and nanoscale materials and devices in electronics.