The adsorption of resorcinol from water using multi-walled carbon nanotubes

Adsorption of resorcinol and other phenolic derivatives on pristine multi-walled carbon nanotubes (MWCNTs) and HNO₃ treated MWCNTs has been investigated in attempt to explore the possibility to use MWCNTs as efficient adsorbents for pollutants. MWCNTs showed higher adsorption ability in a rather wide pH range of 4–8 for resorcinol, while decreased uptake capacity was found for acid-treated MWCNTs. Other phenolic derivatives such as phenol, catechol, hydroquinone and pyrogallol were employed to study the influence of the number and position of hydroxyl groups on the adsorption capacity. The amounts adsorbed by MWCNTs increased with the increasing number of hydroxyl. The substitution of phenol with a hydroxyl in meta-position leads to a much higher absorption ability than substitution in ortho- or para-position, which suggested that MWCNTs possess a great potential in removal of resorcinol from water, as well as the other phenolic derivatives.     

Determination of Salidroside in Medicinal Plants Belonging to the Rhodiola L. Genus Originating from the Qinghai–Tibet Plateau

The Rhodiola L. genus (Crassulaceae) is one of the most important medicinal plant products used by Tibetans in Chinese phytotherapy. Fourteen species were examined for their content of salidroside. A considerable quantitative variation was observed using high-performance liquid chromatography and this depended on species and regional factors. It was found that all samples contained salidroside at concentrations ranging between 0.02 mg g^?1 (R. sinuate) and 15.95 mg g^?1 (R. sacra), respectively. The content of salidroside in R. sacra was significantly higher than in other popular medicinal plants of this genus. This finding indicated that there may be more Rhodiola species present in the Qinghai–Tibet Plateau which may be used as a potential source of salidroside.     

Study of the superconducting transition in YBa2Cu3O7−δ single crystal by thermopower measurements

We have determined the superconducting transition in YBa₂Cu₃O_7−δ single crystal by measurements of thermopower. Two transitions were observed in both the ab-plane and the c-direction. The high temperature transition may have a close relation to the surface shell of the crystal.     

应用双面电极的PLZT横向电光调制器电场的精确解

使用保角变换方法导出了横向电光调制器中双面电极结构的电场和电容的解析表达式，给出了用于ＰＬＺＴ电光陶瓷介质中二次电光效应分析的电场分布的物理图像。通过计算对比表明，双面电极结构电极边级区域由于过剩双折射引起的强度调制非均匀性较单面电极有所改善。