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981.
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984.
文章从工艺矿物学的角度分析了广西难处理金精矿难浸的原因及其提金工艺研究现状,进而提出了广西难处理金精矿提金工艺研究方法及发展方向。 相似文献
985.
壳聚糖载药微球的制备及应用研究进展 总被引:2,自引:0,他引:2
壳聚糖是一种天然聚阳离子碱性多糖,其化学名称为(1,4)-2-氨基-2-脱氧-βD-葡聚糖,是甲壳素脱乙酰基衍生物.近年来,对其研究特别侧重于生物医学及药物制剂等领域,研究证实壳聚糖具有生物黏附性和多种生物活性,它能与活体组织相容,不会引起过敏反应和排斥现象,其被体内的溶菌酶、胃蛋白酶降解后,降解产物能完全地被人体吸收,无毒、无副作用,比较适于作为缓控释辅料[1~5].壳聚糖包封药物后,可使其释放减慢、疗效延长,毒副作用降低,利用壳聚糖制备缓释、控释制剂已成为近年来新剂型研究的热点[6],作者综述了壳聚糖药物缓释微球研究的应用进展. 相似文献
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GUO Lugang) )) WANG Haizeng) * ) Key Laboratory of Marine Chemistry Theory Technology Ministry of Education Ocean University of China Qingdao P. R. China ) Institute of Automation of the Chinese Academy of Sciences Beijing P. R. China ) Beijing Municipal Institute of Science Technology Information Beijing P. R. China 《中国海洋大学学报(英文版)》2009,8(3):229-232
A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption
of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis,
surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time
and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can
be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature
and the optimal temperature for phenol removal was 40 °C. The optimum adsorption time was 10 min, and desorption would happen
afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir
equation better. 相似文献
988.
Polyphenols from the ethanol extracts of Sargassum tenerrimum (ST) with potent antiallergic effects were studied to optimize separation process through column chromatography. The adsorption
and desorption characteristics of three widely used adsorbents: macroporous resin, silica gel, and polyvinylpolypyrrolidone
(PVPP), were critically evaluated respectively and studied for the optimization of preparative separation of polyphenols.
Static operations on these adsorbents showed that macroporous resin had the best adsorption and desorption capability among
the three adsorbents. Dynamic adsorption and desorption with macroporous resin packed column were also conducted to optimize
the parameters such as: with the optimal values shown in brackets, the concentration of extract solution (4 times diluted),
pH value (6–7), adsorption speed (3 BV h−1, bed volumes/per hour), concentration of ethanol (80%), elution speed (3 BV h−1) and elution volume (7 BV). The chromatographic process so optimized gave a purity of 62.43% from the crude polyphenols,
providing a promising basis for large scale preparation of bioactive polyphenols upon further scaling up tests. 相似文献
989.
Polyphenols from the ethanol extracts of Sargassum tenerrimum (ST) with potent antiallergic effects were studied to optimize separation process through column chromatography. The adsorption and desorption characteristics of three widely used adsorbents: macroporous resin, silica gel, and polyvinylpolypyrrolidone (PVPP), were critically evaluated respectively and studied for the optimization of preparative separation of polyphenols. Static operations on these adsorbents showed that macroporous resin had the best adsorption and desorption capability among the three adsorbents. Dynamic adsorption and desorption with macroporous resin packed column were also conducted to optimize the parameters such as: with the optimal values shown in brackets, the concen- tration of extract solution (4 times diluted), pH value (6-7), adsorption speed (3BVh-1, bed volumes/per hour), concentration of ethanol (80%), elution speed (3 BV ht) and elution volume (7 BV). The chromatographic process so optimized gave a purity of 62.43% from the crude polyphenols, providing a promising basis for large scale preparation of bioactive polyphenols upon further scaling up tests. 相似文献
990.
林继雄 《广东海洋大学学报》2000,20(3):60-63
6kV电缆中间接头的爆炸是工厂配电设备的常见故障。本文从电缆的绝缘结构方面入手,以绝缘热击穿理论分析了湛江电厂#3循环水泵电机电缆中间接头爆炸原因,查找导致电缆头热击穿的关键因素并进行排除,运用新的材料与方法重新制作#3循环水泵电机电缆中间接头,运行可靠性大有提高。改进的结果表明,减少缆芯的接触电阻和环境温度与绝缘结构的适当选取是杜绝高压电缆中间接头爆炸的关键。 相似文献