排序方式: 共有4条查询结果,搜索用时 15 毫秒
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以Na2SiO4和Al2(SO4)3为原料,采用复合法制备聚合硅酸硫酸铝(PASS):先在碱性条件下制备聚硅酸,然后在酸性条件下制备PASS。将自制的PASS应用于实际废水的处理并与聚合氯化铝(PAC)进行了比较,研究结果表明,所制备的PASS具有优良的絮凝性能,其在除浊、脱色及去除COD等方面较PAC具有更好的絮凝效果,是一种有广阔发展前景的新型高效净水剂。 相似文献
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The review focuses on sulfated steroids that have been isolated from seaweeds, marine sponges, soft corals, ascidians, starfish, and other marine invertebrates. Sulfur-containing steroids and triterpenoids are sourced from sedentary marine coelenterates, plants, marine sediments, crude oil, and other geological deposits. The review presents the pharmacological profile of sulfated steroids, sulfur-containing steroids, and triterpenoids, which is based on data obtained using the PASS program. In addition, several semi-synthetic and synthetic epithio steroids, which represent a rare group of bioactive lipids that have not yet been found in nature, but possess a high level of antitumor activity, were included in this review for the comparative pharmacological characterization of this class of compounds. About 140 steroids and triterpenoids are presented in this review, which demonstrate a wide range of biological activities. Therefore, out of 71 sulfated steroids, thirteen show strong antitumor activity with a confidence level of more than 90%, out of 50 sulfur-containing steroids, only four show strong antitumor activity with a confidence level of more than 93%, and out of eighteen epithio steroids, thirteen steroids show strong antitumor activity with a confidence level of 91% to 97.4%. 相似文献
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María Dolores Simón Manuel Nieves-Cordones María Jesús Sánchez-Blanco Trinitario Ferrández Manuel Nieves 《Journal of plant nutrition》2013,36(9):1466-1478
The ornamental value of plants used in semiarid areas can be improved by knowledge of their required nutrients and of their nutritional responses under saline conditions. We present a long-term study concerning the nutritional status in Chamaerops humilis and Washingtonia robusta. Two-year-old plants were grown for two years outdoors in pots using water with electrical conductivity values of 2 (control) or 8 dS m?1 (saline conditions). Nutrient specific absorption rates and leaf nutrient transport rates were estimated by fitting a Richards function regression. We suggest fertilizing C. humilis and W. robusta plants with nitrogen (N): phosphorus pentoxide (P2O5): dipotassium oxide (K2O) ratios of 4:1:5 and 5:1:3, respectively. Diagnosis and Recommendation Integrated System (DRIS) and Plant Analysis with Standardized Scores (PASS) norms were also evaluated. PASS norms provided better nutritional diagnosis than DRIS norms. In saline conditions, PASS-INI (Independent nutrient index) pointed to a deficiency (10) of phosphorus in C. humilis and of nitrogen in W. robusta. 相似文献
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