排序方式: 共有38条查询结果,搜索用时 15 毫秒
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研究了胶原纤维固化黑荆树单宁对V(V)的吸附。采用不同温度、pH值等条件进行吸附研究,并进一步探讨了固化黑荆树单宁的吸附动力学和吸附柱动力学及其吸附机理。结果表明,该材料对V(V)的吸附平衡符合Freund lich方程,温度对吸附平衡的影响不明显;吸附动力学可用拟二级速度方程来描述,该材料同时具有良好的柱动力学特性;V(V)的吸附过程可能存在三个反应,即V(V)与吸附剂之间发生氧化还原反应生成V(IV),V(IV)和-COOH之间发生离子交换反应,以及V(IV)与单宁的邻位羟基发生螯合。 相似文献
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海洋环境中的重金属及其对海洋生物的影响 总被引:8,自引:0,他引:8
综述了在海洋环境中重金属输入的各种途径及其重金属对海洋生物的影响,重点介绍了重金属在几种海洋生物体内的富集效应及其吸附机理,讨论了海洋重金属污染的现况,并展望了海洋重金属污染研究的前景。 相似文献
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自然界中铊的分布及对人体健康的影响 总被引:3,自引:0,他引:3
铊是一种剧毒且对动植物的新陈代谢不起任何促进作用的金属元素。分布于土壤、水体中的铊及其化合物的污染物可以通过食物链进入生物体,并对生物体特别是人类健康造成巨大的威胁。因此,致力于铊的长远研究对于综合治理铊污染具有十分重要的意义。 相似文献
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掺镍型层状LixNiyMn1-yO2正极材料的合成与电性能研究 总被引:6,自引:0,他引:6
A kind of cathode material of layered LixNiyMn1-yO2 characterized with the O2 type has been synthesized by a simple method. Its precursor NaxNiyMn1-yO2 has been prepared from manganese dioxide, nickel hydroxide and sodium carbonate at high temperature in air and quickly cooled in cold water, then it has been exchanged by the melted LiNO3 at 300~400℃ in air. The effects of calcine-temperature for the precursors and its compositions (the content of Na and Ni) on the electrochemical properties of the material LixNiyMn1-yO2 have been investingated by XRD and electrochemical tests. The results show that the sample Li0.7Ni0.3Mn0.7O2, has the best electrochemical properties which shows only one charge-discharge potential stage of 2.8~3.0V and has a high specific capacity over 180mAh·g-1 cycled between 2.0~4.20V. A significant structure transformation to the spinal-type phase has not been found in the charge-discharge cycling and the discharge specific capacity around 165mAh·g-1 has re-mained after the 20th cyclings for the material. 相似文献