期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
基于B-IBI的长江源生态健康评价
1
作者 简文杰 张斌兴 +2 位作者 罗洪波 万雷 马祥元 《人民长江》 北大核心 2023年第11期31-35,共5页
基于底栖动物完整性指数(B-IBI)对长江源各个河段进行生态健康评价分析,可为长江源河流管理提供参考依据。根据2022年8月(丰水期)和10月(枯水期)对长江正源沱沱河和长江南源当曲7个典型断面的大型底栖无脊椎动物调查监测的结果,经判别... 基于底栖动物完整性指数(B-IBI)对长江源各个河段进行生态健康评价分析,可为长江源河流管理提供参考依据。根据2022年8月(丰水期)和10月(枯水期)对长江正源沱沱河和长江南源当曲7个典型断面的大型底栖无脊椎动物调查监测的结果,经判别能力分析和冗余度分析,选取了总分类单元数、摇蚊个体数百分比、优势类群个体数百分比和粘附者个体数百分比4个参数计算了B-IBI。基于该指数,构建了长江源生态健康的评价指标体系和标准,并对其进行了评价。结果显示:长江源总体处于健康状态,局部评分较低,尤其是波陇曲汇入口至唐古拉山镇河段受损较为严重。初步推断该段经过人口较为密集区域,污染物负荷较大导致。建议对受损河段重点关注,并有针对性地开展生态修复整治。 展开更多
关键词 河流健康评价 大型底栖无脊椎动物 B-IBI 生态健康度 长江源
下载PDF
Extraction and purification of deguelin from Derris trifoliata Lour root
2
作者 jian wenjie Fang Yuchun +2 位作者 Gan Chunji Wu Yunhui Pang Jie 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2009年第4期98-103,共6页
This article deals with extraction and purification of deguelin,which is a main rotenoid occurred in the root of Derris trifoliate Lour.Deguelin has gained much attention of scientists because of its potential ability... This article deals with extraction and purification of deguelin,which is a main rotenoid occurred in the root of Derris trifoliate Lour.Deguelin has gained much attention of scientists because of its potential ability to inhibit cancer cell proliferation.The dried root powder was extracted with ethanol by ultrasonic-assisted extraction for 30 min,and then filtrated and concentrated to give pasty concentrate.The concentrate was loaded onto silica gel column chromatography subsequently;and the chemical was eluted using a binary solvent mixture of petroleum ether(60-90ºC)-ethyl acetate(4:1,v/v).All tentative identification was carried out by high performance liquid chromatography(HPLC).Most crystal of deguelin was obtained after the fractions mainly containing deguelin were pooled and placed in the dark at 4ºC for three days.With recrystallization from carbon tetrachloride for three times,the purity of deguelin crystal was 99.15%and the yield was 0.55%of the dried weight of D.trifoliate Lour root. 展开更多
关键词 DEGUELIN EXTRACTION PURIFICATION silica gel column chromatography
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部