首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   64篇
  免费   0篇
  国内免费   2篇
废物处理   1篇
环保管理   24篇
综合类   13篇
基础理论   15篇
污染及防治   5篇
评价与监测   2篇
社会与环境   6篇
  2022年   2篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2016年   2篇
  2015年   1篇
  2013年   12篇
  2012年   2篇
  2011年   4篇
  2009年   2篇
  2007年   4篇
  2006年   2篇
  2005年   4篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1997年   3篇
  1996年   1篇
  1995年   4篇
  1994年   2篇
  1992年   1篇
排序方式: 共有66条查询结果,搜索用时 46 毫秒
41.
论述了安徽省黄山市分布的百合科野生药用植物的种质资源、地理分布、药用部位,为进一步开发利用提供依据。  相似文献   
42.
中国药用植物资源现状   总被引:14,自引:0,他引:14  
对中国药用植物资源的种类、分布特点及其开发利用现状做了简要介绍,总结了我国针对近年来资源大量浪费采取的一系列保护措施,希望能对下一步资源的可持续利用提供帮助.  相似文献   
43.
重庆珍稀濒危药用植物资源的调查研究   总被引:3,自引:0,他引:3  
经调查鉴定,重庆地产属国家重点保护的珍稀濒危药用植物有86种,其中国家Ⅰ级保护13种,国家Ⅱ级保护38种,国家Ⅲ级保护21种.重点论述了它们的种类组成、起源和特有性,分布特点与规律,资源保护现状及应采取的保护对策;指出重庆市现有的86种珍稀濒危药用植物,除约有48%的种类在自然保护区受到保护外,还有52%的种类尚未得到有效的保护;提出应制定其资源保护和管理的有关细则,建立重庆市药用植物园,对三峡库区特有珍稀种类进行迁地保护等4项保护措施,建议将重庆地产的8种有重大药用价值的珍稀植物纳入国家重点保护计划.  相似文献   
44.
四川重楼属药用植物资源研究   总被引:10,自引:0,他引:10  
经调查鉴定,四川重楼属药用植物有10种7变种,均在我省民间广泛应用。目前川产商品重楼原植物有3种6变种,除中国药典收载的华重楼和滇重楼外,其分布广、产量大的还有七叶一枝花、狭小重楼和短梗重楼等3种4变种。  相似文献   
45.
采用翻转振荡方式以水为浸提剂浸提钢渣、尾矿渣、铬渣、铅渣、粉煤灰和电镀污泥试样,过滤后的浸提液经DDTC/CCl4体系萃取富集后,用ICP-AES法同时测定了Cu、Pb、Zn、Cd、Ni、Fe、Mn、Co和V等多种金属元素.方法具有较好的精密度和准确度,宜于推广应用。  相似文献   
46.
中国药用植物的数值区划   总被引:19,自引:0,他引:19  
本文根据药用植物的地理分布,运用计算机以组平均法做聚类分析研究中药区划,将全国为4个区和8个亚区,并探讨了各区和亚区的生态环境条件,植物区系和植被特征,为中药区划和药用植物的引种栽培研究提供了一定的基础。  相似文献   
47.
The level of accumulation of selected essential and non-essential metals, namely; Ca, Cu, Fe, Zn, Mn, Cd, Pb, and Cr have been investigated in the seeds, fruits, and flowers of some medicinal plants utilized for tapeworm treatment in Ethiopia and their respective soil samples. These include seed of Cucurbita maxima (Duba), fruit of Embelia abyssinica (Ankoko), flowers of Hagenia abyssinica (Kosso), and fruits of Rosa abyssinica (Kega) and their respective soil samples. A wet digestion procedure with a mixture of conc. HNO3 and HClO4 for the plant samples and a mixture of conc. HNO3, HCl, and H2O2 for soil samples were used to solubilize the metals. Ca (1280–12,670?mg?kg?1) was the predominant metal followed by Fe (104–420?mg?kg?1), and Zn (18–185?mg?kg?1) in all the plant materials except for Hagenia abyssinica flower from Hirna in which Mn (16–42?mg?kg?1) followed by Fe. Among the non-essential toxic metals, Pb was not detected in Cucurbita maxima of Boji, Gedo and Hirna origins and in Rosa abyssinica of Hirna site. Similarly, Cr was not detected in Rosa abyssinica fruits of Boji and Gedo sites. The sampled soils were found to be between strongly acidic to weakly basic (pH: 4.7–7.1). In the soil samples, Ca (8528–18,900?mg?kg?1) was the most abundant metal followed by Fe (417–912?mg?kg?1), Zn (155–588?mg?kg?1), Mn (54–220?mg?kg?1), Cr (21–105. mg?kg?1), Cu (11–58?mg?kg?1), Pb (13–32?mg?kg?1) and Cd (2.8–4.8?mg?kg?1). The levels of most of the metals determined in the medicinal plants and the respective soil samples are in good agreement with those reported in the literature and the standards set for the soil by various legislative authorities.  相似文献   
48.
Under Chinese culture it is believed that herbal medicine is always safe and wild food is always healthy. Generally, the rarer a plant, the higher its value. The booming economy in China has promoted tourism development in wilderness areas and wild medicinal and food plants are part of the attraction to tourists. Conflicts between wild plant exploitation and protection have emerged in many parts of China, such as Changbai Mountain. Changbai Mountain supports numerous medicinal and food plants but many have become rare and endangered. This paper numerically evaluates 30 plant species that have relatively high conservation value for each type (medicinal, ornamental and food), and briefly describes the uses of four to five top ranked species per type that need more protection on Changbai Mountain. This paper also addresses some tree species with important timber values on Changbai Mountain. Over 90% of China's medicinal, ornamental and food plant species, as well as valuable timber trees are found in the conifer–broadleaf mixed forest zone across the boundary of Changbai Mountain Nature Reserve. It is a major challenge to protect the native biodiversity of mixed forest on Changbai Mountain and more efforts need to be made to protect rare and endangered plant species with high economic value.  相似文献   
49.
The technology convergence integrating multiple devices into a single one is now a distinct trend in electronic industry. This trend can lead to a decrease in the use of rare and toxic heavy metals due to resource sharing, or an increase due to the application of new and auxiliary technology. This study investigates the effect of technology convergence for tablet PC on hazardous waste, resource depletion, and toxicity potentials from heavy metals in electronic devices, considering how many single devices (i.e., netbook computer, electronic dictionary, mp3 player, digital camera, cell phone, and vehicle GPS system) can be displaced by a tablet PC depending on users. The hazardous waste potential from heavy metals is examined with existing U.S. federal and California state regulations, and the resource depletion and toxicity potentials from heavy metals are evaluated based on life cycle impact assessments. The potentials of a specific tablet PC are compared to the total of those of displaced single products. Overall, the tablet PC has lower hazardous waste, resource depletion, and toxicity potentials from heavy metals. However, in case the tablet PC displaces only two or three single devices, it requires more gold, molybdenum, and vanadium. Therefore, technology convergence should take into account materials consumption and user behavior to develop more sustainable products.  相似文献   
50.
采用原子吸收光谱法测定了多维元素药片中矿物质含量。样品用硝酸消解,用火焰原子吸收法测定钙、镁、钾、铜、铁、锰,用石墨炉原子吸收法测铬和镍。方法灵敏可靠,测量相对标准偏差<2.4%,回收率在90%~100%之间,能满足药品检测要求。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号