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   160篇
  免费   7篇
  国内免费   6篇
安全科学   6篇
废物处理   1篇
环保管理   39篇
综合类   63篇
基础理论   18篇
污染及防治   6篇
评价与监测   6篇
社会与环境   22篇
灾害及防治   12篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   6篇
  2015年   3篇
  2014年   2篇
  2013年   7篇
  2012年   3篇
  2011年   7篇
  2010年   10篇
  2009年   11篇
  2008年   12篇
  2007年   14篇
  2006年   17篇
  2005年   6篇
  2004年   5篇
  2003年   7篇
  2002年   11篇
  2001年   9篇
  2000年   11篇
  1999年   6篇
  1998年   4篇
  1997年   2篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1975年   1篇
排序方式: 共有173条查询结果,搜索用时 15 毫秒
81.
An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed. The index system includes indicators of cost, resources, environmental improvement, and social effects. The calculation method for an objective value of each index based on its attributes and weights was presented. The Foshan Channel, which is a seriously polluted, black and malodorous urban river in Foshan City, China, was selected as a case study. The values of the attributes and the weights of the indices for the Foshan Channel were determined. The technologies for the rehabilitation of the Foshan Channel were evaluated based on this index system. Finally, a rehabilitation scheme for the Foshan Channel was proposed.  相似文献   
82.
石羊河流域的生态环境问题、引发原因与治理对策   总被引:17,自引:0,他引:17  
石羊河是甘肃省三大内陆河之一,在河西乃至全省经济社会发展中起着十分重要的作用.目前该流域出现森林面积减少,雪线上升,水土流失加重,地下水位下降,水体污染,水质恶化,荒漠化蔓延等一系列生态环境问题,已经严重影响和制约到流域及其周边地区的经济建设和社会安定团结.为实现流域生态大系统及其子系统稳定、健康、持续发展,应坚持"南保水源,中建绿洲,北治风沙"的基本原则.对流域大系统,要切实加强流域水资源统一管理,完善政策体系,加强环境保护的执法、宣传,提高流域民众的生态意识,加强生态建设工程的科技支撑.对流域南部祁连山区,要加强林区管理,理顺体制,加强山区植被保护和建设,提高水源涵养能力,减少水土流失,合理调整水库,减少汛期蓄水.对中部绿洲,要发展二三产业,加快小城镇建设,调整农业产业结构,加强农田防护林体系建设,加大节水力度,实施外流域调水工程.对北部荒漠区,要恢复、重建退化固沙植被,退耕还草还荒,严禁新的土地开垦,适度发展沙产业.  相似文献   
83.
The aim of this paper is to compare the rehabilitation result between two ash disposal sites with regard to its vegetation establishment and soil nutrient status. The study areas were situated in close proximity, in the Mpumalanga coalfield, South Africa. Although both areas received a similar amelioration treatment and were seeded with similar seed mixture the vegetation composition were significantly different. Both areas were poor in essential nutrients, this probably being one of the most limiting factors for vegetation establishment. No serious phytotoxic conditions, as is frequently experience with coal ash, could be identified. A regular monitoring and low level maintenance program is therefore proposed to improve the sustainability of the vegetation. The study proposed that results form such evaluations be used to identify performance standards for rehabilitated derelict land.  相似文献   
84.
NOAA卫星云雾自动检测和修复方法   总被引:7,自引:0,他引:7  
云雾在时间和空间上具有不稳定性。不同高度、厚度、面积和太阳高度角情况下,NOAA卫星可见光波段的海面反射率和红外波段亮度温度都不相同。据此,根据云雾光谱和红外特征,研究并找出了可见光波段海面最小反射率、云雾区最大反射率与云雾最佳判别阈值之间的关系,得出了不同月份东海海面最低温度和NOAA卫星红外波段亮温特征;通过采用光谱和结构分析相结合的方法,研究和研制了NOAA气象卫星云雾自动检测和修复模型,取得了较好的运行和检测、修复效果。  相似文献   
85.
Intensified surface mining, power generation, and smelting operations in the Hunter River lowlands, NSW, Australia have posed numerous new environmental management problems. Legislative controls over water, soils, and land use management have been clearly insufficient and remain so. The complex range of environmental changes is challenging government agencies as well as coal developers. While water demands are increasing in the region the proportionally greatest competitors are power generation and irrigation. Comprehensive regional water quality assessment is inadequate and divided between a number of agencies with fragmentary interests. Coal development inquiries signal further controversy over appropriate management solutions and are an ongoing phenomenon in the region. The early 1980s resource boom has been followed by lower rates of economic growth, which have resulted in disparate agency responses to major ongoing environmental questions. While issue attention cycles are often remarkably short in environmental management, matters of water, land, and air quality require intensive and ongoing monitoring and policy development.  相似文献   
86.
本文客观地分析了延津县沙区的自然资源状况,开发潜力及存在的问题,提出了开发治理的方向和关键技术,为我国同类地区风沙化土地的开发治理提供了经验。  相似文献   
87.
The use of magnetic particles in environmental remediation and wildlife rehabilitation is currently under investigation at Victoria University, in collaboration with the Phillip Island Research Centre, Victoria, Australia. Iron powder has been shown to be very effective for the magnetic cleansing of feathers and plumage and is almost ideal for this purpose, being non-toxic, a non-irritant and recyclable. Detailed investigations have demonstrated that by varying particle size, particle structure and surface texture, the efficacy of oil removal from feathers and plumage can be successfully manipulated. In this regard, it is possible to identify a grade of iron powder whereby, within experimental error, effectively 100% removal of a variety of fresh contaminants from different matrices, including feathers, can be achieved. Our investigations have been extended to the application of such particles to the successful removal of tarry and weathered/tarry contamination. The results of these investigations have indicated that, for such contaminants, removals ranging from 97–99% may be achieved. Magnetic particle technology may also be adapted for the screening of pre-conditioning agents that can further assist in the removal of tarry and weathered/tarry contamination from feathers. These investigations suggest that magnetic particles could have an important role to play in environmental remediation and wildlife rehabilitation as a clean and effective technology.  相似文献   
88.
县域土地利用影子规划初探——以山东省定陶县为例   总被引:1,自引:0,他引:1  
科学的利用规划土地资源,取得合理、高效的综合效益,进而保障乡镇社会经济的可持续发展是中国探讨的主要问题。土地利用总体规划正式修编前,浅析了为解决定陶县当前土地利用规划指标不够而实行的“影子规模”规划的具体内容。  相似文献   
89.
丹江口水库是中国南水北调中线工程的水源地,其库区湿地已被列入《中国重要湿地名录》。温地具有截留污染、蓄洪防旱、保护生物多样性等一系列重要的生态功能,因此维持丹江口库区温地生态系统的健康对中线调水工程具有非常重要的意义。在此结合丹江口库区湿地相关的研究资料,概括出库区内三种主要的湿地类型,根据生境状况重点阐述了库区消涨带湿地生态系统的特征,并分析了库区湿地的重要生态功能。在总结了丹江口库区湿地保护现状的同时分析了库区温地存在的生态环境问题,并提出了相应的管理和研究对策,以期从生态学的角度服务于库区湿地生态系统管理及中线调水工程。  相似文献   
90.
三江平原湿地的生态保护与修复   总被引:2,自引:0,他引:2  
三江平原是中国最大的平原沼泽分布区,从二十世纪七十年代中后期国家开始对三江平原进行多次大规模的开垦,这些开垦基本上是天然湿地,从而导致了土地退化和生态环境恶化,使湿地的面积不但减少,其功能不断退化,引起一系列生态环境问题。因此,积极采取措施保护现有的湿地,开展受损湿地的生态恢复,战缓和消除导致温地退化因素的影响,实现三江平原湿地资源的可持续利用、人与自然和谐相处,是湿地生态保护和修复的目标。  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