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   777篇
  免费   39篇
  国内免费   99篇
安全科学   24篇
废物处理   141篇
环保管理   156篇
综合类   408篇
基础理论   56篇
污染及防治   66篇
评价与监测   12篇
社会与环境   50篇
灾害及防治   2篇
  2024年   2篇
  2023年   7篇
  2022年   19篇
  2021年   19篇
  2020年   21篇
  2019年   12篇
  2018年   13篇
  2017年   15篇
  2016年   26篇
  2015年   22篇
  2014年   72篇
  2013年   65篇
  2012年   75篇
  2011年   73篇
  2010年   43篇
  2009年   62篇
  2008年   72篇
  2007年   50篇
  2006年   49篇
  2005年   40篇
  2004年   39篇
  2003年   30篇
  2002年   15篇
  2001年   22篇
  2000年   10篇
  1999年   6篇
  1998年   12篇
  1997年   4篇
  1996年   3篇
  1995年   4篇
  1994年   6篇
  1993年   1篇
  1992年   1篇
  1988年   1篇
  1983年   1篇
  1982年   1篇
  1977年   1篇
  1974年   1篇
排序方式: 共有915条查询结果,搜索用时 171 毫秒
61.
随着人们生活水平的提高,服装更新速度越来越快,废旧衣服既污染环境,其再利用价值也没有发挥出来.把循环经济中的“3R原则”应用到废旧衣服回收中,以发挥废旧衣服的最大价值.  相似文献   
62.
再生资源产业对于破解我国资源环境约束、推动新型城镇化建设和促进产业结构调整具有重要的支撑作用.但是我国再生资源产业处于发展初期,面临管理体系不善、技宋鬟备落后、产业规 缺位和产业政策不清等突出问题.对此,提出六点具体建议,包括:加强立法和产业发展的顶层设计,构建再生资源高效回收体系,推动技术装备升级和推广,完善配套财税政策,强化产业规划统筹和部门政策衔接,加强与新型城镇化建设的融合等.  相似文献   
63.
随着工业化进程和社会生活的丰富,各种小型电器电子产品不断问世,相关废弃产品的拆解和资源化利用已经成为资源综合利用的重要课题.基于其分类与回收利用现状,就国内精细拆解与资源化利用问题进行了探讨,并以废弃手机为例,就处理原则、工艺流程设置和高值利用方法提出了一些建议.  相似文献   
64.
目前“三位一体”(回收网点→分拣中心→集散市场)回收体系模式,因集散市场功能单一、产业链短,不能带动行业走向产业化。回收网点建设适应我国国情,而集散市场成为先进的完整的回收体系的短板。按照示范基地建设标准,把集散市场改造升级为拥有深加工利用产业链,拥有平台支撑优势,能够进行资源的规模化高值化利用的产业园区。把回收和利用两大产业板块融合一体,是再生资源产业化的发展方向。  相似文献   
65.
田万慧 《资源开发与保护》2012,(11):982-985,989
综合评价值的计算已成为农业循环经济发展水平定量评价的主要方法,也是目前循环经济研究领域定量研究的热点之一。构建一套系统科学的农业循环经济发展评价指标体系,对区域农业循环经济发展水平进行综合评价,以改善农业环境,杜绝资源浪费,实现农业可持续发展具有重要的理论和现实意义。依据循环经济发展的“4R”原则和可持续发展理论,构建了甘肃省农业循环经济评价指标体系,采用因子分析法和加权函数法对甘肃省及其14个地州市的农业循环经济发展水平进行了综合评价与分析,提出了甘肃省及其各区域的农业循环经济发展建议。  相似文献   
66.
Spent hydroprocessing catalysts from refineries have been classified as hazardous solid waste by the United States Environmental Protection Agency (USEPA), refiners must find a viable but economical solution to solve this serious environmental issue. Catalyst rejuvenation is an attractive option for minimizing the environmental problems associated with spent catalysts. In this study, a preliminary design for such a process and the corresponding economic analysis are performed to assess the proposed catalyst rejuvenation process for metal-fouled spent catalysts generated in residue hydroprocessing units. The scenarios used in the economic assessment are based on three options of process synthesis and two operator modes. It is found that the option of rejuvenating medium and lightly fouled spent catalyst produced by the refinery will be the best solution for refiners, both environmentally and economically.  相似文献   
67.
The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS) > tannic acid (TA) > methylcellulose (MC) > triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%.  相似文献   
68.
Carbon-black-filled, biodegradable, copolyester mulch film (Eastar®, or EA, Tennessee Eastman, Kingsport, TN) and commercial carbon-black-filled, high-density polyethylene (HDPE) mulch film were exposed for 12 weeks to commercial vegetable crop growing conditions by being placed directly on irrigated soil in the field of the University of Tennessee Alcoa Highway State Agriculture Experiment Station (Knoxville, TN) and by being placed on a plywood exposure rack as described by the American Society of Testing and Materials (ASTM) Standard Test Method 1435: Outdoor Weathering of Plastics. Mechanical properties and weather information were collected in order to evaluate the feasibility of using the newly developed biodegradable EA mulch film to replace the nonbiodegradable HDPE mulch film. Results indicate that the EA mulch film exhibited favorable tensile strength and elongation-at-break during outdoor exposure rack testing and outdoor, in-field, placed directly on the soil, exposure testing, suggesting biodegradable EA could be a substitute for the HDPE nonbiodegradable material.  相似文献   
69.
报废汽车的回收拆解处理在我国已经逐渐兴起,但由于该产业尚处于发展初期,环保技术手段和可持续性发展意识还不够,因此在回收拆解过程中会产生大量的废水和其他污液。针对某汽车回收拆解厂的废水特性进行实验研究,形成“电荷凝集过滤一活性炭吸附”组合工艺,对报废汽车回收拆解企业的废水处理提供了一定的参考价值。  相似文献   
70.
ABSTRACT: An index of residential water efficiency - a “W-Index” - can serve as a measure of effectiveness of water conservation features in the home. The index provides a calculated numerical value for each dwelling unit, derived from the number and kind of water-saving features present, including indoor and outdoor water savers and water harvesting or recycling systems. A W-Index worksheet, devised for on-site evaluation of single-family residences in the Tucson, Arizona, region shows that a nonconserving residence with all the water-using features would use 151,000 gallons per year or 148 gallons per capita per day (gpcpd), while the fully conserving model would use 35,300 gallons per year or 35 gpcpd and with water harvesting and graywater recycling systems would have a maximum W-Index of W-160. A Tucson water conservation demonstration home, Casa del Agua, received a rating of W-139, and field tests of about 30 homes in new Tucson subdivisions show values ranging from W-75 to W-100, indicating the incorporation of some water conservation in current new models. By adjustment of some climatic or water-use parameters, the W-Index format can be applied to various types of dwelling units or to other urban areas. The W-Index can be used by individual homeowners or builders to evaluate water efficiency of residential units, or by water providers or water management agencies as a device for promoting and achieving water conservation goals.  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