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   10382篇
  免费   941篇
  国内免费   1179篇
安全科学   1191篇
废物处理   155篇
环保管理   2505篇
综合类   5633篇
基础理论   980篇
环境理论   47篇
污染及防治   419篇
评价与监测   696篇
社会与环境   809篇
灾害及防治   67篇
  2024年   48篇
  2023年   126篇
  2022年   172篇
  2021年   269篇
  2020年   283篇
  2019年   289篇
  2018年   271篇
  2017年   508篇
  2016年   527篇
  2015年   552篇
  2014年   489篇
  2013年   761篇
  2012年   765篇
  2011年   742篇
  2010年   615篇
  2009年   570篇
  2008年   404篇
  2007年   657篇
  2006年   646篇
  2005年   592篇
  2004年   511篇
  2003年   483篇
  2002年   364篇
  2001年   356篇
  2000年   347篇
  1999年   238篇
  1998年   178篇
  1997年   153篇
  1996年   108篇
  1995年   124篇
  1994年   73篇
  1993年   69篇
  1992年   44篇
  1991年   27篇
  1990年   24篇
  1989年   16篇
  1988年   10篇
  1987年   5篇
  1986年   7篇
  1984年   5篇
  1982年   5篇
  1981年   6篇
  1980年   6篇
  1979年   10篇
  1977年   8篇
  1976年   5篇
  1975年   7篇
  1974年   4篇
  1973年   6篇
  1972年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
党的十五大提出发展多种形式的公有制经济,在这种新形势下,环境管理如何转轨,本文进行了探讨和研究。  相似文献   
992.
论建立和完善我国环境税   总被引:7,自引:0,他引:7  
本文在重新认识税收作用、资源价值和税收优惠政策的基础上,提出了建立环境税、完善资源能源税、逐步实施费改税、公平税负与对等环境税附加的建议。  相似文献   
993.
经济结构变动对环境污染物排放的影响分析   总被引:11,自引:0,他引:11  
本文利用投入产出技术给出一类经济结构变动对环境污染物排放的影响分析模型,该方法着重分析了各产业部门的生产技术变动、最终需求变动及收入变动对环境污染物排放量的影响。  相似文献   
994.
Will Limits of the Earth's Resources Control Human Numbers?   总被引:1,自引:1,他引:0  
The current world population is 6 billion people. Even if we adopted a worldwide policy resulting in only 2.1 children born per couple, more than 60 years would pass before the world population stabilized at approximately 12 billion. The reason stabilization would take more than 60 years is the population momentum – the young age distribution – of the world population. Natural resources are already severely limited, and there is emerging evidence that natural forces already starting to control human population numbers through malnutrition and other severe diseases. At present, more than 3 billion people worldwide are malnourished; grain production per capita has been declining since 1983; irrigation per capita has declined 12% during the past decade; cropland per capita has declined 20% during the past decade; fish production per capita has declined 7% during the past decade; per capita fertilizer supplies essential for food production have declined 23% during the past decade; loss of food to pests has not decreased below 50% since 1990; and pollution of water, air, and land has increased, resulting in a rapid increase in the number of humans suffering from serious, pollution-related diseases. Clearly, human numbers cannot continue to increase.  相似文献   
995.
Delivering on the Promise of Agroforestry   总被引:1,自引:0,他引:1  
Agroforestry – the traditional practice of growing trees on farms for the benefit of the farm family and for the environment – was brought from the realm of indigenous knowledge into the forefront of agricultural research less than two decades ago. It was promoted widely as a sustainability-enhancing practice that combines the best attributes of forestry and agriculture. Based on principles of natural resource management and process-oriented research, agroforestry is now recognized as an applied science, that is instrumental in assuring food security, reducing poverty and enhancing ecosystem resilience at the scale of thousands of smallholder farmers in the tropics.Trees on farms provide both products and services: they yield food, fuelwood, fodder, timber and medicines, which farm families can use at home or take to market to bring in much-needed cash; they replenish organic matter and nutrient levels in soils and they help control erosion and conserve water. The International Centre for Research in Agroforestry, and its partners, are working to integrate the functions of trees with policy and institutional improvements that aim at facilitating wide-scale adoption by farmers.Two examples described in this paper are replenishing soil fertility in sub-Saharan Africa using short-term improved tree and shrub fallows and the results of agroforestry research to support significant land tenure policy in southeast Asia.Although just one option in sustainable land-use, science-based agroforestry has the potential to produce economically, socially and environmentally sound results for the billions of people who depend on this ancient practice and modern science.  相似文献   
996.
ABSTRACT

Ecological democracy confronts a challenge of not only reconciling democracy and ecology, but doing so where human activities and their environmental consequences are increasingly global. Deliberative scholars dealing with these issues emphasise reflexive governance, involving the contestation of discourses, as part of the solution, mostly aimed at high-level institutions and intergovernmental cooperation. However, even at this level democracy demands responsiveness to the citizen. To this end, the paper explores citizen-level deliberation to inform possibilities for ecological democracy writ large, via a growing literature on deliberative governance and polycentrism. Different system levels are connected via ecologically reflexive capacity and the discursive conditions under which it is enhanced, including in small-scale minipublics. This understanding informs mechanisms for ‘scaling up’ deliberative quality to the wider public sphere via regulating the manipulation of public discourse. Minipublic deliberation, properly harnessed, can serve to decontaminate public debate of anti-reflexive strategic arguments and reshape public discourse. Such anti-reflexive strategies seek to shape the public will, specifically by de-emphasising ecology via intuitive arguments that short-cut public reasoning. Acting as discursive regulatory trustees, minipublics can improve reflexivity in the wider system via a nested polycentric approach that discursively connects citizens’ deliberation to the global system both horizontally and vertically.  相似文献   
997.
碳中和愿景下电力部门低碳转型路径研究   总被引:1,自引:0,他引:1  
碳中和愿景一方面加速了全社会电气化发展,致使电力需求持续增加,另一方面对尽早实现零碳电力提出要求,电力部门低碳转型进程更加紧迫而复杂。本文首先定性分析碳中和背景下电力部门的总体转型思路和技术不确定性影响,其次采用电力部门与终端部门耦合的C~3IAM/NET模型对电力需求进行预测,同时根据关键低碳技术发展的保守预期和积极预期设计多种情景,以开展电力低碳转型路径优化和成本效益研究。结果显示,发电碳排放量峰值可能出现在40亿~42亿吨,在2049—2060年有望实现零碳电力,电力部门低碳转型速度和效果因技术不确定性而存在明显差异。2021—2060年电力低碳转型累计投入为171万亿~180万亿元,CCS技术累计减排贡献超过250亿吨,可再生能源电力占比需达到68%以上,风电和光电将成为主要电力。  相似文献   
998.
随着非道路移动机械保有量与使用量的不断增加,其排放造成的环境问题日益严重,相关的防治策略研究亟待加强。本研究首先总结了中国与欧美对非道路移动机械类型的划分方式及标准;其次,对中国与欧美的非道路移动机械排放标准进行归纳;最后,对现行中国与欧美的非道路移动机械排放标准进行了全面对比分析,分析发现,国内标准与欧美标准之间仍存在显著差距,以期为国内制定科学的非道路移动机械排放标准提供参考,为污染物防治策略的制定提供理论支撑。  相似文献   
999.
The micronucleus test of peripheral blood erythrocytes was used to study cytogenetic stability in bream (Abramis brama L.), perch (Perca fluviatilis L.), roach (Rutilus rutilus L.), and pike (Esox lucius L.) from a eutrophic water body not affected by anthropogenic factors. The dependence of the rate of spontaneous micronucleus formation on fish age was estimated. The effect of natural variation in abiotic environmental factors on the cytogenetic stability of species was analyzed.  相似文献   
1000.
基于遥感与GIS的土地利用动态变化研究   总被引:31,自引:0,他引:31  
土地是人类社会经济活动的载体;土地利用是指人类对作为生产生活资料的土地的利用方式和强度;而土地利用动态变化则反映了土地利用方式的发展变化趋势。土地利用动态变化在数量,方式,强度,结构和趋势等方面存在很大的差异。全面,客观地反映土地利用动态变化有利于正确认识当前土地利用中合理和不合理的利用方式,为制定长期,可持续发展的土地管理和土地规划提供依据。遥感技术提供巨大而丰富的信息源,GIS技术具有强大的数据处理,空间分析等功能,二者的结合有着传统方式无法比拟的优越性,具有周期短,效率高,费用低等特点,在土地利用变化监测中发挥着巨大的作用。制定详细的技术手段,对重庆市15年间的土地利用及其动态变化在时间序列和空间序列上加以分析,阐明这种变化的外在表象,即耕地,林地的减少和城镇用地的增加;同时分析这种变化的内在驱动力主要为自然环境(坡度,高程,土壤等)和人文要素(经济条件与人口压力等)。为国土资源的有效可持续利用提供决策依据。  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