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   516篇
  免费   9篇
  国内免费   57篇
安全科学   7篇
废物处理   22篇
环保管理   51篇
综合类   123篇
基础理论   117篇
污染及防治   172篇
评价与监测   69篇
社会与环境   18篇
灾害及防治   3篇
  2023年   4篇
  2022年   10篇
  2021年   13篇
  2020年   14篇
  2019年   9篇
  2018年   9篇
  2017年   19篇
  2016年   23篇
  2015年   14篇
  2014年   23篇
  2013年   62篇
  2012年   11篇
  2011年   20篇
  2010年   25篇
  2009年   23篇
  2008年   23篇
  2007年   25篇
  2006年   23篇
  2005年   23篇
  2004年   18篇
  2003年   13篇
  2002年   19篇
  2001年   21篇
  2000年   11篇
  1999年   9篇
  1998年   4篇
  1997年   3篇
  1996年   7篇
  1995年   9篇
  1994年   7篇
  1993年   7篇
  1992年   3篇
  1991年   4篇
  1989年   4篇
  1988年   4篇
  1987年   3篇
  1986年   2篇
  1982年   5篇
  1979年   2篇
  1975年   3篇
  1974年   2篇
  1971年   4篇
  1966年   4篇
  1965年   5篇
  1964年   4篇
  1963年   5篇
  1961年   6篇
  1960年   2篇
  1958年   2篇
  1955年   2篇
排序方式: 共有582条查询结果,搜索用时 796 毫秒
571.
我国的土壤污染日益严重,由于污染物对土壤生物产生的毒性效应与其生物有效态含量相关,以污染物总量为指标的土壤环境质量标准已无法满足当前土壤管理的需求,亟需开展以生物有效性为基础的土壤环境质量基准的研究工作。目前对土壤中重金属的生物有效性的研究较为深入,但是针对有机污染物的土壤生物有效性研究相对匮乏。本研究综述了有机污染物在土壤中的结构形态、吸附吸收和迁移转化,以及影响土壤中有机污染物生物有效性的关键因素。从我国有机污染物的污染现状、土壤类型分布情况,以及物种选择3个方面对基于生物有效性的土壤环境质量标准/基准的制定进行探讨,以期为我国根据国情制定适合本土特征的生态安全土壤质量标准提供借鉴。  相似文献   
572.
The five largest social safety net (SSN) programmes in the world are being implemented in India, China and Brazil. Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) is one of these programmes and regarded as the world’s largest SSN. MGNREGA aims at enhancing livelihood security of households in rural India by providing guaranteed wage employment. The scheme has resulted in the creation of sustainable assets that promote the economic and infrastructure development. More than 33 million assets were built in the process of MGNREGA. These assets were spread out in 262,380 smallest units of administration covering 6887 sub-districts with the participation of more than 250 million human manpower. The Sustainable Development Goals (SDG) aims to end poverty, protect the planet and ensure that all people enjoy peace and prosperity. The 17 goals tackle the root cause of poverty and attempts to make a positive change for both people and planet. Ecological regeneration or rejuvenation during the development of the assets generated numerous tangible and intangible benefits to the community in a sustainable way. MGNREGA, a federal government-sponsored scheme, using a decentralized approach is directly or indirectly helping to achieve all the 17 goals of sustainable development in India. This article takes a holistic approach to correlate and map the concepts and outcomes of MGNREGA programme with SDG. This article emphasises the fact that community-based participation in the planning and development activities at the regional levels will yield benefits to the biosphere, society and economy at the national level.  相似文献   
573.
稀土湿法冶炼废水处理与资源化研究   总被引:3,自引:0,他引:3  
对某稀土湿法冶炼工艺进行了以清洁生产为核心的技改方案研究,在清洁工艺设计的基础上,通过工艺原理分析和试验,说明其革新工艺的经济有效性;从酸浸废液中年回收硫酸亚铁3000t,从碱转废液中年回收硫酸钠3000t;从废水回收冰晶石,氟回收86%;  相似文献   
574.
The success of conserving biological resources in any Biosphere Reserve or protected area depends on the extent of support and positive attitudes and perceptions of local people have towards such establishments. Ignoring the dependence of the local people for their subsistence needs on resources of such areas leads to conflicts between protected area managers and the local inhabitants. Crop yield losses and livestock depredation were serious problems observed in most buffer zone villages of Nanda Devi Biosphere Reserve. In the present study 10 villages situated in the buffer zone of Nanada Devi Biosphere Reserve (1612 km2 area) in Chamoli district of Uttaranchal, India were studied during 1996-97 using a questionnaire survey of each household (419 = households; 2253 = total population in 1991; 273 ha = cultivated area). Estimates of crop yield losses were made using paired plots technique in four representative villages for each crop species. The magnitude of crop yield losses varied significantly with the distance of agricultural field from forest boundary. The total crop yield losses were high for wheat and potato in all the villages. The spatial distribution of total crop yield losses in any village indicated that they were highest in the area near to forest and least in the area near to village for all crops. Losses from areas near to forest contributed to more than 50% of total losses for each crop in all villages. However, in Lata, Peng and Tolma villages, the losses are high for kidney bean and chemmi (local variety of kidney bean) which varied between 18.5% to 30% of total losses in those villages. Potato alone represents 43.6% of total crop yield loss due to wildlife in Dronagiri village in monetary terms. Among the crops, the monetary value of yield losses are least for amaranth and highest for kidney bean. The projected total value of crop yield losses due to wildlife damage for buffer zone villages located in Garhwal Himalaya is about Rs. 538,620 (US$ 15,389). Besides food grains, horticultural crops i.e. apple, also suffered maximum damage. Major wildlife agents responsible for crop damage were wild boar, bear, porcupine, monkey, musk deer and partridge (chokor). Monkey and wild boar alone accounted for about 50% to 60% of total crop damage in the study villages. Goat and sheep are the major livestock killed by leopard. The total value of livestock losses at prevailing market rates is about Rs. 1,024,520 (US$ 29,272) in the study villages. Due to existing conservation policies and laxity in implementation of preventive measures, the problems for local inhabitants are increasing. Potential solutions discussed emphasize the need to undertake suitable and appropriate protective measures to minimize the crop losses. Change in cropping and crop composition, particularly cultivation of medicinal plants (high value low volume crops), were also suggested. Besides, fair and quick disbursement of compensation for crop loss and livestock killing need to be adopted. Local people of the buffer zone area already have a negative attitude towards park/reserve establishment due to socio-political changes inducing major economic losses and this attitude may lead to clashes and confrontations if proper ameliorative measures are not taken immediately.  相似文献   
575.
Studies on estrogenic disrupting compounds(EDCs) occurrence and identification of main responsible compounds in river water discharged into the sea are of significance.In the present research,we screened estrogenic activities of 10 river water samples from 3 main rivers discharged into Bohai Sea in Tianjin using a recombinant two-hybrid yeast assay and chemical analysis by gas chromatography-mass spectrometry.All sample extracts induced significant estrogenic activity,with 17β-estradiol equivalents(EEQ) of raw water ranging from 5.72 to 59.06 ng/L.Six most concerned EDCs in the river water samples including estrone,17β-estradiol,17α-ethinylestradiol,estriol,diethylstilbestrol and estradiol valerate were determined,with their concentrations up to 50.70,31.40,24.40,37.20,2.56,and 8.47 ng/L,respectively.Through causality analysis by comparing the EEQ values of yeast assay and chemical analysis,17α-ethinylestradiol and 17β-estradiol were identified as the main contributors to the estrogenic effects of the river samples,accounting for the whole estrogenic activities(62.99% to 185.66%),and estrogen antagonistic compounds might presented in the heavy polluted water samples.The proposed approach using both chemical analysis and bioassay could be used for identification and evaluation of the estrogenic activity of EDCs in river water.  相似文献   
576.
Environmental Science and Pollution Research - Multi-drug resistance (MDR) in bacteria is regarded as an emerging pollutant in different food production avenues including aquaculture. One hundred...  相似文献   
577.
Environmental Science and Pollution Research - Oxygen plays a crucial role in coal spontaneous combustion (CSC), and the magnitude of oxygen concentration determines the oxidation reaction...  相似文献   
578.

China’s pilot free trade zone (PFTZ) is an important national strategy to achieve high-quality development, so it is necessary to discuss the effect of PFTZ implementation on green total factor productivity (GTFP). Based on the data from 279 cities in China from 2004 to 2018, this study takes the establishment of PFTZ as a quasi-natural experiment and uses the difference-in-differences (DID) method to systematically evaluate the effect of PFTZ on urban GTFP. The empirical results of this paper are shown as follows: Firstly, the construction of PFTZ has a significant effect on urban GTFP, and this effect has increased gradually over time. Secondly, the construction of PFTZ mainly promotes the urban GTFP by increasing the level of science and technology innovation, reducing government intervention and improving the level of human capital. Thirdly, the effect of PFTZ construction on GTFP is more pronounced in regions with earlier waves of PFTZ and in western regions where environmental concerns are higher. In addition, there is a significant positive linkage between the construction of the PFTZ and the Belt and Road Initiative to improve the urban GTFP. The findings of this paper enrich the relevant literature on PFTAs and sustainable development and provide a theoretical basis for further promotion of PFTZ construction.

  相似文献   
579.
580.
Environmental Science and Pollution Research - Secondary metabolism, which helps a plant cope with external stress, is sensitive to environmental changes and plays a prominent role in maintaining...  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