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   817篇
  免费   2篇
  国内免费   38篇
安全科学   61篇
废物处理   59篇
环保管理   64篇
综合类   72篇
基础理论   97篇
环境理论   1篇
污染及防治   344篇
评价与监测   108篇
社会与环境   46篇
灾害及防治   5篇
  2023年   25篇
  2022年   98篇
  2021年   93篇
  2020年   19篇
  2019年   36篇
  2018年   22篇
  2017年   41篇
  2016年   30篇
  2015年   15篇
  2014年   25篇
  2013年   75篇
  2012年   38篇
  2011年   47篇
  2010年   33篇
  2009年   27篇
  2008年   25篇
  2007年   29篇
  2006年   14篇
  2005年   13篇
  2004年   10篇
  2003年   15篇
  2002年   16篇
  2001年   15篇
  2000年   10篇
  1999年   8篇
  1998年   3篇
  1997年   7篇
  1996年   3篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   6篇
  1990年   4篇
  1988年   3篇
  1987年   4篇
  1986年   2篇
  1985年   4篇
  1984年   4篇
  1983年   3篇
  1982年   3篇
  1981年   2篇
  1980年   4篇
  1979年   5篇
  1978年   2篇
  1968年   1篇
  1965年   1篇
  1964年   2篇
  1962年   1篇
  1961年   1篇
  1959年   1篇
排序方式: 共有857条查询结果,搜索用时 62 毫秒
221.
Environmental Science and Pollution Research - Biomass energy is an important source of energy consumption. It is a renewable, abundant, and easily produced energy source. Its usage supports...  相似文献   
222.
Environmental Science and Pollution Research - A comprehensive study was conducted to appraise the concentrations of 30 endocrine disrupting pesticides (EDPs) in soil and vegetable samples...  相似文献   
223.
Environmental Science and Pollution Research - Economic growth in modern-day world get attention primarily through innovation and higher productivity, which places technology and knowledge at the...  相似文献   
224.

Over the last few decades, the atmospheric carbon dioxide emission has been amplified to a great extent in Pakistan. This amplification may cause global warming, climate change, and environmental degradation in Pakistan. Consequently, ecological condition and human life may suffer in the near future from these indicated threats. Therefore, an attempt was made to test the relationship between globalization and carbon dioxide emissions in case of Pakistan. The study covers the time series data over the period of 1975–2014. We employed modern econometric techniques such as Johansen co-integration, ARDL bound testing approach, and variance decomposition analysis. Results of the Johansen co-integration test show that there is a significant long-run relationship between carbon dioxide emissions and globalization. The long-run elasticities of the ARDL model show that a 1% increase in economic globalization, political globalization, and social globalization will increase carbon dioxide emissions by 0.38, 0.19, and 0.11%, respectively. Further, our findings reveal that the environmental Kuznets curve (EKC) hypothesis prevails an inverted U-shaped relationship between carbon dioxide emission and economic growth. Therefore, the EKC hypothesis is valid in the presence of globalization. The diagnostic test results show that the parameters of the ARDL model are credible, stable, and reliable in the current form. Finally, variance decomposition analysis displays that economic, political, and social globalization are contributing significantly to carbon dioxide emissions in Pakistan.

  相似文献   
225.
Environmental Science and Pollution Research - Cadmium is an important widely distributed heavy metal in the environment due to its several industrial uses, while milk thistle is an important herb...  相似文献   
226.
This paper reports a sensitive and cost effective method of analysis for aflatoxins B1, B2, G1 and G2. The sample preparation method was primarily optimised in peanuts, followed by its validation in a range of peanut-processed products and cereal (rice, corn, millets) matrices. Peanut slurry [12.5 g peanut + 12.5 mL water] was extracted with methanol: water (8:2, 100 mL), cleaned through an immunoaffinity column and thereafter measured directly by ultra-performance liquid chromatography-fluorescence (UPLC-FLD) detection, within a chromatographic runtime of 5 minutes. The use of a large volume flow cell in the FLD nullified the requirement of any post-column derivatisation and provided the lowest ever reported limits of quantification of 0.025 for B1 and G1 and 0.01 μg/kg for B2 and G2. The single laboratory validation of the method provided acceptable selectivity, linearity, recovery and precision for reliable quantifications in all the test matrices as well as demonstrated compliance with the EC 401/2006 guidelines for analytical quality control of aflatoxins in foodstuffs.  相似文献   
227.

Pakistan is an agricultural country and due to the shortage of clean water, most of the irrigated area (32,500 ha) of Pakistan was supplied with wastewater (0.876?×?109 m3/year). Concentrations of heavy metals in radish (Raphanus sativus) and turnip (Brassica rapa) taken from vegetable fields in Sargodha, Pakistan, were measured. Untreated wastewater was used persistently for a long time to irrigate these vegetable fields. A control site was selected that had a history of fresh groundwater irrigation. Mean metal concentrations were found for irrigation water, soil, and vegetables. In irrigation water, concentrations of Mo and Pb at three sites and Se at sites II and III were higher than the recommended limits. In vegetables, concentrations of Mo and Pb were above the maximum permissible limits. High bioconcentration factor was observed for Zn (12.61 in R. sativus and 11.72 in B. rapa) at site I and high pollution load index was found for Pb (3.89 in R. sativus and 3.87 in B. rapa) at site II. The differences in metal concentrations found in samples depended upon different soil nature and assimilation capacities of vegetables at different sites which in turn depended upon different environmental cues. The entrance of metal and metalloids to human body may happen through different pathways; however, the food chain is the chief route through which metals are transferred from vegetables to individuals. Health risk index observed for metals, (Mo, As, Ni, Cu, and Pb) higher than 1 indicated high risk through consumption of these vegetables at three sites.

  相似文献   
228.
PM2.5 sampling was conducted at a curbside location in Delhi city for summer and winter seasons, to evaluate the effect of PM2.5 and its chemical components on the visibility impairment. The PM2.5 concentrations were observed to be higher than the National Ambient Air Quality Standards (NAAQS), indicating poor air quality. The chemical constituents of PM2.5 (the water-soluble ionic species SO42-, NO3?, Cl?, and NH4+, and carbonaceous species: organic carbon, elemental carbon) were analyzed to study their impact on visibility impairment by reconstructing the light extinction coefficient, bext. The visibility was found to be negatively correlated with PM2.5 and its components. The reconstructed bext showed that organic matter was the largest contributor to bext in both the seasons which may be attributed to combustion sources. In summer season, it was followed by elemental carbon and ammonium sulfate; however, in winter, major contributions were from ammonium nitrate and elemental carbon. Higher elemental carbon in both seasons may be attributed to traffic sources, while lower concentrations of nitrate during summer, may be attributed to volatility because of higher atmospheric temperatures.

Implications: The chemical constituents of PM2.5 that majorly effect the visibility impairment are organic matter and elemental carbon, both of which are products of combustion processes. Secondary formations that lead to ammonium sulfate and ammonium nitrate production also impair the visibility.  相似文献   
229.
Environmental Management - While urban forests are often identified as part of climate change adaptation and mitigation strategies, less attention has been given to vulnerabilities urban trees may...  相似文献   
230.
Environmental and Ecological Statistics - The paper proposes a new perspective in the environmental and resource economics literature by examining innovation (measured by R&D expenditures),...  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