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   709篇
  免费   7篇
  国内免费   32篇
安全科学   9篇
废物处理   39篇
环保管理   40篇
综合类   50篇
基础理论   101篇
污染及防治   409篇
评价与监测   56篇
社会与环境   40篇
灾害及防治   4篇
  2023年   28篇
  2022年   151篇
  2021年   141篇
  2020年   46篇
  2019年   45篇
  2018年   40篇
  2017年   54篇
  2016年   43篇
  2015年   25篇
  2014年   35篇
  2013年   36篇
  2012年   21篇
  2011年   19篇
  2010年   7篇
  2009年   9篇
  2008年   10篇
  2007年   9篇
  2006年   6篇
  2005年   6篇
  2004年   2篇
  2003年   3篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1985年   1篇
  1974年   1篇
排序方式: 共有748条查询结果,搜索用时 31 毫秒
501.
South Asia faces increasing flooding risks due to climatic and socio-economic changes. Various measures have been adopted by the governments of the countries in this region. However, these measures are not adequate to protect the vulnerable communities from ever-increasing flood losses. This study assesses the policy and planning processes and flood-related scientific research in India, Pakistan and Bangladesh. Based on a systematic review, a comparison of the existing flood management systems of the three countries is undertaken, and a framework for sustainable flood management in the region is suggested. Insights from the literature show that Bangladesh has been able to develop an effective governance structure to address flood hazards, while Pakistan’s approach to flood management planning is found to be largely inadequate. This inadequacy is mainly attributed to missing links in policy formulation and planning processes, along with a lack of institutional coordination. The results of the literature analysis reveal poor support from scientific research focusing on flooding issues in the case of Pakistan, while Bangladesh and India seem to have benefited from research support in formulating their flood management strategies. Based on these findings, an alternative framework is suggested, emphasizing the need to enhance institutional linkages, community participation and evidence-based research.  相似文献   
502.
503.
This investigation describes the use of specially cultivated, nonliving biomass of Trichoderma harzianum as a biosorbent for the batch removal of Pb(II) from a stirred system under different experimental conditions. The metal removal depended upon pH, sorbent particle size, initial Pb(II) concentration, shaking speed, and sorption time. The optimal experimental conditions for the removal of Pb(II) by T. harzianum with an initial metal concentration of 100 mg L?1 were obtained at a particle size of 53 μm, a pH of 4.5, a shaking speed of 200 rpm, and a contact time of 720 min. The results were analyzed in terms of adsorption isotherms and kinetic models. The Freundlich isotherm model and pseudo second-order model fitted well in the data. T. harzianum proved to be a good biomaterial for accumulating Pb(II) from aqueous solutions (q = 460 mg g?1).  相似文献   
504.
This study was conducted to examine adsorption of pesticides bifenthrin, carbosulfan, λ-cyhalothrin, cypermethrin, endosulfan, parathion methyl, monocrotophos and 4-nitrophenol by sandy clay loam (S.C.L) and sandy loam (S.L) soils (with varying organic content). There was no significant difference between the observed soil water partitioning coefficient values (K d) derived from linear and nonlinear Freundlich isotherms. Adsorption of pesticides on S.C.L soils was higher than those on S.L soils. K d values showed significant correlations (r 2?=?0.8???0.99 and 0.65???0.97) with soil organic carbon content (OC) and weak correlations (r 2?=?0.2???0.29 and 0.1???0.18) with clay contents of S.C.L and S.L soil at p?≤?0.05, respectively for all pesticides (except monocrotophos). Observed K oc values (soil-water partitioning constants based on the organic C fraction of the soil) were in accordance with the literature values of Wauchope and Tomlin with a maximum deviation of less than 0.5 log units. Ten Quantitative Property-Property Relationships (QPPR) among water solubility, n-octanol water coefficient (K ow) and K oc were proposed for studied pesticides except monocrotophos. The models were considered acceptable when predicted-observed difference for log?K ow and log?K oc were ≤?0.3 and ≤?0.5?log units, respectively, during the validation procedure. This work indicates that the log?K oc derived from the log Kow, from some of existing relationships, may be a fair predictor where observed values (i.e., K d and K oc) are not available. Furthermore, predicted leaching potential by groundwater ubiquity scores (GUS) equation was solved by using observed K oc values and literature reported half lives of pesticides. GUS ranked the mobility of nonvolatile compounds i.e., bifenthrin, λ-cyhalothrin, cypermethrin and endosulfan extremely low; methyl parathion very low; 4-nitrophenol low; carbofuran and monocrotophos very high in S.C.L and S.L soils, respectively. Results discussed in this paper provide background to prioritize pesticides or chemical groups that should be evaluated under field conditions with regard to their leaching potential to groundwater in arid climates.  相似文献   
505.
Radionuclide contamination in terrestrial ecosystems has reached a dangerous level. The major artificial radionuclide present in the environment is 137Cs, which is released as a result of weapon production related to atomic projects, accidental explosions of nuclear power plants and other sources, such as reactors, evaporation ponds, liquid storage tanks, and burial grounds. The release of potentially hazardous radionuclides (radiocesium) in recent years has provided the opportunity to conduct multidisciplinary studies on their fate and transport. Radiocesium’s high fission yield and ease of detection made it a prime candidate for early radio-ecological investigations. The facility setting provides a diverse background for the improved understanding of various factors that contribute toward the fate and transfer of radionuclides in the terrestrial ecosystem. In this review, we summarize the significant environmental radiocesium transfer factors to determine the damaging effects of radiocesium on terrestrial ecosystem. It has been found that 137Cs can trace the transport of other radionuclides that have a high affinity for binding to soil particles (silts and clays). Possible remedial methods are also discussed for contaminated terrestrial systems. This review will serve as a guideline for future studies of the fate and transport of 137Cs in terrestrial environments in the wake of the Fukushima Nuclear Power Plant disaster in 2011.  相似文献   
506.
Environmental Science and Pollution Research - In a developing country such as Pakistan, adopting biogas technology is a complicated process. The government has taken several steps to address...  相似文献   
507.

The transportation sector is a crucial driver of energy intensity and environmental degradation. Therefore, we aim to explore the nexus of transportation taxes, energy intensity, and CO2 emissions for the BICS economies. The econometric approaches, CS-ARDL and PMG-ARDL, have been employed to compute the estimates. The long-run estimates of the green transportation tax variable are negatively significant in both energy intensity and CO2 emissions models irrespective of the estimation technique. These findings imply that green transportation taxes help reduce energy intensity and CO2 emissions in BICS economies. Conversely, in the short-run, the effects of transportation taxes on energy intensity and CO2 emissions are mixed and inconclusive. Hence, transportation taxes are necessary to keep the polluters under control not only from the transport sector but also serve as a deterrent for other sectors as well.

  相似文献   
508.
Environmental Science and Pollution Research - Microplastics (MPs), together with microfibers, have emerged as a contaminant of concern all around the globe. MPs have been detected in freshwater,...  相似文献   
509.
Environmental Science and Pollution Research - Antibiotic resistance genes (ARGs) and antimicrobial resistance elements (AMR) are novel environmental contaminants that pose a significant risk to...  相似文献   
510.
Environmental Chemistry Letters - In the context of climate change and the circular economy, there is an urgent need to develop biofuels and value-added chemicals from lignocellulosic waste such as...  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