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   13674篇
  免费   147篇
  国内免费   104篇
安全科学   460篇
废物处理   641篇
环保管理   1915篇
综合类   2740篇
基础理论   3093篇
环境理论   8篇
污染及防治   3496篇
评价与监测   832篇
社会与环境   651篇
灾害及防治   89篇
  2022年   108篇
  2021年   121篇
  2020年   78篇
  2019年   94篇
  2018年   206篇
  2017年   186篇
  2016年   296篇
  2015年   238篇
  2014年   310篇
  2013年   1036篇
  2012年   406篇
  2011年   569篇
  2010年   445篇
  2009年   521篇
  2008年   545篇
  2007年   621篇
  2006年   557篇
  2005年   444篇
  2004年   441篇
  2003年   470篇
  2002年   392篇
  2001年   479篇
  2000年   354篇
  1999年   240篇
  1998年   144篇
  1997年   155篇
  1996年   135篇
  1995年   177篇
  1994年   181篇
  1993年   151篇
  1992年   147篇
  1991年   171篇
  1990年   131篇
  1989年   136篇
  1988年   148篇
  1987年   131篇
  1986年   96篇
  1985年   116篇
  1984年   135篇
  1983年   141篇
  1982年   141篇
  1981年   120篇
  1980年   105篇
  1979年   115篇
  1978年   95篇
  1977年   92篇
  1976年   80篇
  1975年   93篇
  1974年   106篇
  1965年   75篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
551.
Sustainable remediation guidance, frameworks, and case studies have been published at an international level illustrating established sustainability assessment methodologies and successful implementation. Though the terminology and indicators evaluated may differ, one common theme among international organizations and regulatory bodies is more comprehensive and transparent methods are needed to evaluate the social sphere of sustainable remediation. Based on a literature review and stakeholder input, this paper focused on three main areas: (1) status quo of how the social element of sustainable remediation is assessed among various countries and organizations; (2) methodologies to quantitatively and qualitatively evaluate societal impacts; and (3) findings from this research, including challenges, obstacles, and a path forward. In conclusion, several existing social impact assessment techniques are readily available for use by the remediation community, including rating and scoring system evaluations, enhanced cost benefit analysis, surveys/interviews, social network analysis, and multicriteria decision analysis. In addition, a list of 10 main social indicator categories were developed: health and safety, economic stimulation, stakeholder collaboration, benefits community at large, alleviate undesirable community impacts, equality issues, value of ecosystem services and natural resources, risk‐based land management and remedial solutions, regional and global societal impacts, and contributions to other policies. Evaluation of the social element of remedial activities is not without challenges and knowledge gaps. Identification of obstacles and gaps during the project planning process is essential to defining sustainability objectives and choosing the appropriate tool and methodology to conduct an assessment. Challenges identified include meaningful stakeholder engagement, risk perception of stakeholders, and trade‐offs among the various triple bottom line dimensions. ©2015 Wiley Periodicals, Inc.  相似文献   
552.
Journal of Material Cycles and Waste Management - Leather production is a technology that boosts the economy because of its versatility and durability. However, the wastes generated throughout the...  相似文献   
553.
Journal of Material Cycles and Waste Management - The daily use of facemask to prevent virus transmission increases the negative effect on the environment because of improper waste disposal. Due to...  相似文献   
554.
This study evaluated the microbiocidal efficacy of a cleaning and disinfection (C&D) treatment using stainless-steel coupons applied to three common types of animal mortality transport vehicles when exposed to agricultural conditions. Metal test coupons, inoculated with bacteriophage MS2, were affixed to the undercarriage of three types of animal mortality transport vehicles at various locations. Coupons were grimed by maneuvering the test vehicles down a series of wet dirt roads. Coupons were attached and extracted at various points to evaluate C&D performance with and without grime. C&D efficacy using a water-supplied pressure washing system and a dilute sodium hypochlorite (NaOCl) solution was determined by comparing the difference in recovered viable virus between positive control coupons and test coupons. The results demonstrated a relatively high surface decontamination efficacy, with all but one location showing >5 log reduction of MS2. Coupons located on the roll-off truck's inside-back bumper contained the highest level of grime and resulted in a 4 log reduction of MS2. There was no significant difference in C&D efficacy across vehicle types, but locations impacted by grime and lack of accessibility achieved lower efficacies on average. These findings suggest that common C&D protocols, when applied to farm mortality transport vehicles, are effective. Hard-to-access locations containing high levels of grime may be candidates for additional targeted treatment.  相似文献   
555.
Climate change is altering nutrient cycling within the Arctic Ocean, having knock-on effects to Arctic ecosystems. Primary production in the Arctic is principally nitrogen-limited, particularly in the western Pacific-dominated regions where denitrification exacerbates nitrogen loss. The nutrient status of the eastern Eurasian Arctic remains under debate. In the Barents Sea, primary production has increased by 88% since 1998. To support this rapid increase in productivity, either the standing stock of nutrients has been depleted, or the external nutrient supply has increased. Atlantic water inflow, enhanced mixing, benthic nitrogen cycling, and land–ocean interaction have the potential to alter the nutrient supply through addition, dilution or removal. Here we use new datasets from the Changing Arctic Ocean program alongside historical datasets to assess how nitrate and phosphate concentrations may be changing in response to these processes. We highlight how nutrient dynamics may continue to change, why this is important for regional and international policy-making and suggest relevant research priorities for the future.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01673-0.  相似文献   
556.
Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy.  相似文献   
557.
558.
559.
By mechanical-biological treatment (MBT) of residual municipal solid waste the behaviour of landfills can be significantly improved. After MBT the organic content (COD and BOD5), total organic carbon, and total nitrogen in the leachate, as well as the gas production rate, are reduced to values lower than 90% of the fresh untreated waste. The volume of the stabilized material to be disposed on landfills decreases enormously, by up to 70%. The monitoring effort for a landfill constructed under these conditions is reduced to a minimum and the stabilized material can be used in other ways, as material for reforestation, for cover material or for thermal utilization to produce energy. Environmental conditions are important in MBT, as well as waste characteristics. This paper describes the results of a pilot project of MBT performed in Rio de Janeiro, Brazil. The results have shown that this technology can be used successfully in developing countries, with economy for the society and important results for the environment.  相似文献   
560.
A laboratory-scale bioreactor was used to investigate the influence of dairy manure addition (as an inoculum and a carbon source) on the biological and thermal kinetics of the composting process of tomato plant residues-wood shavings mixture. Urea was added (as a nitrogen source) to correct the initial C:N ratio to 30:1 and the initial moisture content was also adjusted to 60%. The result of this study indicated that manure addition to the tomato residues-wood shavings mixture is a good source of macro and micronutrients required for supporting the composting microorganisms. Manure addition increased the rate of temperature increase and the duration of maximum temperature and reduced the lag and the peak time, all of which resulted in a significant reduction in the retention time. However, thermophilic temperature (> or = 40 degrees Celsius) was only achieved with 30%, 40% and 50% manure addition for 3, 7 and 9h. Total carbon reductions were in the range of 9.4-10.8% and TKN reductions were in the range of 3.4-6.0%. Neither the nitrogen nor the moisture content were limiting factors as the C:N ratio remained in the range of 26:1 to 28:1 and the moisture content remained within the optimum range of 58-61%. The maximum temperature of each mixture correlated with the reduction of total carbon, but carbon availability was a limiting factor in these experiments. In order to attain and sustain a thermophilic phase during the composting process, the addition of a readily available carbon source to the tomato should be investigated and carbon type (carbohydrates, proteins and fats) should be taken into account.  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