全文获取类型
收费全文 | 3405篇 |
免费 | 197篇 |
国内免费 | 205篇 |
专业分类
安全科学 | 146篇 |
废物处理 | 31篇 |
环保管理 | 775篇 |
综合类 | 967篇 |
基础理论 | 493篇 |
环境理论 | 54篇 |
污染及防治 | 498篇 |
评价与监测 | 336篇 |
社会与环境 | 363篇 |
灾害及防治 | 144篇 |
出版年
2024年 | 7篇 |
2023年 | 70篇 |
2022年 | 58篇 |
2021年 | 82篇 |
2020年 | 119篇 |
2019年 | 131篇 |
2018年 | 150篇 |
2017年 | 143篇 |
2016年 | 150篇 |
2015年 | 169篇 |
2014年 | 108篇 |
2013年 | 304篇 |
2012年 | 198篇 |
2011年 | 290篇 |
2010年 | 194篇 |
2009年 | 240篇 |
2008年 | 222篇 |
2007年 | 184篇 |
2006年 | 144篇 |
2005年 | 90篇 |
2004年 | 95篇 |
2003年 | 90篇 |
2002年 | 70篇 |
2001年 | 57篇 |
2000年 | 98篇 |
1999年 | 73篇 |
1998年 | 33篇 |
1997年 | 39篇 |
1996年 | 30篇 |
1995年 | 16篇 |
1994年 | 20篇 |
1993年 | 46篇 |
1992年 | 22篇 |
1991年 | 11篇 |
1990年 | 17篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有3807条查询结果,搜索用时 343 毫秒
991.
石化工业园区造成的累积环境影响随着其蓬勃发展而逐步显现,其污染物质在周边土壤与河流底质中的积累影响较为显著[1],目前,我国已有不少关于化工园区环境污染的研究,多集中在水和空气污染问题的研究[2-5],较少针对石油化工园区土壤累积影响的研究[6-7]。本文以我省某石化园区为调查对象,通过该园区废气污染物排放监测及土壤环境现状调查,了解我省新型石化工业园区环境污染状况,对提高石化行业土壤污染防控有重要指导意义。 相似文献
992.
土壤环境质量检测是土壤污染防治行动计划的先行任务,在整体土壤环境监测工作中,应该贯穿质量控制措施。本文结合样品采样、制样、实验室两方面质量控制进行深入分析,论述采取质量控制的措施,总结归纳土壤环境监测工作过程中质量控制措施。 相似文献
993.
土壤的重金属含量情况是反应土壤受污染情况的重要指标,也是体现土地出产农产品健康质量的重要信号,因而受到越来越多的高度关注。本文以福建省闽某地区域内的农田保护区为研究对象,对农田土壤的重金属含量进行检测,采用科学研究方法 ,对重金属分布特征、污染现状及潜在风险进行分析评价,深入查找形成因素,以期为更好地保护和开发当地土地资源,促进农田经济的可持续发展提供科学依据。 相似文献
994.
Two means by which climate change may increase surface soil erosion in mountainous terrain are: (1) increasing the frequency of extreme rainfall events and (2) decreasing the duration of snow cover on bare soil. We used output from four general circulation models (GCMs) and two greenhouse gas trajectories to produce a suite of hydrologic variables at a daily time‐step for historic and projected 21st Century conditions. We statistically disaggregated the daily rainfall to hourly, using hourly rainfall from a network of nine weather stations in the Tahoe Basin, and filtered out rain falling on a snowpack. We applied published equations to convert hourly intensity to raindrop kinetic energy (KE) for each day and grid cell in the Basin, averaged across grid cells, and created time series of total annual and maximum annual hourly kinetic energy (TKE and MKE) on snow‐free ground. Using the Generalized Extreme Value distribution, we calculated the significance of long‐term trends in KE on snow‐free ground, and estimated energy levels for return periods of 2, 20, and 100 years. We then detrended the snowpack data and compared the resulting trends in KE with the trends resulting from changes in both rainfall energy and snowpack under two GCMs. Principal findings include (1) upward trends in MKE, (2) stronger upward trends in TKE; and (3) an effect of increasing rainfall intensities on KE in some cases, and a strong effect of reduced snowpack in all cases examined. 相似文献
995.
重金属是工业生产的废弃物,可随着雨水渗透至低处,通过在植物体内聚集停留于土壤,导致土壤退化,农作物品质降低。同时,还会污染地下水,恶化水文环境,威胁人类生命。本文首先分析了重金属污染土壤的来源和现状,然后分析了重金属污染土壤的特点和危害,最后探讨了污染土壤稳定化修复效果的评估方法和二次污染防治,以供参考。 相似文献
996.
997.
Christopher J. Woltemade Timothy W. Hawkins Claire Jantz Scott Drzyzga 《Journal of the American Water Resources Association》2020,56(3):507-527
Changing climate and land cover are expected to impact flood hydrology in the Delaware River Basin over the 21st Century. HEC‐HMS models (U.S. Army Corps of Engineers Hydrologic Engineering Center‐Hydrologic Modeling System) were developed for five case study watersheds selected to represent a range of scale, soil types, climate, and land cover. Model results indicate that climate change alone could affect peak flood discharges by ?6% to +58% a wide range that reflects regional variation in projected rainfall and snowmelt and local watershed conditions. Land cover changes could increase peak flood discharges up to 10% in four of the five watersheds. In those watersheds, the combination of climate and land cover change increase modeled peak flood discharges by up to 66% and runoff volumes by up to 44%. Precipitation projections are a key source of uncertainty, but there is a high likelihood of greater precipitation falling on a more urbanized landscape that produces larger floods. The influence of climate and land cover changes on flood hydrology for the modeled watersheds varies according to future time period, climate scenario, watershed land cover and soil conditions, and flood frequency. The impacts of climate change alone are typically greater than land cover change but there is substantial geographic variation, with urbanization the greater influence on some small, developing watersheds. 相似文献
998.
Elia M. Tapia‐Villaseor Eylon Shamir Sharon B. Megdal Jacob D. Petersen‐Perlman 《Journal of the American Water Resources Association》2020,56(3):409-430
Assessing groundwater resources in the arid and semiarid borderlands of the United States and Mexico represents a challenge for land and water managers, particularly in the Transboundary Santa Cruz Aquifer (TSCA). Population growth, residential construction, and industrial activities have increased groundwater demand in the TSCA, in addition to wastewater treatment and sanitation demands. These activities, coupled with climate variability, influence the hydrology of the TSCA and emphasize the need for groundwater assessment tools for decision‐making purposes. This study assesses the impacts of changes in groundwater demand, effluent discharge, and climate uncertainties within the TSCA from downstream of the Nogales International Wastewater Treatment Plant to the northern boundary of the Santa Cruz Active Management Area. We use a conceptual water budget model to analyze the long‐term impact of the different components of potential recharge and water losses within the aquifer. Modeling results project a future that ranges from severe long‐term drying to positive wetting. This research improves the understanding of the impact of natural and anthropogenic variables on water sustainability, with an accessible methodology that can be globally applied. 相似文献
999.
Lei Xu Xiangyu Xing Hongbiao Cui Jianbiao Peng Jingfeng Bai 《Chemistry and Ecology》2020,36(5):419-433
ABSTRACTIn order to evaluate the ecological risk reductions of copper (Cu) and cadmium (Cd) and the change of nutrient contents and stoichiometry in a smelter-impacted farmland in Guixi, Jiangxi Province, China, with ~ 800?mg Cu kg?1 soil and 0.8?mg Cd kg?1 soil, an three years in situ experiment was conducted. The field trial consisted of 4 ×?5?m plots in a completely randomised block design. Hydroxyapatite was added at 10?g kg?1 soil and Sedum plumbizincicola, Elsholtzia splendens, and Pennisetum sp. were planted. Post-treatment soil and plant samples were collected annually and analysed for Cu and Cd bioaccessibility, soil carbon: nitrogen: phosphorus (C:N:P), and the stoichiometries of soil β-glucosidase (BG), N-acetylglucosaminidase (NAG), and acid phosphatase (AP) activity levels. The results indicated that the hydroxyapatite treatments significantly reduced Cu and Cd bioaccessibility as well as the ratio of C:P and N:P. Moreover, BG, NAG, and AP activity levels all increased relative to those in untreated soil. Plants may also influence soil BG, NAG, and AP activity. This study demonstrated that in situ Cu and Cd stabilisation by hydroxyapatite and phytoextraction is ecologically safe and can alter soil mineral nutrient ecological stoichiometry and enzyme activity. 相似文献
1000.
Zhenyu Yang Rong Xing Wenjun Zhou Lizhong Zhu 《Frontiers of Environmental Science & Engineering》2020,14(3):41