全文获取类型
收费全文 | 10781篇 |
免费 | 1383篇 |
国内免费 | 3112篇 |
专业分类
安全科学 | 2026篇 |
废物处理 | 167篇 |
环保管理 | 1685篇 |
综合类 | 7159篇 |
基础理论 | 1483篇 |
环境理论 | 3篇 |
污染及防治 | 778篇 |
评价与监测 | 728篇 |
社会与环境 | 766篇 |
灾害及防治 | 481篇 |
出版年
2024年 | 93篇 |
2023年 | 317篇 |
2022年 | 597篇 |
2021年 | 643篇 |
2020年 | 638篇 |
2019年 | 519篇 |
2018年 | 456篇 |
2017年 | 556篇 |
2016年 | 587篇 |
2015年 | 652篇 |
2014年 | 618篇 |
2013年 | 692篇 |
2012年 | 915篇 |
2011年 | 962篇 |
2010年 | 736篇 |
2009年 | 763篇 |
2008年 | 585篇 |
2007年 | 675篇 |
2006年 | 653篇 |
2005年 | 483篇 |
2004年 | 390篇 |
2003年 | 374篇 |
2002年 | 356篇 |
2001年 | 288篇 |
2000年 | 273篇 |
1999年 | 210篇 |
1998年 | 216篇 |
1997年 | 186篇 |
1996年 | 142篇 |
1995年 | 125篇 |
1994年 | 111篇 |
1993年 | 89篇 |
1992年 | 74篇 |
1991年 | 44篇 |
1990年 | 27篇 |
1989年 | 30篇 |
1988年 | 25篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1982年 | 9篇 |
1981年 | 13篇 |
1980年 | 16篇 |
1979年 | 15篇 |
1978年 | 13篇 |
1977年 | 5篇 |
1972年 | 4篇 |
1971年 | 9篇 |
1970年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
671.
672.
Katerina Zemankova Josef Brechler 《Environmental pollution (Barking, Essex : 1987)》2010,158(2):462-469
This paper describes a method of estimating emission fluxes of biogenic volatile organic compounds (BVOCs) based on the approach proposed by Guenther et al. (1995) and the high-resolution Corine land-cover 2000 database (1 × 1 km resolution). The computed emission fluxes for the Czech Republic (selected for analysis as being representative of a heavily cultivated, central European country) are compared with anthropogenic emissions, both for the entire country and for individual administrative regions. In some regions, BVOC emissions are as high as anthropogenic emissions; however, in most regions the BVOC emissions are approximately 50% of the anthropogenic emissions. The yearly course of BVOC emissions (represented by monoterpenes and isoprene) is presented, along with the spatial distribution of annual mean values. Differences in emission distributions during winter (January) and summer (June) are also considered. 相似文献
673.
Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model 总被引:3,自引:0,他引:3
Ruiying Guo Clive Rahn Qing Chen 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2218-2229
Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model. EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. 相似文献
674.
Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season 总被引:1,自引:0,他引:1
Anup K. Prasad Hesham El-Askary Menas Kafatos 《Environmental pollution (Barking, Essex : 1987)》2010,158(11):3385-3391
The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe. 相似文献
675.
Gan Zhang Jun Li Yue Xu Jian-Hui Tang Xiang Liu 《Environmental pollution (Barking, Essex : 1987)》2010,158(11):3392-3400
Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC = 8.7 ± 4.5 μg/m3, EC = 2.5 ± 1.9 μg/m3) among the three sites, and Jianfeng Mountains in Hainan Island (OC = 5.8 ± 2.6 μg/m3, EC = 0.8 ± 0.4 μg/m3) and Tengchong mountain over the east edge of the Tibetan Plateau (OC = 4.8 ± 4.0 μg/m3, EC = 0.5 ± 0.4 μg/m3) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region. 相似文献
676.
阐述了农业面源污染的主要来源及危害,指出农业面源污染是当前农业可持续发展的主要障碍之一。由于我国农村过量和不合理地使用农药、化肥、地膜等,造成了农业面源不同程度的污染,给农业生产和农民生活带来了隐患,直接关系到农业可持续发展,应该采取有效措施加以解决。 相似文献
677.
Kapil Arora Steven K. Mickelson Matthew J. Helmers James L. Baker 《Journal of the American Water Resources Association》2010,46(3):618-647
Arora, Kapil, Steven K. Mickelson, Matthew J. Helmers, and James L. Baker, 2010. Review of Pesticide Retention Processes Occurring in Buffer Strips Receiving Agricultural Runoff. Journal of the American Water Resources Association (JAWRA) 46(3):618-647. DOI: 10.1111/j.1752-1688.2010.00438.x Abstract: Review of the published results shows that the retention of the two pesticide carrier phases (runoff volume and sediment mass) influences pesticide mass transport through buffer strips. Data averaged across different studies showed that the buffer strips retained 45% of runoff volume (ranging between 0 and 100%) and 76% of sediment mass (ranging between 2 and 100%). Sorption (soil sorption coefficient, Koc) is one key pesticide property affecting its transport with the two carrier phases through buffer strips. Data from different studies for pesticide mass retention for weakly (Koc < 100), moderately (100 < Koc < 1,000), and strongly sorbed pesticides (Koc > 1,000) averaged (with ranges) 61 (0-100), 63 (0-100), and 76 (53-100) %, respectively. Because there are more data for runoff volume and sediment mass retention, the average retentions of both carrier phases were used to calculate that the buffer strips would retain 45% of weakly to moderately sorbed and 70% of strongly sorbed pesticides on an average basis. As pesticide mass retention presented is only an average across several studies with different experimental setups, the application of these results to actual field conditions should be carefully examined. 相似文献
678.
Richard J. Brazee 《中国人口.资源与环境(英文版)》2010,8(3)
Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regeneration level of forest resources and the diverse ecological value functions. In this article, the mainstream model paradigm of forest economics, that is, the basic framework of the Faustmann model and its evolution process are made in a more detailed explanation, especially the extended model in... 相似文献
679.
以动态生成的CaO孔隙网络为骨架,按照不退行随机行走模型(NRRW),模拟气体分子在CaO孔隙中的扩散过程,计算了SO2分子的扩散系数和行走维数,并在SO2非线性扩散反应方程基础上,分析了CaO颗粒孔隙中SO2浓度的分布特性。 相似文献
680.
本研究首先介绍了DPSIR模型构建的原理,接着以合肥市为对象,从驱动力、压力、状态、影响、响应5个方面来构建的共36个指标,并采用层次分析法对指标权重的确定和多级灰色关联分析对指标进行综合评价,得出评价结果。合肥市在2004~2005年处于较低可持续发展水平(0.3398、0.3876)、在2010年处于中等可持续发展水平(0.5369)、在2015年处于较高可持续发展水平(0.6016)、在2020年处于较高可持续发展水平(0.7847),该预测评价结果与合肥市城市可持续发展趋势相符。最后采用改进熵值法验证多级灰色关联综合分析结论,计算得出的结果表明,该两种方法评价结论基本相同。因此,本研究对城市总体规划环境影响评价的评价方法的建立与完善,有着较强的实践意义和参考价值。 相似文献