全文获取类型
收费全文 | 590篇 |
免费 | 67篇 |
国内免费 | 313篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 25篇 |
环保管理 | 87篇 |
综合类 | 538篇 |
基础理论 | 111篇 |
污染及防治 | 65篇 |
评价与监测 | 46篇 |
社会与环境 | 42篇 |
灾害及防治 | 9篇 |
出版年
2024年 | 6篇 |
2023年 | 26篇 |
2022年 | 29篇 |
2021年 | 30篇 |
2020年 | 21篇 |
2019年 | 20篇 |
2018年 | 29篇 |
2017年 | 47篇 |
2016年 | 38篇 |
2015年 | 47篇 |
2014年 | 66篇 |
2013年 | 60篇 |
2012年 | 69篇 |
2011年 | 63篇 |
2010年 | 36篇 |
2009年 | 38篇 |
2008年 | 26篇 |
2007年 | 38篇 |
2006年 | 39篇 |
2005年 | 30篇 |
2004年 | 26篇 |
2003年 | 25篇 |
2002年 | 22篇 |
2001年 | 22篇 |
2000年 | 24篇 |
1999年 | 17篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 14篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 16篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有970条查询结果,搜索用时 234 毫秒
31.
Hannah Fraser Kylie Soanes Stuart A. Jones Chris S. Jones Matthew Malishev 《Conservation biology》2017,31(3):540-546
The objectives of conservation science and dissemination of its research create a paradox: Conservation is about preserving the environment, yet scientists spread this message at conferences with heavy carbon footprints. Ecology and conservation science depend on global knowledge exchange—getting the best science to the places it is most needed. However, conference attendance from developed countries typically outweighs that from developing countries that are biodiversity and conservation hotspots. If any branch of science should be trying to maximize participation while minimizing carbon emissions, it is conservation. Virtual conferencing is common in other disciplines, such as education and humanities, but it is surprisingly underused in ecology and conservation. Adopting virtual conferencing entails a number of challenges, including logistics and unified acceptance, which we argue can be overcome through planning and technology. We examined 4 conference models: a pure‐virtual model and 3 hybrid hub‐and‐node models, where hubs stream content to local nodes. These models collectively aim to mitigate the logistical and administrative challenges of global knowledge transfer. Embracing virtual conferencing addresses 2 essential prerequisites of modern conferences: lowering carbon emissions and increasing accessibility for remote, time‐ and resource‐poor researchers, particularly those from developing countries. 相似文献
32.
33.
Livison Mashoko Charles Mbohwa Valerie M. Thomas 《Journal of Environmental Planning and Management》2010,53(6):793-807
A life cycle assessment of sugar produced in South Africa evaluates the environmental impacts and energy consumption of the different life cycle phases of sugar production. The system studied includes sugar cane farming, fertiliser and herbicide manufacture, cane burning, sugar cane transportation and sugar manufacture. Inventory and impact assessment results show that non-renewable energy consumption is 5350 MJ per tonne of raw sugar produced and 40% of this is from fertiliser and herbicide manufacture. Reduction in the use or impact of fertiliser for cane farming could bring considerable savings in terms of fossil energy consumption and a reduction in greenhouse gas emissions. 相似文献
34.
35.
E.I. Vanguelova S. Benham A.J. Moffat T. Nisbet N. Barsoum F. Bochereau S. Broadmeadow P. Taylor 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1857-1869
Long term trend analysis of bulk precipitation, throughfall and soil solution elemental fluxes from 12 years monitoring at 10 ICP Level II forest sites in the UK reveal coherent national chemical trends indicating recovery from sulphur deposition and acidification. Soil solution pH increased and sulphate and aluminium decreased at most sites. Trends in nitrogen were variable and dependant on its form. Dissolved organic nitrogen increased in bulk precipitation, throughfall and soil solution at most sites. Nitrate in soil solution declined at sites receiving high nitrogen deposition. Increase in soil dissolved organic carbon was detected - a response to pollution recovery, changes in soil temperature and/or increased microbial activity. An increase of sodium and chloride was evident - a possible result of more frequent storm events at exposed sites. The intensive and integrated nature of monitoring enables the relationships between climate/pollutant exposure and chemical/biological response in forestry to be explored. 相似文献
36.
毒气泄漏事故居民疏散心理行为特征相关性研究 总被引:1,自引:1,他引:0
为了研究在毒气泄漏事故中居民的心理行为特征,选择发生过毒气泄漏事故的某化工企业,采用问卷法对其周边居民进行调查,并运用SPSS软件对调查问卷的结果进行独立性分析,从而得出居民在疏散过程中的各种心理行为反应的相关因素,为制定有效的应急疏散管理预案提供科学的依据。 相似文献
37.
Pierluigi Caboni Giorgia Sarais Alberto Angioni Francesco Lai Fabrizio Dedola Paolo Cabras 《Journal of environmental science and health. Part. B》2013,48(6):598-605
The degradation of the main azadirachtoids on tomatoes was studied after greenhouse treatment. These experiments were carried out at 1 and 5× the concentration recommended by the manufacturer. In all experiments the deposition of azadirachtin A (AZA-A) was below the maximum residue level (MRL). Even if at the highest dose, AZA-A half-life time calculated as pseudo first order kinetic was 1.2 days in agreement with the recommended preharvest interval (PHI) of 3 days. Experiments with a model system showed that sunlight photodegradation is the main factor influencing the rate of disappearance of AZA-A after greenhouse treatment while tomato epicuticular waxes doubled the photodegradation rate of AZA-A in a commercial formulation. 相似文献
38.
The Pechelbronn oilfield (Rhine Graben, France), where mining activity ended in the 1960s, has been used for waste disposal for twenty years. Since the wastes are varied, work is underway to identify the discharged materials and their derivatives, as well as to locate and quantify potential discharge sites. Two major goals were assigned to the present work. The first was to identify or refine the location of hidden structures that could facilitate gas emanation up to the surface, by studying soil gas concentrations (mainly 222Rn, CO2, CH4 and helium) and carbon isotope ratios in the CO2 phase. The second was devoted to examining, from a health and safety viewpoint, if the use of the oilfield as a waste disposal site might have led to enhanced or modified gas emanation throughout the area.It appeared that CO2 and 222Rn evolution in the whole area were similar, except near some of the faults and fractures that are known through surface mapping and underground observations. These 222Rn and CO2 anomalies made it possible to highlight more emissive zones that are either related to main faults or to secondary fractures acting as migration pathways. In that sense, the CO2 phase can be used to evaluate 222Rn activities distant from tectonic structures but can lead to erroneous evaluations near to gas migration pathways. Dumping of wastes, as well as oil residues, did not appear to have a strong influence on soil gaseous species and emanation. Similarly, enhanced gas migration due to underground galleries and exploitation wells has not been established. Carbon isotope ratios suggested a balance of biological phenomena, despite the high CO2 contents reached. Other monitored gaseous species (N2, Ar, H2 and alkanes), when detected, always showed amounts close to those found subsurface and/or in atmospheric gases. 相似文献
39.
40.
Diffusive fluxes of elements (NO-2, NO-3, NH+4, SiO2, PO3-4, Cl-, SO2-4, Fe, Mn) have been measured by applying the Fick's first law in two stations of the Tigullio Gulf: the first one characterized by sandy sediments rich in vegetal detritus and the second one, located to within the tourist harbour, characterized by a silty-clay sediments.
Benthic fluxes were measured only in the second station by means of benthic chamber experiments. Although the significant presence of dissolved oxygen in the surface sediments, and the evidence of processes usually occurring in oxidised sediments such as nitrification, both stations also presented characteristics of anoxic sediments such as high oxygen consumption rate and high pore water concentrations of ion, manganese and N-ammonia and reactive orthophosphate.
In both stations, sediments seemed to represent a potential source for most of the chemical species studied, although fluxes were not confirmed for ion, manganese and reactive orthophosphate in benthic chamber experiments.
Diffusive fluxes presented a general agreement for both stations, with higher fluxes of N-nitrate and N-nitrite at the first station were oxidative processes of N-ammonia in the upper layer of the sediments seemed to be more active. the comparison between diffusive and benthic fluxes showed a possible contribution of bioturbation. 相似文献
Benthic fluxes were measured only in the second station by means of benthic chamber experiments. Although the significant presence of dissolved oxygen in the surface sediments, and the evidence of processes usually occurring in oxidised sediments such as nitrification, both stations also presented characteristics of anoxic sediments such as high oxygen consumption rate and high pore water concentrations of ion, manganese and N-ammonia and reactive orthophosphate.
In both stations, sediments seemed to represent a potential source for most of the chemical species studied, although fluxes were not confirmed for ion, manganese and reactive orthophosphate in benthic chamber experiments.
Diffusive fluxes presented a general agreement for both stations, with higher fluxes of N-nitrate and N-nitrite at the first station were oxidative processes of N-ammonia in the upper layer of the sediments seemed to be more active. the comparison between diffusive and benthic fluxes showed a possible contribution of bioturbation. 相似文献