全文获取类型
收费全文 | 2716篇 |
免费 | 96篇 |
国内免费 | 32篇 |
专业分类
安全科学 | 125篇 |
废物处理 | 114篇 |
环保管理 | 662篇 |
综合类 | 239篇 |
基础理论 | 738篇 |
环境理论 | 6篇 |
污染及防治 | 667篇 |
评价与监测 | 179篇 |
社会与环境 | 82篇 |
灾害及防治 | 32篇 |
出版年
2023年 | 24篇 |
2022年 | 44篇 |
2021年 | 52篇 |
2020年 | 39篇 |
2019年 | 45篇 |
2018年 | 72篇 |
2017年 | 87篇 |
2016年 | 103篇 |
2015年 | 73篇 |
2014年 | 97篇 |
2013年 | 242篇 |
2012年 | 123篇 |
2011年 | 173篇 |
2010年 | 118篇 |
2009年 | 134篇 |
2008年 | 158篇 |
2007年 | 149篇 |
2006年 | 155篇 |
2005年 | 90篇 |
2004年 | 83篇 |
2003年 | 94篇 |
2002年 | 81篇 |
2001年 | 43篇 |
2000年 | 70篇 |
1999年 | 36篇 |
1998年 | 37篇 |
1997年 | 22篇 |
1996年 | 43篇 |
1995年 | 37篇 |
1994年 | 36篇 |
1993年 | 20篇 |
1992年 | 23篇 |
1991年 | 13篇 |
1990年 | 13篇 |
1989年 | 25篇 |
1988年 | 17篇 |
1987年 | 23篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 16篇 |
1982年 | 21篇 |
1981年 | 18篇 |
1980年 | 6篇 |
1979年 | 11篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1975年 | 5篇 |
1969年 | 4篇 |
1958年 | 2篇 |
排序方式: 共有2844条查询结果,搜索用时 15 毫秒
961.
Fred Luthans James B. Avey Bruce J. Avolio Steven M. Norman Gwendolyn M. Combs 《组织行为杂志》2006,27(3):387-393
After first providing the meaning of psychological capital (PsyCap), we present a micro‐intervention to develop it. Drawn from hope, optimism, efficacy, and resiliency development, this PsyCap Intervention (PCI) is shown to have preliminary support for not only increasing participants' PsyCap, but also financial impact and high return on investment. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
962.
963.
Daniel C. L. Satgé Marie-Annick Laumond François Desfarges Marie-Pierre R. Chenard 《黑龙江环境通报》2001,21(4):284-288
A therapeutic abortion was conducted on a 17-week-old male fetus with a large umbilical cord teratoma associated with an exomphalos. A review of the literature revealed ten other cases of umbilical cord teratoma and shows that these tumors have a very polymorphic presentation. Four fetuses and infants died from various causes indicating that there is a need for close follow-up of pregnancies with umbilical cord teratoma. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
964.
Visual techniques for the detection of water quality trends: Double-mass curves and cusum functions 总被引:1,自引:0,他引:1
Daniel A. Cluis 《Environmental monitoring and assessment》1983,3(2):173-184
There is a great need for quantitative techniques to assess changes in water quality related to progressive watershed land-use developments, water-related impoundments or to evaluate the impact of recent sanitation programs. In choosing a physically representative variate for the water quality of the run-off, both concentrations and fluxes of pollutants must be taken into account. The importance of the climatic seasonal and hydrological factors associated with unstable event-related contributions of point and non-point pollution sources of the pollutants has lead us to simultaneously study water-discharge and pollutant flux time-series. The mass-discharge time-series are, in practice, far from being ideal for the application of classical trend analysis: they are relatively short and inaccurate: their distribution, orginating from mixed parent populations is very often highly skewed; they show a high level of serial dependence and the seasonal effects represent a large percentage of the variance, concealing possible long-term trends. Faced with the poor structure of these series which prohibits the use of statistical tests, experiments have been carried out with progressive-regressive inertial techniques, which imply the stationarity of water discharges. The double-mass technique was developed originally as a visual technique, to assess the homogeneity of precipitation records and was extended to study variations in sediment transport in modified watersheds. More recently confidence ‘rails’ and slope change detection have rendered its use more quantitative. Based on the same inertial principles, the Cumulative Sum (CUSUM) functions allow simultaneous evaluation of the covariability of the two series. An example involving weekly sampled nitrate concentrations and continuously monitored water discharges is developed. 相似文献
965.
Steven Kragten Krijn B. Trimbos Geert R. de Snoo 《Agriculture, ecosystems & environment》2008,126(3-4):163-167
The aim of this study was to analyse the effects of differences in cropping pattern between organic and conventional arable farms on the breeding activity of skylarks and to assess the effects of arable crop management on skylark nest survival. Skylark nest density was seven times higher on organic farms than on conventional farms (0.63 vs. 0.09 nest per 10 ha). Skylarks showed a strong preference for spring cereals, lucerne and grass leys, all of which were mainly or exclusively grown on organic farms. On organic farms nests were initiated during the entire breeding season, but on conventional farms no nesting activity was found during the peak of the season (early May to early June). On organic farms 27% of all nests was successful. Increasing the availability of suitable breeding habitat during the peak of the breeding season on conventional farms might provide one means of enhancing breeding skylark populations. On organic farms, crop management should focus on reducing nest loss due to farming operations. 相似文献
966.
Of the recent sauropsid skin appendage types, only feathers develop from a cylindrical epidermal invagination, the follicle, and show hierarchical branching. Fossilized integuments of Mesozoic diapsids have been interpreted as follicular and potential feather homologues, an idea particularly controversially discussed for the elongate dorsal skin projections of the small diapsid Longisquama insignis from the Triassic of Kyrgyzstan. Based on new finds and their comparison with the type material, we show that Longisquama's appendages consist of a single-branched internal frame enclosed by a flexible outer membrane. Not supporting a categorization either as feathers or as scales, our analysis demonstrates that the Longisquama appendages formed in a two-stage, feather-like developmental process, representing an unusual early example for the evolutionary plasticity of sauropsid integument. 相似文献
967.
Peter Viebahn Daniel Vallentin Samuel H?ller Manfred Fischedick 《Mitigation and Adaptation Strategies for Global Change》2012,17(6):707-730
The study presents the results of an integrated assessment of carbon capture and storage (CCS) in the power plant sector in Germany, with special emphasis on the competition with renewable energy technologies. Assessment dimensions comprise technical, economic and environmental aspects, long-term scenario analysis, the role of stakeholders and public acceptance and regulatory issues. The results lead to the overall conclusion that there might not necessarily be a need to focus additionally on CCS in the power plant sector. Even in case of ambitious climate protection targets, current energy policy priorities (expansion of renewable energies and combined heat and power plants as well as enhanced energy productivity) result in a limited demand for CCS. In case that the large energy saving potential aimed for can only partly be implemented, the rising gap in CO2 reduction could only be closed by setting up a CCS-maximum strategy. In this case, up to 22% (41 GW) of the totally installed load in 2050 could be based on CCS. Assuming a more realistic scenario variant applying CCS to only 20 GW or lower would not be sufficient to reach the envisaged climate targets in the electricity sector. Furthermore, the growing public opposition against CO2 storage projects appears as a key barrier, supplemented by major uncertainties concerning the estimation of storage potentials, the long-term cost development as well as the environmental burdens which abound when applying a life-cycle approach. However, recently, alternative applications are being increasingly considered?Cthat is the capture of CO2 at industrial point sources and biomass based energy production (electricity, heat and fuels) where assessment studies for exploring the potentials, limits and requirements for commercial use are missing so far. Globally, CCS at power plants might be an important climate protection technology: coal-consuming countries such as China and India are increasingly moving centre stage into the debate. Here, similar investigations on the development and the integration of both, CCS and renewable energies, into the individual energy system structures of such countries would be reasonable. 相似文献
968.
García-Espinoza Josué Daniel Robles Irma Durán-Moreno Alfonso Godínez Luis A. 《Environmental science and pollution research international》2022,29(28):42305-42318
Environmental Science and Pollution Research - In this work, a cylindrical flow-through electro-Fenton reactor containing graphite felt electrodes and an Fe(II) loaded resin was evaluated for the... 相似文献
969.
Ramello Gloria Duke Guy Dekker Rene W. R. J. van der Mije Steven Movalli Paola 《Environmental science and pollution research international》2022,29(12):17017-17030
Environmental Science and Pollution Research - This paper provides a novel survey of current collections of frozen raptor carcasses and tissue samples in natural history museums (NHMs),... 相似文献
970.
Jarvin Mariyadhas Kumar Sundararajan Ashok Rosaline Daniel Rani Foletto Edson Luiz Dotto Guilherme Luiz Inbanathan Savariroyan Stephen Rajkumar 《Environmental science and pollution research international》2022,29(38):57330-57344
Environmental Science and Pollution Research - In this work, Ag-doped ZnO nanoparticles (NPs) were synthesized by a simple green method using a toxic agent-free route for photocatalytic purposes,... 相似文献