全文获取类型
收费全文 | 10544篇 |
免费 | 10篇 |
国内免费 | 36篇 |
专业分类
安全科学 | 44篇 |
废物处理 | 835篇 |
环保管理 | 1294篇 |
综合类 | 1009篇 |
基础理论 | 3258篇 |
环境理论 | 1篇 |
污染及防治 | 2074篇 |
评价与监测 | 1135篇 |
社会与环境 | 933篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 21篇 |
2022年 | 128篇 |
2021年 | 98篇 |
2020年 | 29篇 |
2019年 | 47篇 |
2018年 | 1487篇 |
2017年 | 1401篇 |
2016年 | 1244篇 |
2015年 | 160篇 |
2014年 | 64篇 |
2013年 | 127篇 |
2012年 | 500篇 |
2011年 | 1386篇 |
2010年 | 717篇 |
2009年 | 637篇 |
2008年 | 900篇 |
2007年 | 1245篇 |
2006年 | 21篇 |
2005年 | 32篇 |
2004年 | 52篇 |
2003年 | 75篇 |
2002年 | 103篇 |
2001年 | 19篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1961年 | 1篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Samari Mohammad Ridha Firas Manovic Vasilije Macchi Arturo Anthony E. J. 《Mitigation and Adaptation Strategies for Global Change》2020,25(1):25-41
Mitigation and Adaptation Strategies for Global Change - Direct air capture (DAC) is a developing technology for removing carbon dioxide (CO2) from the atmosphere or from low-CO2-containing... 相似文献
72.
Chris J. Matthews David B. Newton Roger D. Braddock Bofu Yu 《Environmental Modeling and Assessment》2007,12(1):27-41
Recently, the New Morris Method has been presented as an effective sensitivity analysis tool for mathematical models. The
New Morris Method estimates the sensitivity of an output parameter to a given set of input parameters (first-order effects)
and the extent these parameters interact with each other (second-order effects). This method requires the specification of
two parameters (runs and resolution) that control the sampling of the output parameter to determine its sensitivity to various
inputs. The criteria for these parameters have been set on the analysis of a well-behaved analytical function (see Cropp and
Braddock, Reliab. Eng. Syst. Saf. 78:77–83, 2002), which may not be applicable to other physical models that describe complex
processes. This paper will investigate the appropriateness of the criteria from (Cropp and Braddock, 2002) and hence the effectiveness
of the New Morris Method to determine the sensitivity behaviour of two hydrologic models: the Soil Erosion and Deposition
System and Griffith University Representation of Urban Hydrology. In the first case, this paper will separately analyse the
sensitivity of an output parameter on a set of input parameters (first- and second-order effects) for each model and discuss
the physical meaning of these sensitivities. This will be followed by an investigation into the sampling criteria by exploring
the convergence of the sensitivity behaviour for each model as the sampling of the parameter space is increased. By comparing
these trends to the convergence behaviour from Cropp and Braddock (2002), we will determine how well the New Morris Method
estimates the sensitivity for each model and whether the sampling criteria are appropriate for these models. It will be shown
that the New Morris Method can provide additional insight into the functioning of these models, and that, under a different
metric, the sensitivity behaviour of these models does converge confirming the sampling criteria set by Cropp and Braddock. 相似文献
73.
74.
Water quality indices (WQIs) have been developed to assess the suitability of water for a variety of uses. These indices reflect the status of water quality in lakes, streams, rivers, and reservoirs. The concept of WQIs is based on a comparison of the concentration of contaminants with the respective environmental standards. The number, frequency, and magnitude by which the environmental standards for specific variables are not met in a given time period are reflected in WQIs. Further, the water quality trend analysis predicts the behavior of the water quality parameters and overall water quality in the time domain. In this paper, the concept of WQI was applied to three selected watersheds of Atlantic region: the Mersey River, the Point Wolfe River, and the Dunk River sites. To have robust study, two different water quality indices are used: Canadian Water Quality Index (CWQI), and British Columbia Water Quality Index (BWQI). The complete study was conducted in two steps. The first step was to organize and process the data into a format compatible with WQI analysis. After processing the input data, the WQI was calculated. The second step outlined in the paper discusses detailed trend analysis using linear and quadratic models for all the three sites. As per the 25 years trend analysis, overall water quality for agriculture use observed an improving trend at all the three sites studied. Water quality for raw water used for drinking (prior to treatment) and aquatic uses has shown improving trend at Point Wolfe River. It is further observed that pH, SO4, and NO3 concentrations are improving at Dunk River, Mersey River, and Point Wolfe River sites. To ascertain the reliability and significance of the trend analysis, a detailed error analysis and parametric significance tests were also conducted It was observed that for most of the sites and water uses quadratic trend models were a better fit than the linear models. 相似文献
75.
Charles S. Tapiero 《Environmental Modeling and Assessment》2005,9(4):201-206
Conclusion In this paper we have considered a specific environmental game emphasizing both control-prevention efforts and the propensity to pollute by a firm which adopts a given pollution abatement technology. A random payoff game was constructed and solved under a risk neutral assumption and quadratic utilities for both the firm and the environmental controller. The game thus defined, provides a wide range of interpretations and potential approaches for selecting a control-inspection policies to prevent environmental risks. There are of course many facets to this problem, which could be considered and have not been considered in sufficient depth. For example, more complex control mechanisms and liabilities, the effects of insurance and risk sharing, the application of cooperative efforts and subvention of pollution abatement investments (through tax incentives and their like), etc. have not been considered [5,7]. These are topics for further research. The basic presumption of this paper is that it is very difficult to fully enforce pollution prevention by firms, as a result, some controls are needed to ensure that firms be controlled so that appropriate efforts are carried. 相似文献
76.
Gottfried Tappeiner Ulrike Tappeiner Janette Walde 《Environmental Modeling and Assessment》2007,12(4):253-256
The complexity of today’s research problems increasingly demands that scientists move beyond the confines of their own discipline.
In this special issue, the basics of a transdisciplinary framework are established and problems analyzed in a specific discipline
are successfully integrated in this transdisciplinary network. The intent has been to go beyond only statements about the
importance of enabling early stage researchers to work across disciplinary boundaries, and to show that important discoveries
are being made at the intersection of disciplines. Embedding various research projects in a more global framework can meet
the demands of an interdisciplinary or transdisciplinary approach (especially for early stage researchers) and contribute
significantly to sustainable research. 相似文献
77.
A study on the orbit of air temperature movement 总被引:1,自引:0,他引:1
Zong-Chang Yang 《Environmental Modeling and Assessment》2007,12(2):131-143
In this paper, we describe an air temperature movement by mapping its time series to the polar coordinates: the value of the
time series is plotted on the radial coordinate and the time on the angular coordinate. In this way, both the yearly and daily
air temperature movements from five different locations of China are used to demonstrate that, in an intuitionistic view,
air temperature movement is neither random nor chaotic, but has its own orbit. We then propose an elliptic orbit model for
the air temperature movement. Our proposed model provides quite good results when it is applied to the evaluation of yearly
air temperature movements in eight locations in various parts of the world, and the evaluation of daily air temperature movements
in five locations in Hunan Province of China on December 17, 2005. Results show that our approach provides a concise and helpful
model for air temperature analysis. 相似文献
78.
Salam A Bauer H Kassin K Ullah SM Puxbaum H 《Journal of environmental monitoring : JEM》2003,5(3):483-490
Aerosol constituents (elemental carbon, organic carbon, soluble ions including organic acids, and selected trace metals) were investigated from samples of a field campaign taking place at Bhola Island in the Bay of Bengal (Bangladesh). The campaign took place in the pre-monsoon season (May 2001) using low volume samplers. Carbonaceous material comprised the majority of the analysed components. The average concentrations of EC and OC were 2.8 and 4.6 microg m(-3), respectively. Oxalic acid was the most abundant dicarboxylic acid (average 268 ng m(-3)) followed by malonic and malic acid. The contribution of carboxylic acids-carbon to organic carbon was 2.0%. Average concentrations observed for sulfate and nitrate were 3.7 microg m(-3) and 1.5 microg m(-3). Two different types of aerosol were identified at the rural background site on Bhola Island during southerly synoptic flow by means of trajectory analysis: air masses were transported from the Bay of Bengal to the sampling site in all cases. However, during "Period 1" they experienced longer residence times over the Indian Ocean, while the "Period 2" trajectories came along the Indian coast or passed over the Indian continent. During Period 1 the concentration levels of soluble ions were a factor of 4-6 lower than during Period 2. The concentrations of EC, OC and K differed less than a factor of 1.5 between the two periods. The Period 1 aerosol showed similarities to the haze layers observed during winter-monsoon conditions south of India during the INDOEX experiment. Based on EC/TC and K/EC ratios we find that around 80% of the carbonaceous aerosol from Period 1 in Bhola is from fossil fuel and only around 50% from Period 2. Absolute concentrations of carbonaceous species, soluble ions and trace metals indicate that the background site on Bhola Island is affected by emissions from urbanized regions of Southeast Asia. 相似文献
79.
Distribution of heavy metals in water and sediments of selected sites of Yamuna river (India) 总被引:2,自引:0,他引:2
Mohammad Ajmal Mujahid A. Khan Azhar A. Nomani 《Environmental monitoring and assessment》1985,5(2):205-214
The concentration of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn metals in water and sediments of Yamuna river were determined by atomic absorption spectrophotometry in the year 1981. The data showed that there was considerable variation in the concentration of elements from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wasters being added to the river at different sampling stations. The sediment samples collected from different sampling stations were also analysed for calcium carbonate, organic matter, potassium, and phosphorus. 相似文献
80.
Assessing land use impacts on flood processes in complex terrain by using GIS and modeling approach 总被引:1,自引:0,他引:1
Y. B. Liu F. De Smedt L. Hoffmann L. Pfister 《Environmental Modeling and Assessment》2005,9(4):227-235
A distributed hydrologic modeling and GIS approach is applied for the assessment of land use impact in the Steinsel sub-basin, Alzette, Grand-Duchy of Luxembourg. The assessment focuses on the runoff contributions from different land use classes and the potential impact of land use changes on runoff generation. The results show that the direct runoff from urban areas is dominant for a flood event compared with runoff from other land use areas in this catchment, and tends to increase for small floods and for the dry season floods, whereas the interflow from forested, pasture and agricultural field areas contributes to the recession flow. Significant variations in flood volume, peak discharge, time to the peak, etc., are found from the model simulation based on the three hypothetical land use change scenarios. 相似文献