全文获取类型
收费全文 | 1299篇 |
免费 | 41篇 |
国内免费 | 103篇 |
专业分类
安全科学 | 160篇 |
废物处理 | 12篇 |
环保管理 | 465篇 |
综合类 | 257篇 |
基础理论 | 216篇 |
环境理论 | 3篇 |
污染及防治 | 142篇 |
评价与监测 | 71篇 |
社会与环境 | 64篇 |
灾害及防治 | 53篇 |
出版年
2023年 | 8篇 |
2022年 | 27篇 |
2021年 | 32篇 |
2020年 | 40篇 |
2019年 | 34篇 |
2018年 | 29篇 |
2017年 | 35篇 |
2016年 | 57篇 |
2015年 | 44篇 |
2014年 | 45篇 |
2013年 | 98篇 |
2012年 | 45篇 |
2011年 | 79篇 |
2010年 | 39篇 |
2009年 | 71篇 |
2008年 | 66篇 |
2007年 | 74篇 |
2006年 | 58篇 |
2005年 | 43篇 |
2004年 | 47篇 |
2003年 | 54篇 |
2002年 | 34篇 |
2001年 | 35篇 |
2000年 | 39篇 |
1999年 | 33篇 |
1998年 | 26篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 13篇 |
1991年 | 18篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 10篇 |
1971年 | 8篇 |
1970年 | 4篇 |
排序方式: 共有1443条查询结果,搜索用时 203 毫秒
911.
Integrated smelter-refineries play an important role in the recovery of multiple metals from complex primary and secondary materials, and hence in closing metals cycles. Processes in these facilities are strongly interconnected, dynamic, and multifunctional, which challenges a typical representation in life cycle assessment (LCA). This is especially true when LCA is applied to calculate the environmental profile of single metals products.This study examines methodological requirements for assessing complex co-product systems using attributional LCA through a static, gate-to-gate inventory model that quantifies the environmental impacts of each of the metal products of an integrated precious metals smelter-refinery. The model is based on a large number of subprocesses and is formulated using detailed industry data, which allows quantification of the sensitivity of the results with respect to allocation rationales and the data collection period.The results within one impact category vary strongly among metals (up to four orders of magnitude for copper compared to rhodium). Moving from mass- to value-based allocation changes the result for a given metal by up to two orders of magnitude. If value-based allocation is used, the selected reference year for metals prices influences the results by up to a factor of two.Allocation rationales are critically analyzed, and it is shown that none reflect the business model or other system drivers. While the model is focused on quantifying environmental impacts of metal outputs, the actual process is economically driven to efficiently treat a continuously changing feed mix. The complexity of a smelter-refinery cannot be captured by static, attributional inventory models, which is why the choice of allocation rationale remains arbitrary. Instead, marginal, parameterized models are needed; however, such models are substantially more time and data intensive and require disclosure of more detailed, process specific data. 相似文献
912.
Stephanie L. Johnson David R. Maidment Mary J. Kirisits 《Journal of the American Water Resources Association》2013,49(4):838-850
Bacterial contamination accounts for more than 60% of the impairments included on the 2008 Texas 303(d) List. Many of these bacterial impairments are along the Texas Gulf Coast because coastal waters often are regulated for oyster harvesting, which have strict water quality standards. Under the Clean Water Act, each one of these impaired waterbodies requires a total maximum daily load (TMDL) study to be performed. A recent, statewide study recommended the development and application of simple modeling approaches to address the majority of Texas's bacteria TMDLs, including “… simple load duration curve, GIS [geographic information systems], and/or mass balance models.” We developed the TMDL Balance model in response to this recommendation. TMDL Balance is a steady state, mass balance, GIS‐based model for simulating pollutant loads and concentrations in coastal systems. The model uses plug‐flow reactor and continuously‐stirred tank reactor equations to route spatially distributed point and nonpoint source loads through a watershed via overland flow, non‐tidal flow, and tidal flow, decaying the loads via first‐order kinetics. In this paper, we explain the development of the watershed loading portion of the TMDL Balance model, demonstrating the methodology through a case study: computing bacterial loads in the Copano Bay watershed of southeast Texas. The application highlights an example of distributing bacterial sources spatially based on land use data. 相似文献
913.
MacMynowski DP 《Environmental management》2007,39(6):831-842
The conceptual rubric of ecosystem management has been widely discussed and deliberated in conservation biology, environmental
policy, and land/resource management. In this paper, I argue that two critical aspects of the ecosystem management concept
require greater attention in policy and practice. First, although emphasis has been placed on the “space” of systems, the
“time”—or rates of change—associated with biophysical and social systems has received much less consideration. Second, discussions
of ecosystem management have often neglected the temporal disconnects between changes in biophysical systems and the response
of social systems to management issues and challenges. The empirical basis of these points is a case study of the “Crown of
the Continent Ecosystem,” an international transboundary area of the Rocky Mountains that surrounds Glacier National Park
(USA) and Waterton Lakes National Park (Canada). This project assessed the experiences and perspectives of 1) middle- and
upper-level government managers responsible for interjurisdictional cooperation, and 2) environmental nongovernment organizations
with an international focus. I identify and describe 10 key challenges to increasing the extent and intensity of transboundary
cooperation in land/resource management policy and practice. These issues are discussed in terms of their political, institutional,
cultural, information-based, and perceptual elements. Analytic techniques include a combination of environmental history,
semistructured interviews with 48 actors, and text analysis in a systematic qualitative framework. The central conclusion
of this work is that the rates of response of human social systems must be better integrated with the rates of ecological change. This challenge is equal
to or greater than the well-recognized need to adapt the spatial scale of human institutions to large-scale ecosystem processes and transboundary wildlife. 相似文献
914.
Use of GIS in siting stabilization pond facilities for domestic wastewater treatment 总被引:1,自引:0,他引:1
Gemitzi A Tsihrintzis VA Christou O Petalas C 《Journal of environmental management》2007,82(2):155-166
Geographic information systems (GIS) use is presented in the problem of sitting areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected areas, mean minimum monthly temperatures and required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The required area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total required surface area of these systems was compared to the available surface area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new areas for construction of such systems. 相似文献
915.
916.
917.
Deep-sea mineral prospecting has raised concerns regarding potential ecotoxicological impacts of deep-sea mineral extraction. Although metal mineral phases are predicted to exhibit low bioavailability, few data explore the relative toxicity of mineral phases and dissolved constituent metals. Acute 96?h chalcopyrite (CuFeS2) (<250?µm grain size) exposures using the shallow-water ecophysiological model organism Palaemon varians as an ecotoxicological proxy for deep-sea hydrothermal vent shrimp revealed no effect in both lethal and sublethal assays up to 2.888?g?L?1, suggesting that chalcopyrite is not bioavailable. Deep-sea species, therefore, appear at greater ecotoxicological risk from dissolved metals during seafloor massive sulphide (SMS) mining. Consequently, an approach combining modelling the release, and spatial and temporal dilution of dissolved metals during SMS mining, with data on sublethal effects of dissolved metals on shallow-water proxies, may best constrain the potential ecotoxicological impacts of SMS mining, and deliver ecotoxicological threshold concentrations for active SMS extraction. 相似文献
918.
Application of public health insecticides for mosquito control has increased dramatically with the recent outbreaks in the continental United States of dengue, chikungunya, and Zika. Mosquito control is often controversial because of the potential impacts on health and the environment due to the chemicals used. The emphasis in this review is to examine the transport, fate, and potential effects of the active ingredients in selected public health insecticides used for mosquito control. Due to the many potential entry points for insecticides, especially in urban areas where use is less monitored and application may be in greater amounts per unit area, this review suggests that a potential focus might be on the prevalence and quantification of the cumulative concentrations of these insecticides in natural systems. Often concentrations resulting from a single application are unlikely to cause mortality, but multiple applications may result in concentrations of environmental concern. Minimizing entrance to waterways and public water supply sources can be achieved by applying insecticides during prime meteorological conditions where drift and volatilization are minimized, using vegetated buffer zones in agricultural areas to prevent runoff, and avoiding application to impervious surfaces in urban areas. 相似文献
919.
Sherman Lewis 《国际发展与全球生态学杂志》2018,25(2):152-165
At high densities, land uses get close enough to each other to support walk, bike, and transit modes above 60% of total trips. The San Francisco Bay Area census was used to define five density levels: rural, exurban, suburban, central city, and urban core. The urban core definition, over 50 persons per neighborhood acre, is much denser than in other research. The California Household Transportation Survey supplied new data on block group area, population, trip stages, trip distances, trip time, and travel mode by density. The National Household Transportation Survey supplied block group population, density, travel mode, and income data. Both sources show a strong nonlinear relationship going from rural to urban core: auto miles and trips decrease as walk and transit miles and trips increase. With density, people travel fewer miles and spend less time traveling. High-income households in dense areas travel far fewer miles than those living at higher densities. With sufficient density, complementary features play a role in furthering mode shift. For planning purposes, the need for parking greatly declines. The findings are a basis for similar research elsewhere on high densities and complementary features. 相似文献
920.
A procedure for incorporating spatial variability in ecological risk assessment of Dutch river floodplains 总被引:9,自引:0,他引:9
Floodplain soils along the river Rhine in the Netherlands show a large spatial variability in pollutant concentrations. For
an accurate ecological risk characterization of the river floodplains, this heterogeneity has to be included into the ecological
risk assessment. In this paper a procedure is presented that incorporates spatial components of exposure into the risk assessment
by linking geographical information systems (GIS) with models that estimate exposure for the most sensitive species of a floodplain.
The procedure uses readily available site-specific data and is applicable to a wide range of locations and floodplain management
scenarios. The procedure is applied to estimate exposure risks to metals for a typical foodweb in the Afferdensche and Deestsche
Waarden floodplain along the river Waal, the main branch of the Rhine in the Netherlands. Spatial variability of pollutants
is quantified by overlaying appropriate topographic and soil maps resulting in the definition of homogeneous pollution units.
Next to that, GIS is used to include foraging behavior of the exposed terrestrial organisms. Risk estimates from a probabilistic
exposure model were used to construct site-specific risk maps for the floodplain. Based on these maps, recommendations for
future management of the floodplain can be made that aim at both ecological rehabilitation and an optimal flood defense. 相似文献