全文获取类型
收费全文 | 958篇 |
免费 | 41篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 38篇 |
废物处理 | 45篇 |
环保管理 | 262篇 |
综合类 | 66篇 |
基础理论 | 240篇 |
环境理论 | 1篇 |
污染及防治 | 263篇 |
评价与监测 | 60篇 |
社会与环境 | 29篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 4篇 |
2018年 | 19篇 |
2017年 | 28篇 |
2016年 | 26篇 |
2015年 | 25篇 |
2014年 | 31篇 |
2013年 | 94篇 |
2012年 | 39篇 |
2011年 | 50篇 |
2010年 | 39篇 |
2009年 | 43篇 |
2008年 | 55篇 |
2007年 | 55篇 |
2006年 | 53篇 |
2005年 | 38篇 |
2004年 | 34篇 |
2003年 | 36篇 |
2002年 | 36篇 |
2001年 | 17篇 |
2000年 | 27篇 |
1999年 | 16篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 13篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有1011条查询结果,搜索用时 226 毫秒
101.
102.
103.
104.
This article presents a case study of an accelerated cleanup conducted by EPA at the Adams Plating Company (APC) Superfund site near Lansing, Michigan. The APC site remediation was a Superfund EPA-lead project under the remedial program in Region 5. An accelerated cleanup was possible at the APC site by consistently identifying, evaluating, and implementing opportunities to streamline the remedial investigation (RI) and remedial design (RD) process. Streamlining opportunities were discovered and implemented in both the technical and administrative aspects of the project. Streamlining components used to accelerate the remedial process included: (1) extensive use of field screening techniques during the Phase II RI; (2) a focused feasibility study (FS) that evaluated only practical alternatives; (3) maintaining project momentum by initiating the RD concurrent with the issuance of the Record of Decision (ROD); (4) a highly accelerated RD with limited predesign work; (5) elimination of the transition period between RD and remedial action (RA) project phases; (6) frequent and effective communication, coordination, and cooperation between all parties involved (EPA, Michigan Department of Natural Resources (MDNR), technical contractor, PRC Environmental Management, Inc. (PRC), and the public); (7) maintaining a consistent project team throughout project duration; and (8) the setting of aggressive project goals. 相似文献
105.
Recent studies suggest that nearshore oceanographic conditions can have important effects on the structure of benthic communities. On Santa Cruz Island (SCI), CA, USA there is a persistent difference in mean annual sea surface temperature (SST) around the island due to its location at the confluence of opposing cold and warm ocean current systems. Over the course of a 4-year study (1997–2001) seawater nutrient and chl-a concentrations, algal tissue C:N ratios, recruitment and growth of filter-feeders (barnacles and mussels), and intertidal community structure were measured at six intertidal sites around the island. There were strong associations between remotely sensed SST and patterns of community structure. Macrophyte abundance was highest at sites with persistently low SST, while recruitment, abundance, and growth of filter-feeding invertebrates were strongly, positively correlated with SST. The cold-water sites were associated with higher nutrient concentrations and lower algal C:N ratios, particularly in the winter months. Values of chl-a were generally low and variable among sites, and were not correlated with the predominant SST gradient. Recruitment of barnacles and mussels was positively correlated with adult abundance across all sites. While detailed experimental studies are needed to further evaluate the mechanisms underlying community dynamics, these results indicate that the confluence of cold- and warm-water masses around SCI may determine the contrasting patterns of intertidal community structure. 相似文献
106.
107.
The results of more than 1 yr of air monitoring inside and outside of five homes in each of two communities are presented for SO2, NO2, mass respirable particles, SO4, Al, Br, Cl, Mn, Na, and V. Outdoor measurements across the home site in each city are consistent with proximity to outdoor sources. Looking across indoor residential sites in each city, the home appears to alter outdoor concentrations in several ways. Indoor level of SO2, SO4, Mn, and V are lower than those measured outdoors. These constituents are thought generally to result from outdoor sources. The other constituents studied are at times found in excess within homes. In some cases the source or sources of excess concentration of a particular constituent could be identified; often, however, the source of excess indoor concentration could not be identified. 相似文献
108.
Environmental technology development, like other ventures, requires decisions regarding where to invest scarce capital. The investment option that offers the greatest benefit relative to the cost should be chosen. The problem is to determine a way to analyze the project and apply a useful measure for comparison to other investment opportunities. In this article, three methods of analysis are presented: return on investment, benefit-to-cost ratio, and payback period. Formulas are developed for each of the methods, and a case study illustrates their application. 相似文献
109.
The purpose of this note is to reconsider the possibility of corner solutions in the theory of externality. Previous theories will be compared and analyzed in an attempt to develop a common perspective when viewing all-or-nothing possibilities. 相似文献
110.
Mosquito control ditches designed to increase tidal circulation are widely used as a physical control alternative to insecticidal applications The impact of such ditching on Pacific Coast marshlands was largely unknown before this five-year study of impact in two types of San Francisco Bay salt marshes, aSalicornia virginica (pickleweed) monoculure and a mixed vegetation marsh Results of our studies suggest that ditches cause less environmental disturbance than insecticidal applications The article describes the following environmental consequences of ditching for mosquito control: increased tidal flushing of soils occurs adjacent to ditches compared with that in the open marsh, thereby reducing ground water and soil surface salinities and water table height; primary productivity ofS. virginica, as determined by both the harvest method and infrared photographic analysis, is higher directly adjacent to ditches than in the open marsh, distribution of selected arthropod populations is similar at ditches and natural channels, although arthropod community response differs seasonally; aquatic invertebrate biomass is similar within ditched and natural ponds, but diversity is lower in ditched habitats, ditching increases fish diversity and density by improving fish access from tidal channels; ditches provide additional salt marsh song sparrow habitat, although ditches are less preferred than natural channels or sloughs. Management criteria can be used to design ditches that provide effective mosquito control and reduced environmental impact 相似文献