全文获取类型
收费全文 | 2151篇 |
免费 | 157篇 |
国内免费 | 518篇 |
专业分类
安全科学 | 162篇 |
废物处理 | 97篇 |
环保管理 | 258篇 |
综合类 | 1088篇 |
基础理论 | 413篇 |
环境理论 | 1篇 |
污染及防治 | 474篇 |
评价与监测 | 158篇 |
社会与环境 | 118篇 |
灾害及防治 | 57篇 |
出版年
2024年 | 3篇 |
2023年 | 39篇 |
2022年 | 81篇 |
2021年 | 81篇 |
2020年 | 90篇 |
2019年 | 64篇 |
2018年 | 102篇 |
2017年 | 93篇 |
2016年 | 100篇 |
2015年 | 119篇 |
2014年 | 147篇 |
2013年 | 205篇 |
2012年 | 168篇 |
2011年 | 160篇 |
2010年 | 132篇 |
2009年 | 124篇 |
2008年 | 143篇 |
2007年 | 128篇 |
2006年 | 136篇 |
2005年 | 117篇 |
2004年 | 83篇 |
2003年 | 84篇 |
2002年 | 78篇 |
2001年 | 58篇 |
2000年 | 46篇 |
1999年 | 36篇 |
1998年 | 25篇 |
1997年 | 32篇 |
1996年 | 19篇 |
1995年 | 28篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1921年 | 1篇 |
1920年 | 1篇 |
1918年 | 1篇 |
排序方式: 共有2826条查询结果,搜索用时 31 毫秒
51.
This study investigates the potential for perchlorate biodegradation in the sediments of the Las Vegas Wash area in Henderson, Nevada. The continuous transport of perchlorate from a contaminated seepage to the Las Vegas Wash, Lake Mead, and the Colorado River has resulted in considerable deposition of perchlorate along the sediments of the Las Vegas Wash. The contaminated sediments act as a distributed source of perchlorate, making efforts to stop the flow of perchlorate to the Colorado River very challenging. In this study, perchlorate‐ reducing bacteria were enumerated and microcosm tests were performed to investigate the role of indigenous microorganisms and the limitations to natural perchlorate biodegradation in the contaminated sediments. The results of microcosm tests revealed that, despite the high number of perchloratereducing bacteria present, natural perchlorate in the area appears to be limited by (1) high salinity levels, the presence of nitrate, and the low perchlorate concentrations present in the sediments and (2) an insufficient carbon source. However, the potential for in situ bioremediation of the sediments along the Wash area is considered to be high due to the presence of significant numbers of perchlorate‐ reducing bacteria and to the ease in which an additional carbon source could be provided to sustain nitrate and perchlorate biodegradation. The economics of this process are expected to be very favorable; however, detailed cost estimates, pilot‐scale testing, and permit applications are required before this concept can be applied. © 2005 Wiley Periodicals, Inc. 相似文献
52.
Michael Greenberg Joanna Burger Michael Gochfeld David Kosson Karen Lowrie Henry Mayer Charles W. Powers Conrad D. Volz Vikram Vyas 《补救:环境净化治理成本、技术与工艺杂志》2005,16(1):91-105
This article discusses creating a sustainably protective engineered and human management system in perpetuity for sites with long‐lived radiological and chemical hazards. This is essential at this time because the federal government is evaluating its property as assets and attempting to reduce its holdings, while seeking to assure that health and ecosystems are not put at risk. To assist those who have a stake in the remediation, management, and stewardship of these and analogous privately owned sites, this article discusses current end‐state planning by reviewing the federal government's accelerated efforts to reduce its footprint and how those efforts relate to sustainability. The article also provides a list of questions organized around six elements of risk management and primary, secondary, and tertiary disease and injury prevention. Throughout the article, the U.S. Department of Energy (DOE) is used as an example of an organization that seeks to reduce its footprint, manage its budget, and be a steward of the sites that it is responsible for. However, the approach and questions are appropriate for land controlled by the Department of Defense (DOD), the General Services Administration (GSA), and other public and private owners of sites with residual contamination. © 2005 Wiley Periodicals, Inc. 相似文献
53.
Water use efficiency (WUE) is an important ecophysiological characteristic of plants, especially in semiarid and arid regions. At the scale of community or ecosystem, WUE is difficult to quantify because the amount of water used per unit dry mass production is a function of microclimatic variables and species composition. In this study, we analyzed corrected intrinsic water use efficiency (IWUE(s)) of grass and shrub species along the western segment of the Northeast China Transect (NECT) and the relationship between IWUE(s) and mean annual rainfall, habitat degradation status, vegetation type, and plant functional type (C3 versus C4) at 22 survey sites. Site intrinsic water use efficiency (IWUE(v)) and its relationship with the aforementioned site variables were analyzed based on species frequencies at each site. First, it was concluded that photosynthetic pathway played a very important role in determining species IWUE(s). Mean IWUE(s) for C4 species was approximately double that of C3 species. Second, mean annual rainfall, vegetation type, and site degradation status significantly affected IWUE(s) (p < 0.01). Mean IWUE(s) at degraded sites was twice as high as that at nondegraded sites. The mean IWUE(s) for meadows was significantly higher than those for other vegetation types (p < 0.05). Third, the frequency of occurrence of C4 plants explained 36% of the variance in IWUE(v) across the survey sites. The mean frequency of C4 occurrence at degraded sites was more than double that at nondegraded sites. Consequently, mean IWUE(v) at degraded sites was more than double that at nondegraded sites. Dominant C4 species in saline-alkaline areas tended to have higher intrinsic WUE than dominant C4 species in sandy shrub communities. 相似文献
54.
In the UK, the Environmental Quality Standard for manganese has recently been lowered to 30 microg/L (annual average), which is less than the UK Drinking Water Inspectorate's Maximum Permitted Concentration Value (50 microg/L). Current passive treatment systems for manganese removal operate as open-air gravel-bed filters, designed to maximize either influent light and/or dissolved oxygen. This requires large areas of land. A novel enhanced bioremediation treatment system for manganese removal has been developed that consists of a passively aerated subsurface gravel bed. The provision of air at depth and the use of catalytic substrates help overcome the slow kinetics usually associated with manganese oxidation. With a residence time of only 8 h and an influent manganese concentration of approximately 20 mg/L, >95% of the manganese was removed. The treatment system also operates successfully at temperatures as low as 4 degrees C and in total darkness. These observations have positive implications for manganese treatment using this technique in both colder climates and where large areas of land are unavailable. Furthermore, as the operation of this passive treatment system continually generates fresh manganese oxyhydroxide, which is a powerful sorbent for most pollutant metals, it potentially has major ancillary benefits as a removal process for other metals, such as zinc. 相似文献
55.
大量电子废弃物的回收处理,不仅是环境问题,更是对资源与发展的战略挑战。武汉市尚未对电子废弃物的报废量进行统计。采取两种方法分别测算武汉市家用电器中"四机一脑"的理论报废量,并对两种算法进行比较与分析,对预测结果进行趋势分析。研究结果有助于政府定量了解"四机一脑"的报废情况,为其制定相关专项发展规划提供技术支撑。 相似文献
56.
57.
Lara-Ramos Jose Antonio Constain-Escobar Angela María Rojas-Ortiz Karen Vanessa Diaz-Angulo Jennyfer Machuca-Martínez Fiderman 《Environmental science and pollution research international》2021,28(19):24079-24091
Environmental Science and Pollution Research - This work proposes a novel approach for the coupling of ozonation and Fenton processes using a new prototype of a high rotation bubble reactor (HRBR),... 相似文献
58.
Xia Chengcheng Liu Guodong Zhou Jing Meng Yuchuan Chen Ke Gu Pengfei Yang Mengxi Huang Xiaohua Mei Jie 《Environmental science and pollution research international》2021,28(30):40160-40177
Environmental Science and Pollution Research - In recent years, the development and utilization of water resources have imposed great impacts on hydrological characteristics and ecological... 相似文献
59.
Cordoba Aldo Hernández Rafael Viveros-Palma Iliana Mendoza Sandra Guevara-González Ramón Gerardo Feregrino-Pérez Ana Angélica Esquivel Karen 《Environmental science and pollution research international》2021,28(28):37130-37141
Environmental Science and Pollution Research - Nowadays, the use of different nanoscale structures has been introduced to a large number of research areas. One of these is the treatment and... 相似文献
60.
Jeong Kyungjun Hong Jiyeon Lee Yongjin Yang Jiyeon Lim Youngwook Shin Dongchun Kim Changsoo 《Environmental science and pollution research international》2021,28(28):37506-37519
Environmental Science and Pollution Research - Preschool children aged 3–6 years are vulnerable to exposed to particulate matter (“PM10” and “PM2.5”). It is required... 相似文献