全文获取类型
收费全文 | 15519篇 |
免费 | 132篇 |
国内免费 | 94篇 |
专业分类
安全科学 | 401篇 |
废物处理 | 571篇 |
环保管理 | 1799篇 |
综合类 | 3410篇 |
基础理论 | 3898篇 |
环境理论 | 14篇 |
污染及防治 | 3889篇 |
评价与监测 | 901篇 |
社会与环境 | 771篇 |
灾害及防治 | 91篇 |
出版年
2022年 | 126篇 |
2021年 | 114篇 |
2020年 | 99篇 |
2019年 | 128篇 |
2018年 | 232篇 |
2017年 | 222篇 |
2016年 | 306篇 |
2015年 | 276篇 |
2014年 | 368篇 |
2013年 | 1051篇 |
2012年 | 445篇 |
2011年 | 660篇 |
2010年 | 519篇 |
2009年 | 581篇 |
2008年 | 707篇 |
2007年 | 669篇 |
2006年 | 590篇 |
2005年 | 522篇 |
2004年 | 447篇 |
2003年 | 455篇 |
2002年 | 470篇 |
2001年 | 534篇 |
2000年 | 402篇 |
1999年 | 250篇 |
1998年 | 167篇 |
1997年 | 189篇 |
1996年 | 203篇 |
1995年 | 227篇 |
1994年 | 235篇 |
1993年 | 184篇 |
1992年 | 171篇 |
1991年 | 197篇 |
1990年 | 195篇 |
1989年 | 184篇 |
1988年 | 137篇 |
1987年 | 132篇 |
1986年 | 142篇 |
1985年 | 113篇 |
1984年 | 126篇 |
1983年 | 128篇 |
1982年 | 136篇 |
1981年 | 133篇 |
1980年 | 112篇 |
1979年 | 128篇 |
1978年 | 95篇 |
1977年 | 102篇 |
1976年 | 88篇 |
1975年 | 94篇 |
1973年 | 96篇 |
1967年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
The past two decades have witnessed an increase in the exploration for, and development of, mineral resources at Arctic latitudes. Such effort has resulted in the commencement of production at a number of different localities in close proximity to the ocean. Since proximity to a source of transportation for the conveyance of concentrates to the market is a primary requirement governing the economic decisions for the mine to proceed, it is logical that ore deposits near a coastline are primary targets for development.
Closely tied to coastal mining developments is the need to dispose of tailings and waste rock in the most economical manner. Prior to the advent of heightened public awareness and environmental concern, and the enactment of pollution legislation, disposal practices were largely based upon convenience. Currently, however, proposed disposal and operating practices receive closer scrutiny, with a view to providing adequate protection for aquatic resources and habitat. This paper summarizes some of the features of three Arctic mines, wastes from which enter the marine environment, and compares the disposal practices used at each to measures of environmental change as indicated by metal concentrations in various media. 相似文献
Closely tied to coastal mining developments is the need to dispose of tailings and waste rock in the most economical manner. Prior to the advent of heightened public awareness and environmental concern, and the enactment of pollution legislation, disposal practices were largely based upon convenience. Currently, however, proposed disposal and operating practices receive closer scrutiny, with a view to providing adequate protection for aquatic resources and habitat. This paper summarizes some of the features of three Arctic mines, wastes from which enter the marine environment, and compares the disposal practices used at each to measures of environmental change as indicated by metal concentrations in various media. 相似文献
13.
14.
Igliski B. Skrzatek M. Kujawski W. Cichosz M. Buczkowski R. 《Environment, Development and Sustainability》2022,24(1):77-111
Environment, Development and Sustainability - Renewable energy (RE) plays an increasingly important role in the economy of almost every country in the world. In order to examine the state of... 相似文献
15.
T. E. Lewis A. B. Crockett R. L. Siegrist 《Environmental monitoring and assessment》1994,30(3):213-246
Concerns over data quality have raised many questions related to sampling soils for volatile organic compounds (VOCs). This paper was prepared in response to some of these questions and concerns expressed by Remedial Project Managers (RPMs) and On-Scene Coordinators (OSCs). The following questions are frequently asked:
- Is there a specific device suggested for sampling soils for VOCs?
- Are there significant losses of VOCs when transferring a soil sample from a sampling device (e.g., split spoon) into the sample container?
- What is the best method for getting the sample from the split spoon (or other device) into the sample container?
- Are there smaller devices such as subcore samplers available for collecting aliquots from the larger core and efficiently transferring the sample into the sample container?
- Are certain containers better than others for shipping and storing soil samples for VOC analysis?
- Are there any reliable preservation procedures for reducing VOC losses from soil samples and for extending holding times?
- Open test pit or trench.
- Surface soils (<5 ft in depth).
- Subsurface soils (>5 ft in depth).
16.
Alan B. Crockett 《Environmental monitoring and assessment》1998,50(3):289-296
McMurdo Station is the largest research station in Antarctica, with a population that ranges each year from 250 to 1200 people. Because of its size and 40-year history of use, a number of locations around the station have become contaminated with wastes. Soils and sediments in these areas have been shown to contain elevated levels of petroleum-related products, PCBs, other organics, and metals. While some remedial investigations have been conducted, background levels of metals in soils have not been determined. This paper reports on background levels of metals in a natural basalt-derived soil (gray soil) and scoria (soft porous rock used as fill, red soil) near McMurdo Station using two fundamentally different analytical procedures, concentrated acid extraction/analysis and total metals. These data facilitate determining the extent and levels of metal contamination near McMurdo Station and provide reference levels of metals for comparison with existing and future remediation data. There were statistically significant differences between metals concentrations in both gray and red soils, and no correlations between the level of extracted versus total metal. Generally, only a small fraction of a metal was extractable. 相似文献
17.
The importance of selenium as an essential trace element has progressively emerged during the last years due to the analysis of selenium deficiency diseases and to the identification and characterization of a number of selenoenzymes. Selenium is incorporated in the catalytic site of the enzymes as an integral selenocysteine residue. The pathway of selenocysteine biosynthesis and incorporation has been elucidated recently for Escherichia coli. This article presents an overview on these subjects and describes the mechanisms which confer selenocysteine specificity in the framework of protein biosynthesis. In addition, some considerations concerning the phylogeny of selenocysteine incorporation are presented and a model for the evolution of the selenocysteine pathway is proposed. 相似文献
18.
19.
20.
M. Blunck W. -D. Busse G. Meister E. Möller A. Mullen L. A. A. van Rooijen 《Die Naturwissenschaften》1989,76(3):96-98
Online searching in publically available patent files opens up interesting possibilities to provide a rapid response to critical questions. A computerized analysis of all patents of leading German pharmaceutical companies over the last decade in important indication areas is described. Supported by subsequent manual processing of individual patents it is shown that duplicate experiments on animals practically never occur. 相似文献