全文获取类型
收费全文 | 1133篇 |
免费 | 47篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 53篇 |
环保管理 | 300篇 |
综合类 | 83篇 |
基础理论 | 281篇 |
环境理论 | 1篇 |
污染及防治 | 309篇 |
评价与监测 | 72篇 |
社会与环境 | 39篇 |
灾害及防治 | 9篇 |
出版年
2023年 | 10篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 16篇 |
2019年 | 7篇 |
2018年 | 23篇 |
2017年 | 31篇 |
2016年 | 32篇 |
2015年 | 31篇 |
2014年 | 35篇 |
2013年 | 115篇 |
2012年 | 47篇 |
2011年 | 57篇 |
2010年 | 41篇 |
2009年 | 49篇 |
2008年 | 66篇 |
2007年 | 62篇 |
2006年 | 64篇 |
2005年 | 48篇 |
2004年 | 38篇 |
2003年 | 42篇 |
2002年 | 43篇 |
2001年 | 20篇 |
2000年 | 30篇 |
1999年 | 17篇 |
1998年 | 20篇 |
1997年 | 16篇 |
1996年 | 23篇 |
1995年 | 25篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 15篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有1192条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Greg R. J. Sutherland Joachim Haselbach Steven D. Aust 《Environmental science and pollution research international》1997,4(1):16-20
Two synthetic superabsorbent crosslinked acrylic polymers were mineralized by the white-rot fungusPhanerochaete chrysosporium. The amount of polymer converted to CO2 increased as the amount of polymer added to the cultures increased. In the presence of sufficiently large amounts of the superabsorbents, such that all of the culture fluid was absorbed and a gelatinous matrix was formed, the fungus still grew and mineralization was observed. Neither the polymers, nor their degradation products were toxic to the fungus. While the rates of mineralization were low, all of the polymers incubated in the liquid fungal cultures were completely depolymerized to water soluble products within 15–18 days. The depolymerization of the polymers was observed only in nitrogen limited cultures of the fungus which secrete the lignin degradation system, however, the water soluble products of depolymerization were mineralized in both nutrient limited and sufficient cultures of the fungus. The rate of mineralization of the depolymerized metabolites was more than two times greater in nutrient sufficient cultures. Following longer incubation periods, most (> 80 %) of the radioactivity was recovered in the fungal mycelial mat suggesting that carbon of the polymer had been converted to fungal metabolites. 相似文献
5.
6.
7.
Summary As stated at the beginning of this paper conclusions reached thus far cannot be discussed in this paper. However, a great deal of information is available for examination.EPA displayed its ability to coordinate widely separated laboratories, both Federal and private, into a smooth working team in a very short period of time. A very comprehensive study plan was also developed and implemented quickly. EPA was fortunate to have already had GCA under contract when the emergency arose. In no small part the success of the field effort was due to the managerial and technical abilities of the GCA team.Within a period of 6 weeks a plan was developed, a prime contractor retained, subcontractors hired, and field activities begun. Within a period of 3 months in excess of 8600 field samples were collected and over 12,000 field and QC samples were analyzed. During this same period 2 major data systems were developed, debugged, and placed into operation.In short this EPA project was probably the most comprehensive multimedia field project ever attempted by EPA and certainly the data is being subjected to the most strenuous quality control measures ever imposed by this Agency. The entire program is presently under peer review and the results are being prepared for publication by EPA Headquarters.Note. Originally intended to be published as part of the special issue on Exposure Monitoring: An International Workshop (Las Vegas, Nevada, October 19–22, 1981). 相似文献
8.
Lenwood W. Hall Jr. William D. Killen Jr. Steven A. Fischer Michael C. Ziegenfuss Ronald D. Anderson Ronald J. Klauda 《Environmental monitoring and assessment》1994,31(3):233-257
The objective of this two-year study was to determine the efficacy of an automated limestone slurry doser to neutralize acidic pulses and improve water quality conditions for enhancing survival of early life stages of migratory fish species in a Maryland coastal plain stream. Implications for survival of early life stages of migratory fish species such as yellow perch (Perca flavescens), white perch (Morone americana), blueback herring (Alosa aestivalis) and alewife (Alosa pseudoharengus) are discussed based on the improved chemical conditions in the dosed area of the stream. Despite problems with overdosing in 1991 and failure of the stage transducer to work properly in 1992, the doser was generally effective in neutralizing acidic pulses (pH depressions) in the stream during three major rain events in both years. Chemical conditions (pH and inorganic monomeric aluminum) reported in the non-dosed area during major rainfall events were potentially stressful to both alewife and blueback herring although neither species was reported spawning in the stream during either year. Mitigating the potential impact of acidic conditions on early life stages of important migratory fish species was not sufficient to ensure spawning. It is therefore recommended that habitat improvement measures and well designed fish stocking programs be implemented concurrently with doser operations if the goal is to create optimum spawning conditions for migratory species. 相似文献
9.
Mary C. Phelan Ph.D. Robert A. Saul Thompson A. Gailey Jr Steven A. Skinner 《黑龙江环境通报》1995,15(3):274-277
Mosaicism for the Wolf-Hirschhorn syndrome, del(4)(p16), is extremely rare and has not been reported in association with a numerical chromosome abnormality. We report the prenatal diagnosis of mosaic del(4)(p16) and non-mosaic trisomy 21 in a 16-week female fetus. The pregnancy ended in spontaneous abortion at 34 weeks secondary to fetal demise. The fetus had features of both 4p – and trisomy 21. 相似文献
10.