全文获取类型
收费全文 | 1996篇 |
免费 | 17篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 67篇 |
废物处理 | 86篇 |
环保管理 | 251篇 |
综合类 | 382篇 |
基础理论 | 436篇 |
环境理论 | 2篇 |
污染及防治 | 554篇 |
评价与监测 | 141篇 |
社会与环境 | 105篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 20篇 |
2022年 | 32篇 |
2021年 | 36篇 |
2020年 | 23篇 |
2019年 | 31篇 |
2018年 | 53篇 |
2017年 | 44篇 |
2016年 | 53篇 |
2015年 | 56篇 |
2014年 | 62篇 |
2013年 | 84篇 |
2012年 | 88篇 |
2011年 | 122篇 |
2010年 | 92篇 |
2009年 | 123篇 |
2008年 | 108篇 |
2007年 | 116篇 |
2006年 | 76篇 |
2005年 | 73篇 |
2004年 | 89篇 |
2003年 | 64篇 |
2002年 | 75篇 |
2001年 | 56篇 |
2000年 | 38篇 |
1999年 | 23篇 |
1998年 | 28篇 |
1997年 | 27篇 |
1996年 | 27篇 |
1995年 | 30篇 |
1994年 | 21篇 |
1993年 | 13篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1990年 | 21篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 16篇 |
1983年 | 11篇 |
1982年 | 18篇 |
1981年 | 7篇 |
1979年 | 10篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1970年 | 6篇 |
1968年 | 6篇 |
1965年 | 6篇 |
1962年 | 4篇 |
排序方式: 共有2031条查询结果,搜索用时 62 毫秒
1.
2.
The situation and the latest findings of forest damage research in Germany are discussed. A newly developed concept for this research is described. This concept allows to identify the drawbacks of the recent damage research concept but also the integration of results compiled up to now. The importance for including natural occurring stress factors such as climate, soil conditions or local situation of individual species is outlined. 相似文献
3.
4.
Ingrid Witters Hans Van Bokhoven A. Goossens Frans-André Van Assche Jean-Pierre Fryns 《黑龙江环境通报》2001,21(13):1119-1122
We report the prenatal diagnosis at 16 weeks' gestation of bilateral split-hand/split-foot malformation (SHSFM) with severe lobster claw deformity of hands and feet in a male fetus without associated malformations. A minor manifestation of SHSFM was present in the father with only mild bilateral foot involvement (syndactyly I–II; cleft II–III; left cutaneous syndactyly III–IV). Mutation analysis of the p63 gene on chromosome 3q27 showed a missense mutation 577A→G (predicting amino acid substitution K193E) in the father. This mutation has not been reported so far in SHSFM but resembles the previously reported 580A→G (predicting amino acid substitution K194E) in a family with SHSFM. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
5.
Le Nguyen Truc Thinh Nguyen An Ha Nguyen Thi Vinh Tien Nguyen Dinh Lam Nguyen Duc Hong Nguyen Van Tuan Nguyen Tat Hanh Ta Van Khanh Nguyen Ngoc Thanh Nguyen Ngoc Hens Luc 《Environment, Development and Sustainability》2022,24(10):12427-12445
Environment, Development and Sustainability - The recent growth of agriculture, industry and urban areas in Vietnam requires a large amount of water consumption as a production factor. This paper... 相似文献
6.
7.
During the last decades, considerable research on methane production in the rumen and its inhibition has been carried out. Initially, as methane production represents a significant loss of gross energy in the feed (2–15%), the ultimate goal of such intervention in rumen fermentation was an increase in feed efficiency. A second reason favouring research on methane inhibition is its role in the global warming phenomenon and in the destruction of the ozone layer. In this review, the authors describe briefly several interventions for reducing methane emission by ruminants. The objective can be reached by intervention at the dietary level by ration manipulation (composition, feeding level) or by the use of additives or supplements. Examples of additives are polyhalogenated compounds, ionophores and other antibiotics. Supplementation of the ration with lipids also lowered methanogenesis. More biotechnological interventions, e.g., defaunation, probiotics and introduction of reductive acetogenesis in the rumen, are also mentioned. It can be concluded that drastic inhibition of methane production is not unequivocally successful as a result of several factors, such as: instantaneous inhibition often followed by restoration of methanogenesis due to adaptation of the microbes or degradation of the additive, toxicity for the host animal, negative effects on overall digestion and productive performance. Therefore, methanogenesis and its inhibition cannot be considered as a separate part of rumen fermentation and its consequences on the animal should be taken into account. 相似文献
8.
Methods derived from time-series analysis are proposed for processing monitoring data. The necessity for the use of these methods is demonstrated. In a case study time-series analysis was applied to assess the impact of the closure of the Grevelingen estuary (S. W. Netherlands) in 1971 on a local wintering population of Oystercatchers (Haematopus ostralegus) in the adjacent Oosterschelde estuary.Communication No. 328 of the Delta Institute for Hydrobiological Research. 相似文献
9.
Off-line solid-phase extraction (SPE) combined with liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS-MS) was used to study the estuarine behaviour of the polar pesticides, atrazine, chloridazon, diuron and metolachlor, and their transformation products (TPs), hydroxyatrazine (HA), desisopropylatrazine (DIA), desethylatrazine (DEA), 3,4-dichlorophenylmethylurea (DPMU) and monuron. The compounds were identified by comparing their LC retention times and product-ion spectra with those of standard solutions. In all but one case the detection limits of the method were sufficient to determine the compounds of interest over the entire salinity range in the estuary. The concentrations of the dissolved pesticides ranged from 70 ng l-1 for chloridazon to 1350 ng l-1 for diuron. The levels of TPs were 3-8% of the levels of their parent pesticide. The mixing plots of polar pesticides and their TPs indicated that TPs, which are present in fresh river water, are conservatively transported to the sea and that no additional amounts of TPs are formed during their transport through the estuary. The one exception was HA, of which approximately 10% of the amount transported to the North Sea is formed in the lower part of the estuary by photochemical oxidation of atrazine. The latter was concluded from the ratios of each analyte over the sum total of the parent pesticide and all TPs along the salinity gradient, which proved to be a useful tool for identifying such estuarine transformations. 相似文献
10.
Hofschreuder P van der Meulen W Heeres P Slanina S 《Journal of environmental monitoring : JEM》1999,1(2):143-147
Passive samplers provide an excellent opportunity to perform indicative measurements or establish a dense network of measuring sites. A drawback compared with conventional active measuring methods is the larger spread of results. This variation can, to a large extent, be attributed to the influence of temperature, sampler geometry and wind on sampling results. A proper design of sampler geometry and optimum choice of draught shield can reduce the influence of wind velocity on a badge type sampler to less than 10%. Wire mesh screens prove to be inadequate in damping turbulence. Filters give good results. Attention should be paid to the size and isolation value of the walls of the sampler to prevent thermal updrafts occurring within the sampler. Tube type samplers are less influenced by wind, provided that turbulence is prevented from influencing diffusion within the sampler. 相似文献