全文获取类型
收费全文 | 94480篇 |
免费 | 1229篇 |
国内免费 | 1118篇 |
专业分类
安全科学 | 3810篇 |
废物处理 | 3403篇 |
环保管理 | 14496篇 |
综合类 | 21301篇 |
基础理论 | 26921篇 |
环境理论 | 73篇 |
污染及防治 | 16736篇 |
评价与监测 | 5633篇 |
社会与环境 | 3870篇 |
灾害及防治 | 584篇 |
出版年
2022年 | 801篇 |
2021年 | 799篇 |
2020年 | 654篇 |
2019年 | 871篇 |
2018年 | 1182篇 |
2017年 | 1225篇 |
2016年 | 2205篇 |
2015年 | 1848篇 |
2014年 | 2592篇 |
2013年 | 9264篇 |
2012年 | 2342篇 |
2011年 | 2761篇 |
2010年 | 3317篇 |
2009年 | 3460篇 |
2008年 | 2358篇 |
2007年 | 2244篇 |
2006年 | 2537篇 |
2005年 | 2461篇 |
2004年 | 2791篇 |
2003年 | 2613篇 |
2002年 | 2194篇 |
2001年 | 2613篇 |
2000年 | 2168篇 |
1999年 | 1578篇 |
1998年 | 1402篇 |
1997年 | 1396篇 |
1996年 | 1522篇 |
1995年 | 1604篇 |
1994年 | 1506篇 |
1993年 | 1348篇 |
1992年 | 1345篇 |
1991年 | 1317篇 |
1990年 | 1259篇 |
1989年 | 1237篇 |
1988年 | 1083篇 |
1987年 | 1002篇 |
1986年 | 1004篇 |
1985年 | 1081篇 |
1984年 | 1171篇 |
1983年 | 1183篇 |
1982年 | 1182篇 |
1981年 | 1104篇 |
1980年 | 951篇 |
1979年 | 937篇 |
1978年 | 833篇 |
1977年 | 729篇 |
1976年 | 658篇 |
1974年 | 630篇 |
1973年 | 656篇 |
1972年 | 671篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
261.
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
262.
263.
264.
Abstract: Broadly conceived and considered in its many usages, sustainability has grave defects as a planning goal, particularly when used by conservationists: it confuses means and ends; it is vague about what is being sustained and who or what is doing the sustaining; it is uninspiring; it is little more than Pinchot-era conservation (and thus ignores the many lessons learned since then); it need not be linked to land, to the land's functioning, or to any ecological science; it need not include a moral component; it is consistent with the view of humans as all-powerful manipulators of the planet; and, in general, it is such a malleable term that its popularity provides only a facade of consensus. When sustainability is defined broadly to include the full range of economic and social aspirations, it poses the particular risk that ecological and biodiversity concerns will be cast aside in favor of more pressing human wants. Given these many defects, the conservation movement should discard the term in favor of a more alluring goal, attentive to nature and its ecological functioning. A sound goal would incorporate and distill the considerable ecological and moral wisdom accumulated since Pinchot's day while giving conservationists the rhetorical tools needed to defend the land against competing pressures. In our view, conservation would be well served by an updated variant of "land health," Aldo Leopold's ecologically grounded goal from the 1940s. Land health as an independent understanding should set the essential terms of how we live and enjoy the earth, providing the framework within which we pursue our many social and economic aims. 相似文献
265.
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
266.
267.
5p deletion syndrome commonly known as cri du chat is well described in affected neonates with catlike cry and hypotonia. Karyotyping will usually show a deletion of the short arm of one chromosome 5 with variable breakpoints. Only a few cases have been reported prenatally, and the fetal form of the syndrome has not been clearly individualised. We report a new case of 5p deletion syndrome diagnosed prenatally in association with Dandy–Walker syndrome and agenesis of the corpus callosum. Other brain anomalies have been reported previously, but this unusual association suggests the use of a specific probe in the investigation of these malformations. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
268.
Christian-D. Schönwiese 《Environmental Sciences Europe》2005,17(3):171-175
The interdependences between climate and humanity are becoming increasingly apparent, which makes climatology an upto-date and strongly discussed subject. Its task is to identify and examine relatively long-term, regional and global, natural and anthropogenic developments. A global, long-term view reveals a striking increase of surfacenear air temperature since the beginning of the industrial age. On a regional scale, trends differ considerably, but also Germany shows an apparent trend of increasing temperature and precipitation. The development of extreme events is more difficult to judge; the heat summer of 2003 in Europe, however, is among the phenomena that are likely to occur more frequently in the future. The influence of different natural and anthropogenic factors on the climate is expressed, amongst others, through their radiative forcings. Greenhouse gases emitted from anthropogenic activities are of particular significance since their concentration in the atmosphere keeps increasing. Mathematical modeling has made it possible to reconstruct the climate development of the past with increasing precision. The currently observed warming can only be comprehended by assuming anthropogenic influences. For the future development different scenarios have been calculated in order to deduce strategies for necessary action. 相似文献
269.
270.
Pollution due to persistent pesticides is not a regional but a global problem. Organochlorine pesticides are persistent chemicals, stored and accumulated in the tissues of a wide variety of invertebrates and vertebrates including marine species. In the present study the organochlorine residues HCHs, DDTs and PCBs were measured in different trophic groups of birds (scavengers, inland piscivores, coastal piscivores, insectivores, granivores and omnivores) collected from Tamil Nadu Coast, India. The residue accumulation as a function of sex did not depict distinct variation. However, females had lower residue levels than males in terms of their mean weight and feeding habits. A continuous monitoring programme is recommended to establish the studied organisms as indicator species. 相似文献