全文获取类型
收费全文 | 2822篇 |
免费 | 20篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 79篇 |
废物处理 | 150篇 |
环保管理 | 270篇 |
综合类 | 519篇 |
基础理论 | 571篇 |
环境理论 | 2篇 |
污染及防治 | 822篇 |
评价与监测 | 248篇 |
社会与环境 | 194篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 30篇 |
2022年 | 87篇 |
2021年 | 104篇 |
2020年 | 51篇 |
2019年 | 42篇 |
2018年 | 101篇 |
2017年 | 104篇 |
2016年 | 126篇 |
2015年 | 73篇 |
2014年 | 115篇 |
2013年 | 174篇 |
2012年 | 133篇 |
2011年 | 169篇 |
2010年 | 118篇 |
2009年 | 113篇 |
2008年 | 124篇 |
2007年 | 120篇 |
2006年 | 78篇 |
2005年 | 121篇 |
2004年 | 156篇 |
2003年 | 160篇 |
2002年 | 96篇 |
2001年 | 74篇 |
2000年 | 33篇 |
1999年 | 34篇 |
1998年 | 16篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1995年 | 23篇 |
1994年 | 18篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 18篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 8篇 |
1968年 | 6篇 |
1964年 | 6篇 |
1962年 | 5篇 |
1958年 | 4篇 |
1933年 | 4篇 |
1931年 | 4篇 |
排序方式: 共有2875条查询结果,搜索用时 15 毫秒
941.
Peter Bröde Kalev Kuklane Victor Candas Emiel A. Den Hartog Barbara Griefahn Ingvar Holmér 《International journal of occupational safety and ergonomics》2013,19(2):231-244
The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments’ material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments. 相似文献
942.
943.
944.
In order to contribute to a future waste management policy related to the presence of technologically enhanced natural occurring radioactive material (TENORM) in the Brazilian petroleum industry, the present work presents the chemical composition and the 226Ra and 228Ra content of sludge and scales generated during the offshore E and P petroleum activities in the Campos Basin, the primary offshore oil production region in Brazil.The 226Ra and 228Ra content on 36 sludge and scales samples were determined by gamma-spectrometry. Based on X-ray diffractometry results, a chemical analysis schema for these samples was developed. The results have shown that scales are 75% barium and strontium sulfates, with a mean 226Ra and 228Ra content of 106 kBq kg−1 and 78 kBq kg−1, respectively. On the other hand, sludge samples have a much more complex chemical composition than the scales. The 226Ra and 228Ra content in sludge also varies much more than the content observed in the scales samples and ranged from 0.36 to 367 kBq kg−1 and 0.25 to 343 kBq kg−1, respectively. 相似文献
945.
Die geschichtliche Entwicklung der kosmologischen Modelle für den homogen–isotropen Kosmos, beginnend mit Alexander Friedmanns
epochalen Arbeiten (1922 und 1924) bis zur heutigen Diskussion aktueller Modelle wird dargestellt. Eine kardinale Rolle spielt
die offene Frage: Besteht die Materie des Kosmos zum weit überwiegenden Teil aus nicht–baryonischer (sog. exotischer) Dunkel–Materie
oder reicht die gesamte baryonische Materie aus, die aus den bekannten Atomen und Molekülen besteht, um die Entwicklung des
Kosmos zu verstehen. Auch von der normalen (baryonischen) Materie im Kosmos ist nur ein geringer Anteil (etwa 20 5 Prozent) in leuchtenden Objekten (Sterne, Gas, Staub) direkt beobachtbar. Im Abschnitt 3 wird der “Einstein–Limit” für
die kosmologische Konstante erl?utert und eine leicht einsichtige Herleitung des Zahlenwertes gegeben. 相似文献
946.
947.
948.
In a study of two unknown compounds in blubber of harbour seals (Phoca vitulina) of the Dutch North Sea coast combined capillary gas chromaiographic mass spectrometric data indicated the presence of trans-nonachlor and oxychlordane. These compounds have never been identified in environmental biota in The Netherlands before. 相似文献
949.
950.
Jean-Luc Volumenie Pascal de Lagausie Jean Guibourdenche Jean-François Oury Edith Vuillard Carole Saizou Dominique Luton 《黑龙江环境通报》2001,21(13):1171-1174
This study aimed to analyse the influence of amnio-infusion on superior mesenteric Doppler velocimetry and to correlate Doppler data with outcome in fetuses presenting with gastroschisis. Umbilical and intra- and extra-abdominal superior mesenteric artery Doppler velocimetry was measured prospectively before and after amnio-infusion in fetuses with gastroschisis. Doppler index values and changes were correlated with the following outcome parameters: importance of fibrous coating, duration of hospitalization in the neonatal intensive care unit, total duration of hospitalization, duration of parenteral feeding, duration of ventilatory assistance, and the interval to initiation of oral feeding. A significant improvement of diastolic flow was observed in the extra-abdominal superior mesenteric artery with amnio-infusion. No similar change was seen in the intra-abdominal superior mesenteric or in the umbilical artery. Pre-amnioinfusion extra-abdominal mesenteric Doppler index was correlated with maximal diameter of exteriorized bowel and slightly with duration of hospitalization in the neonatal intensive care unit, but no other relation between Doppler index and outcome parameter could be ascertained. Amnio-infusion induces modifications in the vascularization of exteriorized bowel in gastroschisis. This could partly explain the beneficial effect of this procedure on fetal gut. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献