全文获取类型
收费全文 | 918篇 |
免费 | 6篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 33篇 |
环保管理 | 104篇 |
综合类 | 200篇 |
基础理论 | 239篇 |
环境理论 | 1篇 |
污染及防治 | 194篇 |
评价与监测 | 95篇 |
社会与环境 | 52篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 3篇 |
2022年 | 10篇 |
2021年 | 21篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 26篇 |
2017年 | 33篇 |
2016年 | 36篇 |
2015年 | 36篇 |
2014年 | 22篇 |
2013年 | 66篇 |
2012年 | 43篇 |
2011年 | 140篇 |
2010年 | 30篇 |
2009年 | 25篇 |
2008年 | 53篇 |
2007年 | 37篇 |
2006年 | 32篇 |
2005年 | 31篇 |
2004年 | 28篇 |
2003年 | 20篇 |
2002年 | 35篇 |
2001年 | 17篇 |
2000年 | 7篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 13篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1983年 | 6篇 |
1973年 | 3篇 |
1964年 | 3篇 |
1959年 | 7篇 |
1957年 | 5篇 |
1955年 | 3篇 |
1929年 | 3篇 |
1926年 | 3篇 |
1925年 | 2篇 |
1924年 | 3篇 |
1923年 | 5篇 |
1921年 | 4篇 |
1920年 | 2篇 |
1916年 | 2篇 |
1913年 | 2篇 |
排序方式: 共有935条查询结果,搜索用时 500 毫秒
101.
Heiderich Diese H. L. Honigmann A. Pütter A. Lazarus Fr. Markgraf 《Die Naturwissenschaften》1921,9(40):795-797
102.
103.
H.W.Fr. 《Die Naturwissenschaften》1916,4(52):849-850
The Science of Nature - 相似文献
104.
105.
106.
Mathieu Sicard Frédéric Chevalier Mickaël De Vlechouver Didier Bouchon Pierre Grève Christine Braquart-Varnier 《Die Naturwissenschaften》2010,97(9):819-826
Ecological factors modulate animal immunocompetence and potentially shape the evolution of their immune systems. Not only
environmental parameters impact on immunocompetence: Aging is one major cause of variability of immunocompetence between individuals,
and sex-specific levels of immunocompetence have also been frequently described. Moreover, a growing core of data put in light
that vertically transmitted symbionts can dramatically modulate the immunocompetence of their hosts. In this study, we addressed
the influence of gender, age and the feminising endosymbiont Wolbachia (wVulC) on variations in haemocyte density, total PO activity and bacterial load in the haemolymph of the terrestrial isopod
Armadillidium vulgare. This host–symbiont system is of particular interest to address this question since: (1) wVulC was previously shown as immunosuppressive in middle-aged females and (2) wVulC influences sex determination. We show that age, gender and Wolbachia modulate together immune parameters in A. vulgare. However, wVulC, which interacts with aging, appears to be the prominent factor interfering with both PO activity and haemocyte density.
This interference with immune parameters is not the only aspect of wVulC virulence on its host, as reproduction and survival are also altered. 相似文献
107.
The feed additive ractopamine hydrochloride was fortified at four concentrations into batch vials containing soils that differed in both biological activity and organic matter(OM).Sampling of the liquid layer for 14 days demonstrated that ractopamine rapidly dissipated from the liquid layer. Less than 20% of the fortified dose remained in the liquid layer after 4 hr,and recoveries of dosed ractopamine ranged from 8 to 18% in the liquid layer at 336 hr. Sorption to soil was the major fate for ractopamine in soil:water systems, i.e., 42%–51% of the dose at14 days. The major portion of the sorbed fraction was comprised of non-extractables; a smaller fraction of the sorbed dose was extracted into water and acetone, portions which would be potentially mobile in the environment. Partitioning coefficients for all soils suggested strong sorption of ractopamine to soil which is governed by hydrophobic interactions and cation exchange complexes within the soil OM. Ractopamine degradation was observed, but to mostly non-polar compounds which had a higher potential than ractopamine to sorb to soil. The formation of volatiles was also suggested. Therefore, despite rapid and extensive soil sorption,these studies indicated a portion of ractopamine, present in manures used to fertilize soils,may be mobile in the environment via water-borne events. 相似文献
108.
Randall Spalding-Fecher Arthur Chapman Francis Yamba Hartley Walimwipi Harald Kling Bernard Tembo Imasiku Nyambe Boaventura Cuamba 《Mitigation and Adaptation Strategies for Global Change》2016,21(5):721-742
The Zambezi River Basin in southern Africa is relatively undeveloped from both a hydropower and irrigated agriculture perspective, despite the existence of the large Kariba and Cahora Bassa dams. Accelerating economic growth increases the potential for competition for water between hydropower and irrigated agriculture, and climate change will add additional stresses to this system. The objective of this study was to assess the vulnerability of major existing and planned new hydropower plants to changes in climate and upstream irrigation demand. Our results show that Kariba is highly vulnerable to a drying climate, potentially reducing average electricity generation by 12 %. Furthermore, the expansion of Kariba generating capacity is unlikely to deliver the expected increases in production even under a favourable climate. The planned Batoka Gorge plant may also not be able to reach the anticipated production levels from the original feasibility study. Cahora Bassa’s expansion is viable under a wetting climate, but its potential is less likely to be realised under a drying climate. The planned Mphanda Nkuwa plant can reach expected production levels under both climates if hydropower is given water allocation priority, but not if irrigation is prioritised, which is likely. For both Cahora Bassa and Mphanda Nkuwa, prioritising irrigation demand over hydropower could severely compromise these plants’ output. Therefore, while climate change is the most important overall driver of variation in hydropower potential, increased irrigation demand will also have a major negative impact on downstream plants in Mozambique. This implies that climate change and upstream development must be explicitly incorporated into both project and system expansion planning. 相似文献
109.
Kevin R. Foster Perttu Seppä Francis L. W. Ratnieks Peter A. Thorén 《Behavioral ecology and sociobiology》1999,46(4):252-257
Queen mating frequency was studied in the European hornet, Vespa crabro, by analyzing four DNA microsatellite loci in 20 workers from each of 14 nests. Queens were found to be predominantly singly
mated (9/14), although double (4/14) and triple mating (1/14) also occurred. For most multiply mated queens, paternity was
significantly biased with the majority male fathering on average 80% of the female offspring. The population-wide effective
mating frequency was therefore low (1.11), and sister-sister relatedness high (0.701 ± 0.023 SE). Low effective mating frequency
in Vespa, in combination with data from other vespines, suggests that high paternity frequency is derived in the group. Some problems
with the non-detection of fathers, where the queen was not sampled or shared alleles with males, are analyzed.
Received: 16 November 1998 / Received in revised form: 29 March 1999 / Accepted: 12 April 1999 相似文献
110.