全文获取类型
收费全文 | 1994篇 |
免费 | 17篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 66篇 |
废物处理 | 86篇 |
环保管理 | 251篇 |
综合类 | 382篇 |
基础理论 | 437篇 |
环境理论 | 2篇 |
污染及防治 | 552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 | 43篇 |
2016年 | 53篇 |
2015年 | 56篇 |
2014年 | 62篇 |
2013年 | 85篇 |
2012年 | 87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 | 17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2029条查询结果,搜索用时 203 毫秒
991.
992.
993.
994.
J. Van Keirsbilck M. Cannie C. Robrechts T. de Ravel S. Dymarkowski T. Van den Bosch D. Van Schoubroeck 《黑龙江环境通报》2006,26(8):684-688
We present a case of sirenomelia diagnosed on a first trimester ultrasound at 10 weeks' gestation and confirmed on 3D-ultrasound and MRI. The pregnancy was terminated at 15 gestational weeks and the post-mortem examination, including RX and microscopy, is presented. The sirenomelia sequence is a rare and lethal anomaly characterized by fusion, rotation, hypotrophy or atrophy of the lower limbs and severe urogenital abnormalities leading to oligohydramnios in the second half of pregnancy. Our case illustrates that the diagnosis of sirenomelia can be reliably made in the first trimester. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
995.
S. Claassens L. Van Rensburg K. J. Riedel J. J. Bezuidenhout P. J. Jansen Van Rensburg 《The Environmentalist》2006,26(1):51-62
Summary Bioremediation has become an important method for the treatment of terrestrial oil spills and is often favoured over strictly
physical-chemical methods. In this study, enzymatic analyses and signature lipid biomarkers were employed to evaluate the
efficacy of selected bioremediation products on control and oil contaminated soil plots. It is envisioned that these biological
indicators may be used as possible adjuncts to the strictly physical-chemical criteria most commonly employed. The application
of the enzymatic and signature biomarker methods for product evaluation proved successful. The enzymatic assays provided a
valuable insight into shifts in the functional diversity of the soil microbial communities resultant from the various treatments.
Stimulation or inhibition of the microbial communities as a result of the various treatments was also demonstrated, particularly
with regards to dehydrogenase activity. Phospholipid fatty acid profiles proved sufficiently sensitive to allow differentiation
between products and resultant microbial communities that corresponded to satisfactory and unsatisfactory petroleum hydrocarbon
removal. 相似文献
996.
997.
998.
We investigated the fledging probability of oystercatcher, Haematopus ostralegus, chicks as a function of hatching order, brood size, territory quality and food availability. Sibling dominance was related
to the hatching order in both low- (’leapfrogs’) and high-quality (’residents’) territories. Differences in hatchling mass
might have aided the establishment of a dominance hierarchy, since breeders produced small late eggs and hatchlings. These
mass differences were most pronounced in leapfrogs, and in large broods in years with lower food availability (’poor’ years).
Late hatchlings fledged less often and with lower body masses compared to early hatchlings in all situations. Leapfrogs produced
smaller broods and hatched their broods more asynchronously in poor years than leapfrogs breeding in years with more available
food (’good’ years) and residents breeding in both poor and good years. Large brood sizes resulted in lower survival of hatchlings
in poor years. These results favour the ’brood reduction’ hypothesis. However, contrary to the expectations of this hypothesis,
hatching order also affected fledging success in residents. Moreover, large brood size resulted in higher survival of hatchlings
in good years, particularly in residents. Thus, although large broods experienced losses due to sibling competition in some
years, they nevertheless consistently produced more fledglings per brood in all years, both as leapfrogs and residents. We
believe this effect is due to parental quality correlating with initial brood size. Most leapfrogs, at best, fledged one chick
successfully each year, losing chicks due to starvation. Nevertheless, leapfrog broods were reduced in size after hatching
significantly less quickly than resident broods. These results suggest that breeders lay and hatch insurance eggs to compensate
for unpredictable losses due to the high predation rates on both nests (ca 50%) and chicks (ca 90%), in accordance with the
’nest failure’ hypothesis.
Received: 14 February 2000 / Revised: 27 September 2000 / Accepted: 10 June 2000 相似文献
999.
S. Wijnhoven G. Van Der Velde R. S. E. W. Leuven H. J. P. Eijsackers A. J. M. Smits 《Chemistry and Ecology》2006,22(6):463-477
Ecotoxicological risks of sediment contamination in floodplains are supposed to be highest in the regularly flooded parts. Therefore, in risk assessments, the non-flooded parts are neglected or considered to be reference areas. We investigated the metal extractability and levels in important food sources for vertebrates, viz. grass shoots and earthworms, in flooded as well as non-flooded parts and compared these with total metal concentrations. A comparison of these areas in the moderately polluted 'Afferdensche en Deestsche Waarden' floodplains along the River Rhine showed that total Zn, Pb, and Cd concentrations were highest in the regularly flooded parts. However, CaCl2-extractable Zn concentrations were highest in non-flooded areas, and those of Pb and Cd were equal in both areas. Total Cu concentrations were not significantly different between the two areas, but CaCl2-extractable Cu concentrations were highest in the regularly flooded areas. The metal concentrations in grass shoots of non-flooded areas were equal to (Zn, Cu, Cd) or higher than (Pb) those in regularly flooded areas. Zn concentrations in earthworms in regularly flooded areas were higher, but concentrations of Cu, Pb, and Cd were not. Ecotoxicological risk assessments require analysis of the total and potentially bioavailable metal concentrations in soils as well as concentrations in biota. This study shows that the less contaminated non-flooded areas in moderately polluted floodplains cannot be neglected in metal accumulation studies and cannot be used as pristine reference areas. 相似文献
1000.