全文获取类型
收费全文 | 2171篇 |
免费 | 53篇 |
国内免费 | 27篇 |
专业分类
安全科学 | 84篇 |
废物处理 | 99篇 |
环保管理 | 442篇 |
综合类 | 294篇 |
基础理论 | 479篇 |
环境理论 | 3篇 |
污染及防治 | 573篇 |
评价与监测 | 165篇 |
社会与环境 | 100篇 |
灾害及防治 | 12篇 |
出版年
2023年 | 21篇 |
2022年 | 32篇 |
2021年 | 35篇 |
2020年 | 32篇 |
2019年 | 25篇 |
2018年 | 50篇 |
2017年 | 55篇 |
2016年 | 58篇 |
2015年 | 55篇 |
2014年 | 73篇 |
2013年 | 153篇 |
2012年 | 100篇 |
2011年 | 124篇 |
2010年 | 88篇 |
2009年 | 109篇 |
2008年 | 112篇 |
2007年 | 131篇 |
2006年 | 101篇 |
2005年 | 90篇 |
2004年 | 86篇 |
2003年 | 76篇 |
2002年 | 79篇 |
2001年 | 49篇 |
2000年 | 46篇 |
1999年 | 32篇 |
1998年 | 40篇 |
1997年 | 29篇 |
1996年 | 39篇 |
1995年 | 37篇 |
1994年 | 29篇 |
1993年 | 19篇 |
1992年 | 24篇 |
1991年 | 12篇 |
1990年 | 20篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1983年 | 15篇 |
1982年 | 17篇 |
1981年 | 7篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 5篇 |
1968年 | 3篇 |
排序方式: 共有2251条查询结果,搜索用时 294 毫秒
1.
2.
3.
4.
Greg R. J. Sutherland Joachim Haselbach Steven D. Aust 《Environmental science and pollution research international》1997,4(1):16-20
Two synthetic superabsorbent crosslinked acrylic polymers were mineralized by the white-rot fungusPhanerochaete chrysosporium. The amount of polymer converted to CO2 increased as the amount of polymer added to the cultures increased. In the presence of sufficiently large amounts of the superabsorbents, such that all of the culture fluid was absorbed and a gelatinous matrix was formed, the fungus still grew and mineralization was observed. Neither the polymers, nor their degradation products were toxic to the fungus. While the rates of mineralization were low, all of the polymers incubated in the liquid fungal cultures were completely depolymerized to water soluble products within 15–18 days. The depolymerization of the polymers was observed only in nitrogen limited cultures of the fungus which secrete the lignin degradation system, however, the water soluble products of depolymerization were mineralized in both nutrient limited and sufficient cultures of the fungus. The rate of mineralization of the depolymerized metabolites was more than two times greater in nutrient sufficient cultures. Following longer incubation periods, most (> 80 %) of the radioactivity was recovered in the fungal mycelial mat suggesting that carbon of the polymer had been converted to fungal metabolites. 相似文献
5.
We investigated the distribution and transport of coal tar-derived polycyclic aromatic hydrocarbons (PAHs) in fine-grained residuum and alluvial floodplain deposits that underlie a former manufactured gas plant. All 16 USEPA priority pollutant PAHs are present at this site and have penetrated the entire 4-5m thickness of clayey sediments, which unconformably overly limestone bedrock. Concentrations of less hydrophobic PAHs (e.g., naphthalene, 0.011-384mg kg(-1)) were about 10 times higher than those of highly hydrophobic PAHs (e.g., benzo[g,h,i]perylene -0.002 to 56.03mgkg(-1)). Microscopic examination of thin-sections of the clay-rich sediments showed that fractures and rootholes, which can act as pathways for flow, occur throughout the profiles. Tarry residue was found coating some fractures and rootholes, indicating that coal tar was, in some cases, able to penetrate as an immiscible phase. However, in the vast majority of samples in which PAHs were detected, there was no detectable tar residue, suggesting that much of the transport occurred in the dissolved phase. Examination of thin-sections with an epifluorescent microscope indicated that PAHs, which fluoresce brightly when exposed to UV light, are distributed throughout the soil matrix, rather than being confined to fractures and rootholes. The widespread distribution of PAHs is most likely due to diffusion-controlled exchange between the fast-flow pathways in the fractures and rootholes and the relatively immobile water in the fine-grained matrix. This implies that fractures and rootholes can play a major role in controlling transport of highly hydrophobic compounds in fine-grained sediments, which would otherwise act as barriers to contaminant migration. 相似文献
6.
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
7.
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
8.
9.
Van der Eerden LJ Lekkerkerk LJ Smeulders SM Jansen AE 《Environmental pollution (Barking, Essex : 1987)》1992,76(1):1-9
Three-year-old Douglas firs (Pseudotsuga menziesii) were fumigated with 180 microg m(-3) NH3 or clean (charcoal-filtered) air. During these fumigations the plants received 15 mm artificial rain weekly, supplemented with 20, 500 or 2500 micromol litre(-1) (NH4)2SO4. Exposure to NH3 and NH4+ for 14 weeks resulted in a change of the nutrient status of the needles. The most remarkable effect was the increase in the N/K ratio, due to both uptake of N and leaching of K. The action of NH3 was stronger than that of NH4+. Both NH3 and (NH4)2SO4 affected the epicuticular wax layer and decreased mycorhiza frequency. Following fumigation and artificial rain treatments, needles were incubated for 8 h in a medium containing 0, 50, 250, 500 and 2500 micromol litre(-1) (NH4)2SO4. Almost no exchange of Ca, Mg and K for NH4+ was found. Therefore this ion exchange probably explains only a minor part of the changes in nutrient status of the whole trees. 相似文献
10.
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