全文获取类型
收费全文 | 2912篇 |
免费 | 71篇 |
国内免费 | 32篇 |
专业分类
安全科学 | 156篇 |
废物处理 | 113篇 |
环保管理 | 788篇 |
综合类 | 278篇 |
基础理论 | 681篇 |
环境理论 | 2篇 |
污染及防治 | 698篇 |
评价与监测 | 171篇 |
社会与环境 | 109篇 |
灾害及防治 | 19篇 |
出版年
2023年 | 16篇 |
2022年 | 21篇 |
2021年 | 30篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 56篇 |
2017年 | 59篇 |
2016年 | 95篇 |
2015年 | 62篇 |
2014年 | 69篇 |
2013年 | 307篇 |
2012年 | 112篇 |
2011年 | 163篇 |
2010年 | 133篇 |
2009年 | 135篇 |
2008年 | 146篇 |
2007年 | 150篇 |
2006年 | 139篇 |
2005年 | 78篇 |
2004年 | 110篇 |
2003年 | 102篇 |
2002年 | 91篇 |
2001年 | 56篇 |
2000年 | 47篇 |
1999年 | 45篇 |
1998年 | 39篇 |
1997年 | 39篇 |
1996年 | 46篇 |
1995年 | 53篇 |
1994年 | 39篇 |
1993年 | 42篇 |
1992年 | 26篇 |
1991年 | 30篇 |
1990年 | 35篇 |
1989年 | 23篇 |
1988年 | 30篇 |
1987年 | 25篇 |
1986年 | 37篇 |
1985年 | 22篇 |
1984年 | 35篇 |
1983年 | 28篇 |
1982年 | 31篇 |
1981年 | 31篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1972年 | 9篇 |
排序方式: 共有3015条查询结果,搜索用时 328 毫秒
991.
Wolfgang Priester (1924–2005) was one of Germany’s most versatile and quixotic astrophysicists, reinventing himself successively
as a radio astronomer, space physicist and cosmologist, and making a lasting impact on each field. We focus in this personal
account on his contributions to cosmology, where he will be most remembered for his association with quasars, his promotion
of the idea of a nonsingular “big bounce” at the beginning of the current expansionary phase, and his recognition of the importance
of dark energy (Einstein’s cosmological constant Λ) well before this became the standard paradigm in cosmology.
In memoriam Wolfgang Priester, 22 April 1924 – 9 July 2005 相似文献
992.
Dampwood termites, Zootermopsis angusticollis (Isoptera: Termopsidae), mount an immune response to resist microbial infection. Here we report on results of a novel analysis that allowed us to electrophoretically assess changes in hemolymph proteins in the same individual before and after exposure to a pathogen. We demonstrate that contact with a sublethal concentration of the entomopathogenic fungus Metarhizium anisopliae (Deuteromycotina:Hypomycetes) induces the production of protective proteins in nymphs, pseudergates (false workers), and soldiers. Termites exposed to an immunizing dosage of fungal conidia consistently showed an enhancement of constitutive proteins (62–85 kDa) in the hemolymph as well as an induction of novel proteins (28–48 kDa) relative to preimmunization levels. No significant differences in protein banding patterns relative to baseline levels in control and naïve termites were observed. Incubating excised and eluted induced proteins produced by immunized pseudergates or immunized soldiers with conidia significantly reduced the germination of the fungus. The fungistatic effect of eluted proteins differed significantly among five colonies examined. Our results show that the upregulation of protective proteins in the hemolymph underscores the in vivo immune response we previously recorded in Z. angusticollis. 相似文献
993.
地下水铀污染的原位微生物还原与固定:在美国能源部田纳西橡树岭放射物污染现场的试验 总被引:4,自引:0,他引:4
吴唯民 Jack Carley David Watson 顾宝华 Scott Brooks Shelly D. Kelly Kenneth Kemner Joy D. van Nostran 吴力游 许玫英 周集中 罗剑 Erick Cardenas 黃家琪 Matthew W. Fields Terence L. Marsh James M. Tiedje Stefan J. Green Joel E. Kostk Peter K. Kitanidis Philip M. Jardine Craig S. Criddle 《环境科学学报》2011,31(3):449-459
总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇... 相似文献
994.
Alain Dejean Bruno Corbara Frédéric Azémar James M. Carpenter 《Die Naturwissenschaften》2012,99(7):579-582
Because group-hunting arboreal ants spread-eagle insect prey for a long time before retrieving them, these prey can be coveted by predatory flying insects. Yet, attempting to rob these prey is risky if the ant species is also an effective predator. Here, we show that trying to rob prey from Azteca andreae workers is a fatal error as 268 out of 276 potential cleptobionts (97.1?%) were captured in turn. The ant workers hunt in a group and use the “Velcro?” principle to cling firmly to the leaves of their host tree, permitting them to capture very large prey. Exceptions were one social wasp, plus some Trigona spp. workers and flies that landed directly on the prey and were able to take off immediately when attacked. We conclude that in this situation, previously captured prey attract potential cleptobionts that are captured in turn in most of the cases. 相似文献
995.
Alebel Abebe Belay Henry Musoke Semakula George James Wambura Labohy Jan 《中国人口.资源与环境(英文版)》2013,11(1):8-17
Abstract River Nile is one of the longest transboundery rivers and it is shared and used by Burundi, Democratic Republic of Congo, Egypt, Ethiopia, Eritrea, Kenya, Rwanda, Sudan, Tanzania and Uganda. As of today, the Nile is a crucial resource for the economic development of the Nile Basin countries and a vital source of livelihood for 160 million inhabitants as well as 300 million people living in the 10 riparian countries. The Nile Basin Initiative (NBI) is one of the international cooperative river basin management program and regional partnership where all the Nile Basin countries except Eritrea unite to pursue long-term sustainable development, improved land use practices and management. This review therefore focused on the challenges not faced on NBI in terms of integrated use of the river and conducted analysis of strengths, weaknesses, opportunities and threats (SWOT) based on secondary data. The result of the review revealed that for decades, the Nile Basin people have been facing many complex environmental, social, economic and political challenges that have made it difficult for the proper management and sustainability of Nile water. The initiative provides training to develop skills in government ministries, non-governmental organizations and local communities in each country. It is also working to raise awareness of critical environmental issues by strengthening networks of environmental education practitioners; developing curriculum in the education sector. The challenges of NBI include the involvement and funding of World Bank, lack of sufficient staff, procedural and policies conflicts, lack of coordination and linkage with other regional institutions and lack of recognition as river basin organization. Considering the complex nature of the project, it is recommended that the NBI should come up with a strong multi-disciplinary monitoring and evaluation team to follow up all implemented projects. The NBI should carry out participatory land use planning in communities along the river basin. Moreover, livelihood analysis should be carried out especially in communities along the Nile to come up with poverty eradication projects which are socially acceptable, applicable, economically viable and affordable. 相似文献
996.
997.
Edward?A.?RoualdesEmail authorView authors OrcID profile
return OK on get Simon?J.?Bonner Thomas?D.?Whitney James?D.?Harwood 《Environmental and Ecological Statistics》2016,23(2):317-336
The literature on modelling a predator’s prey selection describes many intuitive indices, few of which have both reasonable statistical justification and tractable asymptotic properties. Here, we provide a simple model that meets both of these criteria, while extending previous work to include an array of data from multiple species and time points. Further, we apply the expectation–maximisation algorithm to compute estimates if exact counts of the number of prey species eaten in a particular time period are not observed. We conduct a simulation study to demonstrate the accuracy of our method, and illustrate the utility of the approach for field analysis of predation using a real data set, collected on wolf spiders using molecular gut-content analysis. 相似文献
998.
Schliep Erin M. Gelfand Alan E. Clark James S. Zhu Kai 《Environmental and Ecological Statistics》2016,23(1):23-41
Environmental and Ecological Statistics - Predictions of above-ground biomass and the change in above-ground biomass require attachment of uncertainty due the range of reported predictions for... 相似文献
999.
1000.
Since the Brundtland Commission's delineation of the term sustainable development in 1987, virtually every country has incorporated the terms sustainability and sustainable development into their planning vocabulary and criteria for decision-making. However, many issues remain unresolved. Broad and sweeping references to sustainability and sustainable development do not necessarily translate into implementable policies to achieve these goals. In particular, unresolved issues include developing an understanding of how one sector of the economy can contribute to the sustainable development of the economy as a whole and the role of ecological resources in sustainable development. Our paper provides an initial conceptual examination of these questions by folding mining and ecological quality into the sustainability discussion. We use the Brazilian Amazon as an application of our sustainable development model. 相似文献