全文获取类型
收费全文 | 12074篇 |
免费 | 17篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 75篇 |
废物处理 | 889篇 |
环保管理 | 1447篇 |
综合类 | 1373篇 |
基础理论 | 3603篇 |
环境理论 | 2篇 |
污染及防治 | 2454篇 |
评价与监测 | 1212篇 |
社会与环境 | 1049篇 |
灾害及防治 | 20篇 |
出版年
2023年 | 26篇 |
2022年 | 85篇 |
2021年 | 103篇 |
2020年 | 51篇 |
2019年 | 42篇 |
2018年 | 1518篇 |
2017年 | 1430篇 |
2016年 | 1281篇 |
2015年 | 192篇 |
2014年 | 125篇 |
2013年 | 169篇 |
2012年 | 570篇 |
2011年 | 1484篇 |
2010年 | 786篇 |
2009年 | 692篇 |
2008年 | 980篇 |
2007年 | 1316篇 |
2006年 | 74篇 |
2005年 | 133篇 |
2004年 | 187篇 |
2003年 | 209篇 |
2002年 | 190篇 |
2001年 | 88篇 |
2000年 | 43篇 |
1999年 | 35篇 |
1998年 | 23篇 |
1997年 | 26篇 |
1996年 | 16篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 16篇 |
1990年 | 9篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 21篇 |
1983年 | 17篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 8篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1964年 | 4篇 |
1961年 | 3篇 |
1935年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach. 相似文献
62.
63.
Andreas Züttel 《Mitigation and Adaptation Strategies for Global Change》2007,12(3):343-365
Hydrogen storage and transportation or distribution is closely linked together. Hydrogen can be distributed continuously in
pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system but also
pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels.
Furthermore, hydrogen is regenerative and environment friendly. There are two reasons why hydrogen is not the major fuel of
toady’s energy consumption: First of all, hydrogen is just an energy carrier. And, although it is the most abundant element
in the universe, it has to be produced, since on earth it only occurs in the form of water. This implies that we have to pay
for this energy, which results in a difficult economic task, because since the industrialization we are used to consuming
energy for free. The second difficulty with hydrogen as an energy carrier is the low critical temperature of 33 K, i.e. hydrogen
is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric
density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure
gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific
surface area (at T < 100 K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent
and ionic compounds (at ambient pressure), oxidation of reactive metals e.g. Li, Na, Mg, Al, Zn with water. These metals easily
react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can
be thermally reduced to the metals in a solar furnace. 相似文献
64.
Goyet Cde V 《Disasters》1993,17(2):169-176
65.
66.
67.
FUENSANTA CARAVACA DINO FIGUEROA ANTONIO ROLDÁn CONCEPCIÓN AZCÓN-AGUILAR 《Environmental management》2003,31(3):0412-0420
The reestablisment of autochthonous plant species is an essential strategy for recovering degraded areas under semiarid conditions.
A field experiment was carried out to assess the short-term effect of two reafforestation methods involving mycorrhizal inoculation
and compost addition on soil quality parameters and Rhamnus lycioides seedling growth. The nutrient content (NPK) and enzymatic activities (dehydrogenase, urease, protease-BAA, acid phosphatase
and β-glucosidase) increased and bulk density decreased in the rhizosphere soil with the organic amendment. Biomass C of rhizosphere
soil increased by at least 240% with respect to the control soil after mycorrhizal inoculation and the combination of compost
addition + mycorrhizal inoculation. Both mycorrhizal inoculation and composted organic residue addition increased R. lycioides seedling growth in the same proportion. In the short term, we conclude that the application of both reafforestation methods
not only enhances the establishment of R. lycioides seedlings, but also improves soil quality. 相似文献
68.
69.
Tamim Younos Raymond de Leon Christine Lewicki 《Journal of the American Water Resources Association》2003,39(1):1-5
ABSTRACT: The objective of this article is to open a dialogue on integrating service‐learning into community based watershed management programs and to discuss opportunities and challenges that a service‐learning program presents to universities and communities. The article presents the concept and definition of service‐learning, and arguments concerning why institutions of higher education and university faculty and students should be involved with community based watershed management programs. The article describes a case study for developing a service‐learning program for watershed management at Virginia Tech and discusses lessons learned from the case study. The paper concluded that to make a service‐learning program sustainable, there should be a long term plan, regular and effective communication with the stakeholders, and some incentives for faculty and students for long term commitment to the community based watershed management programs. 相似文献
70.
The article focuses on fossil energy resources in the Andean Group and Mexico, and argues for a dynamic approach to calculating reserves to production ratios. Individual countries are surveyed in terms of estimated reserves of fossil energy resources, current production rates and future prospects; energy policy options for individual countries are analysed. As a primary objective of energy policy is to ensure security of supply, it is important that calculations of reserves to production ratios accurately estimate the desired level of investment in exploration. The calculations need to take into account a variety of parameters, including different energy sources, availability and risk; geographic considerations including proximity, transport, storage capacity and commercial aspects; the competitive and environmental implications of developing indigenous resources; and the use of instruments to establish contingency plans for emergencies.
The opinions expressed in this article are those of the authors, and do not necessarily reflect the views of OLADE, ECLAC or GTZ. The authors apologize for any inaccuracies or omissions in the article. 相似文献
The opinions expressed in this article are those of the authors, and do not necessarily reflect the views of OLADE, ECLAC or GTZ. The authors apologize for any inaccuracies or omissions in the article. 相似文献