全文获取类型
收费全文 | 10525篇 |
免费 | 10篇 |
国内免费 | 19篇 |
专业分类
安全科学 | 32篇 |
废物处理 | 815篇 |
环保管理 | 1307篇 |
综合类 | 1078篇 |
基础理论 | 3306篇 |
环境理论 | 2篇 |
污染及防治 | 2001篇 |
评价与监测 | 1060篇 |
社会与环境 | 948篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 3篇 |
2022年 | 17篇 |
2021年 | 18篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 1487篇 |
2017年 | 1391篇 |
2016年 | 1210篇 |
2015年 | 154篇 |
2014年 | 48篇 |
2013年 | 108篇 |
2012年 | 504篇 |
2011年 | 1402篇 |
2010年 | 739篇 |
2009年 | 649篇 |
2008年 | 936篇 |
2007年 | 1275篇 |
2006年 | 52篇 |
2005年 | 53篇 |
2004年 | 63篇 |
2003年 | 93篇 |
2002年 | 119篇 |
2001年 | 24篇 |
2000年 | 18篇 |
1999年 | 8篇 |
1998年 | 17篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 15篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1981年 | 4篇 |
1977年 | 2篇 |
1965年 | 7篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 9篇 |
1961年 | 11篇 |
1958年 | 2篇 |
1954年 | 2篇 |
1941年 | 2篇 |
1935年 | 2篇 |
1932年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
Stratigraphy, lithology and depositional structures of Liassic red limestone-breccias of the Adnet Formation, including the 'Adnet Scheck', were studied at several outcrops of the Northern Calcareous Alps (NCA) south-east of Salzburg. A four-fold lithostratigraphic division is proposed for the Adnet Formation of the Osterhorn Mountains: the hemipelagic Schmiedwirt (Sinemurian) and Kehlbach (Carixian) members are separated from the pelagic Saubach Member (Toarcian) by a layer of amalgamated breccias (Scheck Member, probably Domerian to early Toarcian). Several other breccia beds occur locally from the base of the Kehlbach Member up to the lower Saubach Member. Although the sediments overlying the Scheck Member breccias are of coeval age, the ages of the underlying strata are very different. This can be explained by submarine Liassic erosion during a period of resedimentation from the middle Carixian until the early Toarcian. At least 10–15?m of partly lithified sediments were eroded by gravity flows. The entire Kehlbach Member and up to two-thirds of the Schmiedwirt Member were removed at Adnet. The breccias originated from submarine debris flows. Repeated flows over a long period and the depositional setting exclude a triggering by sea-level fluctuations. Most probably they arose from tectonically triggered slumps and slides of superficial sediments. The 'Scheck' was initiated on the steep upper slope of the drowned Triassic Adnet reef and flowed to the north-east.The Pliensbachian to early Toarcian period of tectonic activity indicated by the breccias was the most important during the Liassic in the Osterhorn Mountains and other parts of the NCA. From the large-scale regional distribution of the breccias and in accord with published data, a roughly north-east trending strike-slip fault zone is proposed, crossing the NCA south of the Osterhorn block, with a peaking activity during the Pliensbachian to early Toarcian as the cause of the tectonic movements. 相似文献
42.
Christian Klixbüll Jørgensen 《Die Naturwissenschaften》1982,69(9):420-427
The “constituents” quarks and leptons of matter (with rest-mass) are compared with the historical development of “elements” in chemistry. If unsaturated quarks induce high (and at the moment unpredictable) rest-masses above l0GeV, we have a new view of nuclei comprising (2Z + N) u-quarks and (Z +2N) d-quarks in their low-energy states, without any reference to protons and neutrons as permanent building-blocks. Recent studies of quarks and possible rishons (sub-quarks) and technicolour hadrons are reviewed, and the rôle of identity and cardinality in quantum mechanics analyzed. 相似文献
43.
44.
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
45.
46.
The Science of Nature - 相似文献
47.
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
48.
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
49.
50.