全文获取类型
收费全文 | 8258篇 |
免费 | 29篇 |
国内免费 | 59篇 |
专业分类
安全科学 | 187篇 |
废物处理 | 430篇 |
环保管理 | 717篇 |
综合类 | 1209篇 |
基础理论 | 2419篇 |
环境理论 | 1篇 |
污染及防治 | 1895篇 |
评价与监测 | 580篇 |
社会与环境 | 881篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 42篇 |
2022年 | 78篇 |
2021年 | 65篇 |
2020年 | 30篇 |
2019年 | 44篇 |
2018年 | 185篇 |
2017年 | 204篇 |
2016年 | 288篇 |
2015年 | 120篇 |
2014年 | 158篇 |
2013年 | 434篇 |
2012年 | 578篇 |
2011年 | 446篇 |
2010年 | 237篇 |
2009年 | 245篇 |
2008年 | 299篇 |
2007年 | 312篇 |
2006年 | 303篇 |
2005年 | 593篇 |
2004年 | 703篇 |
2003年 | 613篇 |
2002年 | 216篇 |
2001年 | 290篇 |
2000年 | 179篇 |
1999年 | 130篇 |
1998年 | 45篇 |
1997年 | 67篇 |
1996年 | 56篇 |
1995年 | 70篇 |
1994年 | 68篇 |
1993年 | 61篇 |
1992年 | 61篇 |
1991年 | 68篇 |
1990年 | 70篇 |
1989年 | 56篇 |
1988年 | 56篇 |
1987年 | 54篇 |
1986年 | 55篇 |
1985年 | 41篇 |
1984年 | 47篇 |
1983年 | 47篇 |
1982年 | 48篇 |
1980年 | 30篇 |
1979年 | 32篇 |
1978年 | 29篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1974年 | 33篇 |
1973年 | 31篇 |
1972年 | 29篇 |
排序方式: 共有8346条查询结果,搜索用时 31 毫秒
121.
Urban Flood Damage and Greenhouse Scenarios - The Implications for Policy: An Example from Australia
Urban flooding is often used as an illustration of the potentially adverse effects of greenhouse-induced climate change on extreme events. There is however, a paucity of studies that convert climate scenarios into changes in flood damage. This account summarises the use of modelling techniques, for three flood prone urban catchments in south eastern Australia, to assess changes to urban flood losses for the 'most wet' and 'most dry' scenarios for the year 2070. The most wet scenario indicates that annual average flood damage could increase within the range of 2.5 to 10 times, under the most dry scenario flood regimes would be similar to those experienced at present. The socio-economic scenarios based on the changes to flood losses are used to consider policy responses. It is unlikely that many local government authorities will respond because of lack of interest and because of major changes to the climate scenarios proposed over the last decade. Any response is likely to be incremental and accord with the 'no regrets' and the precautionary principle'. 相似文献
122.
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
123.
A. Kr?ner A. P. Willner E. Hegner A. Frischbutter J. Hofmann R. Bergner 《Geologische Rundschau》1995,84(3):437-456
Single zircons from two orthogneiss complexes, the Grey Gneiss and Red Gneiss, the lowermost tectonic units in the Erzgebirge, were dated. The grey Freiberg Gneiss is of igneous origin and has a 207Pb/206Pb emplacement age of 550±7 Ma. A quartz monzonite from Lauenstein contains idiomorphic zircons with a mean 207Pb/206Pb age of 555±7 Ma as well as xenocrysts ranging in age between 850 and 1910 Ma. Red gneisses from the central Erzgebirge contain complex zircon populations, including numerous xenocrysts up to 2464 Ma in age. The youngest, idiomorphic, zircons in all samples yielded uniform 207Pb/206Pb ages between 550±9 and 554±10 Ma. Nd isotopic data support the interpretation of crustal anatexis for the origin of both units. Nd(t) values for the grey gneisses are –7.5 and –6.0 respectively, (mean crustal residence ages of 1.7–1.8 Ga). The red gneisses have a wider range in Nd(t) values from –7.7 to –2.8 (T
DM ages of 1.4–1.8 Ga). The zircon ages document a distinct late Proterozoic phase of granitoid magmatism, similar in age to granitoids in the Lusatian block farther north-east. However, Palaeozoic deformation as well as medium pressure metamorphism ( 8 kbar/600–650° C) are identical in both gneiss units and distinguish these rocks from the Lusatian granitoids. The grey and red gneisses were overthrust by units with abundant high-pressure relicts and a contrasting P-T evolution. Zircon xenocryst and Nd model ages in the range 1000–1700 Ma are similar to those in granitoid rocks of Lusatia and the West-Sudetes, and document a pre-Cadomian basement in parts of east-central Europe that, chronologically, has similarities with the Sveconorwegian domain in the Baltic Shield. 相似文献
124.
125.
The nature of the cosmic redshift is one of the most fundamental questions in modern science. Hubble's discovery of the apparent Expansion of the Universe is derived from observations on a small number of galaxies at very low redshifts. Today, quasar redshifts have a range more than 1000 times greater than those in Hubble's sample, and represent more than 100 times as many objects. A recent comprehensive compilation of published measurements provides the basis for a study indicating that quasar observations are not in good agreement with the original predictions of the Expanding Universe theory, but are well fit by the predictions of an alternative theory having fewer adjustable parameters. 相似文献
126.
Michael H?der 《Die Naturwissenschaften》1989,76(7):340
Naturwissenschaften Aktuell
Großforschung mit anderen Namen 相似文献127.
128.
129.
130.