全文获取类型
收费全文 | 2217篇 |
免费 | 52篇 |
国内免费 | 5篇 |
专业分类
测绘学 | 61篇 |
大气科学 | 57篇 |
地球物理 | 1024篇 |
地质学 | 523篇 |
海洋学 | 19篇 |
天文学 | 486篇 |
综合类 | 4篇 |
自然地理 | 100篇 |
出版年
2018年 | 43篇 |
2017年 | 42篇 |
2016年 | 78篇 |
2015年 | 55篇 |
2014年 | 63篇 |
2013年 | 85篇 |
2012年 | 66篇 |
2011年 | 58篇 |
2010年 | 64篇 |
2009年 | 55篇 |
2008年 | 50篇 |
2007年 | 62篇 |
2006年 | 50篇 |
2005年 | 47篇 |
2004年 | 40篇 |
2003年 | 49篇 |
2002年 | 42篇 |
2001年 | 32篇 |
2000年 | 36篇 |
1999年 | 29篇 |
1998年 | 23篇 |
1997年 | 29篇 |
1996年 | 31篇 |
1995年 | 33篇 |
1994年 | 32篇 |
1993年 | 35篇 |
1992年 | 26篇 |
1991年 | 31篇 |
1990年 | 23篇 |
1989年 | 36篇 |
1988年 | 30篇 |
1987年 | 42篇 |
1986年 | 37篇 |
1985年 | 37篇 |
1984年 | 40篇 |
1983年 | 39篇 |
1982年 | 46篇 |
1981年 | 41篇 |
1980年 | 38篇 |
1979年 | 36篇 |
1978年 | 37篇 |
1977年 | 35篇 |
1976年 | 34篇 |
1975年 | 34篇 |
1973年 | 31篇 |
1972年 | 30篇 |
1971年 | 45篇 |
1970年 | 22篇 |
1969年 | 26篇 |
1968年 | 28篇 |
排序方式: 共有2274条查询结果,搜索用时 78 毫秒
111.
Summary The hypothesis of an expanding Earth is discussed on the basis of lunar laser ranging It is provcd that the given data do not indicate a secular increase in the principal moment of the Earth's inertia which would have to occur if the Earth were really expanding.
¶rt;amunma au u mu u ammuu a¶rt;u u ¶rt;a n a auu . aam, m n mu ¶rt;a m umamu amaua ma uuu u, m ¶rt; nmmam auu, u n¶rt; u m.相似文献
112.
aamuam uu am a (m u naamuu n) u u (a) uu a uu mu uu. mam (19), (28) naam, m amua am mau u m ¶rt; am amu: a) na ¶rt;um am, n n a uu am u uu a uu; ) ma ¶rt;um am, m aam uu a uu. 相似文献
113.
Summary The morphology of the Wadati-Benioff zone in the region of Southern Kuriles and Hokkaido, based on the distribution of 4015 earthquake foci, verified the existence of an intermediate depth aseismic gap and its relation to active andesitic volcanism. A paleosubduction zone activated by an intermediate depth collision with the active subduction zone was found and described.
u Wadati-Benioff amu uu - u a¶rt;, aa a an¶rt;uu 4015 a mu, nm¶rt;ua mau n¶rt; au u amu a¶rt;um au. a a¶rt;a u nuaa a na¶rt;uu, amuuuaa nmu mu amu ¶rt;uu.相似文献
114.
¶rt;au uu aum nuuumu u aumnuu ¶rt; aa aam n¶rt; am amuu u namuu ¶rt;au. amu uu aumnuu nuuumu, a amu ¶rt;au, m ¶rt;mu au ma nma aaumu m¶rt; ¶rt;a, m a amu uu aum m mnu n¶rt;u ¶rt; mm uaum amua n¶rt; ¶rt;au. u aumnuu nu a namu ¶rt;auu(<1%) a uuu m nuuumu i uaum amua. u aumnuu ¶rt;mu uu uum aauuau ¶rt;ua am m uu, m, m ¶rt; u au namu ¶rt;auu. 相似文献
115.
Summary The linearization approach is used to compute the travel times in inhomogeneous slightly anisotropic media. The basic formulae are outlined and their accuracy demonstrated in comparison with the exact solution based on the zero-order ray theory and the Backus formula (1965). The linearization is extended also to complex media with curved interfaces. The computer program for calculating travel times in 2D, inhomogeneous, slightly anisotropic, complex media is briefly described. The numerical results obtained for a realistic situation and various types of waves are presented to enable the effects of anisotropy and the effects of inhomogeneity on the resulting travel times to be compared.
na uauua n¶rt;¶rt; ¶rt; ama¶rt;aa , anmau aaumn ¶rt;a. ¶rt; u n¶rt; au m u n muu nuuuu u m¶rt; aa (1965). a uauua n¶rt;¶rt; ¶rt; a ¶rt; uuuauau a¶rt;a. am nuaa uuma naa ¶rt; ama¶rt;a ¶rt; ¶rt;. u mam ¶rt; a mun ¶rt;am m um m aumnuu u m ¶rt;¶rt;mu a a anmau .相似文献
116.
¶rt;naa, m ma um uu maunuu m am muu ¶rt;uauu um. nua a mau ammama a, n¶rt; mnu ma u u au uu u¶rt;mu. 相似文献
117.
The influence of ultraviolet light, heating, freezing and weathering on the mercury concentration in the primary feathers from Guillemot and Black Guillemot has been examined. Even within 8 months of exposure variation in mercury concentration due to either loss of mercury or weight loss of the feathers has been found to be less than 10% relative. 相似文献
118.
The paper considers a puff diffusion in its inertial stage when particle separation obeys the laws of the inertial subrange and depends only on eddy energy dissipation rate . The can be determined in the surface layer by the turbulent kinetic energy equation. Similarity equations connect with diffusion measure .A simple analytical model has been deduced to estimate pollutants diffusion during calms. 相似文献
119.
The orthogneiss bodies of the Moldanubicum in the western part of the Bohemian-Moravian Heights (eskomoravská vrchovina) are apoleucogranites, presumably of Precambrian age and probably of anatectic origin. Most orthogneiss bodies have been shown to contain greisens transformed by regional metamorphism. The greisens have maintained their identity during regional metamorphism below higher almandine-amphibolite facies grade, i.e. over the stability field of muscovite. Massive quartz (metamorphosed vein quartz) is frequent, and mineralization is associated with it in a few localities. Greisens in orthogneisses may serve as evidence of magmatic origin. 相似文献
120.
Summary The partial differential equations of electromagnetic induction in a 3-D Earth of inhomogeneous conductivity are reduced to a system of ordinary differential equations of the 2nd order for the spectral coefficients of the field.
au am nu¶rt; ¶rt; maum u¶rt;uu u m ¶rt;¶rt; n n¶rt;umu n¶rt; um ¶rt;uua au m n¶rt;a ¶rt; nma uum n.相似文献