全文获取类型
收费全文 | 398篇 |
免费 | 8篇 |
国内免费 | 5篇 |
专业分类
测绘学 | 1篇 |
大气科学 | 5篇 |
地球物理 | 80篇 |
地质学 | 205篇 |
海洋学 | 15篇 |
天文学 | 88篇 |
综合类 | 2篇 |
自然地理 | 15篇 |
出版年
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 36篇 |
2017年 | 29篇 |
2016年 | 20篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 24篇 |
2012年 | 17篇 |
2011年 | 14篇 |
2010年 | 19篇 |
2009年 | 22篇 |
2008年 | 14篇 |
2007年 | 18篇 |
2006年 | 22篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1966年 | 2篇 |
排序方式: 共有411条查询结果,搜索用时 15 毫秒
171.
A. A. Tomilenko T. A. Bul’bak M. O. Khomenko D. V. Kuzmin N. V. Sobolev 《Doklady Earth Sciences》2016,468(2):626-631
The composition of volatiles from fluid and melt inclusions in olivine phenocrysts from Yakutian kimberlite pipes of various ages (Olivinovaya, Malokuonapskaya, and Udachnaya-East) were studied for the first time by gas chromatography–mass spectrometry. It was shown that hydrocarbons and their derivatives, as well as nitrogen-, halogen-, and sulfur-bearing compounds, played a significant role in the mineral formation. The proportion of hydrocarbons and their derivatives in the composition of mantle fluids could reach 99%, including up to 4.9% of chlorineand fluorine-bearing compounds. 相似文献
172.
G. A. Pal’yanova E. S. Sobolev V. N. Reutsky N. S. Bortnikov 《Geology of Ore Deposits》2016,58(6):456-464
Pyritized bivalve mollusks have been revealed for the first time in upper Norian sedimentary rocks at the large orogenic Sentachan gold–antimony deposit in eastern Yakutia. It has been established that they are related to species of the genus Monotis (M. ex gr. jacutica (Teller) (specimen no. 2077/1, CSGM) and M. pachypleura (Teller) (specimen no. 2077/2, CSGM), which existed during the Monotis densistriata phase of the Norian Age of the Triassic Epoch presumably 211.5–214 Ma ago. The occurrence of two pyrite generations differing in morphology, sulfur impurity, and isotopic compositions corroborates the suggestion that pyritization of fauna was a discrete process. It has been shown that sulfur that formed owing to bacterial sulfate reduction and interaction with organic matter was involved in the pyritization of bivalve mollusks, whereas mixing of magmatic sulfur and sulfur derived from host sedimentary rocks participated in deposition of Au–Sb ore. 相似文献
173.
174.
175.
N. Yu. Bragin A. G. Konstantinov E. S. Sobolev 《Stratigraphy and Geological Correlation》2012,20(6):541-566
The thorough study of the Upper Triassic reference section located at the Tikhaya River in the central part of Kotel??nyi Island and characterized by uniform clayey lithology and containing diverse cephalopod, molluscan, and radiolarian assemblages made it possible to specify its structure and paleontological characteristic and establish for the first time the upper Anisian Sirenites yakutensis Zone. It is shown that different Late Triassic faunal groups are represented by mixed dominant Boreal and subordinate Tethyan elements. Such proportions are observable through the entire section beginning from the lower Carnian to upper Norian layers. The peculiar taxonomic composition of Late Triassic radiolarian and cephalopod assemblages provides grounds for attributing the region to an autonomous paleobiochore (New Siberian subprovince). The occurrence of both Siberian and Canadian elements in the Late Triassic faunas emphasizes the specific position of this paleobiochore determined by wide connections between basins at that time. 相似文献
176.
Olga V. Vikent’eva Gennady N. Gamyanin Nikolay S. Bortnikov 《Central European Journal of Geosciences》2012,4(2):310-323
Inductively coupled plasma-mass spectrometry (ICP-MS) has been used to determine rare earth element concentrations in aqueous solutions extracted from fluid inclusions. Quartz has been sampled from ores of three major types of polygenic gold hydrothermal systems of North-Eastern Russia: (1) gold-quartz-sulphide (Au-Q, Nezhdaninsk); (2) gold-antimony (Au-Sb, Sarylakh) and (3) intrusion-related gold-bismuth-siderite-polysulphide (Au-Bi-Sid, Arkachan) large deposits located in terrigenous rocks of the Verkhoyansk fold belt. The total concentration of REE in the fluid inclusions is not high (up to 52 ppm). The contribution of LREE dominates in REE balance (??LREE/??HREE=7.4?C112.1). The chondrite-normalized REE patterns of inclusion fluids for the Au-Q and Au-Bi-Sid deposits are characterized by LREE enrichment with a positive or negative Eu anomaly. REE patterns for the regenerated quartz from Au-Sb deposits are characterized by pronounced differentiation between light and heavy lanthanides in fluid inclusions. Significant total REE concentration decreasing (on 1?C2 order) from early to late stages of Nezhdaninsk and Arkachan deposits is revealed. The positive correlations of total REE concentrations with Rb, Cs, Li and B contents in fluid inclusions are shown. The REE distribution in fluid inclusions can be used as indicators of the contribution of magmatic fluid in the hydrothermal system. 相似文献
177.
Ute V. Möstl Nikolay V. Erkaev Michael Zellinger Helmut Lammer Hannes Gröller Helfried K. Biernat Daniil Korovinskiy 《Icarus》2011,216(2):476-484
The Kelvin–Helmholtz instability gained scientific attention after observations at Venus by the spacecraft Pioneer Venus Orbiter gave rise to speculations that the instability contributes to the loss of planetary ions through the formation of plasma clouds. Since then, a handful of studies were devoted to the Kelvin–Helmholtz instability at the ionopause and its implications for Venus. The aim of this study is to investigate the stability of the two instability-relevant boundary layers around Venus: the induced magnetopause and the ionopause. We solve the 2D magnetohydrodynamic equations with the total variation diminishing Lax–Friedrichs algorithm and perform simulation runs with different initial conditions representing the situation at the boundary layers around Venus. Our results show that the Kelvin–Helmholtz instability does not seem to be able to reach its nonlinear vortex phase at the ionopause due to the very effective stabilizing effect of a large density jump across this boundary layer. This seems also to be true for the induced magnetopause for low solar activity. During high solar activity, however, there could occur conditions at the induced magnetopause which are in favour of the nonlinear evolution of the instability. For this situation, we estimated roughly a growth rate for planetary oxygen ions of about 7.6 × 1025 s−1, which should be regarded as an upper limit for loss due to the Kelvin–Helmholtz instability. 相似文献
178.
179.