全文获取类型
收费全文 | 377篇 |
免费 | 20篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 7篇 |
大气科学 | 35篇 |
地球物理 | 98篇 |
地质学 | 114篇 |
海洋学 | 82篇 |
天文学 | 61篇 |
自然地理 | 4篇 |
出版年
2021年 | 6篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 7篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 21篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 19篇 |
2009年 | 11篇 |
2008年 | 20篇 |
2007年 | 14篇 |
2006年 | 15篇 |
2005年 | 14篇 |
2004年 | 22篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 8篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 7篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有401条查询结果,搜索用时 250 毫秒
1.
2.
3.
Dr. M. Shimizu Dr. C. J. Stanley Dr. A. J. Criddle Dr. A. Kato Dr. S. Matsubara 《Mineralogy and Petrology》1991,45(1):11-17
Summary New compositional and optical data are reported for antimonian and antimonianbismuthian varieties of hemusite from epithermal Au-Ag-Cu deposits in Japan. The empirical formula for the antimonian variety, from the Iriki mine is: (Cu5.83Fe0.14Ag0.01)5.98Mo1.03(Sn0.54Sb0.41Te0.03Bi0.02)1.00(S7.85Se0.15)8.00, and that of the Sb-Bi variety from the Kawazu mine is: (Cu5.84Fe0.14Ag0.01)5.99Mo1.03(Sn0.82Sb0.11Bi0.l0Te0.04)1.07(S7.80Se0.12)7.92. The theoretical formula of hemusite is Cu+
4Cu2+
2MO4+Sn4+S8, whilst the most probable formula of the Iriki hemusite is Cu+
4.5CU2+
1.5Mo4+Sn4+
0.5Sb5+
0.5S8, with Sb5+ substituting for Sn4+ and forming (SbS4)3– tetrahedra as might be expected, given that the metal to sulphur ratio is 1, and given the sphalerite-like structure of the mineral. However Bi3+ cannot be so accommodated, resulting in a deficiency in (S + Se) for Kawazu hemusite. Reflectance spectra for both are compared with those of the tungsten analogue (compositional) of hemusite, kiddcreekite. The relationship between hemusitesensu stricto and these newly reported varieties is discussed in terms of simple and coupled chemical substitutions, and inferences are drawn on the valency of Sb, Bi, Mo and Cu in the hemusite structure.
Neue chemische und optische Daten für antimon- und bismuthführende Varietäten von Hemusit aus Japan
Zusammenfassung Neue chemische und optische Daten für antimon- und bismuthführende Hemusite auf epithermalen Au-Ag-Cu Lagerstätten in Japan werden vorgelegt. Die empirische Formel für die antimon-führende Varietät aus der Iriki-Mine ist: (Cu5.83Fe0.14Ag0.01)5.98Mo1.03(Sn0.54Sb0.41Te0.03Bi0.02)1.00 (S7.85Se0.15)8.00, und die der Sb-Bi Varietät aus der Kawazu Mine ist: (Cu5.84Fe0.14Ag0.01)5.99M01.03(Sn0.82Sb0.11Bi0.l0Te0.04)1.07 (S7.80Se0.12)7.92. Die theoretische Formel von Hemusit ist Cu+ 4Cu2+ 2Mo4+Sn4+S8, während die wahrscheinlichere Formel für den Hemusit von Iriki Cu+ 4Cu2+ 1.5Mo4+Sn4+ 0.5Sb5+ 0.5S8, mit Sb5+ an der Stelle von Sn4+, das(SbS4)3– Tetraeder bildet, wie zu erwarten ist, unter der Voraussetzung, da das Metall zu Schwefelverhältnis 1 und die Struktur sphaleritähnlich ist. Bi3+ kann jedoch nicht in dieser Weise untergebracht werden, und das führt zu einem Mangel an (S + Se) für den Hemusit von Kawazu. Die Reflektions-Spektren beider Minerale werden mit denen des Wolfram-Equivalents von Hemusit (Kiddcreekit) verglichen. Die Beziehung zwischen Hemusitsensu stricto und diesen jetzt beschriebenen Varietäten wird auf der Basis einfacher und gekoppelter chemischer Substitution diskutiert. Auf dieser Basis werden Schlüsse auf die Valenz von Sb, Bi Mo und Cu in der Hemusit-Struktur gezogen.相似文献
4.
Mauro Lo Cascio Yan Liang Nobumichi Shimizu Paul C. Hess 《Contributions to Mineralogy and Petrology》2008,156(1):87-102
The grain-scale processes of peridotite melting were examined at 1,340°C and 1.5 GPa using reaction couples formed by juxtaposing
pre-synthesized clinopyroxenite against pre-synthesized orthopyroxenite or harzburgite in graphite and platinum-lined molybdenum
capsules. Reaction between the clinopyroxene and orthopyroxene-rich aggregates produces a melt-enriched, orthopyroxene-free,
olivine + clinopyroxene reactive boundary layer. Major and trace element abundance in clinopyroxene vary systematically across
the reactive boundary layer with compositional trends similar to the published clinopyroxene core-to-rim compositional variations
in the bulk lherzolite partial melting studies conducted at similar P–T conditions. The growth of the reactive boundary layer takes place at the expense of the orthopyroxenite or harzburgite and
is consistent with grain-scale processes that involve dissolution, precipitation, reprecipitation, and diffusive exchange
between the interstitial melt and surrounding crystals. An important consequence of dissolution–reprecipitation during crystal-melt
interaction is the dramatic decrease in diffusive reequilibration time between coexisting minerals and melt. This effect is
especially important for high charged, slow diffusing cations during peridotite melting and melt-rock reaction. Apparent clinopyroxene-melt
partition coefficients for REE, Sr, Y, Ti, and Zr, measured from reprecipitated clinopyroxene and coexisting melt in the reactive
boundary layer, approach their equilibrium values reported in the literature. Disequilibrium melting models based on volume
diffusion in solid limited mechanism are likely to significantly underestimate the rates at which major and trace elements
in residual minerals reequilibrate with their surrounding melt.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Yuhei Yamamoto Yoshio Takahashi Yutaka Kanai Yoshio Watanabe Tomoya Uruga Hajime Tanida Yasuko Terada Hiroshi Shimizu 《Applied Geochemistry》2008,23(8):2452-2461
The uranium LIII-edge XANES spectra for natural rocks at the concentration range of 0.96–124 mg kg−1 were measured using a log spiral bent crystal Laue analyzer (BCLA) combined with a multi-element Ge detector. It was found that the quality of the XANES spectra using the BCLA was greatly improved due to a reduction of interfering fluorescence from major components such as Rb and Sr. The ratio of signal to background intensities in the U LIII-edge XANES spectra increased by a factor of 2.9–17 with the use of the BCLA, which greatly enhanced the detection limit for the speciation of the oxidation states of U or the U(IV)/U(VI) ratio of natural samples. In addition, it was demonstrated that the fluorescence XANES method coupled with the BCLA enable determination of the speciation of U for various natural samples such as acidic igneous rocks, ferromanganese nodules, sediments, and some sedimentary rocks such as shale and limestone. 相似文献
6.
Mihoko Hoshino Mitsuyoshi Kimata Norimasa Nishida Masahiro Shimizu 《Physics and Chemistry of Minerals》2008,35(2):59-70
Dissakisites from Trimouns dolomite mine, France, have two kinds of single crystals: chemical-zoned and homogeneous types.
Back-scattered electron microprobe (BSE) images of these dissakisites reveal both Ca–Al rich dark zones and Fe-ΣREE rich bright
zones. Crystal structures of three dark and two bright zones in a chemical-zoned dissakisite and of a homogeneous zone in
unzoned dissakisite were refined to individual R indices (about 3.0–5.0%) based on 1,400 observed [|F
0| > 4σF
0] reflections measured with MoKα X-radiation using the single crystal diffractometer. The differences in brightness between
their BSE images arise from those in coupled substitutions of the elements occupying A2 and M3 sites. The main reason for
these differences is that ten-coordinated A2 polyhedra and M3 octahedra are directly linked through their shared edge, which
creates a great potential for making this coupled substitution. This zoning indicates that formation of the whole zoned crystal,
where each zone could be grown steadily with its crystallographic axes mutually parallel to each other, may be identified
as autoepitaxy. 相似文献
7.
The study of the Kuroshio in the East China Sea and the currents east of the Ryukyu Islands 总被引:3,自引:0,他引:3
In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and i 相似文献
8.
Horiguchi T Li Z Uno S Shimizu M Shiraishi H Morita M Thompson JA Levings CD 《Marine environmental research》2004,57(1-2):75-88
Gastropods and bivalves were collected at 15 sites at Vancouver and Victoria, Canada between 24 May and 7 June, 1999, to establish tissue concentrations of butyltin and phenyltin compounds, to record imposex symptoms in gastropods, and to assess the present status of organotin contamination around Vancouver. No neogastropods (such as Nucella lima) were found around Vancouver. Neogastropod populations could have been extirpated by severe TBT contamination in Vancouver, as relatively high concentrations of TBT were detected in tissues of Mytilus trossulus from Vancouver, and the neogastropods distributed in Vancouver might be sensitive to TBT. Recovery from imposex, however, was observed in neogastropod populations from three sites at Victoria and Mission Point. TBT contamination has continued around Vancouver, arising from continuous use of TBT in antifouling paints for vessels larger than 25 m in length; however, TBT has decreased around Victoria and Mission Point. Different patterns of TBT accumulation in tissue were observed among the bivalve species from Vancouver. The highest TBT concentration detected in Tresus capax suggested some possible adverse effects. TBT was the most predominant butyltin component in almost all bivalve specimens surveyed, suggesting a low rate of TBT metabolism. Phenyltin compounds were not detected in any molluscan specimens in this study. 相似文献
9.
Masahiro Endoh 《Journal of Oceanography》1975,31(1):51-52
It is shown by a numerical experiment with fine grid that the finite difference form of rotation of the Coriolis force used in ENDOH (1973) gives practically the same solution as that obtained by the use of the finite difference form pointed out byTakano (1974). 相似文献
10.