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1.
The study of Mg isotopes has been carried out for about 40 years since 1970 s. With analytical progress, the study is not only limited to the excess of 26Mg due to decay of short-lived 26Al in primitive meteorites, also extended to mass-dependent fractionation of Mg isotopes in meteorites and terrestrial rocks. This paper reviews recent development in Mg isotope researches.  相似文献   
2.
南极格罗夫山100块陨石的矿物-岩石学特征   总被引:2,自引:2,他引:0       下载免费PDF全文
本文主要报道了南极格罗夫山新回收的100块陨石的岩石学和矿物化学特征。并根据矿物-岩石学特征,划分了它们的化学-岩石类型:6块属于非平衡型普通球粒陨石(H3和L3群各3块);92块属于平衡型普通球粒陨石,包括:H群24块(13块H4,10块H5,1块H6),L群64块(2块L4,44块L5,18块L6),LL群4块(3块LL4,1块LL5);另外两块属于石-铁陨石。6块非平衡型普通球粒陨石保存了原始的岩石学和矿物化学特征,包括:清晰的球粒结构、橄榄石和低钙辉石具有明显的成分环带以及极不均一的化学组成等。92块平衡型普通球粒陨石中的橄榄石和低钙辉石显示出均一的化学组成,表明它们达到了一定的热力学平衡。这些普通球粒陨石受到的风化作用以W1和W2为主,所占比例高于90%,表明南极陨石受到的风化作用不强烈。有约40%的陨石样品受到了强烈的冲击作用,并产生冲击脉或者冲击囊,它们是研究高压冲击矿物和冲击作用的理想样品。  相似文献   
3.
Meteorites are the extraterrestrial rocks, which provide insights into the origin and evolution of the solar system. During the past half century, a great number of meteorites has been discovered on the Antarctic Ice Sheet, confirming that the Antarctica is the most important meteorite concentration area on the earth. Since the first four Antarctic meteorites were found in Grove Mountains in 1998, a total of 9834 meteorites have been collected by four subsequent expeditions. It opens a new field of meteorite study in China, and also accumulates a great deal of scientific samples for China. Recently, classification of Grove Mountains meteorites has been carried out for 6 years, and made following progresses: (1) 2433 meteorites, which include many special meteorites, e.g. Martian meteorites, ureilites and carbonaceous chondrites, have been classified. (2) the Antarctic meteorite curation and the sample sharing system are set up preliminarily. (3) the classification procedure, the management of meteorite samples, and the application procedure for the Antarctic meteorites are completed after the systematic classification during these years. (4) young generation researchers on meteorite are trained through the cooperation of many universities and institutes on meteorite classification.  相似文献   
4.
不同球粒陨石群的物理和岩石学性质,包括球粒的平均大小、球粒结构类型、复合球粒、带火成边球粒及含硫化物的比例、化学组成及矿物学特征等可用以划分球粒陨石的化学-岩石类型和小行星类型,这些性质提供了不同球粒陨石群有用的分类参数及其形成环境的信息.由于不同球粒陨石群的△17O与日心距离存在有相关关系,因此,依据不同球粒陨石群形...  相似文献   
5.
王桂琴  王道德  杨晶 《极地研究》2011,23(4):328-337
Cr同位素作为一个新的研究手段,在天体化学领域中主要应用于追溯太阳系早期历史演化和定年.Cr同位素组成测定的主要技术是二次离子探针、热电离质谱和多接收等离子质谱,本文对这些分析技术的特点和发展作了论述.随着分析技术的发展,目前对ε(53Cr)和ε(54Cr)测定精度分别达到6 ppm和12 ppm(2σ).高精度Cr同...  相似文献   
6.
Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evolution of terrestrial planets. A new meteorite-rich region, Grove Mountains (GRV), was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of olivine. GRV 052382 probably experienced heavy shock metamorphism followed by fast cooling, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and are classified into subtype II (with medium FeO content, Fa15-18) and subtype I (with high FeO content, Fa>18) based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.  相似文献   
7.
Progress in study of Chinese Antarctic Meteorites   总被引:1,自引:0,他引:1  
This paper reviews and summarizes the Chinese Antarctica meteorite search, classification and research. During the past four antarctic explorations, a total of 9834 meteorites were collected in the Grove Mountains region. Among them, 2431 meteorites were classified by the end of 2008. So far, 684 meteorites have been officially published in the Meteoritical Bulletin, Meteoritical Society, including 2 martian meteorites, 2 eucrites, 6 ureilites, 5 mesosiderites, 1 pallasite, 1 iron and 10 carbonaceous chondrites. Comprehensive studies were carried out on a number of these rare type meteorites. In addition, we propose to continue the meteorite searching project in Grove Mountains and other regions in Antarctica. We also suggest several key topics of the future researches on the Chinese Antarctic meteorites.  相似文献   
8.
Petrography and mineral chemistry of four carbonaceous chondrites (GRV 020017, GRV 020025, GRV 021579, GRV 022459) collected from the Grove Mountains (GRV), Antarctica, were reported here. All four chondrites are unequilibrated, as indicated by well shaped chondrules and the chemical variations of olivine and low-Ca pyroxene. The modal abundance ratio of matrix/chondrule are 2(GRV 020017), 2.8(GRV 020025), 1.2(GRV 021579), 1(GRV 022459). GRV 022459 has the largest chondrules(0.6-2.0mm). A total of 30 Ca-Al-rich inclusions were found in the four meteorites. Most inclusions were highly altered, with abundant phyllosilicates in the inclusions of GRV 020017 and GRV 020025. On the base of petrography and mineral chemistry, these chondrites are classified as CM2 (GRV 020017 and 020025), CO3 (GRV 021579) and CV3 (GRV 022459).  相似文献   
9.
10.
缪秉魁  王道德 《极地研究》2008,20(2):95-104
陨石是来自地球之外的岩石样品,是研究太阳系的起源与演化的重要窗口。半个多世纪以来,国际上在南极冰盖上发现了大量陨石样品,证实了南极是地球上最重要的陨石富集区。1998年中国首次在格罗夫山地区发现南极陨石,经过4次南极考察,共收集陨石样品9834块。这不但填补了中国在该领域的空白,也为中国积累了大量珍贵的科学样品。目前,中国先后6年开展了陨石分类研究工作,并取得了显著进展:(1)完成了684块陨石的分类命名,其中发现了许多特殊类型陨石,如火星陨石、橄辉无球粒陨石、碳质球粒陨石等;(2)初步建立了陨石库和资源共享网络平台;(3)通过南极系统分类研究,建立了南极陨石分类程序、样品管理和申请程序;(4)通过国内陨石分类合作研究,培养了一批年轻专业人才。  相似文献   
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