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631.
632.
矿业开采诱发的地质环境负效应及综合治理工程 总被引:2,自引:1,他引:2
采矿必然扰动环境,诱发各种各样的地质环境负效应;西方发达国家已实行了矿山环境保护和治理工作;中国作为发展中国家,矿山环境综合治理工程对我国矿产资源的可持续开发具有重要意义。 相似文献
633.
Geochemical Characteristics of a Veinlet Kupferschiefer Profile from the Lubin Mine, Southwestern Poland 总被引:3,自引:0,他引:3
Previous studies have shown that the ascending, oxidizing brines play a very important role in Kupferschiefer mineralization. Fractures could be the pathway of the brines. In order to clarify the influences of the brines on bulk organic matter, aromatic hydrocarbons and Kupferschiefer mineralization, one veinlet Kupferschiefer profile from the Lubin mine, southwestern Poland was studied with the microscopic, geochemical and Rock-Eval methods. The microscopic results indicate that organic matter of the veinlet sample consists dominantly of bitumen. Its extract content is higher than in other samples. The dominant aromatic compounds are naphthalene and alkylated naphthalenes (Na-PAH), which have migrated into the veinlet sample from other sediments. The content of phenanthrene and its methylated derivatives (Ph-PAH) is much lower than in other samples. The reason may be due to their heavier mass than Na-PAH. It is more difficult for Ph-PAH to migrate. The Na-PAH was probably removed from the shale by dist 相似文献
634.
Abstract: As a part of the main activities of Japan‐China technical cooperation project, a test survey area, approximately 5,000 km2, was established for the implement of its geological and geochemical research program. A major mineralization zone called Huanggang–Ganzhuermiao–Wulanhaote Sn‐Cu polymetallic mineralization zone is recognized in the southern Da Hinggan Mountains area. The southern half of this zone is known as the sole Sn‐mineralization zone in North China. The survey area lies in this prominent zone. As the most of the papers presented in this issue have concerns to the geology and mineralization in this survey area, this report was prepared to introduce geo‐tectonic situation of the Sn‐Cu polymetallic mineralization zone in the Inner Mongolia orogenic belt. The belt is divided into four tectonic facies (from NW to SE); I: Wuliyasitai volcano‐plutonic zone, II: Hegenshan ophiolite mélange zone, III: Sunitezuoqi volcano‐plutonic zone, IV: Wenduermiao ophiolite mélange zone. The subject Sn‐Cu polymetallic mineralization zone is situated in the southeastern part of the Sunitezuoqi magmatic zone. About this Sunitezuoqi magmatic zone, three geo‐tectonic characteristics are pointed out. In late Carboniferous to early Permian period, subduction of Hegenshan oceanic crust occurred, which accelerated volcano‐plutonic activities and brought about basic to intermediate volcanic rocks of tholeiitic to calc‐alkaline series represented by Dashizhai Group in the Sunitezuoqi magmatic zone. Late Jurassic to early Cretaceous acidic rocks representing the most culminated volcanism and plutonism in Mesozoic era in the Da Hinggan Moutains area are distributed very extensively in and around the Sn‐Cu polymetallic mineralization zone. The Proterozoic metamorphic basement rocks called Xilinhaote complex are distributed close to the mineralized area in the Sunitezuoqi magmatic zone. Although the real mineralization was known associated with Mesozoic acidic to intermediate volcano‐plutonic activities, it is thought that the lower Permian Dashizhai volcanic rocks and pre‐Cambrian basement rocks might have played certain significant role in the process respectively of extraction of elements and formation of the magma favorable for such mineralization in the Sunitezuoqi magmatic zone. It would be necessary to give further considerations to these three geological units in relation to the Sn‐Cu polymetallic mineralization. 相似文献
635.
Generation and Evolution of Ore Fluids for Porphyry Cu-Au Mineralization of the Santo Tomas II (Philex) Deposit, Philippines 总被引:1,自引:0,他引:1
Akira IMAI 《Resource Geology》2001,51(2):71-96
Abstract: The Santo Tomas II (Philex) deposit is a porphyry Cu‐Au deposit, located in the southern part of the Baguio mineral district, Benguet Province, northern Luzon, Philippines. The Santo Tomas II deposit is associated with an intrusive complex consisting of four rock types that are distinguished based on petrography. They are 1) post‐ore clinopyroxene‐bearing hornblende andesite porphyry, 2) ore‐generating hornblende andesite porphyry, 3) hornblende quartz diorite porphyry and 4) porphyritic hornblende quartz diorite. K‐Ar age of hydrothermal biotitization was estimated to be 1.5±0.4 Ma. A number of intrusive bodies having broadly similar petrography and K‐Ar age occur in the vicinity of the Santo Tomas II deposit, such as at Clifton, Ligay (Binang), Bumolo (Waterhole) and Philex Main Camp areas. The intrusions at the Santo Tomas II deposit and in the vicinity are characterized by high XMg (Mg/[Mg+Fe] atomic ratio, about 0.7 or higher) of mafic silicate phenocrysts such as hornblende, and high sulfur contents (> 0.2 wt% as SO3) in accessory microphenocrystic apatite, suggesting a highly oxidizing condition. Sulfur is accommodated dominantly as oxidized species since the crystallization of phe‐nocrysts. Sub‐dendritic rim of tremolitic amphibole on hornblende phenocryst in the ore‐generating andesite porphyry at the Santo Tomas II deposit suggests interaction of magma and aqueous fluid(s) exsolved due to decompression during intrusion. Dissemination of magnetite is associated with hydrothermal biotitization and is followed by sheeted and stockwork quartz veinlets having silician magnetite and rare titanohematite instead of Cu‐Fe sulfides. The silician magnetite‐rich quartz veinlet was formed at fO2 near the hematite‐magnetite buffer at nearly magmatic temperature, where sulfur dominantly existed as oxidized species such as SO2. Chalcopyrite and bornite, which commonly exhibit micrographic texture often accompanying Pd telluride and native gold/Au‐rich electrum, are associated with subsequent anhydrite (‐quartz) veinlets and stringers. Both intermediate solid solution (iss) and bornite solid solution (bnss) are thought to have coprecipitated primarily at above 500°C based on fluid inclusion microthermometry and sulfur isotope thermometry applied for anhydrite and associated chal‐copyrite and bornite. The initial iss is considered to have converted to chalcopyrite partly replacing bnss during cooling. The hypersaline polyphase fluid inclusions abundantly found in the sheeted and stockwork quartz as well as anhydrite veinlets with scarce gaseous inclusions suggest that they have been trapped in the two aqueous fluid immiscible region. The western Luzon arc associated with porphyry Cu mineralization is characterized by oxidized hydrous magmatism and shallow emplacement, and by the source of sulfur enriched in 34S. 相似文献
636.
Open cast mining of lignite leads to dumps containing highly mineralised pore waters. To predict the impact of the dump waters on the undisturbed aquifers two steps are necessary. (1) The prediction of dump water quality at times when steady state flow conditions will be established. (2) The simulation of the dump ground water migration with a model that is able to handle the complexity of the homogeneous and heterogeneous interactions of the migration process.For the investigated site Jänschwalde, which is still dewatered, a chemical mass balance was performed. The predicted alkalinity potentials exceed acidity potentials for the dump as a whole. The distribution of these parameters show high alkalinity potentials for the northern part.In order to model the migration process the transport code PCGEOFIM® [Anwenderdokumentaion, IBGW Leipzig, (in German)] was coupled with the geochemical equilibrium code PHREEQC [USGS, Water-Resources Investigations Report]. This was done to simulate redox reactions, mineral dissolution and precipitation, and cation exchange in the ground water zone. The model is verified by a column flow test. The results of the simulations show a small effect of the migrating dump waters on the quartenary aquifer with respect to acidity changes. This results from calcite buffering and cation exchange. The impact on the quartenary aquifer by sulphate is much higher. 相似文献
637.
甘肃马泉金矿二十号矿带地质特征 总被引:5,自引:0,他引:5
通过对二十号矿带与矿床主体三、四号矿带地质特征的对比和ZK4 0 1孔伴生元素特征的研究 ,认为二十号矿带是四号矿带东延部分 ,其露头位于矿体头部附近。预测在二十号矿带180 0m标高以下一定还有较大盲矿体存在。 相似文献
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