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41.
针对矿业权核查单矿权成果数据具有文件小、数量多、异构、多源等特点,为了有效地存储这些数据到Oracle数据库中,实现快速提取及显示,并能够将一个矿业权的提取时长控制在1秒以内,本文给出了从建立数据库实体到查询、显示过程所涉及诸多问题的一个完整的优化方案。首先建立了一个完整的、科学的数据存储模型,并采用范围-列表分区模式对大型表进行分区,同时采用通过调整Oracle系统高速缓冲区、减少表连接、优化SQL查询语句、在客户端分页显示查询结果等优化方案,有效提升表中数据的查询速度,以达到优化目的。 相似文献
42.
缅甸联邦实皆省MTT金铜矿床位于曼德勒以西约200km新生代安山岩中,属块状硫化物金铜矿床。对其成矿地质特征进行了研究,有助于在新生代安山岩中发现相同类型的矿床。矿体产在缅甸中部盆地地体之西缘,赋矿地层(即含矿岩系)为陆相安山岩,硫化物矿体呈层状、似层状和透镜体状。矿石具块状构造,矿石中主要成矿元素为Cu、Au、S;铜矿石品位较高,属富铜矿。该类型矿床的找矿标志是:具有低阻高极化的物探异常。 相似文献
43.
芒亨河断裂的次级断裂是主要控矿构造,含矿围岩为上三叠统小定西组(T3xd)富钠质安山岩、玄武岩。受构造、层位、碎屑粒度的制约。 相似文献
44.
Zhen Tao Quanzhou Gao Wenping Guo Zhengang Wang Yongling Zhang Chenji Xie Xiakun Huang Hongwei Zhong 《山地科学学报》2011,8(5):694-703
A whole year analysis of riverine dissolved organic carbon (DOC) concentrations in the Xijiang River (XJR), South China, showed that the mean riverine DOC concentration (1.24 mg L-1) in the XJR was notably lower than the averaged value (5.75 mg L-1) of the global riverine DOC concentration in several major rivers. There is an inconspicuous monthly fluctuation of the DOC signal in the XJR, but on a semi-yearly time scale, however, the riverine DOC concentration had significant difference between hydrological... 相似文献
45.
M. L. Fiorentini S. W. Beresford B. Grguric S. J. Barnes W. E. Stone 《Australian Journal of Earth Sciences》2013,60(6):801-824
A new style of komatiite-associated sulfide-poor platinum-group element (PGE: Os, Ir, Ru, Rh, Pt, Pd) mineralisation has been identified at Wiluna in the strongly nickel sulfide (NiS) mineralised Agnew – Wiluna Greenstone Belt, Western Australia. The komatiite sequence at Wiluna is ~200 m thick and comprises a basal pyroxenite layer, a thick ortho-to-mesocumulate-textured peridotite core, which is overlain by rhythmically layered wehrlite, oikocrystic pyroxenite and thick upper gabbroic margins. Pegmatoid and dendritic (harrisitic) domains are common features, whereas spinifex-textured horizons and flow-top breccias are absent. The presence of anomalous PGE-enriched horizons (ΣPt – Pd = 200 – 500 ppb) in the oikocrystic pyroxenite and in the layered melagabbro and gabbronorite horizons directly overlying the wehrlite unit is due to the presence of fine-grained (1 – 10 μm) platinum-group minerals (PGMs). More than 70 PGM grains were identified, and a considerable mineralogical variability was constrained. However, only Pd – Pt-bearing phases were identified, whereas no Ir – Ru-bearing PGMs were found in any of the sections examined. Interestingly, all PGMs are not in paragenetic association with sulfides, and only sulfide-poor/free intervals contain significant PGM concentrations. The whole-rock PGE sequence largely reflects the PGM distribution. It is hypothesised that the Pd – Pt enrichment in the oikocrystic pyroxenite and melagabbros and the overall Ir – Ru depletion in the upper mafic section of the sequence are the result of extensive olivine and chromite crystallisation in the basal ultramafic section. PGE saturation was driven by extensive crystallisation of silicate and oxide phases in a sulfide-undersaturated environment. The crystallisation of clinopyroxene in the oikocrystic pyroxenite horizon may have triggered the formation of Pt – Pd-bearing alloys and arsenides, which were the first PGMs to form. Stratiform sulfide-poor PGE mineralisation at Wiluna is more similar in stratigraphic setting, style and composition to PGE-rich sulfide-poor mineralisation zones in thick differentiated intrusions, rather than to other PGE-enriched zones in komatiite-hosted systems, where PGE enrichment is directly associated with accumulations of magmatic sulfides. 相似文献
46.
Experimental Study of Gold and Platinum Solubility in a Complex Fluid under Hydrothermal Conditions 总被引:2,自引:0,他引:2
Abstract: The solubility of gold was studied in water and aqueous NaCl (1– 5 m) solutions under oxygen and sulfur buffered conditions between 300–500C at a constant pressure 1 kb. Two buffer assemblages HMP and PPM were used. Analysis of the scatter in measured values in log mAu–mNaCl–T frame fixed linear dependence between log mAu and T at any studied iso‐pleth (mNaCl) in the form of log mAu = a. T(C) + b. Coefficients of the equation were calculated for water and NaCl (1, 3, 5 m) solutions. The maximum solubility characterizes the NaCl‐free system in the presence of HMP. In the case, Au solubility increases from (log mAu) –6. 72 to –5. 04 at 300 and 500C, respectively. In the presence of PPM, maximum of Au solubility was obtained for the 5 mNaCl solution. In a similar manner solubility rises from –6. 54 to –5. 77 at 300 and 500C, accordingly. In studied fO2/fS2 area the behavior of Au solubility testified that: (i) – a composite interaction between chloride and hydrosulfide speciation of gold affects its total solubility; (ii) – in addition of NaCl up to about 1. 5 m the solubility decreases, more pronounced in the presence of HMP; (iii) – the contribution of chloride in total Au solubility is more for PPM despite of lower fO2value, than for HMP. The solubility of platinum was studied in the Pt–Cl–S–H2O system between 300 and 500C, 1 kb. PPM solid buffer controlled oxidation state, pH and sulfur activity of solutions (H2O, 1 mNaCl and 0. 1 mHCl). Under the conditions, PtS precipitated from the solutions with increasing temperature and acidity. The PtS solubility in the 0. 1 mHCl solutions lowers slightly in the range of 300–500C from –5. 30 to –5. 60 (in log mPt) that is typical to the hydrosulfide species. It was deduced that reducing media, regulated by the PPM assemblage, suppress activity of chloride species of Pt. More oxidizing conditions were modeled in runs using mixtures of Mn(II), Mn(III) and Mn(IV) oxides to buffer the aqueous‐chloride solutions between 300 and 500C, 1 kb. It was found that MnO tends to oxidize at T below 400C forming intermediate Mn‐hydroxides (β–MnOOH, Mn (OH)2 and Mn2(OH)3Cl). These phases are metastable and transfer to Mn3O4 with increasing duration. Generation of the Mn‐hydroxides leads to a change of physical‐chemical parameters of the solutions, such as water activity, pH and Eh. The last results in abrupt increase in the noble metals dissolution. At stable existence of only Mn3O4, the solubility of both Pt and Au lowers to equilibrium values. Essential catalysis effect of Pt on intensity and rate of Mn(II) oxidation was found. The dominant role of chloride of Pt and Au was defined under most oxidized conditions, specified by Mn2O3–MnO2 buffer. So at 400C, dissolved Au (log mAu) increases from –4. 40 in water to –1. 00 in 0. 1 mHCl, and ones of Pt (log mPt) from –4. 80 to –2. 90 accordingly. Thus, mixing of hydrosulfide and chloride solutions, as well as transformation of the systems to the stable state act upon total solubility of the noble metals. 相似文献
47.
Rio Tinto estuary (Spain): 5000 years of pollution 总被引:6,自引:0,他引:6
R.A. Davis Jr. A. T. Welty J. Borrego J. A. Morales J. G. Pendon J. G. Ryan 《Environmental Geology》2000,39(10):1107-1116
Mining of massive sulfide deposits in southwestern Spain extending back to the Copper and Bronze Ages has resulted in the
pollution of the Rio Tinto fluvial-estuarine complex, the site of Columbus' departure for the New World in 1492. Additional
sources of potential pollution include the large industrial complex at Huelva near the lower portion of the estuary. Extensive
analysis of surface sediment samples and cores has established that there are no geographic trends in the distribution of
the pollutants, which include Cu, Fe, Pb, Zn, Ti, Ba, Cr, V and Co. These data have, however, demonstrated that tidal flux
within the estuary carries phosphorus and perhaps other elements from the industrial complex at Huelva to the tidal limit
of the system, several kilometers upstream from the discharge site. Radiometric analysis of short cores shows that sedimentation
rates over at least the past couple of centuries have been about 0.3 cm/year. These data and that from a single deep core
demonstrate that the estuary was polluted from mining activity long before the large-scale operations began in the late nineteenth
century.
Received: 3 May 1999 · Accepted: 18 October 1999 相似文献
48.
辽北太古宙由花岗岩-绿岩带组成。绿岩生成于岛弧构造环境,时间在3.0—2.8Ga,火山岩属拉斑玄武质及钙碱性火山岩。花岗岩在绿岩之后侵入,具多旋回特点。块状硫化物矿床与长英质火山岩有关,具有2—3含矿层位,透镜状矿体数目较多,未发现管状细脉带。矿石中Cu>Zn>>Pb,具有明显贫铅的特点,Cu×100/Cu+Zn为88—25。矿床类型属活火山型火山热液矿床。成矿温度为350—250℃,压力为9.5—4.0MPa,fo_2为10~(-30)-10~(-44)Pa,fs_2为2.57×10~(-9)-8.13×10~(-14)Pa,pH值为4.5—5。共生有阿尔戈马型铁矿与火山成因金矿。块状硫化物矿床遭受变质、变形、伟晶岩的改造,并在主褶皱幕期迭生与基性岩有关的热液多金属矿化。 相似文献
49.
More than 200 analyses of the sulfur isotopic composition of sulfides from various terrigenous and intrusive host rocks, metasomatically altered wall rocks, and gold lodes of the Upper Kolyma region are presented. In accessory pyrite of the metaterrigenous rocks, δ34S varies from ?23.1 to +5.7‰ δ34S of pyrite and arsenopyrite from gold-quartz mineralization is within the range ?10.6 to ?0.4‰ and is close to the average δ34S of pyrite from the metaterrigenous rocks (?4.4‰). In the intrusive rocks, δ34S of pyrite varies from ?3.8 to +2.6‰ (+0.7‰, on average) and drastically differs from δ34S of arsenopyrite from postmagmatic gold-rare-metal mineralization (?7.9 to ?2.7‰; ?5.2‰, on average). The comparison of the δ34S of accessory sulfides from the host rocks with δ34S of sulfides from the gold deposits suggests that sulfur mobilized from the terrigenous sequences participated in the hydrothermal process. The results obtained are consistent with the metamorphic model of the formation of gold-quartz deposits in the Upper Kolyma region. 相似文献
50.