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171.
Dr. J. J. Pamić 《Mineralogy and Petrology》1974,21(3-4):261-279
Summary Gabbros of two kinds, one related to dolerite and the other related to peridotite, are widespread in the Dinaride ophiolite zone. Gabbros within the Krivaja-Konjuh peridotite massif, along the Gostovii River and near Romanovac Mountain, exemplify the second kind. The gabbroic rocks range from feldspathic wehrlite and feldspathic dunite through troctolite and olivine gabbro to olivine-free gabbro, all of which are more or less serpentinized or uralitized.The gabbro is characterized by foliation and layering in which cumulus textures are well shown. Peridotite and gabbro intergrade and are interlayered, but in places feldspar seems to have been introduced metasomatically into peridotite along gabbro dikes. The gabbro masses, like their internal structures, parallel layering in the surrounding peridotite. Intrusive relations, however, are indicated by gabbro dikes in peridotite, and xenoliths of peridotite in gabbro. Absence of gabbro dikes in the surrounding Jurassic rocks shows that the gabbro was intruded into peridotite before both were emplaced tectonically.Chemically, the gabbros are typically alpine, with high ratios of CaO: Na2O, high MgO: FeO ratios, and low K2O and TiO2. Plots of chemical composition suggest a close affinity between gabbro and olivine tholeiite and olivine basalt.It is proposed that a primary magma of olivine tholeiite composition was produced by partial melting of the upper mantle material below an ancient Jurassic(?) Mid-oceanic ridge at a depth of 35 to 70 km. The melt was moved to higher levels and it was intruded into the peridotites moving upwards and crystallization began at a depth below 30 km. The trends of differentiation processes have been disscused in detail.
With 7 Figures 相似文献
Alpinotype Gabbros innerhalb des Ultramafit-Massivs von Krivaja-Konjuh in der Ophiolith-Zone der Dinariden, Jugoslawien
Zusammenfassung In der Ophiolith-Zone der Dinariden kommen verbreitet Gabbros zweierlei Art vor: die eine steht zu Doleriten in Beziehung, die andere zu Peridotiten. Gabbros innerhalb des Peridotit-Massivs von Krivaja-Konjuh, längs des Flusses Gostoviéi und nahe dem Berg Romanovac sind Beispiele für die zweite Art. Die gabbroiden Gesteine variieren von Feldspat-führenden Wehrliten und Feldspat-führenden Duniten über Troktolithe und Olivin-Gabbros bis zu Olivin-freiem Gabbro; sie sind alle mehr oder weniger serpentinisiert oder uralitisiert.Der Gabbro ist durch Faltung und Bänderung, in der Cumulus-Texturen gut erkennbar sind, charakterisiert. Peridotit und Gabbro gehen ineinander über und zeigen Wechsellagerung, aber an manchen Stellen scheint der Feldspat längs Gabbrogängen metasomatisch in den Peridotit eingedrungen zu sein. Die Gabbromassen liegen ebenso wie ihre internen Strukturen parallel zur Schichtung der umgebenden Periodotite. Gabbrogänge in Peridotit und Xenolithe von Peridotit in Gabbro zeigen indessen intrusive Beziehungen an. Die Abwesenheit von Gabbrogängen in den umgebenden jurassischen Gesteinen zeigt, daß der Gabbro in den Peridotit vor deren gemeinsamen tektonischen Platznahme intrudierte.Vom chemischen Standpunkt aus sind die Gabbros typisch alpin, mit großen (CaO: Na2O)- und (MgO: FeO)-Verhältnissen und kleinen TiO2-und K2O-Werten.Es wird vorgeschlagen, daß ein primäres Magma von olivintholeiitischer Zusammensetzung durch partielle Aufschmelzung von Material des Oberen Mantels unterhalb einer alten jurassischen(?) mittelozeanischen Schwelle in einer Tiefe von 35–70 km entstand. Die Schmelze wurde in höhere Niveaus bewegt und in die sich aufwärts bewegenden Peridotite intrudiert; die Kristallisation begann in einer Tiefe von unter 30 km. Die Tendenzen der Differentiationsprozesse werden im Detail diskutiert.
With 7 Figures 相似文献
172.
Variability and probability of annual and extreme precipitation over Serbia and Montenegro 总被引:1,自引:0,他引:1
Summary Annual precipitation over Serbia and Montenegro is studied in terms of its variability. The dependence of three selected absolute measures of variability (standard deviation, absolute mean deviation and mean absolute interannual variability) from the mean annual precipitation are examined for the area of interest. Two cases of extreme precipitation in Serbia were analysed using the gamma probability density function and some transformations. 相似文献
173.
The emission targets adopted in the Kyoto Protocol1 far exceed thelikely level of emissions from Russia and Ukraine. These countries could selltheir surplus if the Protocol is followedand industrialized countries establish an international emission tradingsystem. Critics have condemned the potentialsale and dubbed the surplus hot air because it does not represent anyreduction in emissions below the level thatwould have occurred anyway. Using the most recent, comprehensive regionalscenarios2 for the emissions of carbon dioxide from the energysystem, we estimate that during the Protocol's2008–2012 budget period the surplus will range from 9 MtC (milliontons of carbon) to 900 MtC for Russia andfrom 3 MtC to 200 MtC for Ukraine. Even scenarios with high economic growthand carbon-intensive technologies donot exhaust the surplus before the budget period. In the central (middlecourse) scenario, the total carbon surplusexceeds 1000 MtC and is worth 22 to 170 billion U.S. dollars (4 to 34 billionU.S. dollars per year). This flow ofrevenues, which could exceed Russian earnings from natural gas exports($10 billion in 19973), is comparable with the projectedtotal investmentsof the Russian energy system for 2008–2012. If directed towardslow-carbon infrastructure investments (e.g., gaspipelines), surplus transfers could reinforce and partially lock-indecarbonization of the world energy system. 相似文献
174.
175.
Lazar Lazić 《Meteorology and Atmospheric Physics》2000,75(1-2):121-130
Summary Following a recent approach of Fox-Rabinovitz an iterative Matsuno or a “Super-Matsuno” style scheme is applied as a filter
in the Eta Model. In contrast to Fox-Rabinovitz, we however apply the scheme not for all of the model’s time-differencing
but for its adjustment terms only. These distinctions compared to the original Fox-Rabinovitz’-method are made easy to implement
by the split time differencing approach of the Eta, and at the same time would appear clearly appropriate for the “initialization”
purpose. In addition, while Fox-Rabinovitz emphasizes the use of the method within a long time-scale data assimilation framework,
we are focusing on the impact of the method in a short-range forecasting environment/time-scale.
After a short one hour “initialization” procedure is completed, standard model integration is continued, now very much free
of noise. The Super-Matsuno style scheme is found to balance initially unbalanced external and internal modes and to significantly
reduce the high-frequency noise during the first 6 time steps. In a control case noise also reduces in amplitude as integration
proceeds, but at a much slower rate. The model integration results with and without “initialization” after 6 hours are however
very similar. Even so, it is to be expected that small differences, given that they have resulted from the removal of spurious
initial noise, have to be beneficial.
Received July 5, 1999/Revised January 11, 2000 相似文献
176.
In the southwestern Carpathians of SW Romania and E Serbia calc-alkaline Upper Cretaceous-Paleogene subduction related magmatic rocks occur in two main zones. The Ridanj-Krepoljin belt (E Serbia) represents the southern part of the western zone. In this belt Early Maastrichtian dacites and subordinate andesites occur, but there are indications of an unexposed granodioritic (?) magmatism about 60 Ma old. Pb-Zn-Ag and only subordinate Cu mineralization is associated with this igneous activity. The Timok magmatic complex (E Serbia) composed of Upper Cretaceous (-Paleocene?) andesites and analogue intrusives represents the eastern zone south of the Danube. Associated with this magmatism are Cu (+Au) and very subordinate Zn (±Pb) mineralization. To the north (SW Romania) in both zones mainly intrusive bodies (diorites, quartz diorites, granodiorites, monzonites) of Campanian-Paleocene age are exposed. Porphyry copper (+Mo) and in north Pb-Zn (±Cu) mineralization are related to those intrusives. The petrological and geochemical features of all these calc-alkaline rocks are very similar. It appears, however, that the associated polymetallic and the copper mineralization are both spatially and vertically separated. 相似文献
177.
Heat wave risk assessment and mapping in urban areas: case study for a midsized Central European city,Novi Sad (Serbia) 总被引:1,自引:0,他引:1
Stevan Savić Vladimir Marković Ivan Šećerov Dragoslav Pavić Daniela Arsenović Dragan Milošević Dragan Dolinaj Imre Nagy Milana Pantelić 《Natural Hazards》2018,91(3):891-911
Risk assessment and mapping methodologies for heat waves as frequently occurring hazards in central and southeastern Europe were applied in this study, and the impact of heat waves on the mortality of urban populations was determined as part of the assessment. The methodology for conducting the heat wave risk assessment is based on European Commission’s Guidelines for Risk Assessment and Mapping. The Novi Sad (Serbia) urban area was studied during summer 2015, which was one of the hottest summers in the last few decades. In situ air temperature measurements from urban stations and mortality of urban populations were used. Nocturnal urban heat island (UHI) intensity values between the various built-up zones and natural surrounding areas were used for the hazard level calculation. Temperature data from 9 p.m. to 5 a.m. were used because during the night, the UHI intensity reached its maximum values. The average daily number of deaths by LCZs was used to define the impact level of the vulnerability index. Calculations for both hazard levels were completed during two intensive heat waves (in July and August 2015) when it was expected that there may be a high level of risk. The results and maps show that the urban area is complex, and the heat wave risk on the population is not uniform. The most densely built-up areas (LCZs 2, 5 and 6) have very high or high risk values that are influenced by a higher rate of mortality. The obtained results and maps can be used by local authorities to prevent and mitigate climate-related hazards, for medical institutions as well as urban planners and for ancillary local, regional or national services. According to these results, the local authorities could define hot spots where they can place medical and rescue teams and install points with water supplies, etc. 相似文献
178.
A new approach is presented for improving the computational efficiency of regional-scale ground water models based on the analytic element method (AEM). The algorithm is an extension of the existing "superblock" algorithm, which combines the effects of multiple analytic elements into Laurent series and Taylor series (superblock expansions). With the new "nested superblock" formulation, Laurent series are nested in a hierarchical (quad-tree) data structure with direct mathematical relationships between parent and child superblock coefficients. Nested superblocks significantly accelerate the evaluation of the complex potential and discharge function in models that contain a large number of analytic elements at multiple scales. This evaluation process, the primary computational cost of AEM models, is required to determine the element coefficients, generate contour plots, and trace pathlines. The performance of the nested superblocks is demonstrated with a simplified model based on the Lake Ontario watershed geometry comprising thousands of hydrogeologic features at multiple geographic scales. 相似文献
179.
Radomir Petrović 《Contributions to Mineralogy and Petrology》1973,41(2):151-170
Coherency stress and coherency strain energy generated by Na+?K+ ion exchange in alkali feldspars are calculated using an isotropic model, and deformation of single crystals of alkali feldspars exposed to molten alkali chlorides at \(P_{H_2 O} \) < 1 bar is described. Coherency stress in alkali feldspars can reach 10–20 kb. When it is large, partial relaxation by fracture and/or plastic deformation takes place under anhydrous conditions, but temporary build-up of stress is unavoidable even under hydrothermal conditions. Because of coherency strain energy, a thin layer of an end-member alkali feldspar produced by cation exchange on a grain of the other end-member alkali feldspar would be unstable with respect to dissolution. Therefore, under hydrothermal conditions one end-member alkali feldspar replaces the other by dissolution and precipitation. The mechanism of the reaction $$Na_x K_{1 - x} AlSi_3 O_{8_{(feld.)} } + yK^ + \rightleftharpoons Na_{x - y} K_{1 + y - x} AlSi_3 O_{8_{(feld.)} } + yNa^ + $$ is primarily controlled by \(P_{H_2 O} \) and by ΔK/(Na + K), the difference between the equilibrium value and the initial value of the atomic K/(Na + K) ratio of the feldspar. When ¦ΔK/(Na + K)¦ is small, the reaction proceeds by cation exchange. When ¦ΔK/(Na + K)¦ is large, cation exchange still occurs if \(P_{H_2 O} \) is very low, but under hydrothermal conditions replacement by dissolution and precipitation occurs. 相似文献
180.
D. Ilić L. Č. Popović A. I. Shapovalova A. N. Burenkov V. H. Chavushyan A. Kovačević 《Journal of Astrophysics and Astronomy》2015,36(4)
The spectral variability of active galactic nuclei (AGN) is one of the key features that enables us to study in more detail, the structure of AGN emitting regions. Especially, the broad line profiles that vary both in flux and shape, give us invaluable information about the kinematics and geometry of the broad line region (BLR) where these lines are originating from. We give here a comparative review of the line shape variability in a sample of five type 1 AGNs, those with broad emission lines in their spectra, of the data obtained from the international long-term optical monitoring campaign coordinated by the Special Astrophysical Observatory of the Russian Academy of Science. The main aim of this campaign is to study the physics and kinematics of the BLR on a uniform data set, focusing on the problems of the photoionization heating of the BLR and its geometry, where, in this paper, we give for a first time, a comparative analysis of the variabilty of five type 1 AGNs, discussing their complex BLR physics and geometry in the framework of the estimates of the supermassive black hole mass in AGN. 相似文献