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171.
Leo Armada Shu-Kun Hsu Chia-Yen Ku Wen-Bin Doo Wen-Nan Wu Carla Dimalanta Graciano Yumul Jr. 《Marine Geophysical Researches》2012,33(4):369-377
The Philippine Fault Zone, a system of left-lateral strike-slip faults traversing the length of the Philippine Islands, is associated with the oblique convergence between the Philippine Sea Plate (PSP) and the Eurasian Plate (EP). Although it is a major deformational structure within the diffuse PSP–EP convergent boundary, some of its segments, particularly its marine extensions, are not well studied. To investigate the crustal deformation in the marine prolongation of the Philippine Fault Zone offshore Luzon Island, multi-channel seismic (MCS) data, gravity data and centroid moment tensor solutions were used in this study. Focal mechanism solutions from the Global CMT catalog were inverted to determine the average principal stress directions and consequently understand the prevailing stress regime in the study area. The stress inversion results indicate that the direction of maximum compression (σ1) is 321°N, which coincides with the PSP–EP convergence direction. From the MCS profiles, the study area was subdivided into deformation zone and a relatively stable zone. Thrust faulting, folding and general uplift are observed in the deformation zone. This zone is further subdivided into the active and inactive segments. In the active segment, uplift is occurring in the submarine ridge. This deformation pattern can be related to the ongoing uplift in some regions bisected by the PFZ. The inactive segment, characterized by intense folding of the sequences and faulting of the basement and overlying sequences, is suggested as the precursor of the Philippine Fault Zone. Deformation appears to be recently shifted to the east as delineated by an uplifted N-NW trending submarine ridge offshore NW Luzon Island. 相似文献
172.
Carla Barnaba Giovanna Laurenzano Luca Moratto Monica Sugan Alessandro Vuan Enrico Priolo Marco Romanelli Paolo Di Bartolomeo 《Bulletin of Earthquake Engineering》2014,12(5):2165-2178
Strong-motion data consisting of peak ground acceleration and velocity and 5 % damped response spectra are presented for 46 earthquakes of the Emilia seismic sequence which occurred in the Po Plain (northern Italy) in 2012. The data were recorded by the OGS temporary network installed close to the town of Ferrara following the main shock of May 20, 2012. Ground-motion peak parameters and spectral responses are compared with the ground-motion prediction equation (GMPE) of Bindi et al. (Bull Earthq Eng 9:1899–1920, 2011) for soft soils and reverse faults. Peak ground accelerations are in general in good agreement with those predicted by GMPE, while predicted peak ground velocities underestimate the observed data, especially for stronger events at more distant stations. The response spectra follow the trend in peak ground velocities, with observed values higher than predicted values at longer periods. This behavior has been interpreted as a site effect due to the deep soft alluvial cover of the Po Plain, which promotes ground motion characterized by a large low-frequency spectral content that is not yet well modeled by the Italian GMPE. A peculiar behavior was shown by the event occurring on June 6, 04:08:33 UTC, \(\hbox {M}=4.5\) , located at the eastern edge of the Po Plain, which produced peak ground accelerations exceeding three times the values estimated by attenuation laws. Such a great discrepancy could be related to post-critically reflected S-waves and multiples from the Moho (SmSM). 相似文献
173.
From accessing to assessing forecasts: an end-to-end study of participatory climate forecast dissemination in Burkina Faso (West Africa) 总被引:1,自引:0,他引:1
Carla Roncoli Christine Jost Paul Kirshen Moussa Sanon Keith T. Ingram Mark Woodin Léopold Somé Frédéric Ouattara Bienvenue J. Sanfo Ciriaque Sia Pascal Yaka Gerrit Hoogenboom 《Climatic change》2009,92(3-4):433-460
This study compares responses to seasonal climate forecasts conducted by farmers of three agro-ecological zones of Burkina Faso, including some who had attended local level workshops and others who had not attended the workshops. While local inequalities and social tensions contributed to excluding some groups, about two-thirds of non-participants interviewed received the forecast from the participants or through various means deployed by the project. Interviews revealed that almost all those who received the forecasts by some mechanism (workshop or other) shared them with others. The data show that participants were more likely to understand the probabilistic aspect of the forecasts and their limitations, to use the information in making management decisions and by a wider range of responses. These differences are shown to be statistically significant. Farmers evaluated the forecasts as accurate and useful in terms of both material and non-material considerations. These findings support the hypothesis that participatory workshops can play a positive role in the provision of effective climate services to African rural producers. However, this role must be assessed in the context of local dynamics of power, which shape information flows and response options. Participation must also be understood beyond single events (such as workshops) and be grounded in sustained interaction and commitments among stakeholders. The conclusion of this study point to lessons learned and critical insights on the role of participation in climate-based decision support systems for rural African communities. 相似文献
174.
André Padua Emilio Lanna Carla Zilberberg Paulo César de Paiva Michelle Klautau 《Marine Ecology》2013,34(1):56-61
Little is known about the recruitment and behaviour of sponge larvae, especially of the class Calcarea. The calcareous sponge Paraleucilla magna is very common in Southeast Brazil, where it is considered a cryptogenic species. This study quantified recruitment rates in shaded and illuminated habitats for 2 years in Rio de Janeiro, Brazil, and analyzed larval photoresponses of this species. Four structures, each containing a shaded and an illuminated surface, were exchanged every 3 months for 2 years. The number of recruits was quantified on each plate. In the laboratory, larvae of P. magna were placed in half‐shaded Petri dishes and the number of settlers in each side was counted after 24 h. Paraleucilla magna recruited continuously throughout the experiment. Recruits occurred in greater abundance on shaded surfaces than on illuminated surfaces, and the larvae were negatively phototactic in vitro. Despite the possible influence of other factors in the recruitment of sponges (such as sedimentation, competition and predation), the prevalence of P. magna in shaded habitats may also be related to larval choice. 相似文献
175.
In ancient times, the name “Peloro” was used to indicate an anthropic area that gradually developed around the first known human settlement on the Sicilian shore near the Straits of Messina. Since the 5th century BC, historians have documented that numerous naval armadas landed for long periods at Peloro. However, the present-day morphology of the Peloro Cape Peninsula does not have any protected inlet that would offer a location to repair hundreds of ships, as has been documented by historical sources. To address this discrepancy, geomorphologic data were collected and analyzed to verify whether historical documents were consistent with the palaeotopography of the area. This approach is based on the analysis of the morphotectonic evolution of the coastal lowland that resulted from regional uplift over the Quaternary and Holocene. The results indicate that the harbour was located in the basin of the Pantano Piccolo salt marsh, and was large and deep enough to have sheltered up to 320 ships. 相似文献
176.
Alessio Rovere Stefano Bellati Valeriano Parravicini Marco Firpo Carla Morri Carlo Nike Bianchi 《Estuaries and Coasts》2009,32(2):333-339
The existence of linkages between ecological and geomorphological processes and the influence of human activities both on
the biota and on geomorphology is well known for terrestrial environments, while it has been seldom reported for submerged
ones. A survey in the Noli-Bergeggi area (NW Mediterranean Sea) has been carried out to test the hypothesis that the harvesting
of Lithophaga lithophaga has an impact not only on the hammered rock, but also on the sediments at the cliff foot. Size and roundness of pebbles have
been measured at different stations and statistical analyses have been used to test the differences between impact and control
situations. Results show a dependence of the roundness of pebbles on the date mussel harvesting, indicating a decrease both
of the roundness index and of its variability at the cliff foot in impacted sites. Conclusions stress the biogeomorphological
nature of this activity, not limited to the present location. 相似文献
177.
Summary The crystal structure of weberite, Na2MgAlF7, was redetermined from 3-dim. X-ray data and refined by least squares methods in space groupImma to a conventional reliability factorR=0.036. Mg and Al have octahedral 6-coordination. Two crystallographically independent kinds of Na atoms form different NaF8-polyhedra with the F atoms at the corners of a flattened hexagonal bipyramid and of a square prism, respectively.
With 2 Figures 相似文献
Neubestimmung der Kristallstruktur des Weberits
Zusammenfassung Die Kristallstruktur des Weberits, Na2MgAlF7, wurde aus 3-dim. Röntgendaten neu hestimmt und mit der Methode der kleinsten Quadrate in RaumgruppeImma auf den konventionellen ZuverlässigkeitsfaktorR=0,036 verfeinert. Mg und Al haben oktaedrische 6-Koordination. Zwei kristallographisch unabhängige Arten von Na-Atomen bilden mit den F-Atomen zwei verschiedene NaF8-Polyeder; in einem sitzen die F-Atome an den Ecken einer abgeflachten hexagonalen Bipyramide, im anderen an den Ecken eines quadratischen Prismas.
With 2 Figures 相似文献
178.
Summary The crystal structure of sarcolite from Monte Somma (Vesuvius), Na(Na, K, Fe, Mg)<1 Ca6[Al4Si6O23](OH, H2O)<2 [(Si,P)O4]0.5[(CO3, Cl)]0.5, space groupI4/m witha=12,343(5)Å,c=15,463(5)Å andZ=4, has been determined from X-ray data collected on an automatic diffractometer. The 1637 independent reflections withI>2 (I) converged to a conventionalR value of 0.054 with partially anisotropic factors.The tetrahedral framework in sarcolite has a sharing coefficient of 1.85. Mean Si–O and Al–O distances are 1.616 and 1.763 Å, respectively. Isolated (Si, P)O4, CO3, OH, H2O and Cl species occupy cavities in the tetrahedral framework in a partially disordered way. The two crystallographically different Ca atoms coordinate respectively with 5 and 6 framework oxygens; further contacts occur with available anions. Ca–O distances range from 2.34 to 2.69 Å. Na atoms coordinate with 4 oxygens of the tetrahedral frame and one from the CO3 groups.A structure analysis of a sarcolite crystal baked out at 1100°C confirmed some structural details involving atoms occupying cavities in the tetrahedral framework.
With 4 Figures 相似文献
Die Kristallstruktur des Sarkoliths
Zusammenfassung Die Kristallstruktur des Sarkoliths vom Monte Somma (Vesuv), Na(Na, K, Fe, Mg)<1 Ca6[Al4Si6O23](OH, H2O)<2[(Si, P)O4]0,5[(CO3, Cl)]0,5, RaumgruppeI4/m,a 0=12,343(5)Å,c 0=15,463(5)Å,Z=4, wurde aus Röntgendaten, die auf einem automatischen Diffraktometer gesammelt worden waren, bestimmt. Der konventionelleR-Wert für 1637 kristallographisch unabhängige Reflexe mitI>2 (I) konvergierte mit partiell anisotropen Temperaturfaktoren auf 0.054.Der Verknüpfungskoeffizient des Tetraedergerüstes in Sarkolith ist 1,85. Die mittleren Si–O-bzw. Al–O-Abstände sind 1,616Å und 1,763 Å. Isolierte Strukturbestandteile (Si, P)O4, CO3, OH, H2O und Cl besetzen zum Teil ungeordnet die Hohlräume des Tetraedergerüstes. Die beiden kristallographisch verschiedenen Ca-Atome werden von funf bzw. sechs Sauerstoffen des Gerüstes koordiniert, weitere Kontakte bestehen zu verfügbaren Anionen. Die Ca–O-Abstände variieren von 2,34 bis 2,69 Å. Die Na–Atome sind von vier Sauerstoffen des Tetraedergerüstes und von einem weiteren der CO3-Gruppen koordiniert. Die Strukturanalyse eines bei 1100°C getemperten Sarkolithkristalls bestätigte einige Details über die Atome, welche die Hohlräume des Tetraedergerüstes besetzen.
With 4 Figures 相似文献
179.
Carla W. Montgomery 《Contributions to Mineralogy and Petrology》1979,69(2):167-176
Uranium and lead isotopic analyses of total-rock and feldspar samples from the Imataca Series indicate an early Archean (3.5+ b.y.) age for the basement gneisses. Lead isotopic evolution in most gneiss samples may approximately be described by a three-stage model. The start of the third stage is marked by a pervasive metamorphic event, locally up to pyroxene-granulite grade, at 2 b.y. ago, which commonly resulted in extensive depletion of uranium relative to lead. 相似文献
180.
Copper is more toxic to all life stages of the copepod Tisbe than cadmium. The most sensitive life stage of Tisbe to both copper and cadmium is the one-day-old nauplius. The resistance of larval stages of Tisbe increases with age (one-day-old nauplii 48h mg Cu l?1. and 0.5384 mg Cd l?1, 0.3415 mg Cu l?1. and 0.645 mg Cd l?1. for five-days-old nauplii and 0.5289 mg Cu l?1. and 0.9061 mg Cd l?1. for ten-days-old nauplii. The two reproductive stages of Tisbe tested (females with ovigerous bands and females bearing the first ovigerous sac) demonstrated an increased sensitivity to metals and proved more sensitive than the ten-days-old copepodids (only females with ovigerous bands had a similar sensitivity to copper with the ten-days-old copepodids). 相似文献