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排序方式: 共有173条查询结果,搜索用时 31 毫秒
141.
Andrea Meoni Antonella D'Alessandro Nicola Cavalagli Massimiliano Gioffré Filippo Ubertini 《地震工程与结构动力学》2019,48(8):910-928
The seismic behavior of unreinforced masonry buildings is typically characterized by premature brittle collapse mechanisms that can cause serious consequences for the protection of human lives and for the preservation of historical and cultural heritage. Structural health monitoring can be a powerful tool enabling a quick post-earthquake assessment of the structure's performance, but its applications are still scarce as a consequence of the severe limitations affecting off-the-shelf sensing technologies, in terms of local nature of the measurements, costs, as well as long-term behavior, installation, and maintenance. To overcome some of these limitations, the authors have recently proposed a new sensing technology, called “smart brick,” that is a durable clay brick doped with stainless steel microfibers, working as a smart strain sensor for masonry buildings. This paper presents the first full-scale application of smart bricks, used for detecting and localizing progressive earthquake-induced damage in an unreinforced masonry building subjected to shaking table tests. Smart bricks are employed to detect changes in load paths on masonry walls, comparing strain measurements acquired after each step of the seismic sequence with those referring to the undamaged structure. Experimental results are interpreted using a 3D finite element model built to reproduce the shaking table tests. Overall, the results demonstrate that the smart bricks can effectively reveal local permanent changes in structural conditions following a progressive damage, therefore being apt for earthquake-induced damage detection and localization. 相似文献
142.
Laura Tommasini Luca Carniello Massimiliano Ghinassi Marcella Roner Andrea D'Alpaos 《地球表面变化过程与地形》2019,44(8):1633-1646
Salt marshes are crucially important ecosystems at the boundary between the land and the sea, that are experiencing significant losses worldwide mainly dictated by the erosion of their margins. Improving our understanding of the mechanisms controlling marsh edge erosion is a key step to address conservation issues and salt-marsh response to changes in the environmental forcing. Here we have employed a complete, coupled Wind-Wave Tidal Model (WWTM) to analyse the temporal evolution of the wave field, and in particular of the mean wave-power density, in the Venice Lagoon over the past four centuries (from 1611 to 2012). We have then related wave-field changes to the observed erosion patterns determined by comparing recent aerial photographs (1978–2010) and historical bathymetric data. The results of our analyses from the Venice Lagoon show that, while wave-fields did not significantly change from 1611 to 1901, a rapid increase in wave-power densities occurred in the last century. This is suggested to depend on the positive feedback between relevant morphological evolutions and changes in the wave field, both influenced by natural forcing and anthropogenic pressures. We also emphasize the existence of a strong positive linear relationship between the volumetric marsh erosion rate and mean wave-power density. We thus suggest that relating salt-marsh lateral erosion rates to properly computed mean wave-power densities provides a valuable tool to address long-term tidal morphodynamics. © 2019 John Wiley & Sons, Ltd. 相似文献
143.
Alessandro Ielpi Mathieu G.A. Lapôtre Alvise Finotello Massimiliano Ghinassi Andrea D'Alpaos 《地球表面变化过程与地形》2020,45(8):1717-1731
The links between flood frequency and rates of channel migration are poorly defined in the ephemeral rivers typical of arid regions. Exploring these links in desert fluvial landscapes would augment our understanding of watershed biogeochemistry and river morphogenesis on early Earth (i.e. prior to the greening of landmasses). Accordingly, we analyse the Mojave River (California), one of the largest watercourses in the Great Basin of the western United States. We integrate discharge records with channel-migration rates derived from dynamic time-warping analysis and chronologically calibrated subsidence rates, thereby constraining the river's formative conditions. Our results reveal a slight downstream decrease in bankfull discharge on the Mojave River, rather than the downstream increase typically exhibited by perennial streams. Yet, the number of days per year during which the channel experiences bankfull or higher stages is roughly maintained along the river's length. Analysis of historical peak flood records suggests that the incidence of channel-formative events responds to modulation in watershed runoff due to the precipitation in the river's headwaters over decades to centuries. Our integrated analysis finally suggests that, while maintaining hydraulic geometries that are fully comparable with many other rivers worldwide, ephemeral desert rivers akin to the Mojave are capable of generating a surprisingly wide range of depositional geometries in the stratigraphic record. © 2020 John Wiley & Sons, Ltd. 相似文献
144.
Fusco Francesco Bordoni Massimiliano Tufano Rita Vivaldi Valerio Meisina Claudia Valentino Roberto Bittelli Marco De Vita Pantaleone 《Natural Hazards》2022,114(1):907-939
Natural Hazards - Assessing hazard of rainfall-induced shallow landslides represents a challenge for the risk management of urbanized areas for which the setting up of early warning systems, based... 相似文献
145.
Antonio Pignalosa Massimiliano Zattin Matteo Massironi William Cavazza 《International Journal of Earth Sciences》2011,100(4):847-859
(U–Th)/He and fission-track analyses of apatite along deep-seated tunnels crossing high-relief mountain ranges offer the opportunity
to investigate climate-tectonic forcing on topographic evolution. In this study, the thermochronologic analysis along the
Simplon tunnel (western-central Alps; Italy and Switzerland) constrains in detail the mechanisms controlling the topographic
evolution of the Simplon Massif. Cooling rates vary from about 10°C/Ma at about 10 Ma to about 35°C/Ma in the last 3 Ma. Such
increase in cooling rates corresponds to the inception of glacial cycles in the northern hemisphere. Age patterns show correlation
with faults distribution until 2 Ma, suggesting that tectonics-controlled rocks exhumed up to that age. After 2 Ma thermo-chronometric
data show that the Simplon area has experienced primarily erosional exhumation. All age patterns provided are not affected
by topographic effects, thus indicating that present-day topography has been carved in the last 2 Ma, most likely controlled
by glacial erosion. 相似文献
146.
Norina Andres Fernando Vegas Galdos Waldo Sven Lavado Casimiro Massimiliano Zappa 《水文科学杂志》2013,58(11):2043-2059
AbstractEstimating water resources is important for adequate water management in the future, but suitable data are often scarce. We estimated water resources in the Vilcanota basin (Peru) for the 1998–2009 period with the semi-distributed hydrological model PREVAH using: (a) raingauge measurements; (b) satellite rainfall estimates from the TRMM Multi-satellite Precipitation Analysis (TMPA); and (c) ERA-Interim re-analysis data. Multiplicative shift and quantile mapping were applied to post-process the TMPA estimates and ERA-Interim data. This resulted in improved low-flow simulations. High-flow simulations could only be improved with quantile mapping. Furthermore, we adopted temperature and rainfall anomalies obtained from three GCMs for three future periods to make estimations of climate change impacts (Delta-change approach) on water resources. Our results show more total runoff during the rainy season from January to March, and temporary storages indicate that less water will be available in this Andean region, which has an effect on water supply, especially during dry season.Editor Z.W. Kundzewicz; Associate editor D. Gerten 相似文献
147.
Massimiliano De Pasquale Dirk Grupe T. S. Poole A. A. Breeveld S. Zane S. R. Rosen M. J. Page K. O. Mason D. N. Burrows H. A. Krimm N. Gehrels J. A. Nousek P. W. A. Roming S. Kobayashi B. Zhang 《Monthly notices of the Royal Astronomical Society》2006,370(4):1859-1866
We present the results of X-ray and optical observations of GRB 050712 performed by Swift . The X-ray light curve of this burst exhibits episodes of flares in the first 1000 s, the same epoch at which the UVOT detected an optical counterpart. A shallow X-ray decay, with a decay slope of α=−0.73 , followed and lasted ∼70 ks. This behaviour can be explained in terms of activity of the gamma-ray burst 'inner engine', with the possibility that the last flare is caused by the interaction of the ejecta with the surrounding medium.
We also find interesting spectral parameters for the X-ray emission. In particular, data suggest the presence of an intrinsic absorption in the first 1000 s, which can be explained if circumburst medium clouds lie along the line of sight. 相似文献
We also find interesting spectral parameters for the X-ray emission. In particular, data suggest the presence of an intrinsic absorption in the first 1000 s, which can be explained if circumburst medium clouds lie along the line of sight. 相似文献
148.
Massimiliano Guzzo 《Icarus》2006,181(2):475-485
The motion of the giant planets from Jupiter to Neptune is chaotic with Lyapunov time of approximately 10 Myr. A recent theory explains the presence of this chaos with three-planet mean-motion resonances, i.e. resonances among the orbital periods of at least three planets. We find that the distribution of these resonances with respect to the semi-major axes of all the planets is compatible with orbital instability. In particular, they overlap in a region of 10−3 AU with respect to the variation of the semi-major axes of Uranus and Neptune. Fictitious planetary systems with initial conditions in this region can undergo systematic variations of semi-major axes. The true Solar System is marginally in this region, and Uranus and Neptune undergo very slow systematic variations of semi-major axes with speed of order 10−4 AU/Gyr. 相似文献
149.
Massimiliano De Pasquale y P. Beardmore S. D. Barthelmy P. Boyd D. N. Burrows R. Fink N. Gehrels S. Kobayashi K. O. Mason R. McNought J. A. Nousek K. L. Page D. M. Palmer B. A. Peterson P. A. Price J. Rich P. Roming S. R. Rosen T. Sakamoto B. P. Schmidt J. Tueller A. A. Wells S. Zane B. Zhang H. Ziaeepour 《Monthly notices of the Royal Astronomical Society》2006,365(3):1031-1038
150.
Apatite fission-track (FT) analyses of sandstone samples collected across the trace of the Ganos segment of the North Anatolian Fault (NAF) in south-western Thrace (Turkey) indicate that a significant structural discontinuity was in existence at least by the latest Oligocene. Such discontinuity had a complex kinematic history, as exhumation south of it occurred during the latest Oligocene and north of it during the mid-Miocene. Our data imply that early Pliocene westward propagation of the NAF in the Marmara region followed a pre-existing structural discontinuity; such discontinuity could be related to the development of the Intra-Pontide Suture, marking the terminal closure of the Intra-Pontide Ocean during the Oligocene. 相似文献