全文获取类型
收费全文 | 182篇 |
免费 | 10篇 |
国内免费 | 3篇 |
专业分类
测绘学 | 8篇 |
大气科学 | 24篇 |
地球物理 | 37篇 |
地质学 | 89篇 |
海洋学 | 17篇 |
天文学 | 8篇 |
综合类 | 1篇 |
自然地理 | 11篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 13篇 |
2015年 | 15篇 |
2014年 | 14篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 15篇 |
2010年 | 11篇 |
2009年 | 12篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有195条查询结果,搜索用时 15 毫秒
51.
52.
Mucerino Luigi Carpi Luca Schiaffino Chiara F. Pranzini Enzo Sessa Eleonora Ferrari Marco 《Natural Hazards》2021,105(1):137-156
Natural Hazards - Rip currents are one of the most significant environmental hazards for beachgoers and are of interest to coastal scientists. Several studies have been conducted to understand rip... 相似文献
53.
Chiara Elmi Maria Franca Brigatti Luca Pasquali Monica Montecchi Angela Laurora Daniele Malferrari Stefano Nannarone 《Physics and Chemistry of Minerals》2010,37(8):561-569
Microprobe analysis, single crystal X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray absorption spectroscopy were applied on Fe-rich osumilite from the volcanic massif of Mt. Arci, Sardinia, Italy. Osumilite belongs to the space group P6/mcc with unit cell parameters a = 10.1550(6), c = 14.306(1) Å and chemical formula (K0.729)C (Na0.029)B (Si10.498 Al1.502)T1 (Al2.706 Fe 0.294 2+ )T2 (Mg0.735 Mn0.091 Fe 1.184 2+ )AO30. Structure refinement converged at R = 0.0201. Unit cell parameter a is related to octahedral edge length as well as to Fe2+ content, unlike the c parameter which does not seem to be affected by chemical composition. The determination of the amount of each element on the mineral surface, obtained through X-ray photoelectron spectroscopy high-resolution spectra in the region of the Si2p, Al2p, Mg1s and Fe2p core levels, suggests that Fe presents Fe2+ oxidation state and octahedral coordination. Two peaks at 103.1 and 100.6 eV can be related to Si4+ and Si1+ components, respectively, both in tetrahedral coordination. The binding energy of Al2p, at 74.5 eV, indicates that Al is mostly present in the distorted T2 site, whereas the Mg peak at 1,305.2 eV suggests that this cation is located at the octahedral site. X-ray absorption at the Fe L2,3-edges confirms that iron is present in the mineral structure, prevalently in the divalent state and at the A octahedral site. 相似文献
54.
In order to define adequate prevention measures and to manage landslide emergencies, real-time monitoring is required. This
paper presents two different applications of the remote sensing technique: the ground-based synthetic aperture radar interferometry,
here proposed as a monitoring and early warning support for slope instability. Data acquisitions carried out through a ground-based
synthetic aperture radar interferometer, operating in Ku band, installed in front of the observed slopes, are discussed. Two case studies, based on the use of the same apparatus
(formerly developed by the Joint Research Center of the European Commission and by Ellegi-LiSALab srl), are reported: the
first one concerns the monitoring of a large landslide, named Ruinon (Valfurva, Italy). The second one deals with the monitoring
of the NW unstable slope in the Stromboli island aimed to implementing an early warning system. Acquired interferometric data
are processed to provide displacements and velocity maps of the monitored area. The monitoring services ongoing on the Ruinon
landslide and on Stromboli demonstrate the capability of this technique to operate in different operative settings (i.e.,
different phenomena and geological framework) and for different aims (monitoring for prevention, early warning, and emergency
assessment). This methodology has also been proved by national and regional authorities of civil protection in order to provide
a real-time monitoring for emergency management. 相似文献
55.
Chiara?Barbieri Barbara?Carrapa Andrea?Di GiulioEmail author Jan?Wijbrans Glen?R.?Murrell 《International Journal of Earth Sciences》2003,92(5):758-778
Mineral chemistry, 40Ar/39Ar geochronology on white micas and Apatite Fission Track Thermochronology (AFTT), are applied here to study the provenance of the synorogenic Molare Formation (lowermost unit of the Tertiary Piedmont Basin clastic sequence). The Molare Formation was deposited during transgression onto the Ligurian Alps nappe stack in the Early Oligocene. Depositional facies show that clastic distribution remained transversal, with local sources located just landward from the coastline. Phengite mineral chemistry together with 40Ar/39Ar data clearly shows two distinctive source areas, each one mirroring the composition of the basement directly beneath the clastic sequence. Amphibole mineral chemistry allows second order provenance distinctions within each sector, reflecting heterogeneous metamorphic evolution of the bedrock complexes. Integrated 40Ar/39Ar dating and AFTT suggest that, following a fast cooling/exhumation episode of the Ligurian Alps during the Oligocene, very little net uplift has since occurred. This is due to a period of general subsidence from the Oligocene–Late Miocene followed by comparable uplift from Late Miocene–Pliocene to the present. In general our data provide an image of the Ligurian Alps during the Oligocene, which is very similar to the present-day one.This revised version was published online in September 2003. 相似文献
56.
I. M. Demina Yu. G. Farafonova A. Sas-Uhrynowski E. Welker 《Geomagnetism and Aeronomy》2006,46(1):129-138
The model of the main geomagnetic field sources, including 12 more dipoles in addition to the main dipole, is presented. The source parameters have been determined for the 100-year-long period at an interval of 5 years. The problem is solved using the iteration method proposed and developed by the authors. Six more sources have been included in the iteration process at its current step. This made it possible to substantially smooth the time variations in the dipole parameters obtained previously and, on the other hand, to describe all global anomalies of the main geomagnetic field using this model. A change in the parameter values can be approximated by rather smooth functions describing specific features of development of the sources operating for 20–30 years. However, the short duration of the obtained series (21 points) makes the problem of prediction substantially more difficult. The parameters of 13 dipoles, extrapolated for 2000 using the linear prediction filter, are in good agreement only with the general development of the sources. 相似文献
57.
Mauro Dolce Elena Speranza Flavio Bocchi Chiara Conte 《Bulletin of Earthquake Engineering》2018,16(9):3791-3818
One major issue in the aftermath of a strong earthquake is the emergency management, which cannot be guaranteed if the physical components necessary for the operability of the contingency plan are either damaged, unusable or inaccessible. In order to assess the physical efficiency of the emergency system on which a contingency plan is based, the I.OPà.CLE method (Indices for evaluation of the Operational efficiency of Limit Condition Emergency) has been set up by the Italian Civil Protection Department. It is basically aimed at supporting civil protection decision makers in evaluating emergency systems and establishing strategies and priorities concerning strengthening interventions at national, regional or municipality level. The method must be potentially applied to any of the around 8000 municipalities all over Italy, and then it must refer to a minimum information dataset readily available for any municipality. Therefore, I.OPà.CLE has been specifically tailored for the minimum standard information that is provided by the analysis of Limit Condition for Emergency, as formulated in 2012 by the Italian Civil Protection Department. This analysis defines the standard framework of the physical layout of a municipal seismic emergency plan, relying on a limited number of information. Notwithstanding the numerically extensive target and limited amount of information available, the ambition of I.OPà.CLE is to perform simplified analyses without renouncing to rigor in the methodology. The present paper illustrates the analytic formulation of I.OPà.CLE and its capabilities, as well as two real examples. In the conclusion, future upgrading of the model are discussed, even in relation to the availability of further pieces of information. 相似文献
58.
Michele Marroni M.Cemal Goncüoglu Chiara Frassi Kaan Sayit Luca Pandolfi Alessandro Ellero Giuseppe Ottria 《地学前缘(英文版)》2020,11(1):129-149
The Anatolian peninsula is a key location to study the central portion of the Neotethys Ocean(s)and to understand how its western and eastern branches were connected.One of the lesser known branches of the Mesozoic ocean(s)is preserved in the northern ophiolite suture zone exposed in Turkey,namely,the Intra-Pontide suture zone.It is located between the Sakarya terrane and the Eurasian margin(i.e.,Istanbul-Zonguldak terrane)and consists of several metamorphic and non-metamorphic units containing ophiolites produced in supra-subduction settings from the Late Triassic to the Early Cretaceous.Ophiolites preserved in the metamorphic units recorded pervasive deformations and peak metamorphic conditions ranging from blueschist to eclogite facies.In the nonmetamorphic units,the complete oceanic crust sequence is preserved in tectonic units or as olistoliths in sedimentary melanges.Geochemical,structural,metamorphic and geochronological investigations performed on ophiolite-bearing units allowed the formulation of a new geodynamic model of the entire"life"of the IntraPontide oceanic basin(s).The reconstruction starts with the opening of the Intra-Pontide oceanic basins during the Late Triassic between the Sakarya and Istanbul-Zonguldak continental microplates and ends with its closure caused by two different subductions events that occurred during the upper Early Jurassic and Middle Jurassic.The continental collision between the Sakarya continental microplate and the Eurasian margin developed from the upper Early Cretaceous to the Palaeocene.The presented reconstruction is an alternative model to explain the complex and articulate geodynamic evolution that characterizes the southern margin of Eurasia during the Mesozoic era. 相似文献
59.
60.
Bocchetti R Lamberti CV Pisanelli B Razzetti EM Maggi C Catalano B Sesta G Martuccio G Gabellini M Regoli F 《Marine environmental research》2008,66(1):24-26
This work investigated the natural variability of several biomarkers in Tapes philippinarum and Mytilus galloprovincialis, sampled from Northern Adriatic where these organisms are important sentinel species for future environmental impact assessment. Levels of metallothioneins, peroxisomal enzymes and acetylcholinesterase, showed a significant seasonality and marked differences between clams and mussels. Among antioxidant enzymes, catalase and GST decreased during the warmer period, the latter enzyme activity resulting particularly high in clams. The total oxyradical scavenging capacity toward peroxyl radicals decreased in mussels from winter to summer, indicating a prooxidant challenge due to higher seawater temperature and intensity of light irradiance. Lysosomal membrane stability did not exhibit significant seasonal variations, while some variations were observed for DNA damages. Overall results indicated a significant influence of seasonal variability on several biomarkers and species-specific differences which should be considered to discriminate the appearance of anthropogenic disturbance. 相似文献