全文获取类型
| 收费全文 | 103篇 |
| 免费 | 13篇 |
| 国内免费 | 5篇 |
专业分类
| 大气科学 | 8篇 |
| 地球物理 | 37篇 |
| 地质学 | 54篇 |
| 海洋学 | 13篇 |
| 天文学 | 7篇 |
| 自然地理 | 2篇 |
出版年
| 2023年 | 2篇 |
| 2021年 | 7篇 |
| 2020年 | 4篇 |
| 2019年 | 2篇 |
| 2018年 | 3篇 |
| 2017年 | 2篇 |
| 2016年 | 11篇 |
| 2015年 | 4篇 |
| 2014年 | 8篇 |
| 2013年 | 14篇 |
| 2012年 | 5篇 |
| 2011年 | 6篇 |
| 2010年 | 11篇 |
| 2009年 | 9篇 |
| 2008年 | 9篇 |
| 2007年 | 4篇 |
| 2006年 | 2篇 |
| 2005年 | 7篇 |
| 2004年 | 1篇 |
| 2003年 | 1篇 |
| 2002年 | 2篇 |
| 2001年 | 2篇 |
| 2000年 | 1篇 |
| 1999年 | 1篇 |
| 1997年 | 2篇 |
| 1981年 | 1篇 |
排序方式： 共有121条查询结果，搜索用时 31 毫秒
61.
62.
Ecological restoration, cultural preferences and the negotiation of ‘nativeness’ in Australia 总被引：1，自引：0，他引：1
The paper addresses cultural assumptions about ‘nativeness’ and ‘belonging’ to place as they are implicated in notions of ‘ecological restoration’. Given the centrality of complex notions of ‘indigeneity’ to the issue of what ecological ‘restoration’ means in Australia, this is a rich area for cultural and historical analysis. Case materials illustrate the negotiated and ambiguous nature of Australian ideas about what ‘belongs’ ecologically and culturally across the broad continent of this relatively young post-Settler nation. We seek to foreground these issues through consideration of what ‘restoring’ nature might mean in the context of debates about native plants, the re-introduction of an iconic species of ground dwelling bird, the removal of cane toads that are demonised as highly ‘alien’, and the multiple ways in which the dingo is regarded ambiguously as both native and a ‘pest’ that needs to be controlled and culled. By showing how ‘restoration’ can be understood and mobilised in a variety of ways – in terms of the ‘re-naturing’, ‘re-valuing’ and/or ‘repatriating’ of indigenous species, as well as impassioned rejection of ‘exotics’ – we emphasise the importance of social science for building a well-grounded sense of how environmental management priorities and approaches are informed by a wider set of cultural assumptions. 相似文献
63.
Earthquake surface rupture is the result of transformation from crustal elastic strain accumulation to permanent tectonic
deformation. The surface rupture zone produced by the 2001 Kunlunshan earthquake (M
w
7.8) on the Kusaihu segment of the Kunlun fault extends over 426 km. It consists of three relatively independent surface rupture
sections: the western strike-slip section, the middle transtensional section and the eastern strike-slip section. Hence this
implies that the Kunlunshan earthquake is composed of three earthquake rupturing events, i.e. the M
w
=6.8, M
w
=6.2 and M
w
⩽=7.8 events, respectively. The M
w
=7.8 earthquake, along the eastern section, is the main shock of the Kunlunshan earthquake, further decomposed into four rupturing
subevents. Field measurements indicate that the width of a single surface break on different sections ranges from several
meters to 15 m, with a maximum value of less than 30 m. The width of the surface rupture zone that consists of en echelon
breaks depends on its geometric structures, especially the stepover width of the secondary surface rupture zones in en echelon,
displaying a basic feature of deformation localization. Consistency between the Quaternary geologic slip rate, the GPS-monitored
strain rate and the localization of the surface ruptures of the 2001 Kunlunshan earthquake may indicate that the tectonic
deformation between the Bayan Har block and Qilian-Qaidam block in the northern Tibetan Plateau is characterized by strike-slip
faulting along the limited width of the Kunlun fault, while the blocks themselves on both sides of the Kunlun fault are characterized
by block motion. The localization of earthquake surface rupture zone is of great significance to determine the width of the
fault-surface-rupture hazard zone, along which direct destruction will be caused by co-seismic surface rupturing along a strike-slip
fault, that should be considered before the major engineering project, residental buildings and life line construction.
Supported by the National Natural Science Foundation of China (Grant No. 40474037) and the National Basic Research Program
of China (Grant No. 2004CB418401) 相似文献
64.
Jean‐Baptiste Charlier Roger Moussa Pierre‐Yann David Jean‐Franois Desprats 《水文研究》2019,33(17):2337-2354
The aim of this paper is to quantify peakflow attenuation and/or amplification in a river, investigating lateral flow from the intermediate catchment during floods. This is a challenge for the study of the hydrological response of permeable/intermittent streams, and our contribution refers to a modelling framework based on the inverse problem for the diffusive wave model applied in a karst catchment. Knowing the upstream and downstream hydrographs on a reach between two stations, we can model the lateral one, given information on the hydrological processes involved in the intermediate catchment. The model is applied to 33 flood events in the karst reach of the Iton River in French Normandy where peakflow attenuation is observed. The monitored zone consists of a succession of losing and gaining reaches controlled by strong surface‐water/groundwater (SW/GW) interactions. Our results show that despite a high baseflow increase in the reach, peakflow is attenuated. Model application shows that the intensity of lateral outflow for the flood component is linked to upstream discharge. A combination of river loss and overbank flow for highest floods is proposed for explaining the relationships. Our approach differentiates the role of outflow (river loss and overbank flow) and that of wave diffusion on peakflow attenuation. Based on several sets of model parameterization, diffusion is the main attenuation process for most cases, despite high river losses of up to several m3/s (half of peakflow for some parameterization strategies). Finally, this framework gives new insight into the SW/GW interactions during floods in karst basins, and more globally in basins characterized by disconnected river‐aquifer systems. 相似文献
65.
Impact of range‐parallel sediment transport on 2D thermo‐mechanical models of mountain belts: Application to the Kyrgyz Tien Shan 
下载免费PDF全文
下载免费PDF全文 Evolving mountain belts dynamics is very sensitive to surface processes. The surface processes affect tectonics by enhancing crust exhumation and thermal weakening, and depositing soft yet cold sediments in surrounding basins. While 2D plane strain models approximate cylindrical tectonic structures well, simple 1D mass transfer cannot capture erosion–sedimentation complexity. The Eastern Kyrgyz Tien Shan, where structures, basins and exhumation rates are well constrained, is used here to illustrate this issue. Thermo‐mechanical models demonstrate that 1D transport cannot adjust both basin geometry and Apatite Fission Track exhumation ages. When out‐of‐plane sediment transfer is considered, the amount of evacuated sediment delays or accelerates the formation of new faults, affecting the relative timing of exhumation. For our case study, lateral drainage must evacuate 80% of the sediments to match the geological constraints, which is consistent with other source to sink analyses. This indicates that lateral drainage should not be neglected in regional 2D models. 相似文献
66.
利用区域双差层析成像方法,基于2008年10月—2018年6月近震资料,对晋冀豫交界地区记录到的地震事件进行震源位置与P波、S波三维速度结构的联合反演。重新定位后,地震空间位置得到明显改善,浅部的速度结构与地形及沉积层厚度对应较好,研究区内控制性断裂和地震多分布在太行山隆起区的高、低速变化梯级带上。对比分析研究区内不同构造单元及同一构造单元不同深度的P、S波速度异常特征及其与中小地震和历史强震的分布关系,结合研究区内历史强震和现今中、小震分析发震构造及深部孕震环境,为该区未来强震危险区判定提供科学依据。 相似文献
67.
68.
69.
Yann Rolland Jean-Marc Lardeaux Stéphane Guillot Christian Nicollet 《Geodinamica Acta》2013,26(2-3):133-148
RésuméÀ la bordure occidentale du massif du Grand Paradis (Alpes occidentales), la zone Piémontaise est constituée des unités océaniques des schistes lustrés et de l’unité continentale du Grand Paradis. Une étude métamorphique nous permet de préciser et de discuter des discontinuités de pression et des conditions de rétro-morphose de trois unités piémontaises déjà distinguées antérieurement. L’unité supérieure des schistes lustrés (LS) métamorphisée dans le faciès des schistes bleus (9.5 ± 2 kbar, 340 ± 30 °C). L’unité inférieure des schistes lustrés (LI) métamorphisée dans le faciès des éclogites (12.5±3 kbar, 480±50 °C). L’unité continentale du Grand Paradis (GP) métamorphisée dans le faciès des éclogites de plus haute pression (12 à 20 kbar, 500 ± 50 °C). L’ensemble des unités enregistre une décompression dans les conditions du faciès amphibolite à épidote, et donc avec une légère augmentation tardive de température, pour les unités LI et GP, et dans celles des schistes verts pour l’unité LS. L’étude des inclusions fluides dans les fentes de tension et dans les plans de cisaillement, en parallèle à l’élude des paragenèses rétromorphiques permet de montrer que c’est tardivement (4 ± 1 kbar, 400 ± 50 °C) que l’histoire tectonomélamor-phique devient commune à l’ensemble des unités. L’étude du champ de la déformation finie met en évidence une tectonique en extension qui débute en conditions ductiles dans le faciès amphibolite à épidote pour LI, et schiste vert pour LS, et se poursuit en conditions fragiles. La déformation ductile se traduit par des trajectoires en dômes et bassins de la foliation, avec une partition entre des domaines en aplatissement au c?ur des dômes et des domaines en cisaillement simple en bordure des dômes, au contact entre les différentes unités. La déformation fragile correspond au continuum plus tardif de la déformation extensive ductile. Cette tectonique extensive n’est qu’en partie responsable des sautes de pression entre les trois unités étudiés. Elle correspond à l’accommodation, en surface, au poinçonnement vertical des unités de haute pression, en contexte de convergence, par l’écaillage progressif de la croûte européenne à l’avant du butoir mantellique apulien. © 2000 Editions scientifiques et médicales Elsevier SAS 相似文献
70.
Marc Hässig Yann Rolland Marc Sosson Ghazar Galoyan Lilit Sahakyan Gültekin Topuz 《Geodinamica Acta》2013,26(3-4):311-330
In the Lesser Caucasus and NE Anatolia, three domains are distinguished from south to north: (1) Gondwanian-derived continental terranes represented by the South Armenian Block (SAB) and the Tauride–Anatolide Platform (TAP), (2) scattered outcrops of Mesozoic ophiolites, obducted during the Upper Cretaceous times, marking the northern Neotethys suture, and (3) the Eurasian plate, represented by the Eastern Pontides and the Somkheto-Karabagh Arc. At several locations along the northern Neotethyan suture, slivers of preserved unmetamorphozed relics of now-disappeared Northern Neotethys oceanic domain (ophiolite bodies) are obducted over the northern edge of the passive SAB and TAP margins to the south. There is evidence for thrusting of the suture zone ophiolites towards the north; however, we ascribe this to retro-thrusting and accretion onto the active Eurasian margin during the latter stages of obduction. Geodynamic reconstructions of the Lesser Caucasus feature two north dipping subduction zones: (1) one under the Eurasian margin and (2) farther south, an intra-oceanic subduction leading to ophiolite emplacement above the northern margin of SAB. We extend our model for the Lesser Caucasus to NE Anatolia by proposing that the ophiolites of these zones originate from the same oceanic domain, emplaced during a common obduction event. This would correspond to the obduction of non-metamorphic oceanic domain along a lateral distance of more than 500?km and overthrust up to 80?km of passive continental margin. We infer that the missing volcanic arc, formed above the intra-oceanic subduction, was dragged under the obducting ophiolite through scaling by faulting and tectonic erosion. In this scenario part of the blueschists of Stepanavan, the garnet amphibolites of Amasia and the metamorphic arc complex of Erzincan correspond to this missing volcanic arc. Distal outcrops of this exceptional object were preserved from latter collision, concentrated along the suture zones. 相似文献