首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   92篇
  免费   1篇
  93篇
  2021年   1篇
  2020年   2篇
  2019年   3篇
  2017年   2篇
  2016年   2篇
  2015年   1篇
  2014年   3篇
  2013年   20篇
  2012年   7篇
  2011年   7篇
  2010年   3篇
  2009年   7篇
  2008年   5篇
  2007年   5篇
  2006年   7篇
  2005年   2篇
  2004年   2篇
  2003年   3篇
  2002年   3篇
  2001年   2篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1987年   1篇
  1983年   1篇
排序方式: 共有93条查询结果,搜索用时 15 毫秒
51.
P. A. CUTILLO  S. GE 《Geofluids》2006,6(4):319-333
The pool in Devils Hole is a sensitive indicator of crustal strain and fluctuates in response to changes in atmospheric pressure, earth tides, earthquakes, large‐scale tectonic activity and ground‐water development. Short‐term and cyclic water‐level fluctuations caused by atmospheric pressure and earth tides were found to be on the order of millimeters to centimeters. The 1992 Landers/Little Skull Mountain earthquake sequence and the 1999 Hector Mine earthquake induced water‐level offsets of greater than ?12 and ?3.6 cm, respectively. The results of a dislocation model used to compute volumetric strain for each earthquake indicates that the coseismic water‐level offsets are consistent in magnitude and sense with poroelastic responses to earthquake‐induced strain. Theoretical postseismic fluid‐flow modeling indicates that the diffusivity of the system is on the order of 0.03 m2 sec?1, and identified areas of anomalous water‐level fluctuations. Interpretation of model results suggests that while the persistent post‐Landers rise in water‐level can be attributed to deformation‐induced channeling of fluid to the Devils Hole fault zone, the cause of the pre‐Hector Mine water‐level rise may be related to postseismic excess fluid pressures or preseismic strain accumulation.  相似文献   
52.
This paper reports on an experiment designed to study the role of trampling in the vertical dispersal of artifacts in the soil, and in the mixing of originally separate sets of materials. The experiment is part of a study of the archaeological stratigraphy and patterns of site use at a large stratified cave in southern France. The experiment was designed to replicate conditions prevailing at the cave. The results strongly suggest caution in the interpretation of living floors and stratified assemblages in sandy deposits.  相似文献   
53.
    
Prehistoric land use and social activity in West New Britain, PNG, are well documented, although the landscapes – largely shaped by catastrophic volcanic eruptions – in which these took place, and the relationships people had with these landscapes, are poorly understood. We define the evolving landscape at Numundo, from prior to the Witori-Kimbe 2 eruption (W-K2, ca. 3600 BP) to after the Witori-Kimbe 4 eruption (W-K4, ca. 1400 BP), using fossil phytolith and coral evidence at eight archaeological sites to provide environmental evidence of the human responses to periodic catastrophic events. From ca. 5900 to 3600 BP, all the sites were coastal and disturbed. Early disturbance reflected natural forest recovery after W-K1 (ca. 5900 BP), whereas the later landscape was largely shaped by human activity. In contrast, forest regrowth was limited after W-K2 and open environments typical of human activity with a mosaic of regenerating, disturbed and managed vegetation, persisted until W-K3. Environmental recovery from W-K3 and W-K4 (ca. 1700 BP and ca. 1400 BP) differed completely, reflecting severity of the volcanism and the short time between eruptions. The landscape after W-K3 was largely a naturally recovering landscape, in contrast to effective vegetation recovery and significant human exploitation of the landscape – again a mosaic of regenerating, disturbed and managed vegetation – after W-K4. The social history is one in which people evolved increasingly flexible land-use practices, enabling them to re-settle this periodically disrupted landscape, and to take advantage of an increasingly broad range of habitats suitable for cultivation. The human response to this highly dynamic landscape represents a close relationship between social and natural processes, as people became increasingly better at re-settling an unpredictably disrupted landscape; both the social and environmental processes within this landscape become equally influential and instrumental in shaping the effects of the other.  相似文献   
54.
    
Natural resource management is typically defined by landscape‐scale management zones, such as the Catchment Management Authority boundaries of the southern Murray‐Darling Basin in Australia. Ecological research generally deals with local‐scale phenomena, with studies at the scale of such landscape management units arising only recently. We developed a method that links local‐scale ecological research to landscape‐scale management zones, which is presented here as a geographical bibliographic database. This research proceeded in four phases. First, we assessed three decades of ecological research in the Goulburn‐Broken Catchment in Victoria, Australia, using this method, revealing the locations where research has taken place across the landscape, and the research themes dominant in different bioregions. Second, we assessed the purposes to which the method could be applied. Third, we tested the method against one of these potential purposes to review ecological research in a subcatchment case study. Last, we interrogated the method to answer an ecological question. This methodological analysis demonstrated that mapping ecological research in this way allows the user to identify geographic gaps in research coverage, assist in limiting search results to a location of interest and to address location‐specific ecological questions. In combination with landscape classification methods, such as biogeographic regionalisation units, this method can be used to evaluate research coverage across similar ecological communities.  相似文献   
55.
The study of settlement patterns must be accompanied by careful evaluation of the processes of formation of the archaeological record and of its recovery. A selective review is offered of Neolithic case studies from central and western Europe, from theLinearbandkeramik culture (fifth millennium bc) to Denmark and Britain (fourth and third millennia bc). The emphasis of the study is upon dispersed settlement patterns. Possibilities of specialization and hierarchy are discussed. Settlement studies should be further exploited for the system, or social rules and contexts, that may be inferred from the patterning of settlements.  相似文献   
56.
The sedimentary sequence at Diepkloof Rock Shelter formed through a complex interaction of depositional and post-depositional processes and was variously influenced by biogenic, geogenic, and anthropogenic agents. Here, we present the results of a micromorphological study of the sediments at Diepkloof, focusing in particular on the numerous anthropogenic inputs and modifications recorded within the sequence. By applying the microfacies concept, we were able to identify hearth burning and maintenance, bedding construction and burning, and surface modification by trampling as major processes that contributed to the formation of the site. The human activities recorded within the sediments show a marked change throughout the sequence, implying a shift in the use of the site over time. The present study also provides a context for evaluating other classes of artifacts and data collected from the site.  相似文献   
57.
Formation processes are all too infrequently addressed by archaeologists excavating in Mesoamerica. This paper examines refuse disposal patterns from the site of Cuauhtémoc on the Pacific coast of Chiapas, Mexico, to provide insight into how the site formed and how artifacts accumulated. This analysis uses materials dating between 1600–800 BCE which encompass the centuries before, during and after the late Early Formative or Early Olmec period (i.e., 1250–900 BCE). First, I employ sherds and daub from shared open-air middens and trash-filled pits to explore trash deposit formation through the 800 years that the site was occupied. Next, I use these same classes of data to make synchronic comparisons between five different depositional contexts dating to the Conchas phase (900–800 BCE). For all phases, these analyses demonstrate that pit features received more debris than open-air middens and that material in the latter contexts were more broken up. Further, the low density of daub from late Early Formative period contexts suggests that distinctive architectural customs may have been practised during this time. Conchas phase refuse indicates that waste disposal locations physically separated an elite residential zone from the rest of society and that elite contexts were more intensively used. Accounting for the formation of archaeological deposits allows for more nuanced interpretations of this early Mesoamerican village.
Robert M. RosenswigEmail:
  相似文献   
58.
一、黄冶窑的概况 河南省巩义市(原巩县)东北部的大、小黄冶村附近,是唐代烧造三彩制品的窑址。该窑址沿黄冶河两岸,长约3公里,宽约0.5公里。南北朝时期,此窑场便与黄冶河上游的白河、铁匠炉等窑场连成一片,主要烧制青瓷、白瓷。唐初开始烧造三彩制品,生产规模不断  相似文献   
59.
Thirty years after Muckelroy's seminal 1976 paper on shipwreck site formation, research on the cultural processes which contribute to the creation and modification of shipwrecks remains limited. It is proposed that by adopting a process-oriented framework, we can integrate and synthesize the documentary, oral and archaeological evidence of human response to shipwreck into a structure which parallels the physical progress of the disaster. Possible cultural responses to shipwreck are considered, from pre-voyage planning through to post-impact salvage, including physical correlations potentially visible in the archaeological record.
© 2006 The Author  相似文献   
60.
The German Continental Deep Drilling Program comprising a pilot borehole down to 4000 m and a main borehole down to 9101 m in southeast Germany (KTB) is continuing to provide a unique opportunity for the identification of important factors and processes in deep‐seated fluid and energy transfer. In situ stress conditions significantly impact flow, transport and exchange characteristics of fracture networks that dominate the permeability of crystalline reservoir rocks. In this paper, several scales of information are combined to present a fully three‐dimensional hydraulic finite element model of the principal KTB fault zones, and linked to a geomechanical model describing the alteration of the hydraulic parameters with stress changes caused by fluid extraction. The concept of geomechanical facies is introduced to define and characterize architectural elements in the subsurface system. Evaluation of a long‐term pump test in the KTB pilot hole, June 2002–July 2003, coupled with a geomechanical model gives an insight into some of the elastic and nonelastic processes controlling hydraulic transport in the basement rocks. Trends in the decline of the permeability and the degree of storage in the system could only partially be explained by elastic processes, clearly indicating the importance of nonelastic processes. A number of inelastic processes are suggested as areas for further research.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号