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   1744篇
  免费   128篇
  2024年   6篇
  2023年   43篇
  2022年   10篇
  2021年   12篇
  2020年   88篇
  2019年   73篇
  2018年   177篇
  2017年   166篇
  2016年   143篇
  2015年   91篇
  2014年   87篇
  2013年   402篇
  2012年   82篇
  2011年   68篇
  2010年   48篇
  2009年   45篇
  2008年   39篇
  2007年   20篇
  2006年   24篇
  2005年   24篇
  2004年   14篇
  2003年   12篇
  2002年   21篇
  2001年   25篇
  2000年   10篇
  1999年   10篇
  1998年   13篇
  1997年   10篇
  1996年   7篇
  1995年   15篇
  1994年   7篇
  1993年   12篇
  1992年   10篇
  1991年   7篇
  1990年   7篇
  1989年   5篇
  1988年   6篇
  1987年   5篇
  1986年   7篇
  1985年   2篇
  1982年   4篇
  1981年   3篇
  1979年   2篇
  1977年   1篇
  1969年   2篇
  1962年   1篇
  1959年   2篇
  1956年   1篇
  1950年   3篇
排序方式: 共有1872条查询结果,搜索用时 15 毫秒
61.
The animal remains found at the fourteenth–fifteenth century Hof van Leugenhaeghe are crucial to reconstruct the life of the noble inhabitants, as all buildings were destroyed with the construction of a later estate on the property called the Blauwhof. The diet confirms the high social status of this nobility with the suspected consumption of pig skulls, a possible sign of wealth in late-medieval Flanders. Other signs of a noble diet are found as well: juvenile cattle, a diverse spectrum of game, partridge and grey heron. The observed pattern of a wealthy diet is consistent with the zooarchaeological assemblages found at other noble sites in late-medieval Flanders.  相似文献   
62.
Despite the large-scale expansion of Bell Beaker phenomenon, there is a tension between the normative Bell Beaker material culture categories and their local objectification in the form of real artefacts. Stone projectile points provide an opportunity to evaluate how much was the general category of such a point influenced by regional and local factors. The aim of this paper is to explore shape and size variation of Central European Bell Beaker projectile points from Moravia (Czech Republic) to elucidate factors responsible for this variation. The sample consists of 194 projectile points from 54 Central European Bell Beaker sites (2500–2300/2200 BC) distributed in Morava River catchment. The size and shape of projectile points were studied by landmark-based geometric morphometrics and expressed as shape groups, which have been assessed in terms of their spatial distribution, raw material, and reutilization. Although several shape categories of points were identified, there is a strong degree of uniformity in the research sample. The dominant shape category (75.4 % of points) was pervasive across geographic space and was not significantly affected either by raw material or reutilization. A lower degree of reutilization of points is interpreted as a consequence of a non-utilitarian role of projectile points, which represented a critical component of Bell Beaker mortuary practices.  相似文献   
63.
A stone bead, part of a necklace found in a middle Hallstatt period—type of settlement—the T?rt?ria site in Alba County, Romania, was investigated following a non-destructive approach, by means of energy-dispersive X-ray fluorescence spectrometry and Fourier transform infrared spectroscopy. The highly heterogenous object, found together with numerous bronze and iron objects, appeared to be a variety of chalcedony rich in iron and copper impurities, still preserving clay minerals from the sedimentary matrix in some of the areas. Organic molecules found at the surface of the stone artefact may indicate the presence of a wax or resin residue, possible evidence of early craft specialization. The non-destructive protocol applied allowed an in-depth characterization of the artefact, providing important information not only on the crystal structure but also on the diagnostic impurities present within this peculiar stone bead.  相似文献   
64.
A reference sample of dental and oral nonmetric traits should represent its biological population from which it stems. The presence of individuals born at different times, different regions, and separate countries in the Coimbra-identified cranial collections provides the test of whether this sample reflects the biological continuity of this Portuguese sample among the late modern (early industrialization, nineteenth century) to early contemporary (early demographic transition, first half of the twentieth century) population of this region of central Portugal. The Coimbra collections were scored for 61 traits using methodology by Hauser and De Stefano (1989), Turner et al. (1991), Scott and Turner (1997), Irish (1998), and Marado and Silva (2016). The 600 individuals in the sample were divided by generation, region, and nationality. Their phenetic diversity was tested with principal component analysis and with the mean measure of divergence statistic. The proximity between the subsamples was generalized, and it mimicked previous genetic marker results. Some small subsamples hindered conclusions; nevertheless, this Coimbra sample is considered a reliable dental reference sample for the Portuguese late modern/early contemporary population.  相似文献   
65.
The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.  相似文献   
66.
67.
An upper molar of a small bat, here described from an early Miocene freshwater lime-stone deposit at Riversleigh, northwestern Queensland, is the oldest record in Australia of the microchiropteran family Vespertilionidae. The new taxon is referred to the cosmopolitan genus Leuconoe, but it does not appear to be closely related to the two extant Australian species of this genus.  相似文献   
68.
Abstract

This paper aims at analyzing what the author calls the “hidden nexus between” Metz and Schmitt. Relying on a Schmittean reference to Metz, pointing to certain conceptual and theoretical, as well as historical components, the paper argues that it is a shared concern about the mistaken modern — utopian reworking of eschatology. The paper also demonstrates how the more recent Metzean rethinking of the problem of theodicy works further this eschatological theme.  相似文献   
69.
This article aims at presenting and discussing the strategies for updating the finite element numerical modeling of stone masonry arch bridges using operational modal analysis. The study comprehended three bridges: two old ones, the St. Lázaro and the Lagoncinha bridges, and a recently constructed bridge in Vila Fria, Portugal. Updating of the bridge models is performed by comparing the numerical and experimental modal parameters. Three-dimensional detailed numerical models are used to perform modal analysis of the bridges. Experimental modal identification of the bridges is based on the measurement of their acceleration responses during normal operation. The assigned material properties are also based on available results obtained from in situ and laboratory tests and on the results of visual inspection and historical research carried out for both old bridges.  相似文献   
70.
At Nunalleq, a pre-contact Yup'ik Eskimo village site in Alaska (14th–17th century AD), abundant insect remains from highly organic substrates preserved within permafrost offer a unique opportunity to investigate past ecological and living conditions. This paper presents the preliminary results obtained from the analysis of two samples collected from floor layers in sod houses. The numerous and diverse insect remains highlight the exciting potential of archaeoentomology for reconstructing past ecological conditions, resource exploitation and the use of space at northern hunter–gatherer sites and have permitted the development of a strategy for the future collection of archaeoentomological data at permafrost-preserved sites in Alaska and elsewhere.  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