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   1698篇
  免费   9篇
  1707篇
  2025年   2篇
  2024年   7篇
  2023年   18篇
  2022年   22篇
  2021年   31篇
  2020年   86篇
  2019年   52篇
  2018年   62篇
  2017年   45篇
  2016年   52篇
  2015年   39篇
  2014年   52篇
  2013年   272篇
  2012年   139篇
  2011年   141篇
  2010年   88篇
  2009年   83篇
  2008年   115篇
  2007年   72篇
  2006年   70篇
  2005年   41篇
  2004年   29篇
  2003年   21篇
  2002年   31篇
  2001年   20篇
  2000年   14篇
  1999年   10篇
  1998年   13篇
  1997年   10篇
  1996年   10篇
  1995年   9篇
  1994年   11篇
  1993年   3篇
  1992年   6篇
  1991年   2篇
  1990年   6篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1983年   2篇
  1981年   1篇
  1980年   6篇
  1979年   2篇
  1978年   4篇
排序方式: 共有1707条查询结果,搜索用时 0 毫秒
31.
The fossil record suggests that modern human morphology evolved in Africa between 150,000 and 50,000 years ago, when the sole inhabitants of Eurasia were the Neanderthals and other equally nonmodern people. However, the earliest modern or near-modern Africans were behaviorally (archaeologically) indistinguishable from their nonmodern, Eurasian contemporaries, and it was only around 50,000-40,000 years ago that a major behavioral difference developed. Archaeological indications of this difference include the oldest indisputable ornaments (or art broadly understood); the oldest evidence for routine use of bone, ivory, and shell to produce formal (standardized) artifacts; greatly accelerated variation in stone artifact assemblages through time and space; and hunting-gathering innovations that promoted significantly larger populations. As a complex, the novel traits imply fully modern cognitive and communicative abilities, or more succinctly, the fully modern capacity for Culture. The competitive advantage of this capacity is obvious, and preliminary dates suggest that it appeared in Africa about 50,000 years ago and then successively in western Asia, eastern Europe, and western Europe, in keeping with an African origin. Arguably, the development of modern behavior depended on a neural change broadly like those that accompanied yet earlier archaeologically detectable behavioral advances. This explanation is problematic, however, because the putative change was in brain organization, not size, and fossil skulls provide little or no secure evidence for brain structure. Other potential objections to a neural advance in Africa 50,000-40,000 years ago or to the wider Out-of-Africa hypothesis, include archaeological evidence (1) that some Neanderthals were actually capable of fully modern behavior and (2) that some Africans were behaviorally modern more than 90,000 years ago.  相似文献   
32.
In a series of recent studies, changes in material culture and settlement pattern in the Late Glacial of Northern Europe have been linked to the eruption of the Laacher See volcano. This eruption occurred c. 13,000 years ago towards the end of the Allerød chronozone. It is argued that the tephra fall-out from this eruption set in motion significant demographic fluctuations along the northern periphery of Late Glacial human settlement and that these led to a number of material culture transformations. In particular, the emergence of the regionally distinct techno-complexes with large tanged points – the Bromme culture in southern Scandinavia and the Perstunian culture in northeastern Europe – and the temporary abandonment of central European regions are thought to relate to this eruption. While numerous archaeological datasets are in accord with this ‘Laacher See hypothesis’, the forcing mechanism or mechanisms that brought about these archaeologically visible changes have remained largely unexplored. A particular challenge is to explain how some of the culture-historical effects of the Laacher See eruption seem to change or become more pronounced with distance from the eruptive centre. We here investigate one potential middle-range link between the Laacher See eruption and Late Glacial fauna and foragers: tephra as dental abrasive. We use instrumented nanoindentation to quantitatively investigate tephra from a number of sites covering the medial and distal fall-out zones as well as the dental enamel of Homo sapiens and key prey species of Late Glacial foragers. Our results show that the Laacher See tephra contained particles roughly twice as hard as even the hardest portions of any of the teeth investigated. We also suggest that fluoride-induced weakening of dental enamel may have further aggravated tooth wear. These mechanisms may have acted in concert to produce elevated levels of, in particular, animal mortality, which in turn may have led to an abandonment of the affected landscapes.  相似文献   
33.
The comparative study of sedimentary fabrics in relation to archaeological fabrics in various levels of the sites of Cova Gran de Santa Linya (Middle and Early Upper Palaeolithic) and the Roca dels Bous (Middle Palaeolithic) has made it possible to analyse the formation dynamics of the deposits and determine the extent of disturbance of the archaeological levels by natural processes. To achieve this, diagrams and two- and three-dimensional indices were calculated from the azimuth and dip angle of natural clasts and artefacts. The results indicate that the sedimentary levels were formed mainly by planar fabric shape gravitational processes (low depositional angles), which differ notably from the archaeological fabrics they contain, characterised by a greater degree of isotropy. This difference in the fabrics would reflect human activity and indicates that the archaeological levels both in Cova Gran and Roca dels Bous have not been subject to significant natural modifications, and are preserved in situ.  相似文献   
34.
Radiocarbon dates on marine shells have not been used as extensively as charcoal or bone dates for the setting up of absolute chronologies because interpreting these dates is complicated by the marine radiocarbon reservoir effect. Nevertheless marine shellfish were used widely at least during the Holocene and their shells are abundant and usually well preserved in archaeological deposits located near shorelines. Consequently prior research concerning the oceanographic conditions and the marine radiocarbon reservoir effect of a particular coastal area is needed in order to set up reliable chronologies for that region. Values of regional marine radiocarbon reservoir effect – ΔR – of coastal waters off Atlantic Iberia, some of its variability along the Holocene and its correlation with the upwelling phenomenon were determined during previous research. More data related to the ΔR values for western Portuguese coastal waters during the Late Neolithic and the Chalcolithic, a time interval badly sampled in previous research, were recently obtained. These values can be compared with ΔR values already determined for the Gulf of Cadiz. Besides the importance of these values for a better knowledge of the palaeoceanography and palaeoclimatology of Atlantic Iberia, from now on archaeologists can set up reliable chronologies for Late Neolithic and Chalcolithic contexts using marine shell samples of that origin for radiocarbon dating.  相似文献   
35.
清代州县衙门经费   总被引:1,自引:0,他引:1  
本文通过对清代州县衙门经费的量化分析,发现州县衙门经制性经费与实际所需之间有很大的差距.清廷虽然试图解决这一问题,但终清之世,效果寥寥.因此,州县官为了保障政务活动的进行,不得不采取征收田赋附加、差徭、杂税盈余等手段加以补苴,结果使百姓的负担日益加重.  相似文献   
36.
以朝鲜殖民地时期华侨制造业中最具代表性的铸造业作为研究对象,对华侨铸造工厂诞生的背景、同乡网络及其生产体制进行了阐述;分析了华侨制造业在朝鲜烧锅制造领域里取得垄断性地位的原因,一是华侨铸造工厂里中国劳动者较低的工资及技术开发的进行;二是全国的华侨铸造工厂形成了以河北省交河县为中心的同乡网络并进行协力合作。中日战争爆发后,日本政府谋求战时经济的强化,朝鲜总督府也加强了战时统治经济,生铁原料的配给发生困难,华侨铸造工厂因而纷纷倒闭,走向衰退。  相似文献   
37.
    
al-Tikha is a mid to large Umm an-Nar (c. 2700–2000 BC) settlement situated near Rustaq at the back of the Southern Batinah coastal plain in the Sultanate of Oman that was discovered (or rediscovered) in 2014. The site is unique because its layout and spatial organisation are very largely (possibly completely) visible on the surface. This includes two separate areas of stone-built housing, a large pottery scatter of varying density, three or four typical Umm an-Nar round towers and a small cemetery consisting of at least four tombs, along with a few other features. The layout of the site is described and discussed in detail, in particular, in relation to what it might tell us about the nature of Umm an-Nar settlement and social organisation more generally. The location of the site within a pattern of repeating Umm an-Nar settlement along Wadi Far (Wādī al-Farʿī) is also described and discussed.  相似文献   
38.
    
Imported ceramics from Early Bronze Age contexts in southeast Arabia illustrate a complex multidirectional network of material and social interactions at this time. Significant socioeconomic changes that occurred in the Hafit (3200–2800 B.C.) and Umm an-Nar (2800–2000 B.C.) periods have been linked to external demand for copper, which is argued to have stimulated a change in subsistence patterns. Similarly, disruption to long-distance exchange networks by external factors has been cited as driving change at the end of the Umm an-Nar period. Archaeological evidence from the region suggests a shift in the direction of exchange from Mesopotamia to the Indus occurred around the middle of the third millennium B.C. However, a recent analysis of Mesopotamian historical sources has highlighted the scale of state-organised textile production for export to the lower Gulf in the later third millennium B.C. The site of Kalba 4 has a stratified sequence of occupation deposits dating from the Umm an-Nar and Iron Age (1300–300 B.C.). In this study, a typological analysis of imported ceramics is used to locate the Kalba in the chronological framework of the region and discuss the changing networks of long-distance exchange that were operating. The imported pottery at Kalba 4 indicates that the inhabitants of the site were exchanging goods with a range of polities, including southern Mesopotamia, the Indus Valley (Meluhha), southeast Iran (Marhashi) and Bahrain (Dilmun). A significant quantity of Late Akkadian ceramics at the site suggests it became an important location for Mesopotamian trade at this time.  相似文献   
39.
40.
    
Human bones from Late Eneolithic graves and Bronze Age settlement pits in Moravia (Czech Republic) were studied to reconstruct their post-mortem histories based on the distribution of their microbial destruction. Backscattered electrons in a scanning electron microscope (BSE-SEM) were used for visual assessment of bioerosion. Visual data from the histological analysis were transformed into quantitative data using the Waikato Environment for Knowledge Analysis (WEKA) toolkit. The results show that the presence of bioerosion is different between the two groups of samples. The bones from settlement pits display extensive bioerosion whereas the bones from graves display no or arrested bioerosion. The absence of bioerosion in graves is most probably linked with tomb burials of Corded Ware Culture. Given the tombs are frequently not preserved archaeologically, the state of bone bioerosion may serve as an indicator of their existence.  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