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   4831篇
  免费   122篇
  2020年   47篇
  2019年   64篇
  2018年   374篇
  2017年   273篇
  2016年   328篇
  2015年   76篇
  2014年   64篇
  2013年   1122篇
  2012年   106篇
  2011年   244篇
  2010年   250篇
  2009年   110篇
  2008年   150篇
  2007年   186篇
  2006年   62篇
  2005年   71篇
  2004年   46篇
  2003年   36篇
  2002年   49篇
  2001年   51篇
  2000年   29篇
  1999年   43篇
  1998年   24篇
  1997年   31篇
  1996年   27篇
  1995年   22篇
  1994年   38篇
  1993年   32篇
  1992年   34篇
  1991年   21篇
  1990年   33篇
  1989年   28篇
  1988年   30篇
  1987年   32篇
  1986年   31篇
  1985年   33篇
  1984年   54篇
  1983年   56篇
  1982年   48篇
  1981年   38篇
  1980年   35篇
  1979年   43篇
  1978年   43篇
  1977年   33篇
  1976年   32篇
  1975年   34篇
  1973年   28篇
  1972年   31篇
  1971年   21篇
  1970年   32篇
排序方式: 共有4953条查询结果,搜索用时 15 毫秒
991.
Kulbulak (Uzbekistan) is among the most important Paleolithic sites in Central Asia. Based on excavations from the 1960s to the 1980s, a stratigraphic sequence yielding 46 archeological horizons of the Lower, Middle and Upper Paleolithic has been described. The lowermost 22 layers were at that time defined as Acheulean, both in cultural and chronological aspects. Based on these previous works, Kulbulak has thus often been cited as one of the rarest occurrences of Lower Paleolithic and Acheulean in the region. However, this attribution was debatable. New excavations at Kulbulak in 2007–2010 provided new material and the first reliable dates that permitted us to tackle this issue. Moreover, a reappraisal of the lithic collections and documents from previous excavations was also conducted. These new data clearly indicate the absence of Acheulean or even Lower Paleolithic at Kulbulak. On the contrary, the lithic assemblages from this site only correspond to Middle and Upper Paleolithic periods. The lowermost layers are particularly interesting due to the presence of an early industry with blade and bladelet technology.  相似文献   
992.
This study presents the results of an archaeometrical investigation performed on 75 black glass beads dated to the ninth–fifth century BC coming from Bologna, Cumae, and Pozzuoli (Italy), and Chotin (Slovakia). The analyses of the major, minor, and trace elements—as well as that of Sr and Nd isotopes performed on a selection of samples coming from Bologna—provided evidence for two different production technologies in Iron Age black glass found in Italy (natron glass, probably produced in Egypt) and Slovakia (wood ash glass, probably produced in Europe). In both cases, the glasses derive their black colouration from the high presence of iron (around 12 % FeO), introduced into the glass batches through the intentional choice of dark sands. The production model appears to be small-scale and experimental, characterised by the use of non-sorted raw materials and poorly defined formulae, producing glass with a high chemical variability. The wood ash technology appears to have dropped out of use in Europe until the Medieval period, while natron production spread quickly, becoming predominant throughout the Mediterranean.  相似文献   
993.
Practically all archeological assemblages are palimpsests. In spite of the high temporal resolution of Abric Romaní site, level O, dated to around 55 ka, is not an exception. This paper focuses on a zooarcheological and taphonomic analysis of this level, paying special attention to spatial and temporal approaches. The main goal is to unravel the palimpsest at the finest possible level by using different methods and techniques, such as archeostratigraphy, anatomical and taxonomical identification, taphonomic analysis, faunal refits and tooth wear analysis. The results obtained are compared to ethnoarcheological data so as to interpret site structure. In addition, activities carried out over different time spans (from individual episodes to long-term behaviors) are detected, and their spatial extent is explored, allowing to do inferences on settlement dynamics. This leads us to discuss the temporal and spatial scales over which Neanderthals carried out different activities within the site, and how they can be studied through the archeological record.  相似文献   
994.
An updated analysis of Paleolithic sites in Siberia and the Urals 14C-dated to the coldest phase of the Last Glacial Maximum (LGM), with its timespan currently determined as ca. 23,000–19,000 BP (ca. 27,300–22,900 cal BP), is presented. It is demonstrated that people continuously occupied the southern and central parts of Siberia and the Russian Far East (up to 58° N latitude), and perhaps sporadically settled regions located even further north, up to 70° N, throughout the LGM. This is in accord with our previous data, but is now based on a larger dataset, and also on a paleoecological analysis of the major pre-LGM archaeological sites in Siberia and the Urals north of 58° N. It is clear that Paleolithic people in northern Eurasia were able to cope with the treeless tundra environment well in advance of the LGM, at least at ca. 34,000–26,000 BP (ca. 38,500–30,000 cal BP). Therefore, a high degree of adaptation to cold conditions allowed people to survive in Siberia during the LGM.  相似文献   
995.
Following on from our previous research into the prehistoric aceramic distillation and production of birch bark tar, this series of exploratory experiments investigated the use of raised structures within a fire. These field-based experiments were conducted using sand, gravel, wood fuel, and bark from Betula pubescens (downy birch). The structures that were created were simple raised sand mounds, which reflected known Neanderthal combustion surfaces from the Middle Palaeolithic. The bulk of the experiments were recorded throughout using a thermocouple to provide temperature readings from the base of the bark pyrolysis chamber. The experiments proved successful at producing birch bark tar and several containers were used to catch the tar for later analysis. Based on the results, the authors contend that not only could Neanderthals control fire but that regular birch bark tar production by Neanderthals was most likely a result of specific chaînes opératoires in order to provide the necessary control and outcomes.  相似文献   
996.
Samples of dental calculus were taken from 11 human individuals buried at Nemrik 9, a Pre-Pottery Neolithic site in Northern Iraq. All of them represented the time span of ca. 9100–8600 bp. In total, 95 microfossils were retrieved from these samples, including 70 phytoliths, 9 starch granules or clusters of starch, 3 pollens, and 1 xylem fragment. Most microfossils could be attributed to C3 cool season cereals, most likely wheat and barley, which is consistent with previous knowledge about the composition of crops in early farming communities living in the Fertile Crescent. In addition, three phytoliths and one starch granule typical of C4 warm season grasses were recovered including one subangular and faceted starch granule, which might derive from a native grass, but is not diagnostic of any genus. Prior to assigning diagnostic status to this starch, exhaustive reference work on native grass seeds is necessary. The presence of one Phragmites phytolith suggests non-alimentary processing of reeds using teeth or perhaps using the stem of this grass as a toothbrush or toothpick.  相似文献   
997.
Palynological researches have been carried out in the framework of cooperative projects with local and national institutions at the Villa Romana del Casale of Piazza Armerina, a small town in central Sicily. The site was studied within a multidisciplinary geo-bio-archaeological set of studies aiming at understanding the economy and environment at a local scale. Analyses allowed us to reconstruct the natural vs cultural landscape dynamics from Roman to medieval periods. On the basis of 85 samples, pollen diagrams show that the site has been built in a low forest cover area, with signs of both natural/semi-natural cover and complex anthropogenic activities. These activities include cereal fields and pastures. There is evidence of ornamental (e.g. Platanus, Buxus) and fruit trees (above all Olea, and also, e.g. Corylus, Prunus and Juglans). The research also includes a detailed study about the finding of Vitis pollen grains in the Roman site. In the subsequent phases, pollen shows again an open, fairly treeless, landscape with Mediterranean and hilly vegetation. Anthropogenic signs are evident in the form of groves and orchards. Our data bring evidence and details about the intense land exploitation that had contributed to transform the environment of central Sicily during the Middle and Late Holocene. Data demonstrate that archaeopalynology may be fruitfully regarded as a tool to understand the current landscape structure.  相似文献   
998.
999.
In this research, typology of bronze ornaments discovered from Jafar-Abad and Tu Ali-Sofla kurgans (second phase of excavations) near Aras River in Khoda-Afarin town was investigated. These kurgans belong to combatant and migrating Eurasian tribes, which migrated to northwest Iran in Iron Age II (1200–800 B.C.). From the total number of 103 discovered objects, 93 objects were bronze ornaments, including rings, bracelet, earring, buttons for clothes, and spiral. Discovery of ornaments of various types’ revealed the existence of a social classification system of people in these tribes. In addition, study on the discovered buttons from these kurgans showed that as a tradition in burial ceremonies, the deceased were buried wearing clothes. To understand the basics of metalworking of combatant and migrating Eurasian tribes, analytical investigations were also conducted on three jewelry items including a bracelet, a ring, and an earring from a total number of 93 bronze ornaments discovered.  相似文献   
1000.
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