全文获取类型
收费全文 | 41928篇 |
免费 | 1640篇 |
出版年
2020年 | 531篇 |
2019年 | 829篇 |
2018年 | 956篇 |
2017年 | 1158篇 |
2016年 | 1245篇 |
2015年 | 935篇 |
2014年 | 910篇 |
2013年 | 14104篇 |
2012年 | 1058篇 |
2011年 | 1085篇 |
2010年 | 1090篇 |
2009年 | 1076篇 |
2008年 | 1024篇 |
2007年 | 935篇 |
2006年 | 842篇 |
2005年 | 581篇 |
2004年 | 577篇 |
2003年 | 531篇 |
2002年 | 513篇 |
2001年 | 519篇 |
2000年 | 459篇 |
1999年 | 523篇 |
1998年 | 463篇 |
1997年 | 429篇 |
1996年 | 409篇 |
1995年 | 414篇 |
1994年 | 359篇 |
1993年 | 410篇 |
1992年 | 394篇 |
1991年 | 300篇 |
1990年 | 295篇 |
1989年 | 310篇 |
1988年 | 307篇 |
1987年 | 322篇 |
1986年 | 307篇 |
1985年 | 420篇 |
1984年 | 446篇 |
1983年 | 453篇 |
1982年 | 396篇 |
1981年 | 390篇 |
1980年 | 426篇 |
1979年 | 417篇 |
1978年 | 405篇 |
1977年 | 428篇 |
1976年 | 382篇 |
1975年 | 382篇 |
1974年 | 286篇 |
1973年 | 269篇 |
1972年 | 245篇 |
1970年 | 222篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The recent application by Burton and Krinsley (1987) of back-scattered electron (BSE) petrography to obsidians from sources located in the south-western United States established that this method can effectively resolve and characterize included micro-crystalline phases that have proven difficult to analyse by optical thin-section microscopy. In the first extension of their original study, we have examined, using BSE petrography, obsidians from island sources located in the Mediterranean, including sources known to have been exploited in prehistory. Because of the kinetic contrasts on their crystallization, these microcrystalline phases reflect the magmatic history of the obsidian, providing information about superheating, supercooling, sub-solidus processes, and other phenomena. This information is of significance for the chemical analysis of Mediterranean obsidians and also as the basis for a powerful alternative to existing non-destructive analytical methods for the sourcing of archaeological and art-historical obsidian. 相似文献
992.
Excavation of Testar del Molí, the only workshop found in the Manises-Paterna area, revealed the existence of a fourteenth-century ceramic workshop covering the remains of the thirteenth-century workshop. This study is concerned with the fourteenth-century production, and forthcoming papers will connect both epochs following the findings of current excavations. The chemical and mineralogical characterization of the ceramic production of this workshop shows the presence of three groups of ceramic pastes which could also be distinguished by, and, thus, related to, their daily use. The raw materials found in the excavation have also been mineralogically and chemically characterized, and a model of possible mixtures of raw materials has also been developed in order to determine their possible use in the manufacture of the pottery previously characterized. 相似文献
993.
Classifying coins found during excavation is a challenging task for the archaeologist. This paper describes a multimedia system designed to assist the archaeologist by enabling him either to classify coins based on a pre-existing catalogue or to draw up his own catalogue for specific purposes. The system can also be used to train novices in the field: following an initial screening, the archaeologist only has to examine coins specifically requiring his expertise. A case study uses coins minted in Salerno 800–1200 AD, but the system has been designed to classify any set of coins by simply changing the underlying knowledge base. Very little training is required to operate the user-friendly system, which runs on multimedia PCs, as it is written using the C++ language and makes full use of the advanced features of Windows 3.11. 相似文献
994.
995.
996.
E. PATRICIA TSURUMI 《Gender & history》1996,8(2):258-276
997.
After over a century of archaeological research in the American Southwest, questions focusing on population aggregation and abandonment continue to preoccupy much of Pueblo archaeology. This article presents a historical overview of the present range of explanatory approaches to these two processes, with a primary focus on population aggregation in those regions occupied by historic and prehistoric Pueblo peoples. We stress the necessarily complementary nature of most of these explanations of residential abandonment and aggregation. Case studies from the northern Southwest illustrate the continuous nature of these processes across time and space. We suggest that additional explanatory potential will be gained by the use of well-defined theoretical units to frame our current approaches. We extend the use of the local community concept as a theoretical unit of organization that, along with explicit archaeological correlates, should help advance our research into population aggregation and abandonment in this and other regions of the world. 相似文献
998.
We review evidence from human biology—paleopathological and isotopic paleodietary studies on ancient Maya skeletons—to assess the validity of ecological models of the Classic Maya collapse, in which elevated disease and deteriorating diet are commonly assumed. To be upheld, the health arguments of ecological models require that the Maya disease burden (1) was greater than that for many other societies and (2) increased over the span of occupation. The dietary argument requires (1) consistent change in diet from Preclassic and Early Classic Periods to the Terminal Classic and (2) increasing social divergence in diet. A correlation between diet and disease is necessary to link these arguments. Neither pathology nor isotopic data consistently support these criteria. Instead, it appears that local environmental and political factors created diversity in both disease burden and diet. In view of the human biological data, we are skeptical of ecological models as generalized explanations for the abandonment of Classic Maya sites in the southern lowlands. 相似文献
999.
SABAH A. JASIM 《Arabian Archaeology and Epigraphy》1996,7(1):1-12
This article reports on the excavations of a coastal site in Sharjah dating to the 5th millennium BC at which examples of painted c Ubaid pottery, probably of Mesopotamian origin, were found. 相似文献
1000.