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   12123篇
  免费   325篇
  2024年   30篇
  2023年   140篇
  2022年   189篇
  2021年   177篇
  2020年   482篇
  2019年   468篇
  2018年   510篇
  2017年   513篇
  2016年   520篇
  2015年   319篇
  2014年   363篇
  2013年   1516篇
  2012年   746篇
  2011年   671篇
  2010年   512篇
  2009年   603篇
  2008年   622篇
  2007年   706篇
  2006年   660篇
  2005年   626篇
  2004年   462篇
  2003年   444篇
  2002年   352篇
  2001年   251篇
  2000年   269篇
  1999年   77篇
  1998年   38篇
  1997年   29篇
  1996年   28篇
  1995年   18篇
  1994年   22篇
  1993年   21篇
  1992年   16篇
  1991年   15篇
  1990年   6篇
  1989年   1篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   7篇
  1982年   3篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
甘肃酒泉、嘉峪关壁画墓霉菌分离鉴定与防治研究   总被引:1,自引:1,他引:0  
通过对墓葬壁画霉菌分离鉴定,筛选出合适的防霉材料,对壁画进行防霉处理是解决未搬迁尚很潮湿壁画墓科学保存问题的一个重要方面。  相似文献   
62.
The Revolution of 1959 brought forth changes in the mission, theoretical orientation, and organization of archaeology in Cuba and created a role for, and constraints on, the profession that are unique in the Western Hemisphere. This paper draws upon examples from substantive field and laboratory research to examine the methods and theoretical perspectives of Cuban archaeology since the Revolution, focusing on the period from 1962 until the collapse of the Soviet Union. Archaeological practice during the Revolutionary period in Cuba has reflected the aims of the Revolutionary government, the influence of Soviet archaeology, the legacy of pre-Revolutionary approaches in North American archaeology, and the Cuban sense ofpatria.  相似文献   
63.
Much practically orientated environmental research is marked by a polarity between functionalist abstraction and ahistorical normative discourse. This paper seeks to bridge the divide between theoretical and empirical research through a case study of New York City's water supply. Current processes of socio-economic restructuring are leading to negative environmental consequences obscured by a failure to extend analysis beyond limited temporal, spatial or sectoral scales. Insights from regulationist theory show that a combination of fiscal, political and other developments are bringing about a wide-ranging reformulation of existing patterns of environmental regulation and service provision in the city. The power of the state is being radically diminished in relation to the power of capital and a plethora of different interest groups. A relatively simple centralized model of environmental regulation is being transformed into a complex decentralized pattern involving the emergence of new approaches to urban governance. Further research is needed on the contradictions between capitalist accumulation and environmental regulation at different spatial scales in order to link New York's changing role within the global economy to the declining political legitimacy and fiscal capability of the state to play an extensive role in environmental management.  相似文献   
64.
The chronology of the period is briefly considered in the light of the dendrochronological results which have appeared in recent years. Patterns of settlement history in different parts of the area are then examined, and it is suggested that in some of them the late fourth millennium was a period of population decline which was not reversed until the Early Bronze Age, 1000 years later. Detailed information about specific local occupation patterns is provided by recent work on the circum-Alpine lake villages. Changes in cultural patterns during the period, especially the appearance of the Corded Ware, are discussed and explanations of them reviewed. It is argued that changing patterns of gender relations were a major feature of the period, linked to processes which eventually led to the development of small-scale chiefdoms. The development of copper and bronze metallurgy and its connection to these processes are discussed.  相似文献   
65.
66.
67.
68.
In the last decade, conversations around queering of GIScience emerged. Drawing on literature from feminist and queer critical GIS, with special attention to the under‐examined political economy of GIS, I suggest that the critical project of queering all of GIS, both GIScience and GISystems, requires not just recognition of the labour and lives of queers and research in geographies of sexualities. Based upon a queer feminist political economic critique and evidenced in my teaching critical GIS at two elite liberal arts colleges, I argue that the “status quo” between ESRI and geography as a field must be interrupted. Extending a critical GIS focus beyond data structures and data ethics, I argue that geographic researchers and instructors have a responsibility in queering our choice and production of software, algorithms, and code alike. I call this production and choice of democratic, accessible, and useful software by, for, and about the needs of its users, good enough software.  相似文献   
69.
The original fineness of coins is very important information that can help us to understand the commercial situation in a wide historical context. This paper deals with a comparison of analytical methods suitable for the evaluation of the actual and original fineness of coins based on a detailed case study of a medieval coin sample. Both non‐destructive (i.e., scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, X‐ray fluorescence, atomic force microscopy and hydrostatic weighing) and destructive (i.e., inductively coupled plasma – mass spectrometry and the Volhard titration method) techniques were used. The original fineness can be also deduced from knowledge of the internal structure of the coin (limited miscibility of copper and silver). A new analytical method based on a combination of a micrograph of the metallographic cross‐section with consequent image analysis was developed for determination of the original fineness. The proposed approach is relatively simple and provides reliable values. Sample heterogeneity and its impact on the determination of fineness are also discussed.  相似文献   
70.
G. Hervé  P. Lanos 《Archaeometry》2018,60(4):870-883
We present a new curve of the directional secular variation of the geomagnetic field in Western Europe between 1500 bce and 200 ce . Its computation relies on a Bayesian framework. The fast secular variation during the Late Bronze and Early Iron Ages makes archaeomagnetic dating efficient with a respective precision of 150–200 and 60–100 years during these periods. The Bayesian method also provides posterior date distributions that refine the dating of reference data, especially during the period of the Hallstattian radiocarbon plateau. Archaeomagnetism becomes a valuable alternative to radiocarbon and will help to improve the archaeological chronologies.  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