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   1056篇
  免费   82篇
  2024年   6篇
  2023年   24篇
  2022年   9篇
  2021年   4篇
  2020年   56篇
  2019年   29篇
  2018年   95篇
  2017年   100篇
  2016年   84篇
  2015年   52篇
  2014年   47篇
  2013年   263篇
  2012年   41篇
  2011年   40篇
  2010年   26篇
  2009年   26篇
  2008年   25篇
  2007年   9篇
  2006年   19篇
  2005年   14篇
  2004年   9篇
  2003年   11篇
  2002年   14篇
  2001年   12篇
  2000年   7篇
  1999年   8篇
  1998年   12篇
  1997年   6篇
  1996年   6篇
  1995年   6篇
  1994年   5篇
  1993年   10篇
  1992年   7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   3篇
  1981年   3篇
  1979年   1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1138条查询结果,搜索用时 31 毫秒
11.
In the Andes, there are several pre-Hispanic irrigation networks with structures destined for water storage. However, it has not been widely discussed in archaeological research. This is probably due to their being difficult to identify. The aim of this study is to explore the use of diatom assemblage analysis as a methodological tool suitable to help in the identification and characterization of these ancient hydraulic structures. We analyzed two archaeological structures interpreted as water reservoirs from north-western Argentina (EH1 in Antofagasta de la Sierra and U-88R1 in Yocavil) and compared them to current reservoirs. The diatom species composition and the changes in the dominant ecological groups in the studied structures highlight different periods of hydraulic behavior. EH1 contained and stored water, but there were periods of time in which there was a lack of use or abandonment of the structure. However, the U88-R1 structure does not have diatom evidence of containing standing water for a prolonged time but presence of wet soils. Thus, the structure could have been used for other water management strategies. The results show that diatom analysis is a methodological tool with a high potential to study ancestral hydrotechnologies.  相似文献   
12.
13.
14.
15.
Tráfico de Indias y política oceánica. By Fernando Bordejé Y Morencos. Madrid: MAPFRE, 1992. Pp. 341.

Relaciones económicas entre España y América hasta la independencia. By John R. Fisher. Madrid: MAPFRE, 1992. Pp. 280.

Las comunicaciones en América. By Secundino‐José Gutiérrez Alvarez. Madrid: MAPFRE, 1993. Pp. 424.

Piratas, bucaneros, filibusteros y corsarios en América. Perros, mendigos y otros malditos del mar. By Manuel Lucena Salmoral. Madrid: MAPFRE, 1992. Pp. 306.

El dinero americano y la política del imperio. By María Emelina Martín Acosta. Madrid: MAPFRE, 1992. Pp. 333.

Cargadores a Indias. By Julian B. Ruiz Rivera and Manuela Cristina García Bernal. Madrid: Mapfre, 1992. Pp. 395.  相似文献   

16.
Concepts of unemployment or of the labour market are not abstract, but develop from each society's own particular logic. Taking the examples of Germany and France at the end of the nineteenth century, it is possible to see how these concepts were constructed in specific national contexts, and how they were then used in practice. This analysis leads us to rethink current ideas about work and unemployment, and to ask what their future will be in a united Europe.  相似文献   
17.
18.
The present paper surveys the discussions conducted by official statisticians regarding the ideal structure according to which a national data collection system should have been designed if it was to meet the challenges put up by the various transformation Western countries have undergone since the beginning of the 19th century. Arguments in favour of coordination, centralization, or decentralization have emerged for the first time in 1832 Britain, when the Statistical Bureau of the Board of Trade was created. Up to 1945, this debate went on, the industrial take-off, the economic crises, and the world wars all being occasions for its protagonists to put forward their preferred view. The perspective we take here is original in two respects: on the one hand, instead of confining ourselves to the major statistical systems (those of France, Britain, and the USA), we intend to evoke a large number of cases and, from this comparative standpoint, propose a general account of the drive towards centralization; on the other hand, instead of restraining our-selves to the 19th century, we cover the entire time-frame extending from 1800 to 1945.  相似文献   
19.
20.
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