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   98篇
  免费   3篇
  2023年   2篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   3篇
  2016年   2篇
  2015年   1篇
  2013年   23篇
  2012年   2篇
  2010年   5篇
  2009年   7篇
  2008年   1篇
  2007年   1篇
  2006年   3篇
  2005年   1篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2001年   2篇
  1999年   4篇
  1998年   1篇
  1997年   1篇
  1995年   4篇
  1993年   2篇
  1992年   2篇
  1991年   4篇
  1990年   2篇
  1986年   1篇
  1985年   2篇
  1983年   1篇
  1982年   3篇
  1977年   1篇
  1976年   2篇
  1975年   2篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
排序方式: 共有101条查询结果,搜索用时 15 毫秒
21.
22.
Gregg, Susan Ailing. Foragers and Farmers: Population Interaction and Agricultural Expansion in Prehistoric Europe. Chicago: The University of Chicago Press, 1988. xx + 275 pp. including index and bibliography. $24.95 cloth, $9.95 paper.

Hastorf, Christine A., and Virginia S. Popper. Current Paleoethnobotany: Analytical Methods and Cultural Interpretations of Archaeological Plant Remains. Chicago: University of Chicago Press, 1988. xii + 236 pp. including chapter references and index. $24.95 cloth, $9.95 paper.

Pearsall, Deborah M. Paleoethnobotany: a Handbook of Procedures. San Diego: Academic Press, 1989. xii + 470 pp. including chapter references and index. $59.95.  相似文献   
23.
Abstract

The collapse of empires is exceedingly difficult to understand. The author examined the distribution of imperial lifetimes using a data set that spans more than three millennia and found that it conforms to a memoryless exponential distribution in which the rate of collapse of an empire is independent of its age. Comparing this distribution to similar lifetime distributions of other complex systems—specifically, biological species and corporate firms—the author explores the reasons behind their lifetime distributions and how this approach can yield insights into empires.  相似文献   
24.
As the only type of instrument capable of determining artifact geochemistry in a wide variety of settings, portable X-Ray Fluorescence (PXRF) may be frequently utilized as probably the best option for collecting data when removal of objects in part or in whole is unfeasible. However, using PXRF in circumstances where sample selection and preparation diverge from standards developed for lab-based instrumentation requires assessing the impact of new and potentially limiting factors to establish the validity of the method in these new contexts. Here we examine the effects of surface contamination and chemical weathering on the ability to assess provenance of igneous building stones used in the Cuzco region of Peru. Surface contamination was assessed through comparing low-impact cleaning methods on diorite and andesite blocks, and weathering was examined by comparing weathered vs. fresh surfaces of samples from two andesite quarries. In general, the lightest elements were most impacted by contamination and weathering while measurements of many of the heavier elements commonly used in provenance studies were relatively unaffected. Concentrations of Pb and Zn were problematic in the urban context of Cuzco because of pollution. Ability to determine provenance of building stones within those limitations (i.e., the validity of this application of PXRF) was demonstrated in a preliminary study by comparing measurements from uncleaned, exposed building stones in the region to fresh quarry samples.  相似文献   
25.
26.
27.
28.
29.
30.
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