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   482篇
  免费   16篇
  2023年   7篇
  2022年   11篇
  2021年   1篇
  2020年   17篇
  2019年   22篇
  2018年   30篇
  2017年   18篇
  2016年   19篇
  2015年   11篇
  2014年   18篇
  2013年   88篇
  2012年   28篇
  2011年   30篇
  2010年   16篇
  2009年   23篇
  2008年   27篇
  2007年   19篇
  2006年   18篇
  2005年   17篇
  2004年   19篇
  2003年   10篇
  2002年   9篇
  2001年   4篇
  2000年   9篇
  1999年   5篇
  1998年   3篇
  1997年   8篇
  1996年   2篇
  1995年   4篇
  1994年   1篇
  1991年   1篇
  1988年   1篇
  1983年   1篇
  1979年   1篇
排序方式: 共有498条查询结果,搜索用时 46 毫秒
1.
The soluble and exchangeable ions for a soil profile from the Roonka archaeological site. Lower Murray Basin, South Australia, are compared with the total elemental content of the soils. Since the chemical composition of post-mortem ionic substitution phases and secondary minerals in archaeological bone will depend on the availability of ions to the soil solution under field conditions, it is suggested that models addressing diagenesis in bone employ soluble and exchangeable ions rather than total elemental soil data.  相似文献   
2.
地理学家的演讲与他们运用文字、图象所作的交流同样值得重视.美国的地理学可以通过下述途径得到加强,即围绕地点、地区和全球联系发展实质性演讲,促进自然地理的发展,恢复地理生态的传统.地理信息系统(geographic information systems)对于完成上述任务,对于改进地理学科以满足不断出现的需要,将是一个非常有用的工具.如果我们能够避免自己拆自己的台,避免不现实的空想,避免玩弄语言技巧,而是坚持在大学里进行高质量的教学,并在教师和从事地理实践工作的人员之间开展学术交流,那么地理学将会变得更加有效.我们有一个前所未有的机会来帮助改进美国的中小学地理教育.  相似文献   
3.
This paper examines middle-range theory (MRT) within processual and postprocessual archaeology. An analysis of the Binford-Schiffer dispute serves as a means of clarifying what MRT in processual archaeology is or is intended to be. Postprocessualists, despite their vigorous criticisms of MRT-based approaches, are found to rely on the same resources and types of reasoning to make their inferences. In their practice they tacitly turn to processualist middle-range principles, and so the justification of postprocessual interpretations is equivalent to that of MRT-based processualist models. If the middle range is functionally defined — a space within a research program occupied by varying theories that are taken from the body of general theory to which the program is committed and that function as background knowledge in the verification of theories — MRT bridges the epistemological gap between processual and postprocessual approaches.  相似文献   
4.
We consider the history, present, and future of radiocarbon dating in the American Southeast. We point out some of the past and present flaws related to archaeological research and dating. Our approach to this review is rooted in the perspective that each radiocarbon date collectively adds to our knowledge of the region and not just a particular site. Based on our observations, we suggest some “good” practices with respect to certain aspects of radiocarbon dating. Our concluding discussion considers Bayesian chronological analysis and the growing contribution of chronological modeling to the Southeast.  相似文献   
5.
There is a wide gap between planning ideology and planning practice in some regimes. In planning practice, contextual differences and traditional practices affect urban spatial configurations and their related societal dimensions, and also influence the legislative and administrative systems that dictate the process and production of the built environment. This is linked to situations where hidden practices and power relations among key actors may limit democratic participation in the planning process and challenge ethical practice. This paper focuses on the emerging traditions of planning practice in Turkey. We argue that by understanding the role(s) of the key actors in the process and investigating approval processes in detail, it can become evident that planning ‘on the ground’ is often tokenistic and circumvented by hegemonic power relations and tactical actions. These latter in turn side-step a requirement for democratic participation and encourage a ‘loosening’ of planning ethics.  相似文献   
6.
7.
Two sets of twelve Portland limestone tablets were attached to carousels outside and under the open, lightweight shelter at Bishop’s Palace (Witney, England) for 18 months to assess the influence of shelters on soiling and microbiological growth on stone. At the start, and at 6-month intervals, tablets were analysed using microscopy (optical and SEM), colour measurement (spectrophotometry), weight change measurement and salt content determination (ion chromatography). Concentrations of NO2 and SO2 were also monitored for a month using diffusion tubes. In addition, results were compared with those obtained by the UK National Materials Exposure Programme (NMEP) on chemical weathering rates. Differences in soiling and biological growth on sheltered and unsheltered samples, and their influence on limestone decay were established. The shelter is likely to reduce biological growth by modifying the micro-environmental conditions. However, it may also exacerbate dust deposition, which might increase decay rates in the long-term.  相似文献   
8.
9.
10.
韦正 《东南文化》2016,(4):6-10
政治史取向和类型学方法在保证汉唐考古取得很大成绩的同时,也制约了汉唐考古的研究范围、理论建设,并影响到汉唐考古研究者的知识结构和思维方式。新出土资料的减少迫使汉唐考古改变"能源型"发展模式,其他人文学科的发展则为汉唐考古向"技术型"转变带来机遇。汉唐考古研究者的主要工作从归纳总结考古资料,转变为以历史文献为基础,借鉴其他人文学科的方法论,对汉唐考古材料的内涵和意义进行解释,是汉唐考古研究的发展趋势。  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