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   4287篇
  免费   121篇
  2020年   42篇
  2019年   50篇
  2018年   176篇
  2017年   162篇
  2016年   184篇
  2015年   74篇
  2014年   68篇
  2013年   1068篇
  2012年   108篇
  2011年   189篇
  2010年   167篇
  2009年   96篇
  2008年   117篇
  2007年   137篇
  2006年   63篇
  2005年   70篇
  2004年   57篇
  2003年   30篇
  2002年   39篇
  2001年   60篇
  2000年   49篇
  1999年   56篇
  1998年   38篇
  1997年   43篇
  1996年   38篇
  1995年   30篇
  1994年   37篇
  1993年   42篇
  1992年   44篇
  1991年   35篇
  1990年   29篇
  1989年   36篇
  1988年   34篇
  1987年   45篇
  1986年   30篇
  1985年   48篇
  1984年   37篇
  1983年   65篇
  1982年   48篇
  1981年   55篇
  1980年   54篇
  1979年   38篇
  1978年   40篇
  1977年   58篇
  1976年   42篇
  1975年   44篇
  1974年   31篇
  1973年   29篇
  1972年   26篇
  1971年   33篇
排序方式: 共有4408条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
The Campania was a fertile area, with a growing population during the eleventh and twelfth centuries, and was economically more advanced than most of the rest of southern Italy. This essay examines the impact of the Norman conquest of the south upon this region, with special reference to the settlement pattern and the aristocracy. It concludes that the role of incastellamento in changing the pattern of settlement was relatively limited, and the extensive incastellamento of the Montecassino lands (a product of Norman pressure upon the abbey) cannot be taken as typical. Furthermore, while the Norman conquest led to colonisation by French aristocrats, this did not entirely displace existing Lombard families, and widespread intermarriage led to a blurring of the distinction between Lombards and Normans. The impact of political crises during the twelfth century was also more limited than might be supposed, and continuity rather than change characterised the nobility of the Norman period.  相似文献   
106.
107.
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   
108.
Charles Edouard Brown-Séquard used observation of recovered patients and experimental animals to support his theory of cerebral localization. Recovery theories assume that the nervous system is composed of one organ or many, and that each organ has one function or many. From his own studies as well as others, Brown-Séquard concluded that the brain contained at least nine separate organs, each with a single distinct function, and that each organ is organized, not as a geographically isolated cluster of neurons, but as a widely disseminated network. According to his view, function is not uniformly distributed in an organ. Focal necrosis of part of an organ temporarily inhibits the action of distant, undamaged parts; resolution of this inhibition results in recovery. Using this theory of cerebral localization and recovery, Brown-Séquard practiced an early form of scientific neurology.  相似文献   
109.
110.
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