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   721篇
  免费   69篇
  2024年   3篇
  2023年   7篇
  2022年   12篇
  2021年   16篇
  2020年   30篇
  2019年   26篇
  2018年   43篇
  2017年   24篇
  2016年   43篇
  2015年   36篇
  2014年   26篇
  2013年   84篇
  2012年   31篇
  2011年   37篇
  2010年   47篇
  2009年   40篇
  2008年   32篇
  2007年   31篇
  2006年   35篇
  2005年   21篇
  2004年   24篇
  2003年   9篇
  2002年   15篇
  2001年   13篇
  2000年   8篇
  1999年   9篇
  1998年   4篇
  1996年   3篇
  1995年   3篇
  1994年   5篇
  1993年   7篇
  1992年   9篇
  1991年   4篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   5篇
  1984年   4篇
  1983年   3篇
  1982年   4篇
  1981年   4篇
  1980年   3篇
  1978年   2篇
  1976年   4篇
  1974年   2篇
  1970年   2篇
  1963年   1篇
  1951年   2篇
  1950年   1篇
排序方式: 共有790条查询结果,搜索用时 15 毫秒
1.
Palace lanterns were important and highly visible decorations in the imperial palace in Beijing, China, during the Qing dynasty (1636–1912). Most lanterns had colourful tassels made of fibres. The study performed a comprehensive investigation of the materials and dyes used for palace lantern tassels preserved in The Palace Museum, Beijing. Eight samples with different colours, including yellow, green and red, from five palace lanterns were analysed. By using ultra-performance liquid chromatography combined with time-of-flight mass spectrometry, the compositions of the dyes were identified quickly, and thus the dyes' origins were explored. A X-ray fluorescence spectrometer assisted in the detection of whether a mordant was used during the dyeing process. As a result, the tassels were all made of silk, discovered through the use of microscopic observation and micro-Fourier transform infrared spectrometry analysis. Different dyeing techniques were found in these tassels: yellow tassels were dyed by cork tree or turmeric by a direct dyeing method; greens were dyed by pagoda bud with an iron mordant, or by the combination of cork tree and indigo using multi-dyeing method; and red tassels were coloured with different acid red industrial dyes. These results provide valuable data for the conservation of ancient textile tassels and contribute to the investigation of other hanging tags.  相似文献   
2.
This article attempts to advance the research on industrial districts and regional development through a study of the restructuring of the clothing industry in Wenzhou Municipality, a regional driver of the Chinese economy. Wenzhou is known for the Wenzhou model of development traditionally centred on family‐owned small businesses embedded in local institutions. The clothing industry is one of the leading industries in Wenzhou, and a cluster with national significance has emerged, where most of the production components can be purchased locally. However, the industry has been scaled up nationally and internationally, with the expansion of sales networks and production facilities across China, and to a lesser extent, abroad. This restructuring has changed the endogenous nature of industrial clusters/districts. The restructuring challenges the orthodox notion of the Wenzhou model and the New Regionalism literature, particularly the orthodox notion of Marshallian industrial districts that overly emphasizes small firms and local assets, and the global production network perspective that highlights coupling with global lead firms in regional development.  相似文献   
3.
4.
5.
ABSTRACT. In a simple urban model, where the only spatial distinction made is between center and suburb, we introduce a uniform distribution of preferences for land. Under a logarithmic utility function, we examine how the location and consumption decisions of individuals differ in consequence of their different preferences for land. Comparative statics indicate that the qualitative response of the city at equilibrium to changes in per capita income and transportation cost is not affected by the introduction of such heterogeneity. Possible extensions are also briefly discussed.  相似文献   
6.
7.
"This paper examines the mechanism and extent of urban concentration using a two-sector growth model. The cause of urbanization is sought in the existence of urban scale economies. Assuming that temporary production decisions are concerned with optimal labor inputs and that profit incomes are reinvested according to relative profitability, the model shows persistent tendency for urban concentration and the transition of the economy from unlimited to limited labor supply. A simple example suggests that urban concentration is more likely than rural expansion with urban contraction."  相似文献   
8.
9.
针对莫高窟在保护利用数据传输过程中出现的问题与发展趋势,提出了利用无线网络深度覆盖技术构建数据传输平台,解决莫高窟大型洞窟内保护利用数据无法传输的问题。为构建实用性强的传输平台,采取了如下措施。首先,针对莫高窟保护利用各项业务数据采集、传输模式、传输机制等各阶段特点,提出了基于无线网络深度覆盖技术构建数据传输试验平台的需求;其次,设计了试验平台构建方案,依据莫高窟洞窟分布与建筑形制确定了试验平台构建位置。结合莫高窟目前无线网络覆盖现状,通过选型分析确定了无线网络深度覆盖关键技术,并应用该技术构建试验平台;最后,对试验平台无线信号覆盖范围、信号强度、传输性能、安全性等进行验证,确保数据传输的完整性与连续性。此试验平台已运行一年有余,应用效果良好。  相似文献   
10.
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