全文获取类型
收费全文 | 623篇 |
免费 | 63篇 |
出版年
2023年 | 3篇 |
2021年 | 8篇 |
2020年 | 21篇 |
2019年 | 29篇 |
2018年 | 37篇 |
2017年 | 32篇 |
2016年 | 44篇 |
2015年 | 22篇 |
2014年 | 20篇 |
2013年 | 108篇 |
2012年 | 24篇 |
2011年 | 28篇 |
2010年 | 26篇 |
2009年 | 38篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 25篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 5篇 |
2002年 | 11篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有686条查询结果,搜索用时 15 毫秒
1.
Y. Zhang L. Wei Z. Cui T. Zhang Y. Lei A. Gu Y. Chen L. Y. Zhang Z. X. Du 《Archaeometry》2020,62(3):660-676
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.
Y. H. Dennis Wei 《Geografiska annaler. Series B, Human geography》2011,93(3):237-251
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.
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
5.
6.
Kubo Y 《Journal of regional science》1986,26(3):579-593
"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
7.
8.
9.
Lucia Lo 《Geographical analysis》1991,23(2):132-146
This paper attempts to distill the relationship among spatial structure, consumer preferences, and spatial interaction. It introduces the notion of substitutability. Destinations are substitutable in both economic-behavioral and physical-locational senses. Inadequate treatment of this can lead to variations in the estimated parameters of conventional spatial interaction models. 相似文献
10.
Daganzo (1977, 1979), Daganzo and Sheffi (1977), Sheffi (1985), and Sheffi and Daganzo (1980) have used one assumption about traveler behavior in developing estimation techniques for the stochastic route-choice problem and another assumption in predicting flows on networks by using the same model. In estimation, they calculate the congested travel costs of the network links from observed flows on the network, and the network is loaded based on these costs. In prediction, they follow their stochastic user-equilibrium assumption by which travelers evaluate costs using the mean of the observed flows (or equilibrium flows). The travel-cost coefficient obtained from the loading method systematically overestimates the true travel-cost coefficient from which the observed flow data (which must be used in loading) is generated. The estimates of the same coefficient, obtained in this paper, by constraining the estimation results to conform to the equilibrium conditions are unbiased, and only marginally less efficient (have larger standard deviations). The average percentage error and inefficiency of the link flow predictions based on the loading method increases as the level of congestion on the network rises. In contrast, the average percentage error of link flow predictions based on the equilibrium estimation method declines and their efficiency remains very high as the level of congestion on the network rises. 相似文献