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   444篇
  免费   35篇
  2024年   2篇
  2023年   15篇
  2022年   1篇
  2021年   7篇
  2020年   15篇
  2019年   33篇
  2018年   47篇
  2017年   46篇
  2016年   39篇
  2015年   26篇
  2014年   27篇
  2013年   81篇
  2012年   23篇
  2011年   21篇
  2010年   21篇
  2009年   18篇
  2008年   9篇
  2007年   4篇
  2006年   3篇
  2005年   10篇
  2004年   5篇
  2003年   3篇
  2002年   5篇
  2001年   5篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1992年   1篇
  1988年   1篇
排序方式: 共有479条查询结果,搜索用时 15 毫秒
31.
In the great civilisations of the past, shapeshifting promised a restoration of order in turbulent times in return for the deference of loyal subjects. It was a strategy of the powerful to maintain advantage and could also be used to bind opponents to an undesired form. This study finds its resonance in the contemporary shapeshifting that is the supposed transition from the fossil fuel economy. With reference to the fusion of oil, grain and sugar companies in Brazil's ethanol sector, it explores how amidst economic, environmental and political insecurity these “old villains” of the carbon economy have fused and emerged as the “new heroes” of the green economy. Accounts of dissenting rural subjects, however, unveil the mythical nature of avowed social gains from this shapeshifting. Amidst rural conflict and a successive weakening of regulation, it becomes evident how their petrification, in a metaphorical and increasingly literal sense is required.  相似文献   
32.
This article analyses the evolution of Community expenditure, on the basis of the data given in the budget and in the EDF, from the origin of the process in 1957 until the year 2002, the last definitive figures. The technique of principal component factor analysis has been applied to these variables. The basic objective of this study is to detect the interrelationships among the policies of the Union and to effect a classification of them, in order to detect the priorities of the European project and to estimate the dimension of the impact of its policies during the period.  相似文献   
33.
The Qhapaq-Ñan Project promotes the integration of shared cultural values among six countries: Argentina, Chile, Bolivia, Peru, Ecuador and Colombia. These countries are collaborating to nominate the Main Andean Road or “Qhapaq-Ñan” for inclusion on UNESCO’s World Heritage List. Although the participants envision local and Indian communities as the true beneficiaries of the project, and the archaeological effort is already under way, communities associated with the road have not been involved. (At the very moment we are editing this article (March 2007) Argentina is holding the first meeting about a project that is already five years old, with some of the Indian communities of the territories where the project will be carried out. The participation, however, was far below what we expected.). Following the guidelines of the World Archaeological Congress and the current emphasis of many heritage professionals on community participation, we strongly advise that these dynamics must be changed and that the program must be developed jointly with affected communities from the beginning of the project and not in subsequent steps, or (even worse) once the project already taken shape.  相似文献   
34.
The remains of the fragmented skeleton of a mature male individual from a Neolithic mass burial (ca. 5000 years BP) are presented. The lesions consist of osteoblastic proliferation and replacement of previously normal haematopoietic tissue. The most affected area seems to have been the iliac blade. So-called ‘seeding’ of tumour tissue has been found in different loci in the femoral neck, sacrum, L4 and scapula. Differential diagnosis points to metastatic carcinoma, most likely from the prostrate gland. In order to support the observations, radiological and histological analyses have been performed. Trace element analyses of tumour and control samples have shown the limited contribution of these data to ascertain the aetiology of secondary neoplasias in buried material.  相似文献   
35.
A. Tarriño 《Archaeometry》2015,57(5):928-948
A new classification system is proposed to describe the volumetric formats of clastic lithic products of geological and archaeological origin. In order to build this operative classification, the rectangular block or cuboid is established as the standard geometric format to represent their three‐dimensional format (the X‐axis being length or long diameter, the Y‐axis being the width or intermediate diameter, and the Z‐axis being the thickness or short diameter) on a two‐dimensional diagram. To obtain this graph, each absolute coordinate (X, Y, Z) defining the prisms is projected on to an auxiliary plane with a new set of relative coordinates (x, y, z), expressed as the percentage of their sum. The projection generates a triangular diagram on which the indices of elongation and flatness are represented. A geometric transformation converting the triangular diagram into a quadrangular diagram has been produced in order to better represent the scatter points. Then, a double scale is necessary: (i) an absolute scale to quantify the indices, and (ii) a relative scale to calculate where the graphic locus is projected. This new graph also allows us to work with statistical parameters. Finally, two classic examples of applications selected from the literature are shown.  相似文献   
36.
This paper evaluates the impact of accessibility on the productivity of Spanish manufacturing firms. We suggest the use of accessibility indicators of workers and commodities, integrating transport, land use, and individual components, computing real distances or traveling times using the Spanish full road network. Estimated firms’ total factor productivity is explained as a function of the accessibility indicators and additional control variables. Results evidence the crucial role on firms’ productivity to the accessibility of commodities and to a slightly lesser extent the workers.  相似文献   
37.
This review article explores the role nationalism has played in the world dominated by the Eastern Orthodox Churches. The focus is on the recent contributions of Paschalis Kitromilides who has written extensively on this topic. The article assesses the four books dealing with the relationship between religion, politics, Enlightenment and nationalism in the Balkans and Eastern Europe. The analysis emphasises the complex and contradictory relationship between nationalisms and the Orthodox Churches pointing to the profound transformation that has taken the place in this relationship over the last 250 years.  相似文献   
38.
We analyse the isotopic values (δ13C, δ15N) of the diet of pre-Columbian horticulturalist populations from tropical and subtropical areas of southeastern South America, belonging to the Guarani and Taquara archaeological units. The data indicate different trends in each one (T?=?4.21; P?=?0.0004), showing a mixed diet with maize consumption in the Guarani samples (δ13Cco?=??15.5?±?1.8‰; δ13Cap ?10.4?±?0.8‰) and a depleted one in the Taquara ones (δ13Cco ?18.2?±?1.7‰; δ13Cap ?11.9?±?0.9‰), with a significant internal dispersion in both populations. The first population has higher nitrogen values (δ15N 11.1?±?0.6‰) compared to the Taquara samples (δ15N 9.3?±?1‰), suggesting a more carnivorous diet. The recognition of these pre-Columbian mixed diets involves the identification of maize cultivation on the Atlantic side of the southernmost area of South America (Parana Delta, 34° SL). Through the analysis of δ18O we have identified two isotopic ecozones, the first along the Paraná River Valley, with an average value of δ18O ?3.7?±?0.5‰ (CV?=?13.5%; CI?=??3.83 / ?3.16), and the second one, located in the Planalto of southern Brazil (Araucaria Forest), with a mean value of δ18O ?1.5?±?0.3‰ (CV?=?16.5%; CI?=??1.69 / ?1.29). The isotopic data (δ13C, δ15N and δ18O) suggest human movements between these two ecozones.  相似文献   
39.
Este artículo propone una lectura de la Historia del Reino de Quito en la América Meridional (1789), de Juan de Velasco, a partir de las ideas políticas y jurídicas de su autor. Sugiere abordar el tomo tercero de la Historia no solamente como un relato del declive social y económico que aqueja a la Audiencia de Quito, sino como un comentario a la crisis de gobernanza que, según Velasco, inicia con el ascenso de los Borbones al trono. La incapacidad jurídica de controlar la mestización de la sociedad y las desacertadas políticas de las autoridades peninsulares, resultan en la Rebelión de los Barrios de Quito, episodio que representa el clímax de las penurias que atraviesa el Reino y que le permite a Velasco cuestionar el modelo de gobierno establecido por los reformistas ilustrados, abogar por la necesidad de un gobierno criollo y restaurar la desgastada imagen de la Compañía de Jesús.  相似文献   
40.
ABSTRACT

This paper contributes to the study of the role of public policies in the origins and evolution of clusters. Building on the existing literature, we set up a taxonomy of nine public policies that may have an impact on the emergence and evolution of clusters. Based on in-depth case studies of six clusters of the Basque Country, particularly representative of the industrial history of the region, we analyse the relevance of the different types of policies both in the emergence and evolution of clusters over time. In agreement with cluster literature, the paper concludes that public policies seem to have played only an indirect role across clusters and over their life cycles. Moreover, it points to the necessity of taking history and context into account, as most of the important policy measures highlighted by cluster literature today do not fit well with the previous policy and economic context. Finally, it also concludes that for cluster policies to be effective, the stages of the life cycle should be taken into consideration.  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