全文获取类型
收费全文 | 1335篇 |
免费 | 87篇 |
专业分类
1422篇 |
出版年
2024年 | 7篇 |
2023年 | 27篇 |
2022年 | 9篇 |
2021年 | 5篇 |
2020年 | 71篇 |
2019年 | 43篇 |
2018年 | 115篇 |
2017年 | 127篇 |
2016年 | 103篇 |
2015年 | 61篇 |
2014年 | 63篇 |
2013年 | 333篇 |
2012年 | 47篇 |
2011年 | 45篇 |
2010年 | 32篇 |
2009年 | 28篇 |
2008年 | 36篇 |
2007年 | 17篇 |
2006年 | 26篇 |
2005年 | 23篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 18篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1969年 | 2篇 |
1962年 | 1篇 |
1959年 | 2篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1950年 | 3篇 |
排序方式: 共有1422条查询结果,搜索用时 0 毫秒
101.
Pauline Burger Armelle Charrié-Duhaut Jacques Connan Pierre Albrecht 《Archaeological and Anthropological Sciences》2011,3(2):185-200
Plant and particularly non-wood forest products have played an important role in the evolution of human cultures all over
the world, as source of food but also of raw substances fulfilling material, spiritual, and medicinal requirements. Plant
exudates and particularly dammar resins (Dipterocarpaceae family) were widely used in the past in Asia notably as waterproofing
and caulking materials. This study focuses on the GC–MS chemical characterisation of freshly collected dammars and establishes
new molecular parameters enabling discrimination between dammars and other types of plant resin, whatever their botanical
origin. Such analyses provide clues for a precise identification (taxonomy, occurrence of other material in addition to the
resin, alteration state) of unknown resinous material discovered in archaeological contexts. The value of our approach is
illustrated by the taxonomic characterisation of two samples collected in jars from the Brunei wreck and a Chinese junk lost
more than 40 km off the Sultanate of Brunei during the end of the fifteenth century or the early beginning of the sixteenth
century. 相似文献
102.
103.
Relying on stochastic frontier analysis we propose a methodology to study the technological characteristics and cost efficiency levels related to the provision of public infrastructure for basic utilities. The methodology assumes a cost minimizing behaviour on the part of public officials when planning the construction of local infrastructure, which is represented by way of a flexible translog cost function. Introducing relevant definitions of scale economies, associated with larger numbers of inhabitants and dwellings, as well as economies of density, brought about by reductions in urban dispersion, we analytically determine the optimal population densities for which average cost is minimized. We illustrate our model with the water cycle sector, including water distribution, sewage collection and cleansing of wastewater, and considering data at the municipality level for the Spanish region of Castilla y León. The obtained results indicate potential cost savings in the form of decreasing average costs, as relevant scale and density economies are present, along with large inefficiency levels. Relevant policy guidelines favouring larger and denser urban sizes are drawn, as the observed cost excess is the result of a general suboptimal urban size in terms of population density, and the negative effects of dispersed settlement patterns. 相似文献
104.
This article analyses European ‘youth riots’ as a social phenomenon after World War II. It also uses a specific riot – the 1948 Stockholm Easter Riots – in order to discuss the limits and potential of some theoretical assumptions underlying the field of historical contentious politics studies, primarily ‘contentious politics’ and ‘claims’. Using police reports and newspapers, the article shows that the riots were part of a European repertoire of post-war ‘youth riots’, but that they also bear similarities to an older popular repertoire of contention in Sweden. However, the riots do not really fit into the concept of ‘contentious politics’, as this concept is built on ‘claim-making’ as a key aspect and the participants did not make explicit claims. This leads to the conclusion that other theoretical tools, inspired by the concept of ‘moral economy’, are better suited for understanding the motivations of the rioters, whose actions are interpreted as a way of defending a perceived moral right of access to the urban public space. 相似文献
105.
Véronique Favre-Bonte Elodie Gardet Catherine Thevenard-Puthod 《European Planning Studies》2019,27(5):1035-1057
As there is little research on the link between territories and interorganisational networks, this paper examines how the nature of a territory influences the characteristics of innovation networks. It compares the innovation network forms of two types of territories (high-altitude and medium-altitude mountain resorts) regarding four characteristics of networks widely debated in the literature: the nature of the relationships between members, the mode of regulation used, the architecture, and the geographical proximity of members. This research makes a significant contribution to both the spatial development and innovation management literature: indeed, our results show that according to the nature of the territory, innovation networks differ in terms of partners, geographical proximity, and regulation mode. However, the nature of the territory does not seem to influence the architecture of the innovation network since those networks need a hub organization that orchestrates the partners’ actions. These results, by providing a better understanding of the characteristics of innovation networks, help tourist territories to better attract customers. 相似文献
106.
107.
Sibrecht Reniere Aurélie Thiébaux Roland Dreesen Éric Goemaere Wim De Clercq 《Oxford Journal of Archaeology》2018,37(3):313-337
The purpose of this paper is to demonstrate cross‐Channel exchange of calcareous sandstone‐type whetstones derived from the Weald (Sussex, UK) in the Roman period. The presence of this particular type of whetstone at several Roman sites on the Continent – more specifically, in Belgium, France and the Netherlands – is reported for the first time. The morphology, geological provenance, petrographic characteristics and distribution patterns are discussed, based on a comparative analysis with archaeological and geological reference material. The geological analysis identifies a common geological source for the Continental finds: the very fine‐grained, thin‐bedded, flagstone‐like calcareous sandstone beds of the Lower Cretaceous Wealden Clay Formation. These sandstones were, most probably, extracted in the north‐western part of the Weald area. The distribution pattern of the archaeological material implies the importance of personal mobility, with potential military affinities. 相似文献
108.
María Isabel Mota-López Rafael Fort Mónica Álvarez de Buergo Antonio Pizzo Rubén Maderuelo-Sanz Juan Miguel Meneses-Rodríguez Duygu Ergenç 《Archaeological and Anthropological Sciences》2018,10(5):1007-1022
The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments. 相似文献
109.
At Nunalleq, a pre-contact Yup'ik Eskimo village site in Alaska (14th–17th century AD), abundant insect remains from highly organic substrates preserved within permafrost offer a unique opportunity to investigate past ecological and living conditions. This paper presents the preliminary results obtained from the analysis of two samples collected from floor layers in sod houses. The numerous and diverse insect remains highlight the exciting potential of archaeoentomology for reconstructing past ecological conditions, resource exploitation and the use of space at northern hunter–gatherer sites and have permitted the development of a strategy for the future collection of archaeoentomological data at permafrost-preserved sites in Alaska and elsewhere. 相似文献
110.
José Luis Hervás Oliver José Albors Garrigós Juan Ignacio Dalmau Porta 《European Planning Studies》2008,16(4):507-520
Classical industrial districts' literature is not focused on the role played by external ties but gives more importance to the local districts' endogenous development. Global value chains connect clusters to other external agents through external linkages and constitute a framework to analyse the complex inter-linkages between clusters and other external agents. In the field of the external ties and the global value chain approach Academia is primarily focused on the ties which link clusters in developing nations to global markets, although global value chains also consider connections between clusters in similar activities and even when both are located in developed nations. Thus, external linkages are mainly performed by multinational enterprise (MNE) affiliates which play fundamental role of knowledge diffusers and absorbers in the process of knowledge exchange throughout global value chains. The work examines the process of knowledge exchange between clusters through external ties using the global value chain approach. For this purpose, empirical work is conducted with 22 face-to-face interviews to provide a case study about a leading cluster in the global ceramic tile industry. Results show that the basic knowledge to successfully compete is locally originated, although it can be complemented with global knowledge learnt or generated in other territories. MNE affiliates bridge structural holes through external ties and reduce knowledge asymmetries within global value chains. External ties on network-based governance chains exist, matter and affect clusters allowing upgrading even between developed nations. 相似文献