全文获取类型
收费全文 | 1256篇 |
免费 | 92篇 |
出版年
2024年 | 7篇 |
2023年 | 37篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 56篇 |
2019年 | 59篇 |
2018年 | 151篇 |
2017年 | 111篇 |
2016年 | 106篇 |
2015年 | 81篇 |
2014年 | 74篇 |
2013年 | 256篇 |
2012年 | 56篇 |
2011年 | 49篇 |
2010年 | 44篇 |
2009年 | 35篇 |
2008年 | 34篇 |
2007年 | 24篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 13篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1348条查询结果,搜索用时 31 毫秒
11.
Human bones from Late Eneolithic graves and Bronze Age settlement pits in Moravia (Czech Republic) were studied to reconstruct their post-mortem histories based on the distribution of their microbial destruction. Backscattered electrons in a scanning electron microscope (BSE-SEM) were used for visual assessment of bioerosion. Visual data from the histological analysis were transformed into quantitative data using the Waikato Environment for Knowledge Analysis (WEKA) toolkit. The results show that the presence of bioerosion is different between the two groups of samples. The bones from settlement pits display extensive bioerosion whereas the bones from graves display no or arrested bioerosion. The absence of bioerosion in graves is most probably linked with tomb burials of Corded Ware Culture. Given the tombs are frequently not preserved archaeologically, the state of bone bioerosion may serve as an indicator of their existence. 相似文献
12.
Darío Alejandro Ramirez María José Herrera-Soto Josefina González Andreu Francisca Santana-Sagredo Mauricio Uribe Rodríguez Rodrigo Nores 《Archaeometry》2023,65(5):1073-1089
Faunal remains from archeological sites worldwide, especially feces and regurgitated pellets, are usually subjected to paleoparasitological examination, allowing the identification of past animal parasites. In this study, we analyzed 10 samples of South American camelid dung, which played an important role for the ancient human groups in the South-Central Andes, dated between 341 and 1635 calCE, from the Iluga Túmulos site (Pampa del Tamarugal, Tarapacá region, Atacama Desert, Chile). Microscopy examination revealed parasite remains in seven samples, in which oocysts of Eimeria macusaniensis and eggs of Lamanema chavezi/Nematodirus lamae, Trichuris sp., Moniezia sp., capillariids, strongylids, and unidentified nematodes were found. Although some of these species pose a potential health risk to camelids, most are not considered to be of major zoonotic importance, which could explain the absence of these parasites on human coprolites from this site analyzed previously. This first paleoparasitological study on camelid fecal remains from northern Chile sheds light on the occurrence of gastrointestinal parasites and its relationship with Andean ancient human populations and the environment. 相似文献
13.
Jan Cvrček Sylva Drtikolová Kaupová Zdeněk Vytlačil Eliška Zazvonilová Petr Velemínský 《Archaeometry》2023,65(6):1336-1352
Research into the family of the Counts Swéerts-Sporck raised doubts regarding their biographical data, particularly concerning a child who died in 1817, later identified as Philipp Swéerts-Sporck, and his siblings Joseph and Barbara. These were alleged to include a pair of dizygotic twins, but DNA could not be used to clarify their relationships. Carbon and nitrogen isotopes were therefore measured in their first permanent molars, whereas Philipp's biological age was estimated based on his skeleton. Philipp died at an older age than the written sources claim; an isotopic similarity was found between Joseph and Barbara, but Philipp differed. 相似文献
14.
A new generation of greenways has emerged in recent years, the most ambitious of which are nationwide, interconnected networks of multi-use, multi-purpose greenways and trails, clustered under a single national vision. However, because these initiatives have been the focus of so few research studies, opportunities to glean lessons from their planning and implementation have been limited. This paper contributes to addressing this knowledge gap by presenting a comparative account of two networks, the Trans Canada Trail in Canada and Sendero de Chile in Chile. Using document analysis and interviews with officials closely involved in their development, the evolution of both networks is documented over time, emphasizing similarities and differences related to their planning and implementation. Both initiatives have faced significant challenges in reaching their connection goals and have availed themselves of a diverse range of opportunities and strategies to advance their agendas. A simple model of a virtuous cycle is proposed to highlight the positive feedback—between political and public support, sustained funding, partnership development, accessibility for urban residents, and connectivity of the network—generated by sustained network expansion over time. It is hoped that the insights offered from this analysis may offer guidance to inform the development of similar scale projects elsewhere. 相似文献
15.
Damiaan Persyn Javier Barbero Jorge Díaz-Lanchas Patrizio Lecca Giovanni Mandras Simone Salotti 《Journal of regional science》2023,63(4):755-792
We analyze the general equilibrium effects of an asymmetric decrease in transport costs, combining a large-scale spatial dynamic general equilibrium model for 267 European NUTS-2 regions with a detailed transport model at the level of individual road segments. As a case study, we consider the impact of the road infrastructure investments in Central and Eastern Europe of the European Cohesion Policy. Our analysis suggests that the decrease in transportation costs benefits the targeted regions via substantial increases in gross domestic product (GDP) and welfare compared to the baseline, and a small increase in population. The geographic information embedded in the transport model leads to relatively large predicted benefits in peripheral countries such as Greece and Finland, which hardly receive funds, but whose trade links cross Central and Eastern Europe, generating profit from the investments there. The richer, Western European nontargeted regions also enjoy a higher GDP after the investment in the East, but these effects are smaller. Thus, the policy reduces interregional disparities. There are rippled patterns in the predicted policy spillovers. In nontargeted countries, regions trading more intensely with regions where the investment is taking place on average benefit more compared to other regions within the same country, but also compared to neighboring regions across an international border. We uncover that regions importing goods from Central and Eastern Europe enjoy the largest spillovers. These regions become more competitive and expand exports, to the detriment of other regions in the same country. 相似文献
16.
Juan Luis Gómez-Reino Santiago Lago-Peñas Jorge Martinez-Vazquez 《Journal of regional science》2023,63(4):793-819
The standard theory of optimal jurisdictional size hinges on the existence of economies of scale in the provision of local public goods and services. However, despite its relevance for forced local amalgamation programs and related policies, the empirical evidence on the existence of such economies of scale remains elusive. The main goal of this paper is to produce an updated and comprehensive quantitative review of the existence of economies of scale in the provision of local public goods using a meta-analysis approach to systematize the wide range of empirical approaches and modeling frameworks found in the previous literature. Our analysis confirms the presence of moderately increasing to constant returns to scale in the provision of local services with no reduction in the average costs of production in the delivery of most local public services beyond a certain, modest jurisdictional size, which many studies have estimated at 10,000 residents. Also, the potential for economies of scale differs at least across three traditional services: education, water and sanitation, and garbage collection, being highest for education and lowest for garbage collection. Our analysis also offers guidelines for future empirical research in this area. Physical output and production cost data should be used, together with translog specifications for the modeling of cost functions. Last, we find evidence that the determinants of output cost elasticity include bidirectional publication bias and population density but do not include the presence or absence of modern “lean” production technologies or the (perceived) capital intensity of the sector, contrary to conventional wisdom. These findings have significant policy implications for countries considering jurisdictional consolidation programs. 相似文献
17.
Samuel Nión-Álvarez Francisco Javier González García 《Oxford Journal of Archaeology》2023,42(1):50-70
This paper analyses social transformations in the Early Iron Age based on a holistic and longue durée approach applied to the first fortified habitats in the Iberian north-west. Through a comprehensive review of two paradigmatic settlements of the EIA in the province of A Coruña (Galicia, north-west Iberia), Punta de Muros and A Graña, a comparison is drawn between the social and territorial dynamics of this period by means of an in-depth analysis of the main characteristics of both settlements. Accordingly, a greater level of social complexity during the phases of occupation of the settlement of Punta de Muros has been identified, in contrast to the resistance to change observed in A Graña. Based on these conclusions, the role of metalworking and its symbolic value in fostering and legitimizing these social and territorial transformations and in the development of Iron Age communities are analysed. 相似文献
18.
Gísli Pálsson 《Anthropology today》2023,39(3):1-2
This guest editorial reflects on the relevance of anthropology for extinction concerns, a rapidly expanding practical, ethnographic and theoretical space at a time of impending mass extinction. While biological extinction is necessarily a multispecies development (usually implicating humans), traditional species talk – focused on taxonomies, collections and classification – needs critical rethinking as it necessarily diverts attention from the vitality of life. The broad discipline of anthropology has much to offer for understanding processes of extinction and recovery, fleshing out habitat problems and prospects of extinction, and advancing meaningful environmentalist practices. 相似文献
19.
John Coates Seán McGrail David Brown Edwin Gifford Gerald Grainge Basil Greenhill Peter Marsden Boris Rankov Colin Tipping Edward Wright 《International Journal of Nautical Archaeology》1995,24(4):293-301
The need for experiments to study physical aspects of craft of the past is stated, as well as the necessity for them to have clear aims and to follow the established principles of scientific enquiry. These principles are discussed in this joint paper by ten maritime archaeologists and others, together with methods and some points of management critical to their application in this field. 相似文献
20.