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   1945篇
  免费   152篇
  2024年   7篇
  2023年   46篇
  2022年   12篇
  2021年   12篇
  2020年   93篇
  2019年   68篇
  2018年   186篇
  2017年   179篇
  2016年   164篇
  2015年   102篇
  2014年   104篇
  2013年   460篇
  2012年   78篇
  2011年   72篇
  2010年   62篇
  2009年   47篇
  2008年   48篇
  2007年   31篇
  2006年   33篇
  2005年   22篇
  2004年   21篇
  2003年   14篇
  2002年   24篇
  2001年   19篇
  2000年   14篇
  1999年   14篇
  1998年   20篇
  1997年   10篇
  1996年   8篇
  1995年   10篇
  1994年   9篇
  1993年   12篇
  1992年   10篇
  1991年   9篇
  1990年   8篇
  1989年   10篇
  1988年   7篇
  1987年   8篇
  1986年   10篇
  1985年   4篇
  1982年   4篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1970年   1篇
  1969年   2篇
  1962年   1篇
  1959年   2篇
  1956年   1篇
  1950年   3篇
排序方式: 共有2097条查询结果,搜索用时 31 毫秒
61.
62.
In the area of cultural heritage, tourists’ experiences emphasise not only the moment and its personal nature but also socio-cultural traits. These experiences when expressed (social communications) are an important gateway to knowledge about tourists’ sense-making processes. This paper reports on the mediation between tourists and heritage sites via comments on a digital platform (TripAdvisor) about two Spanish tourist destinations with opposing characteristics and four heritage sites, which are analysed. The methodology used seeks to transcend the individual and anecdotal aspects of tourists’ comments. Indeed, the results obtained show the relevance of the humanisation and the discursive weight of heritage contexts in emotional/personal stories. Tendencies observed in non-regulated contexts confirm the role of a complex negotiation at cultural heritage sites and highlight the need to explore possible exchanges of sense in tourists’ encounters with such sites.  相似文献   
63.
The restoration of paintings on elements in cultural heritage buildings (fundamentally, churches) involves two structural problems: capturing the geometry of the construction element and its development. In many cases, the geometries are regular (e.g., cylinders, spheres, elliptical domes). However, there are cases in which the elements cannot be adapted to any known geometry, much less one that can be mathematically developed. The development of surfaces becomes essential for the restoration of paintings over “flat elements” (over which work is performed on the ground) that are subsequently transferred to the real surface (ceilings). The mathematical transformations that allow regular geometries to be developed are widely known (cartographic projections). However, when the geometry is irregular, there is no development. This study presents a new methodology based on differential rectification and its application for the development of oculi in the Los Santos Juanes Church (Valencia), whose geometry is completely irregular both in shape and as a result of construction defects (and damage caused by fire). The present study focuses on the restoration of paintings damaged by fire.  相似文献   
64.
This paper narrates Puerto Rico's fiscal and financial crisis through a reading of San Juan's urban landscape. We underscore the role of capital in the city, primarily embodied by the local capitalist class (the Criollo bloc) and foreign capitalists. Historically excluded from the manufacturing sector (dominated by US capitalists), the Criollo bloc accumulates its wealth by concentrating financial assets in the city. In times of crisis, the Criollo bloc resorts to the acquisition of new assets and asset exchange with foreign capitalists to remain solvent and provide short‐term solutions to the state's fiscal and financial limits. The survival of the local capitalist class, we demonstrate, is dependent on asset stripping. Drawing on Clyde Woods, we document how asset stripping unevenly redistributes wealth and risks along class and racial lines within a colonial economy. The finance capital/asset stripping basis of San Juan's economy renders it an extremely fragile city, we contend.  相似文献   
65.
Epistemic communities are an established concept in the study of international relations but can also explain policy change at the domestic level. This article asks why some epistemic communities manage to convince decision makers of their preferred policies while others do not. It suggests that the reason lies in the causal mechanism of epistemic communities' influence on decision makers, mediated by decision makers' demand for expert input. Most epistemic communities scholarship focuses on single case studies where the communities' influence on policy was strong and clear, leading to an overestimation of the groups' influence. To help correct this probable bias, this article compares a successful case of epistemic community influence (health technology assessment in Poland) with an unsuccessful example of the same policy (in the Czech Republic). The juxtaposition allows for unpacking of the necessary parts of the causal mechanism (emergence of an epistemic community, its activity, access to decision makers, and successful suasion) and separating them from the crucial scope condition. Decision makers' uncertainty about the policy issue at hand has traditionally been the key scope condition for epistemic communities but the successful Polish case demonstrates that epistemic communities can be influential even in highly certain areas of routine policymaking, leading to a reconceptualization of uncertainty as policymakers' demand for expert input. Demand can originate from various sources, but any change of it affects individual parts of the causal mechanism, leading to a success or failure of epistemic communities' policy enterprise.  相似文献   
66.
From early April to late June 2018, the nearly 2,600 immigrant children – mostly refugees fleeing violence and poverty in Central America – were forcibly taken from their parents at the United States’ southern border following implementation of the Trump administration's ‘zero tolerance’ policy. The policy took effect when the US Justice Department began aggressively prosecuting undocumented immigrants crossing the US‐Mexico border. Following a public outcry and growing protests, President Trump issued an executive order declaring an end to family separations on 20 June. Several days later, a federal court mandated that the government reunite those immigrant families affected by the ‘zero tolerance’ policy. In mid‐August, more than 550 children who had been detained following the implementation of the policy remained in federal custody. Thousands more ‘unaccompanied minors’ – typically teenagers who were caught crossing the border without adults –remain in indefinite detention. This editorial analyzes this situation from an anthropological perspective by reviewing relevant ethnographic literature on undocumented Latin American immigrants in the US.  相似文献   
67.
Very small, green colored, partially mummified remains of a perinate individual were found buried in a ceramic pot with a copper coin in the Late Medieval cemetery of Nyárl?rinc-Hangár út (“Nyárl?rinc 3. lel?hely”) in southern Hungary. The remains must date back to the second half of the nineteenth century AD. In this paper; we present data gathered in a series of multidisciplinary investigations targeted to the partially mummified remains (ind. no. 14426) and two other non-mummified perinates (ind. no. 10662 and no. 14336) possibly buried under similar circumstances in the cemetery. Besides standard macromorphological and stereomicroscopic examinations, we compared Cu concentrations in the remains using ICP-AES and mapped Cu concentration changes using μXRF. The partially mummified perinate showed the highest Cu concentrations, while the individual buried without a possible Cu source showed the lowest. Body parts in the closer proximity of the copper coins always showed higher concentration. The mummified individual showed 497 times higher Cu values than average, and even the perinate buried without copper coin measured higher than the otherwise normal Cu content of the soil. Extremely high Cu values may be related to the corrosion of the coins included in the burials. Mummification must have been facilitated by copper deriving from the coins. Uneven Cu concentrations and only partial mummification of one of the individuals refer to the importance of other environmental factors involved in a possible quasi-natural mummification process. However, the Nyárl?rinc perinate burial no. 14426 may be the first solely copper-driven mummification case ever reported, and hopefully, more cases are to appear in the future.  相似文献   
68.
We investigated the contribution of freshwater resources to the diet of seven Late Mesolithic hunter-gatherers (ca. 5300–7000 BC) from Northern France and Luxembourg using stable isotope ratios. In addition to the carbon and nitrogen stable isotope ratios (δ13C, δ15N), we explored the potential of the sulphur isotopic ratios (δ34S) to detect and quantify the proportion of protein derived from aquatic foodstuff. In only two sites, animal remains from an associated settlement were available and subsequently examined to decipher the isotopic differential between terrestrial and freshwater resources. The quantification of their relative contribution was simulated using a Bayesian mixing model. The measurements revealed a significant overlap in δ13C values between freshwater and terrestrial resources and a large range of δ15N values for each food category. The δ34S values of the aquatic and terrestrial animals were clearly distinct at the settlement in the Seine valley, while the results on fish from Belgium demonstrated a possible overlap in δ34S values between freshwater and terrestrial resources. Local freshwater ecosystem likely contributed to ca. 30–40 % of the protein in the diet of the individuals found in the Seine settlement. Out of this context, the isotopic signature and thus contribution of the available aquatic foods was difficult to assess. Another potential source of dietary protein is wild boar. Depending on the local context, collagen δ34S values may contribute to better assessment of the relative contribution of freshwater and terrestrial resources.  相似文献   
69.
The animal remains found at the fourteenth–fifteenth century Hof van Leugenhaeghe are crucial to reconstruct the life of the noble inhabitants, as all buildings were destroyed with the construction of a later estate on the property called the Blauwhof. The diet confirms the high social status of this nobility with the suspected consumption of pig skulls, a possible sign of wealth in late-medieval Flanders. Other signs of a noble diet are found as well: juvenile cattle, a diverse spectrum of game, partridge and grey heron. The observed pattern of a wealthy diet is consistent with the zooarchaeological assemblages found at other noble sites in late-medieval Flanders.  相似文献   
70.
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   
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