全文获取类型
收费全文 | 542篇 |
免费 | 17篇 |
出版年
2024年 | 9篇 |
2023年 | 10篇 |
2022年 | 7篇 |
2021年 | 4篇 |
2020年 | 26篇 |
2019年 | 14篇 |
2018年 | 20篇 |
2017年 | 18篇 |
2016年 | 22篇 |
2015年 | 22篇 |
2014年 | 10篇 |
2013年 | 60篇 |
2012年 | 31篇 |
2011年 | 45篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 29篇 |
2007年 | 34篇 |
2006年 | 18篇 |
2005年 | 21篇 |
2004年 | 21篇 |
2003年 | 13篇 |
2002年 | 14篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有559条查询结果,搜索用时 15 毫秒
1.
This paper contributes to a critical methodological discussion that has direct ramifications for policy studies: how computational methods can be concretely incorporated into existing processes of textual analysis and interpretation without compromising scientific integrity. We focus on the computational method of topic modeling and investigate how it interacts with two larger families of qualitative methods: content and classification methods characterized by interest in words as communication units and discourse and representation methods characterized by interest in the meaning of communicative acts. Based on analysis of recent academic publications that have used topic modeling for textual analysis, our findings show that different mixed‐method research designs are appropriate when combining topic modeling with the two groups of methods. Our main concluding argument is that topic modeling enables scholars to apply policy theories and concepts to much larger sets of data. That said, the use of computational methods requires genuine understanding of these techniques to obtain substantially meaningful results. We encourage policy scholars to reflect carefully on methodological issues, and offer a simple heuristic to help identify and address critical points when designing a study using topic modeling. 相似文献
2.
3.
4.
Investigating Human Migration and Horse‐Trading in Yelang (夜郎) Through Strontium Isotope Analysis of Skeletons from Zhougshui Sites,South‐West China (1300 bc – ad 25) 下载免费PDF全文
Yelang (夜郎), a mysterious state located in the south‐western area of early China and dating from the Bronze Age to the Early Iron Age (1300 bc – ad 25), is a cultural interactive junction between the Yunnan–Guizhou Plateau and the Yangtze River Basin. The Zhongshui Basin in Weining County, Guizhou Province, was one of the important distribution areas of the Yelang civilization. This area, which includes sites at Jigongshan (鸡公山; 1300 – 800 bc ), Hongyingpan (红营盘; 700 – 400 bc ) and Yinzitan (银子坛; 400 bc – ad 25), has provided a very integrated chronology, spanning from the Bronze Age to the Early Iron Age in the eastern Yunnan – western Guizhou area. To investigate human migration and horse‐trading at these Yelang sites, we conducted a strontium isotopic analysis on the teeth enamel of humans and horses unearthed from these three sites. The results indicated the following: (1) people at the earlier sites (Jigongshan and Hongyingpan) were all indigenous, whereas in the Yinzitan cemetery, there was a more immigrant population, and all the people who were buried in an upper limb flexed supine position were non‐local; and (2) most of the horses found at the Jigongshan and Yinzitan sites show different provenances, probably related to the famous Dian (滇) and Zuo (筰) horses recorded in historical documents, providing more clues for further study on horse‐trading in South‐West China during the Bronze Age and the Early Iron Age. 相似文献
5.
许多出土饱水木质文物因其降解严重、含水率较高,容易在脱水过程中出现不可逆的收缩变形以及开裂现象,从而遭到严重破坏。因此,饱水木质文物脱水方法的研究是文物保护工作中的重要课题。为探究风冷冷冻法对饱水木质文物脱水的效果,以一批无法复原的出土饱水木质文物为研究对象,在对其材种、含水率、基本密度及化学成分进行了测定和分析后,使用一台风冷电冰箱在-18℃条件下对样品进行了风冷干燥脱水处理,记录脱水时间和脱水效果,并分析了该方法的传质传热特点,证明了风冷干燥法用于饱水木质文物的脱水干燥能够取得良好效果,并且具有对文物干预小、适用性广、操作简便、成本低廉等优点,为饱水木质文物的脱水处理提供了一种新的思路。 相似文献
6.
Dietlind Hüchtker 《European Review of History》2018,25(6):868-884
AbstractThe article discusses the meanings of popular culture, authenticity and history in People’s Republic of Poland. As an example it uses a popular film trilogy. The trilogy Sami swoi, Nie ma mocnych and Kochaj albo rzu? (‘All friends here’, ‘Take it easy’ and ‘Love or leave me’) was shown in Polish cinemas between 1967 and 1977. The reviews were written just after the premières. The article uses the concepts of time and space elaborated by Mikhail Bakhtin and Doreen Massey to analyze the different chronotopes of the films. It analyses both the films and the reviews as strategies of creating authenticity and creating cultural meanings: the meaning of history and the meanings of rurality. I will show how history and present, memory and society are interwoven in the light of popular production. In addition, I will emphasize the diverse interpretation possibilities resulting from this micro-historical view and the transnational critique of modernism highlighting the small and local which emerged throughout Europe in the 1970s. 相似文献
7.
Lorraine Ryan 《Romance Quarterly》2015,62(2):83-96
Rafael Chirbes's En la orilla has been proclaimed as “la novela de la crisis,” and it has garnered an impressive amount of distinction in the short length of time since its publication in May 2013. It was voted the 2013 novel of the year by readers of El País, and in January 2014 it won the Premio Francisco Umbral, as well as reaching its fifth edition. Unsparingly critical, En la orilla forms an integral part of the cultural requestioning of social values in the wake of the Spanish crisis, “la literatura de la crisis,” which stresses the human and material consequences of the suspension of human values stemming from the social endorsement of market imperialism. En la orilla thematizes the corrosion of moral character during Spain's economic boom, in its multiple forms, such as selfishness, disregard for the elderly, and arrant mercenariness, while also fictionalizing neoliberal Spain's exclusion of immigrants and the poor. Integral to Chiribes's historically contextualized critique of the recession, and the object of my study, is a perceptive vision of the historical degeneration of masculinity from the Second Republic, 1931–1936, to the present day. This article will first provide a brief overview of “la literatura de la crisis,” while the second part illumines the economic and ideological distortion of the father–son relationship in this novel. 相似文献
8.
9.
K. Su J.‐P. Latham D. Pavlidis J. Xiang F. Fang P. Mostaghimi J. R. Percival C. C. Pain M. D. Jackson 《Geofluids》2015,15(4):592-607
Accurate simulation of multiphase flow in fractured porous media remains a challenge. An important problem is the representation of the discontinuous or near discontinuous behaviour of saturation in real geological formations. In the classical continuum approach, a refined mesh is required at the interface between fracture and porous media to capture the steep gradients in saturation and saturation‐dependent transport properties. This dramatically increases the computational load when large numbers of fractures are present in the numerical model. A discontinuous finite element method is reported here to model flow in fractured porous media. The governing multiphase porous media flow equations are solved in the adaptive mesh computational fluid dynamics code IC‐FERST on unstructured meshes. The method is based on a mixed control volume – discontinuous finite element formulation. This is combined with the PN+1DG‐PNDG element pair, which has discontinuous (order N+1) representation for velocity and discontinuous (order N) representation for pressure. A number of test cases are used to evaluate the method's ability to model fracture flow. The first is used to verify the performance of the element pair on structured and unstructured meshes of different resolution. Multiphase flow is then modelled in a range of idealised and simple fracture patterns. Solutions with sharp saturation fronts and computational economy in terms of mesh size are illustrated. 相似文献
10.
Stavros K. Kourkoulis Ermioni D. Pasiou 《International Journal of Architectural Heritage》2015,9(3):177-194
The restoration of destroyed connections of epistyles joined together by means of metallic connectors is among the most difficult problems encountered by scientists working for the conservation/restoration of monuments made of marble. The complexity of the geometry and the interaction of three completely different materials (metal-filling material-marble) constituting the connection render the study (either experimental or analytic) extremely complicated. In this direction a numerical analysis is presented here in order to deeply understand the response of a typical ancient connection subjected to axial loads as well as to quantify the influence of some geometric parameters on its response. The parameters studied include the length of the connector, the width of its flanges, the depth of the groove (mortise), the existence or not of relieving space and the filling material’s volume. The numerical model was calibrated and validated according to the results of an earlier experimental study realized on the worksite of the Parthenon Temple. It was concluded that the interventions required to relieve the stress field by changing the size of the connector are disproportional to the respective positive effect on the response of the connection. Moreover it was proved that the most beneficial parameter is the relieving space. 相似文献