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   93篇
  免费   5篇
  2024年   1篇
  2023年   1篇
  2021年   1篇
  2020年   3篇
  2019年   5篇
  2018年   6篇
  2017年   13篇
  2016年   3篇
  2015年   7篇
  2014年   5篇
  2013年   7篇
  2012年   4篇
  2011年   7篇
  2010年   3篇
  2009年   3篇
  2008年   4篇
  2006年   2篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  1999年   3篇
  1998年   1篇
  1996年   1篇
  1995年   6篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
排序方式: 共有98条查询结果,搜索用时 31 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.
Significant advances in our understanding of ancient agricultural practices in the Americas have been made in recent years. This review of the literature focuses on studies published between 1987 and early 1994. Issues pertaining to the transition from foraging to farming include the habitability of the American tropics prior to the development of agriculture, theories on plant domestication and the origins of agriculture, regional syntheses of agricultural development, and the origin, evolution, and dissemination of domesticates in the Americas. Other topics reviewed include new techniques that have recently been applied to the study of prehistoric agriculture in the Americas, various approaches to the study of agricultural change, and ways in which research on ancient agricultural practices is being applied in modern experimental agriculture and rural development projects.  相似文献   
3.
Recent fieldwork has considerably increased our knowledge of early Holocene settlement in Southwest Arabia. Neolithic settlement occurred within an environmental context of increased monsoonal moisture that continued during the mid-Holocene. A now well-attested Bronze Age exemplified by village- and town-scale settlements occupied by sedentary farmers developed toward the end of the mid-Holocene moist interval. The high plateau of Yemen was an early focus for the development of Bronze Age complex society, the economy of which relied upon terraced rain-fed and runoff agriculture. On the fringes of the Arabian desert, the precursors of the Sabaean literate civilization have been traced back to between 3600 and 2800 B.P., and even earlier, so that a virtually continuous archaeological record can now be described for parts of Yemen. In contrast to the highlands these societies relied upon food production from large-scale irrigation systems dependent upon capricious wadi floods. Bronze Age settlement, while showing some links with the southern Levant, now shows equal or stronger linkages with the Horn of Africa across the Red Sea. Although some regions of Yemen show breaks in occupation, others show continuity into the Sabaean period when a series of major towns grew up in response to the incense trade with the north. It is now clear that these civilizations grew up on the foundations of earlier Bronze Age complex societies.  相似文献   
4.
ABSTRACT

Early colonial officials and other newcomers frequently lamented the poor copra production in Wallis and Futuna, positioning the continued consumption of coconuts by Islanders as a waste. This article explores the contested uses of coconuts and the divergent visions of the islands’ landscape and future held by Islanders, officials, missionaries and traders during opening decades of French colony rule. In particular, a variety of incidents in the 1920s – from an indigenous co-operative to French expulsions – highlight the centrality of the emergent copra trade to the social and political status of these different groups. More broadly, however, the article demonstrates the failure of elites – both indigenous and newcomer – to substantially increase copra exports prior to the Depression in 1930, indicative of the limits of their ability to demand labour and transform the lifeways of the wider population.  相似文献   
5.
In the late 1980s, a collaborative effort between Harvard University’s Lower Mississippi Survey and Tulane University’s Center for Archaeology launched a study examining the causes and consequences of subsistence change in the Lower Mississippi Valley. The Osceola Project contributed the first formal study of late prehistoric faunal remains within the Alluvial Plain, becoming the standard against which all subsequent Coles Creek faunal assemblages have been measured. Recent evidence recovered from three sites located in the Eastern Uplands presented the opportunity to compare and contrast vertebrate subsistence in these two distinct physiographic regions. We hypothesize that a clear distinction exists between lowland and upland Coles Creek procurement strategies. This article evaluates this claim by examining species diversity, spatial patterns, and temporal trends evident within an eight-site sample. The results suggest that the primary factor influencing Coles Creek fauna procurement was the immediate environment, and that the composition of Late Woodland period diets may be a reflection of efficiency of effort rather than food access or scarcity.  相似文献   
6.
郭立新 《华夏考古》2006,34(3):33-39
长江中游地区新石器时代晚期的主要生计方式是稻作农业,因渔猎所占比重不同而又可细分为山地型与平原型。水田稻作农业具有集约化程度高,产出也较高的特点。稻田耕作系统的形成与维护需要大量劳力,从而刺激人口迅速增长,结果造成人口压力。自然环境的数次波动更加剧了这种压力。因人口压力而引发的移民、战争和社会重组等,成为推动初期社会复杂化进程的主要原因。  相似文献   
7.
Knowledge about human subsistence and the role of animal economy in the Islamic period of south‐east Arabia is still sketchy. The analysis of faunal remains from the coastal fort at Luluyyah (Sharjah, UAE), dated to the late thirteenth and early fourteenth century CE, provides some information. People depended on marine resources and domestic animals, a trait observable in the region since the Neolithic. Livestock breeding was not particularly developed. Judging by the distribution of their skeletal remains, the animals were slaughtered at the fort, implying that they either lived there or reached it alive.  相似文献   
8.
16-18世纪英国宪制和宪制思想演进   总被引:2,自引:1,他引:1  
阎照祥 《史学集刊》2006,2(4):51-59
英国16-18世纪宪制的演变比较曲折。内战前混合宪制已形成多年,其相应思想长期流行并影响后世。17世纪中期共和国的兴衰和分权制有名无实,给后人留下经验和教训。贵族寡头权力垄断和内阁制的形成发展,增强了18世纪英国混合制的特色。  相似文献   
9.
This paper provides a comprehensive analysis of the pattern of hospital utilization (rather than provision) in England prior to the establishment of the NHS, showing the extent to which the probability of obtaining hospital treatment was a function of residence. Access to hospital care depended on the vigour of voluntarism and the political priorities of local governments. The pattern of voluntary hospital utilization is shown to have been markedly unequal, but the effect of municipal provision was to reduce disparities in access to services. The paper demonstrates variations in hospital utilization and discusses contemporary assessments of the situation. This work contributes to debates about the efficacy of non-profit forms of welfare delivery; it provides a novel British study to complement American work in this field. It also raises questions about the contemporary vogue for partnerships in health care delivery between the public and private sectors, arguing that such proposals rest on an optimistic view of history.  相似文献   
10.
Temporally and spatially discontinuous pulses of heavy prehistoric exploitation of red abalone (Haliotis rufescens) have been documented along the southern and central California coast. This article examines the very late (post-950 cal BP) appearance of numerous red abalone processing sites on the Monterey Peninsula in central California. We test three prominent explanations offered for the sudden onset of red abalone processing sites: trophic cascades resulting from human predation on sea otters, logistical foraging by inland residents, and changes in sea surface temperature. A trophic cascade appears to have occurred but does not fully explain the nature or timing of the phenomenon in the region.  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