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   11篇
  免费   3篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2016年   1篇
  2015年   2篇
  2013年   1篇
  2012年   1篇
  2011年   1篇
  2008年   1篇
  2002年   1篇
  2001年   1篇
  1999年   1篇
排序方式: 共有14条查询结果,搜索用时 62 毫秒
1.
In the context of global warming, changes in extreme weather and climate events are expected, particularly those associated with changes in temperature and precipitation regimes and those that will affect coastal areas. The main objectives of this study were to establish the number of extreme events that have occurred in northeastern New Brunswick, Canada in recent history, and to determine whether their occurrence has increased. By using archived regional newspapers and data from three meteorological stations in a national network, the frequency of extreme events in the study area was established for the time period 1950–2012. Of the 282 extreme weather events recorded in the newspaper archives, 70% were also identified in the meteorological time series analysis. The discrepancy might be explained by the synergistic effect of co‐occurring non‐extreme events, and increased vulnerability over time, resulting from more people and infrastructure being located in coastal hazard zones. The Mann Kendall and Pettitt statistical tests were used to identify trends and the presence of break points in the weather data time series. Results indicate a statistically significant increase in average temperatures and in the number of extreme events, such as extreme hot days, as well as an increase in total annual and extreme precipitation. A significant decrease in the number of frost‐free days and extreme cold days was also found, in addition to a decline in the number of dry days.  相似文献   
2.
This paper examines the rock art of the nyau secret society of eastern Zambia and central Malai. The art dates principally from the nineteenth and early twentieth centuries. It has been known to researchers since the 1970s but has given up few of its secrets. I examine the questions of why the art was made and why the tradition ceased. Key to answering these is the realization that the art belonged to a specific historical and geographic context: the era and area where nyau was forced to become an underground movement because of its suppression by Ngoni invaders, missions, and the later colonial government. The art provides us with detailed insights into the way nyau has served in the process of overcoming and manipulating the traumatic social changes faced by Chea society in the last few centuries.Cet article examine l'art rupestre de la société secrète de nyau au est du Zambia et Malai centrale. L'art date principalement aux dix-neuvième et bas vingtième siècles. Recherchers ont su l'art depuis les années soixante-dix, mais ils ont appris peu de ses secrets. J'examine les questions de pourquoi l'art était fabriquer et pourquoi la tradition a cessé. Pour résoudre ces questions c'est important à réaliser que l'art était à sa place dans un milieu spécifique d'histoire et géographie: au temps et place où nyau était forcer à devenir un mouvement clandestin à cause de sa répression par les envahisseurs Ngoni, les missions et, plus tard, le gouvernement colonial. L'art nous donne les aperçus détaillé sur comment nyau a servi dans le procès à surmonter et manipuler les changements traumatiques que la société Chea a bravé dans les siècles récents.  相似文献   
3.
师■鼎铭"困伯太师武"一句的"困(韋東)"二字,原文写法非常奇怪。裘锡圭先生释为"東(韋東)",读为"范围",认为是遵循、效法之意。本文同意把后一字释为"(韋東)",但把前一字改释为"困"。"困(韋東)"也是遵循、效法的意思。  相似文献   
4.
张爱萍 《清史研究》2020,118(2):1-12
清初,迭遭兵燹的湖南地区经历了兴垦、均编粮里、清丈等重建赋役秩序的过程。其中,衡山县于康熙四十三年实施的"废甲编区"更是呈现出清初里甲赋役改革的丰富面相。因应偏沅巡抚赵申乔革除里排、滚单催征的举措,衡山县打破原有里甲规制的束缚,改革中坚持粮不过区、就地编区的原则,孕育了字区的地缘性色彩,重塑十七字四百三十七区的赋役区划体系。以康熙五十三年新一轮的清丈为契机,知县葛亮臣在业已建立的区划结构内清查荒籍,使字区成为地方重要的赋役征派和土地登记单位。在这一区域变迁的历史过程中,字区的行政区划功能逐渐得到强化和延续,以赋役征派为目的建立起来的基层赋役区划向实体化与政区化迈进,与之相应的行政话语也深刻地影响着民间契约文本的表达。  相似文献   
5.
In Indochina, overseas Chinese were organized by dialect group into associations called congregations, which shared many of the functions of huiguan in China. The spread of overseas Chinese economic and social networks followed a Skinnerian model in which large urban con?régations wielded more political and economic authority than did smaller, rural con?régations. By examining the impacts of French colonialism upon overseas Chinese networks within Indochina and upon overseas connections with their Chinese native places, this paper proposes that the Skinnerian model of local-system hierarchy fits quite comfortably when applied to the world of French colonial Indochina and its overseas Chinese. Furthermore, it argues that French colonialism actually reinforced the Skinnerian hierarchy of politics and markets in ways that endured long after the collapse of Imperial China.  相似文献   
6.
Recent advances in local spatial statistics and operational computing capacity have led to growing interest in the detection of disease clusters for public health surveillance and for improving understanding of disease pathogenesis. Although conceptual reviews and applied examples have appeared in the literature, few studies have addressed the connection between conceptual and practical issues that confront researchers interested in using local statistics to detect disease clusters. Here we review recent literature on the use of local statistics for cluster assessment and focus on the practical issue of assigning correct geographic coordinates. The process of assigning geographic coordinates to an address or postal code, known as ‘geocoding’, is a necessary step in conducting smallarea health analyses. With a study of mortality data from Hamilton, Ontario, we illustrate inaccuracies that may be encountered when using Statistics Canada postal code conversion files. Using the Moran's I and Getis‐Ord Gi and Gi* local spatial statistics to identify significant mortality clusters or ‘hot spots’, we demonstrate that small geocoding errors, even those that affect less than one percent of a total dataset, can have a discernible impact on analytic results. To assist other researchers, we supply guidelines to minimize error introduced by geocoding. These results emphasize the importance of accurate geocoding in local health analyses. Les avancées récentes en statistiques spatiales localisées et en capacité informatique opérationnelle ont conduit à un intérêt croissant dans la détection de foyers de maladies pour fins de surveillance de santé publique, et dans l'approfondissement de la compréhension de leur pathogénèse. Bien que des revues conceptuelles et des exemples concrets aient été publiés dans la littérature, peu d'études ont adressé le lien entre les problèmes conceptuels et pratiques auxquels sont confrontés les chercheurs intéressés à utiliser les statistiques locales pour détecter les foyers de maladies. Nous revoyons ici la littérature récente sur l'utilisation de statistiques locales dans l'évaluation de foyers et focalisons sur le problème pratique d'assigner des coordonnées géographiques correctes. Le procédé d'assigner des coordonnées géographiques à une adresse ou à un code postal, nommé‘géocodage’, est une étape nécessaire dans la conduite d'analyses de santéà petite échelle. À l'aide d'une étude sur des données de mortalitéà Hamilton, en Ontario, nous illustrons que des inexactitudes peuvent être rencontrées lorsque les fichiers de codes postaux et de conversion de Statistique Canada sont utilisés. En utilisant les statistiques spatiales localisées I de Moran, Gi and Gi* de Getis et Ord pour identifier des foyers de mortalité significatifs ou des ‘points chauds’, nous démontrons que de petites erreurs de géocodage, même celles n'affectant moins qu'un pour cent de la base de données, peuvent avoir un impact discernable sur les résultats analytiques. Afin d'aider d'autres chercheurs, nous fournissons des recommandations pour minimiser les erreurs introduites par le géocodage. Ces résultats soulignent l'importance d'un géocodage exact dans les analyses de santé locale.  相似文献   
7.
Public participation geographic information systems (PPGIS) increasingly are utilized in geographic research, yet researchers rarely are provided with guidance on how to implement PPGIS in an appropriate and effective manner. This article reports on the process of research that explores responses to current and future local tourism development offered by a sample of residents using a modified PPGIS approach called ‘community action geographic information system’ (CAGIS). The conceptual development of CAGIS is reported and the challenges encountered during its implementation in Churchill, Manitoba during 2005–2007 are reviewed. It is suggested that researchers wishing to conduct similar research should undertake thorough preliminary fieldwork to assess the likelihood of finding agreement on a common problem; acquiring adequate resources; establishing collective responsibility for the project's outcome; attaining stakeholder support; developing trust and meaningful relationships; and incorporating indigenous knowledge appropriately. Feedback of results to community members also should be an integral part of the research process. A number of feedback mechanisms are reported, including an interactive weblog, which helped facilitate communication between heterogeneous groups in Churchill. Although ambitions for a truly participatory GIS approach to this project have been set aside, it is held that PPGIS can yield positive outcomes for communities and academia. Sharing this research experience will be useful to others who venture into PPGIS research, especially in northern communities.  相似文献   
8.
Cet article analyse les grands traits de la diffusion spatiale du Web en France et montre la nécessité et les possibilités d'aborder spatialement Internet en dépit de nombreux problèmes techniques. L'analyse se base sur la cartographie de 7000 sites en avril 1997 et met en évidence une assez bonne ressemblance d'ensemble avec la hiérarchie urbaine. Mais le milieu rural montre aussi de fortes différenciations et en particulier des concentrations dans la partie méridionale du pays: les sites touristiques et de produits de terroir les expliquent largement.
This article analyses the main features of the spatial diffusion of the Web in France. It argues that it is necessary and possible to approach the Internet from a spatial point of view, in spite of the many technical problems this presents. The analysis is based on the cartography of 7000 sites in April 1997 and shows a good correspondence to the urban hierarchy. But rural space also shows strong differentiations, particularly some concentrations in the meridional part of the country: these are explained largely by tourist sites and products of the soil.  相似文献   
9.
Initiatives aimed at protecting aquatic ecosystems often prove difficult to implement—particularly in water‐stressed, semi‐arid regions where the demand for water for human consumption is high. This article reports on an investigation of the factors that shaped the development and implementation of policies for aquatic ecosystem protection in the Oldman River Basin (ORB), a crucial watershed in semi‐arid southern Alberta. The analysis reveals critical cultural and historical considerations that confront those attempting to protect and restore aquatic ecosystems in the ORB and highlights specific factors that influence implementation of measures to protect it. In addition to the most basic consideration—demand for water exceeds supplies—eight specific factors that influenced aquatic ecosystem protection in this region are identified and evaluated. These include (1) clarity of actors’ roles/ jurisdictional responsibilities; (2) communication; (3) definition of key terms; (4) funding and organizational capacity; (5) leadership; (6) legal standing; (7) data and monitoring; and (8) public education. We argue that while these factors are important, critical cultural and historical considerations that influence water policy in the province also must be addressed in any efforts to protect aquatic ecosystems in southern Alberta.  相似文献   
10.
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