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   137篇
  免费   26篇
  2024年   1篇
  2023年   8篇
  2021年   1篇
  2020年   17篇
  2019年   15篇
  2018年   12篇
  2017年   6篇
  2016年   6篇
  2015年   9篇
  2014年   13篇
  2013年   15篇
  2012年   10篇
  2011年   6篇
  2010年   5篇
  2009年   5篇
  2008年   7篇
  2007年   4篇
  2006年   1篇
  2005年   5篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   3篇
  1998年   2篇
  1997年   2篇
  1994年   1篇
  1991年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有163条查询结果,搜索用时 31 毫秒
81.
82.
83.
84.
This paper investigates the establishment of trading regions in the global economy at the national level using a measure of trade intensity and a regional assignment algorithm that generates economically meaningful trading regions. Although there is definite regionalization in the global economy with regard to international trade, there is no evidence of an increase in the concentration of that regionalization over time. The geography of international trade is incredibly dynamic, with change related to political, historical and economic forces. Overall, trading regions have relatively few members and are increasingly a set of geographically close countries.  相似文献   
85.
This paper explores the concepts of old‐growth forests, preservation and natural disturbance and demonstrates how contemporary biogeographic theory contributes to successful preservation of old‐growth forests. The case study analyzes the composition, structure, age and growth histories of trees in Big Timber Park, Whistler, British Columbia. Composition. The structure of the forest was diverse and tree ages ranged from 122 to 305 years. The densities of large old Douglas‐fir, shade‐tolerant trees and all snags are indicative of old‐growth forests; however, maximum tree diameters and densities of large snags and logs do not meet quantitative criteria for old‐growth forests. The abundance of tree regeneration and understory vegetation are relatively low. We conclude that some aspects of Big Timber Park are transitional between the mature and old‐growth stages of forest development. In the future, fine‐scale canopy gaps caused by tree senescence and interactions among insects, pathogens and wind are expected to dominate stand dynamics. Forest structure will become increasingly complex, exemplifying the dynamic nature of old‐growth forests. To successfully preserve Big Timber Park and La préservation des forêts other old‐growth forests in Canada requires understanding of natural disturbances. Preservation and the criteria and indicators used to measure successful preservation must explicitly include elements of natural change.  相似文献   
86.
This paper examines the relative earnings and wages of immigrants working in the hi‐tech sector in Canada's cities. Between 1990 and 2000, a sizeable earnings advantage of immigrants over nonimmigrants employed in the hi‐tech sector evaporated, and this change was most noticeable in the largest cities. We use population census microdata to examine the geographical dimensions of this shift. After controlling for individual characteristics, we show that immigrants in the largest and tech‐intensive cities earn significantly less relative to nonimmigrants than those in midsized and smaller cities. We also present results comparing the hi‐tech immigrant wage and earnings gap for the five largest Canadian cities. The findings are consistent with the notion that geographic differences are an important component of the overall earnings gap between immigrants and nonimmigrants.  相似文献   
87.
The empirical foci of this paper are a content and discourse analysis of four years (1994 to 1997) of media reporting on ‘homelessness’ in The Ottawa Citizen, the premier, English language daily newspaper in the region. Examining these reports in juxtaposition with governmental and community‐based reports from the same period has provided useful insights into how public opinion might be influenced to regard antihomeless laws as more or less legitimate. This paper's approach was influenced by certain regulation theorists who argue that an examination of key discourses has the potential to enhance understanding about how economic, political and social restructuring is taking place, as well to shed light on how to intervene effectively at a variety of geographic scales in shaping its key elements. The results of the media analysis suggest that very particular messages are emphasized vis‐à‐vis “the homeless”: the ‘stubborn’ unchanging nature of the problem, and the difficulties that housed citizens have in helping these passive, isolated, overwhelmingly white, male, substance abusers and contained (in the downtown) ‘others’. They generally neglect or dismiss stories that might expose the demographic and geographic diversity of those who currently are homeless, and their complex and difficult past histories. When hints of such complexities are mentioned, they come with subtle messages about the deserving individuals who might be redeemed, in contrast to the hapless majority. Cette recherche présente une analyse du contenu des articles sur les personnes sans‐abri, publiés entre 1994 et 1997 dans le quotidien anglais le plus important dans la région d'Ottawa le “Ottawa Citizen”. L‘étude de ces articles ainsi que les rapports gouvernementaux et communautaires durant la même période soulèvent des idées intéressantes autour de l'impact que le discours public peut avoir sur l'acceptation de lois discriminatoires contre les personnes qui sont sans‐abri. Le présent travail est influencé par certains théoriciens de la régulation qui proclament que l'analyse des discours clés dans la société peut potentiellement améliorer notre compréhension de la restructuration économique, politique et sociale et clarifier la manière d'intervenir efficacement pour l'influencer. Les résultats de l'analyse des articles médiatiques suggèrent que des messages particuliers sont communiqués au sujet des personnes qui sont sansabri: c.‐à‐d. la nature invariable du problème et les difficultés vécues par les citoyens logés, à savoir comment aider cette population qui est présentée comme passive, isolée, à prédominance blanche, qui souffre de toxicomanie et qui réside dans le centre‐ville. Généralement, les médias négligent l'information qui expose la grande diversité démographique et géographique des gens qui sont sans‐abri ainsi que leurs histoires de vie personnelles difficiles et complexes. Quand ils mentionnent ces complexités, elles sont accompagnées de messages subtiles suggérant que seulement une minorité de l'ensemble des personnes sans abri méritent notre aide.  相似文献   
88.
GISystems have strong and longstanding roots in Geography, stemming from early developments in the 1960s and 1970s that defined a first phase of their relationship. But as the uses and sophistication of geospatial technology have grown and spread across virtually all areas of the academy, reducing Geography's claim to ownership, that relationship to Geography has evolved in new directions, forming a second phase. The critiques of the early 1990s have led to research into the societal context and social implications of GISystems that remains largely centred in Geography; techniques for the analysis of data embedded in space and time remain strongly associated with Geography; and rigorous principles have been discovered under the umbrella of GIScience that are widely recognized within and outside Geography. Today the relationship has entered a third phase, defined by the new opportunities that are being created by the growth of data science, by new sensors, and by new areas of application, suggesting that the relationship between Geography and GIScience will continue to evolve in interesting and exciting ways.  相似文献   
89.
Sport and exercise are prominent activities in the daily routines of prisoners around the world, yet the spatial significance of these activities in carceral environments has not been deeply investigated. With a focus on the experiences of former federal prisoners in Canada, this paper addresses this scholarly gap by bringing together emerging trends in the literatures on sociology of sport, sports geography, and carceral geography to investigate the complex social meanings of prison sport and exercise. Specifically, we explore the folding of sports space into carceral space, often with the effect of reinforcing violent and exclusionary situations, but which also helps construct alternative spatial and temporal realities. Indeed, our overarching theoretical analysis considers how prisoners use sport to produce space in ways that assert a limited degree of agency over their daily lives and temporarily transcend their unpleasant conditions of confinement. By drawing from diverse theoretical frameworks and literatures, we advance novel arguments about the socio‐spatial significance of sport in prisons and raise some important questions for further research.  相似文献   
90.
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