全文获取类型
收费全文 | 181篇 |
免费 | 4篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 11篇 |
2012年 | 4篇 |
2011年 | 12篇 |
2010年 | 14篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
71.
POTENTIAL IMPACTS OF GLOBAL SEA-LEVEL RISE ON CANADIAN COASTS 总被引:3,自引:0,他引:3
JOHN SHAW ROBERT B. TAYLOR STEVEN SOLOMON HAROLD A. CHRISTIAN DONALD L. FORBES 《The Canadian geographer》1998,42(4):365-379
The sea-level rise that may result from global climate change is placed within the context of past and present sea-level changes on Canadian coasts. To assess future impact, a dimensionless index of sensitivity is determined. Coasts with low, moderate, and high sensitivity constitute 67%, 30%, and 3% of the total coastline, respectively. The most sensitive regions are: (1) several parts of the Maritime Provinces; (2) two areas of the British Columbia coast; and (3) a large part of the Beaufort Sea coast. Impacts in four regions - Bay of Fundy, Beaufort Sea, Fraser Delta, and Eastern Shore of Nova Scotia - are discussed in detail. It is argued that the societal response to changes in sea level should favour retreat and accommodation strategies.
Il est possible que les changements climatiques globaux provoqueront une élévation du niveau de la mer. Nous examinons ce scénario dans le contexte des changements passés et présents du niveau de la mer sur les côtes canadiennes. Pour évaluer l'impact de l'élévation prévue un indice non dimensionnel de vulnérabilité est déterminé. Les côtes à la vulnérabilité basse, modérée et élevée constituent, respectivement, 67%, 30%, et 3% de tout le littoral. Les régions les plus vulnérables sont: (1) plusieurs régions dans les provinces maritimes; (2) deux zones sur la côte de la Colombie britannique; et (3) la plupart de la côte de la mer de Beaufort. Nous discutons en détail les impacts dans quatre régions, soit la baie Fundy, la mer Beaufort, la delta du Fraser et la rivage dit 'Eastern Shore' de la Nouvelle-Écosse. Nous estimons que la réponse sociale aux changements du niveau de la mer devrait favoriser des stratégies de retraite et d'accommodement. 相似文献
Il est possible que les changements climatiques globaux provoqueront une élévation du niveau de la mer. Nous examinons ce scénario dans le contexte des changements passés et présents du niveau de la mer sur les côtes canadiennes. Pour évaluer l'impact de l'élévation prévue un indice non dimensionnel de vulnérabilité est déterminé. Les côtes à la vulnérabilité basse, modérée et élevée constituent, respectivement, 67%, 30%, et 3% de tout le littoral. Les régions les plus vulnérables sont: (1) plusieurs régions dans les provinces maritimes; (2) deux zones sur la côte de la Colombie britannique; et (3) la plupart de la côte de la mer de Beaufort. Nous discutons en détail les impacts dans quatre régions, soit la baie Fundy, la mer Beaufort, la delta du Fraser et la rivage dit 'Eastern Shore' de la Nouvelle-Écosse. Nous estimons que la réponse sociale aux changements du niveau de la mer devrait favoriser des stratégies de retraite et d'accommodement. 相似文献
72.
Transparent high lead and tin-opacified lead-alkali glazes have been extensively used throughout Europe and the Near East from their first appearance in the Roman era and the tenth- to eleventh-century Islamic world, respectively, up until the present day. Using, to a large extent, information which is widely scattered through a diverse range of literature, the methods employed in the production of these two glaze types are first outlined and their merits are then compared with those of alkali glazes in terms of ease of preparation of the glaze mixture, ease of application of the glaze, ease of firing, cost of production, glaze-body fit and visual appearance. The principal advantages of transparent high lead glazes as compared to alkali glazes are shown to be ease of preparation and application of the glaze suspension, low susceptibility to glaze ‘crazing’ and ‘crawling’ and high, optical brilliance. Factors that influence the choice of tin-opacified lead-alkali glazes include ease of production of tin oxide by melting tin and lead metals together; a reduced risk of reduction of lead oxide to lead metal and consequent blackening of the glaze; and, again, low susceptibility to ‘crazing’ and ‘crawling’. Limits of current knowledge regarding these two glaze types and requirements for future research are outlined. 相似文献
73.
In the first part of this paper, the economic development objectives, strategies, and structures adopted by First Nations of Canada are examined, and seven significant characteristics are identified. In the second, current theories on economic development are considered, and a contingency perspective is proposed that addresses First Nations economic development within the global economic system. In the third part, the forestry-related development activities of a particular group of First Nations -the Meadow Lake Tribal Council - and its joint venture with a major pulp firm Millar Western, Ltd., are described, and the relevance of the proposed contingency perspective is considered. The paper concludes with comments about the potential for the contingency perspective as a theoretical framework for the economic development activities of the First Nations in Canada in a post-Fordist economy. 相似文献
74.
75.
Currently, the impacts of Covid-19 are receiving significant global attention. This also applies to the extractive industries, where this global crisis is directing the gaze of policymakers, donors and academics alike. Covid-19 is seen as having far-reaching and disruptive consequences, especially in the case of artisanal and small-scale mining. While the authors consider this attention important, their work on artisanal and small-scale mining in Ghana – and West Africa more broadly – reveals that for many miners, Covid-19 is ‘just’ another interruption to their lives and lifeworlds which are chronically affected by interruptions of different scales, magnitudes and temporalities. As anthropologists have shown, foregrounding this structural condition – which is emblematic for the lives of many people, especially in the Global South – is key to questioning, understanding and contextualizing the current moment of ‘global’ crisis and must be an element of any policy and research emerging from it. 相似文献
76.
77.
Summary: The authors consider the specific nature and possible provenance of the various rock types commonly described as 'jades'or 'greenstones'from which some of the prehistoric axes and adzes in southern Italy and Sicily were made. Despite the presence of jadeite-rich pyroxenes in Calabrian metamorphic rocks, a non-local origin, probably in the north Italian or Alpine zone, seems more likely for 'jadeite'implements in the south. By contrast, nephrite and serpentinite artifacts probably derive from sources in southern Basilicata, Calabria, and possibly northeastern Sicily, where alluvial deposits or natural outcrops could have been exploited. Certain aspects of procurement and techniques of manufacture are comparable with others recorded ethnographically. Evidence emerges for long-distance as well as local and interregional exchange. 相似文献
78.
Migration to non-metropolitan areas of high environmental amenity and low population is a lifestyle choice made by a small percentage of people on or about the age of retirement from the workforce Although the proportion of older people involved is low, their numbers are significant to host towns. An aspect of retirement migration which has received little attention by researchers in Australia is the extent to which such moves realise hoped for benefits for the migrants. This paper reports results of interviews undertaken in 1986 with 146 people who had migrated, on or about retirement, to the New South Wales north coast town of Port Macquarie. Several indicators of life and place satisfaction were used They all showed high absolute and relative levels of satisfaction. Although there was tittle dissatisfaction with the results of moves, search behaviour undertaken prior to moving and a number of personal characteristics of migrants, are analysed to explain some variance in satisfaction levels. 相似文献
79.
80.