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   50篇
  免费   0篇
大气科学   5篇
地球物理   8篇
地质学   12篇
海洋学   2篇
天文学   1篇
综合类   1篇
自然地理   21篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2017年   1篇
  2016年   2篇
  2014年   2篇
  2013年   5篇
  2012年   1篇
  2011年   2篇
  2010年   3篇
  2009年   1篇
  2008年   3篇
  2007年   1篇
  2006年   3篇
  2005年   4篇
  2003年   4篇
  2002年   3篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   3篇
  1997年   1篇
  1986年   1篇
  1979年   1篇
排序方式: 共有50条查询结果,搜索用时 15 毫秒
21.
Microgeographies of Retailing and Gentrification   总被引:2,自引:0,他引:2  
It has long been argued that gentrification is a process of consumption as well as production but, in the main, analyses of consumption and gentrification have only tangentially or anecdotally considered the retail spaces of gentrified neighbourhoods. In this paper we investigate the nature of the retail landscapes of gentrification, using empirical evidence from Sydney, Australia. We point to micro retailscapes that differ between gentrified neighbourhoods that suggest a divergence of consumption practices between different groups of gentrifiers. These consumption practices are considered both in terms of their relations to identity (through food and the conception of the body) and to the spaces of the city. The paper concludes by drawing out the implications for future research on the consumption practices of the new middle class and the working class in an international context .  相似文献   
22.
Three upper Miocene calc-alkaline volcanic centers are spaced about 100 km apart in the northeast-trending transition zone between the Columbia Plateau and Basin and Range geologic provinces. These centers are transverse to contemporaneous andesitic vents of the western Cascades Sardine Formation. Some of the Miocene volcanic features in northeast Oregon resemble those of linear volcanic belts that are associated with subduction, but structural patterns do not support the existence of an upper Miocene subduction zone in northeast Oregon. Major east-trending fold axes and northwest-trending faults indicate that north-south compression and east-west extension were the dominant deformational events in this region. It is suggested that the origin of these calc-alkaline rocks is related to their particular tectonic setting and not to subduction.  相似文献   
23.
Abstract: ‘Place matters’ in the production of knowledge. This article examines the production of feminist geographical knowledge at a particular place – the Department of Geography, Tourism and Environmental Planning at the University of Waikato. Feminist geography at Waikato represents a nexus of international, national, regional, and local politics. It represents the efforts, personalities, political and personal motivations of particular individuals, at particular times, in a particular space. While international trends are important, they can also mask the unfolding of events in different ways in ‘other’ places.  相似文献   
24.
25.
Heat Wave Hazards: An Overview of Heat Wave Impacts in Canada   总被引:1,自引:2,他引:1  
Extreme heat events are natural hazards affecting Canada and many other regions of the world. This paper presents an overview of the issues involved in defining heat waves and harmful hot weather events, followed by a spatial and historical overview of heat waves across Canada, and an assessment of heat wave adaptation potential in selected cities. The Prairies, Southern Ontario, and areas in the St. Lawrence River Valley of both Ontario and Quebec demonstrate the highest temperatures and most frequent occurrences of heat waves, with minimal effects in the North, Pacific Coast, and Maritimes. Montreal frequently experiences extreme heat, and based on its low air conditioning rates and older, high-density housing, it demonstrates limited potential for adaptation to heat events. A scientific assessment was done to identify the effects of heat waves on various sectors of Canadian life including agriculture, livestock, fisheries, construction, transportation, utilities, the environment, and human health. Heat stress has been linked to excess human mortality and illness, violent behaviour, drought, forest fires, tornadoes, decreased agricultural and livestock productivity, construction and transportation difficulties, and reduced electrical power supply. Despite limited research on heat waves in Canada, this study demonstrates that the impacts of heat are profound and far-reaching.  相似文献   
26.
An approach is proposed to predict the spatial distributions of undiscovered petroleum resources. Each pool is parameterized as a marked-point. The independence chain of the Hastings algorithm is used to generate an appropriate structure for pool combinations in a play. Petroleum-bearing favorability estimated from geological observations is used to represent the sampling probabilities of pool locations. An objective function measuring the distance between characteristics of the realization and constraints is constructed from both the pool size distribution and entropy maximum criterion, in which the entropy criterion places all undiscovered pools in the most favorable positions. The geometrical convergence property of the proposed Hastings algorithm is presented. The method is illustrated by a case study from the Western Canada Sedimentary Basin.  相似文献   
27.
Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi River locations, in 2007-2008. The range of CDOM was 0.092 m−1 at Barataria in June 2008 to 11.225 m−1 at Mississippi in February 2008. An indicator of organic matter quality was predicted by the spectral slope of absorption coefficients from 350 to 412 nm which was between 0.0087 m−1 at Mississippi in May 2008 and 0.0261 m−1 at Barataria in June 2008. CDOM was the dominant component of light attenuation at Terrebonne and Barataria. Detritus and CDOM were the primary components of light attenuation at Vermilion, Atchafalaya, and Mississippi. DOC ranged between 65 and 1235 μM. PIM ranged between 1.1 and 426.3 mg L−1 and POM was between 0.3 and 49.6 mg L−1.  相似文献   
28.
A study investigated the effect of truck‐traffic intensity and road water‐content on the quality of runoff water from unsealed forest roads. Three sections of a gravel‐surfaced forest road were instrumented and exposed to low and high levels of truck traffic during wet winter conditions and dry summer conditions between July 2001 and December 2002. Rainfall, runoff, road moisture, and traffic were measured continuously, and suspended and bedload sediments were integrated measurements over 2‐week site‐service intervals. The median suspended sediment concentration from the three road segments under low truck‐traffic conditions (less than nine return truck passes prior to a storm) was 269 mg l?1, increasing 2·7‐fold to a median of 725 mg l?1 under high truck‐traffic conditions (greater than or equal to nine return truck passes prior to a storm). These concentrations, and increases due to traffic, are substantially less than most previously reported values. When these data are expressed as modified universal soil loss equation (MUSLE) erodibility values K, accounting for differences in rainfall energy, site characteristics and runoff, high traffic resulted in a road surface that was four times more erodible than the same road under low traffic conditions. Using multiple regression, traffic explained 36% of the variation in MUSLE erodibility, whereas road water content was not significant in the model. There was little difference in the erodibility of the road when trafficked in low water‐content compared with high water‐content conditions (MUSLE K values of 0·0084 versus 0·0080 respectively). This study shows that, for a good quality well‐maintained gravel forest road, the level of truck traffic affects the sediment concentration of water discharging from the road, whereas the water content of the road at the time of that traffic does not (note that traffic is not allowed during runoff events in Victoria). These conclusions are conditional upon the road being adequately maintained so that trafficking does not compromise the lateral drainage of the road profile. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
29.
This article focuses on embodied geographies of food, belonging and hope for a group of migrant women in the small city of Hamilton, Aotearoa New Zealand. We explore the complex nature of multiculturalism as it is produced via place and food-sharing. Interviews and cooking sessions with 11 migrant women in Hamilton, each from a different country, prompted a range of emotions highlighting the numerous ways in which migrant women feel that they belong, or do not belong, to their ‘old home’, and their ‘new home’. Furthermore, the sharing of food and feelings helps establish affective ties between women migrants – across ethnic differences – and to the place of Hamilton. These hopeful intercultural encounters – discussed and digested in kitchens – are moments of reciprocity and mutual recognition between ethnically and culturally ‘different’ women. This account provides a means of not only highlighting the difficulties that migrant women face, but also the possibilities of multicultural place sharing.  相似文献   
30.
The effects of temperature, water stress, hydration–dehydration cycles and seed priming on the germination of Callitris verrucosa and Callitris preissii, two Australian semi-arid coniferous tree species, were investigated. Optimum germination occurred at 18°C, with a minimum germination time of 8–9 days for both species. At this temperature, germination was inhibited at osmotic potentials lower than −1·0 MPa, but the capacity to germinate at low osmotic stress increased as the temperature decreased. Seed priming and hydration–dehydration cycles did not reduce seed viability, and Callitris seeds appear to retain the physiological changes induced by short-term hydration, as the time to the onset of germination was decreased to about 3 days. The capacity of Callitris seeds for incremental germination is likely to increase overall germination success in a low rainfall environment.  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