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   523篇
  免费   8篇
  2024年   1篇
  2023年   5篇
  2022年   7篇
  2021年   8篇
  2020年   16篇
  2019年   19篇
  2018年   20篇
  2017年   19篇
  2016年   24篇
  2015年   9篇
  2014年   10篇
  2013年   67篇
  2012年   24篇
  2011年   32篇
  2010年   29篇
  2009年   36篇
  2008年   32篇
  2007年   33篇
  2006年   18篇
  2005年   24篇
  2004年   21篇
  2003年   19篇
  2002年   25篇
  2001年   11篇
  2000年   7篇
  1999年   6篇
  1998年   3篇
  1997年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
排序方式: 共有531条查询结果,搜索用时 0 毫秒
101.
Drawing together insights from neo‐Innisian geography and environmental history, this paper explores the landscape and environmental changes engendered by ‘cyclonic’ patterns of development associated with uranium production at Uranium City, Saskatchewan. Strong postwar demand for uranium led to the establishment and rapid expansion of Uranium City on the north shore of Lake Athabasca as a ‘yellowcake town’, dedicated to producing uranium oxide concentrate to supply federal government contracts with the US military. In spite of optimistic assessments for the region's industrial future, the new settlement remained inherently unstable, tied to shifting institutional arrangements and external markets, and haunted by the spectre of resource depletion. The planning and development of the townsite at Uranium City reflected both neocolonial desires to open the north to Euro‐Canadian settlement and efforts by the state to buffer the stormy effects of resource dependency. Ultimately, however, quixotic government efforts to implant an outpost of industrial modernity in the Athabasca Region failed to forestall the inevitable winds of change, which left in their wake destructive legacies of social dislocation and environmental degradation, already evident with the near‐collapse of the uranium export market by the early 1960s.  相似文献   
102.
<正>2006年12月,根据吕遵谔提供的线索,北京师范大学历史学院与洛阳市文物钻探办公室的考古人员,在洛阳市进行了为期一个多月的旧石  相似文献   
103.
黄南州文化产业发展及其借鉴意义   总被引:2,自引:0,他引:2  
王华平 《攀登》2010,29(1):97-100
黄南藏族自治州是一个以藏民族为主体的多民族聚居区,其历史悠久,文化资源十分丰富。近年来,黄南州以丰富的有形及无形文化遗产为依托,探索出一条少数民族地区发展文化产业的新路子,其做法及经验对全省发展文化产业具有一定的借鉴意义。  相似文献   
104.
Is Greener Whiter Yet? The Sustainable Slopes Program after Five Years   总被引:2,自引:0,他引:2  
This study focuses on two basic questions: Are voluntary programs effective in promoting higher environmental performance by participant firms? If so, which distinct areas of environmental performance are more likely to be improved by firms joining a voluntary environmental program? We address these questions by assessing the environmental effectiveness of the ski industry’s Sustainable Slopes Program in the western United States between 2001 and 2005. We found no evidence in our five-year analysis to conclude that ski areas adopting the SSP displayed superior performance levels than nonparticipants for the following areas of environmental protection: overall environmental performance, expansion management, pollution management, and wildlife and habitat management. SSP participants only appear to show a statistically significant correlation with higher natural resource conservation performance rates. For policymakers, these results suggest that caution is needed before a priori assuming that strictly voluntary programs can be effective in promoting comprehensive superior environmental performance.  相似文献   
105.
This paper draws on export data from four of Iran’s key trade partners—the European Union, China, the United Arab Emirates (UAE), and Turkey—to examine the robust and positive correlations between the export of parts and machinery to Iran and Iran’s industrial output, as measured by production index data published by the Central Bank of Iran for industrial enterprises with over 100 employees. The period of analysis is 2000 to 2017. It may seem intuitive that the output of Iranian manufacturers depends on the ability of companies to source intermediate goods such as parts and machinery. However, the imposition of sanctions on Iran is shown to have temporarily decoupled the relationship between European industrial exports to Iran and the Iranian industrial production index—the index remained stable even as European exports fell. An analysis of trade data for the other three trade partners included in this study quantitatively substantiates reports noting that in order to sustain the industrial production index, Iran engaged in processes that can be collectively described as “import reflection.” This entails substituting European intermediate inputs with Chinese inputs while also circumventing sanctions pressures on trade by sourcing European inputs via re‐export from the UAE and Turkey. These processes were fundamental to Iran’s economic resilience in the face of multilateral sanctions and have played a central role in Iran’s defense of its industrialized economy and particularly its non‐oil exports as the administration of US President Donald Trump pursues a new unilateral campaign of “maximum pressure” sanctions.  相似文献   
106.
李磊  刘红兰  陶卓民  陆林 《人文地理》2022,37(5):32-41+88
通过对Web of Science数据库中1435篇文献的梳理,回顾和评述了“COVID-19对旅游业影响”的早期研究进展。结果表明,新冠肺炎直接威胁人的生命健康,加剧了旅游者的负面情绪和感知风险,降低了旅游者的出游意愿,并改变了以往的行为模式。新冠肺炎通过旅游者在旅游目的地、旅游企业、旅游交通之间传播,从而对旅游系统产生全面、持久的影响,对全球旅游业造成史无前例的巨大冲击。同时,新冠肺炎还引发了对于旅游业发展方式和增长模式的反思,转型发展成为后新冠时代全球旅游业恢复重建的重要手段。最后,从“目标—要素—保障”视角对未来研究进行了展望。  相似文献   
107.
《汪氏典业阉书》研究——清代徽商典当业的一个实例   总被引:6,自引:1,他引:5  
汪庆元 《安徽史学》2003,(5):90-92,98
《汪氏典业阉书》是研究徽商的新资料。其内容反映了徽州典商跨入近代社会门槛时资本运作的情况。阄书之“总帐”载明清代徽典资本构成为两部分:“承祖业分受财本”和“生息资本”。其中社会存款约占总资本的28%。“墨议”中“四典并无会票在外”一款说明徽典普遍经营会票,具有良好的商业信用。汪氏典业析产和徽典经营会票不能获利的情况表明,在当时市场条件下,徽商资本已难以壮大。  相似文献   
108.
The paper gives a comparative and historical assessment of climatic and economic hazards in the five main fruit‐growing areas of Canada, and how the industry has responded. The northern location of fruit growing in Canada poses a number of climatic hazards. The most serious hazard is winter low‐temperature injury to trees and vines, which results in a capital loss and crop loss for up to five years. The industry has responded to this hazard by abandoning fruit growing in areas with unfavourable climatic conditions and concentrating in areas with the most favourable climatic conditions. Other responses include changing to hardier varieties, improving management practices, and government subsidies. The fruit‐growing industry has also had to face many economic hazards, including changes in technology and consumer preferences, changes in international trade rules, increased foreign competition, a cost‐price squeeze, and urbanization of the industry's land base. These economic hazards area a greater threat to the industry than the natural hazards because, in most cases, there are limited coping mechanisms available to growers, and economic globalization is preventing the federal and provincial governments from providing an adequate safety net. L'article nous présente une évaluation comparative et historique des risques climatiques et économiques des cinq principales régions agricoles du Canada, ainsi que les réactions de cet industrie face à ceux‐ci. La situation géographique nordique des champs de fruits au Canada amène un certain nombre de risques climatiques. Les basses températures de la saison hivernale causent le plus de dommages aux arbres et aux vignes, ce qui se traduit en une perte de capitaux et une perte de récoltes allant jusqu'à cinq ans. La réaction de l'industrie de l'agriculture face à ces risques fût d'abandonner les endroits dont les conditions climatiques ne favorisaient pas la récolte de fruits. II a aussi été question d'utiliser des variétés plus résistantes au froid, d'améliorer les pratiques de management, et les subventions gouvernementales. L'industrie de la culture de fruits a aussi fait face à des risques économiques, incluant les changements technologiques et les préférences alimentaires des consommateurs, les changements au niveau des règles d'échanges internationaux, la compétition croissante au niveau international, une réduction du prix‐coûtant, et l'urbanisation des terres agricoles. Ces risques économiques représentent un plus grand danger pour l'industrie que les risques naturels puisque, dans la plupart des cas, les agriculteurs se retrouvent avec des moyens de rechange limités et la mondialisation économique empêche les gouvernements fédéral et provincial de fournir des mesures de sécurité adéquates.  相似文献   
109.
深圳市民休闲时间利用特征研究   总被引:22,自引:3,他引:19  
以对深圳市民的活动日志调查为基础,着重研究作为一个完整休闲日的休息日中深圳市民休闲活动的时间利用特征。通过聚类分析将深圳市民休息日的休闲时间利用结构分为六种类型,在考察不同类型的居民属性结构的基础上,分析了休闲时间总量对城市居民休闲时间利用的影响以及不同休闲时间利用类型的休闲活动的节奏与空间特征,提出了与对城市休闲服务设施规划与城市休闲产业发展相应的建议。  相似文献   
110.
我国酒店类上市公司经营业绩下滑原因初探   总被引:1,自引:0,他引:1  
1999年我国酒店类上市公司经营业绩又出现较大滑坡,这已是酒店业上市公司连续第四年下降。本文通过对上市公司业绩下滑原因作出分析,探讨了上市公司走出目前困境的途径。  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