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   2990篇
  免费   57篇
  3047篇
  2020年   23篇
  2019年   37篇
  2018年   314篇
  2017年   251篇
  2016年   292篇
  2015年   42篇
  2014年   45篇
  2013年   485篇
  2012年   71篇
  2011年   209篇
  2010年   216篇
  2009年   86篇
  2008年   120篇
  2007年   95篇
  2006年   37篇
  2005年   66篇
  2004年   45篇
  2003年   36篇
  2002年   32篇
  2001年   29篇
  2000年   29篇
  1999年   15篇
  1998年   30篇
  1997年   25篇
  1996年   19篇
  1995年   16篇
  1994年   23篇
  1993年   17篇
  1992年   12篇
  1991年   13篇
  1990年   14篇
  1989年   8篇
  1988年   12篇
  1987年   16篇
  1986年   19篇
  1985年   16篇
  1984年   25篇
  1983年   20篇
  1982年   23篇
  1981年   11篇
  1980年   15篇
  1979年   17篇
  1978年   8篇
  1977年   18篇
  1976年   14篇
  1975年   11篇
  1974年   11篇
  1972年   8篇
  1970年   7篇
  1968年   7篇
排序方式: 共有3047条查询结果,搜索用时 0 毫秒
81.
82.
Abstract

The loss of agricultural land and its implications have been of great concern in the last decade. By undertaking a spatial analysis of the appropriation of agricultural land for urban use with an overlay of population and urban data, a focus on the consequences of certain regulations on the dynamics of land-use change is explored. This is achieved by integration of data inventories of agricultural land use for Portugal, and linking this information with CORINE Land Cover data as to assess change in the Algarve. An integrated assessment of agricultural land loss follows, undermined by the consequences of urban sprawl. In this sense, this paper expands on the currently existing decrees which provide support to sustainable development in the region while providing a qualitative assessment of future roles based on ethical values and economic efficiency and offering a feasible framework for policy-makers regarding the trends of urban/agricultural dichotomy in a planning and decision-making context.  相似文献   
83.
84.
In 1665, Robert Hooke published his major work in microscopy, Micrographia, a defense of experimental philosophy. The following year, Margaret Cavendish, Duchess of Newcastle, published at her own expense a treatise and a novel that undermined the basis of this new science. The dispute broke out at the initiative of the Duchess, in the context of a vast controversy about the legitimacy and the efficiency of optical instruments in natural philosophy. All the figures of the dual are used, except one: the counterattack. Cavendish, indeed, was alone on the battlefield. Is it possible to call a dual a battle with only one combatant? This particular case of dispute that stops owing to the shortage of combatants is the subject of this article.  相似文献   
85.
The reemergence of cognitive studies in comparative psychology and ethology, coupled with ongoing archaeological discoveries and recent advances in genomics, have contributed to the current explosion of scientific interest in dogs (Canis lupus familiaris). The long and complex evolution of a human-dog relationship is explored from the differing perspectives of ethology, cognitive sciences, evolutionary anthropology, archaeology, and paleoanthropology. Our understanding of dogs is again shedding light on human cognitive evolution and the complex, and at times controversial, process of domestication.  相似文献   
86.
Companies' community involvement turns out to be spatially relevant and–in many cases–to be focused on the near surroundings of the place of business. Some companies strategically align their involvement in order to systematically address local challenges. The essay at hand addresses the subject of corporate social responsibility from a local development perspective. Using the example of two family-owned enterprises based in Duisburg, Haniel and Grillo, it illustrates how socially committed companies can get involved with their local community by acting as good neighbours. Furthermore, it argues that socially committed companies can function as producers of space concerning matters of urban and local development. The specific local settings as well as the economic conditions of the local community serve as an explanatory background of the companies' involvement. The cases presented in this paper prove the firms' specific knowledge of local development needs and possibilities. This makes them qualified partners for local government actors and civil society actors. Thus, in the future, it is worth addressing corporate local responsibility from a governance point of view both in theory and in practice.  相似文献   
87.
88.
Urban green space is a key subject of actual urban negotiation processes on how the city shall develop. Visions of the ideal city are reflected in the meanings currently ascribed to urban gardening. Thereby the relation between human and nature as well as between build and natural environment in the city plays a central role. Results from different Swiss cities show that allotment gardens as well as newer forms of urban gardening are oscillating between a compensatory and a complementary understanding of nature, and they equally combine the desire for pristine nature with the demand for functional green space in the city.  相似文献   
89.
Mapungubwe (AD 1220–1290) is generally regarded as the first urban centre in southern Africa, functioning as the seat of power for an extensive but short-lived polity. More than 80 years of excavations here, and at its nearby predecessor K2 (c. AD 1000–1220), resulted in a substantial assemblage of material remains from elite and commoner contexts. This assemblage includes a large collection of worked bone objects, such as needles, awls, tubes and objects of personal adornment. Of particular interest are the bone arrowheads and link-shafts, of which a significant number of specimens were found complete and intact. Such quantities of well-preserved worked bone objects are unique in the archaeological record of the region. The worked bone assemblages from these two sites provide a rare opportunity to study multiple components of the production process as well as the use context of bone objects. In this paper, we characterise the K2 and Mapungubwe worked bone industries through various morphological, technological, use-trace and contextual approaches and discuss the significance of these aspects in terms of raw material selection and manufacture and archaeological use context. In particular, this study shows the complexity of these worked bone industries over time.  相似文献   
90.
Located in northeastern South Africa in the Kruger National Park, the wild-dominated faunal assemblages at Le6 and Le7 allow for a site-level examination of the treatment of wild species within the highly variable spectra of Early Iron Age animal use. Looking at hunting beyond pure subsistence choices, this paper couples traditional morphological analysis with taphonomic analysis and theoretical frameworks of intensification to ask new socially focussed zooarchaeological questions of these assemblages. Through this, both the procurement and processing methods utilized at Le6 and Le7 are identified and the significance of these choices is discussed. In so doing, the paper addresses possible specialization in both the hunting and the processing of large wild mammals. The socio-economic implications and potential drivers of these faunal choices are then considered within the broader context of the southern African Early Iron Age, and a potentially new faunal use strategy and site type are introduced.  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