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   820篇
  免费   29篇
  2023年   9篇
  2022年   7篇
  2020年   28篇
  2019年   27篇
  2018年   39篇
  2017年   49篇
  2016年   48篇
  2015年   34篇
  2014年   39篇
  2013年   237篇
  2012年   29篇
  2011年   28篇
  2010年   25篇
  2009年   18篇
  2008年   28篇
  2007年   22篇
  2006年   16篇
  2005年   13篇
  2004年   16篇
  2003年   5篇
  2002年   12篇
  2001年   7篇
  2000年   4篇
  1999年   8篇
  1998年   15篇
  1997年   6篇
  1996年   10篇
  1994年   11篇
  1993年   3篇
  1992年   5篇
  1991年   5篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   3篇
  1985年   6篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1975年   3篇
  1973年   4篇
  1972年   3篇
  1971年   3篇
  1970年   1篇
  1966年   1篇
排序方式: 共有849条查询结果,搜索用时 15 毫秒
821.
The historical Norberg mining district in central Sweden with its shallow, easily accessible iron ores figures prominently in the earliest documents from the 14th century concerning mining or metallurgy. This 1000-km2 district is considered to be one of the first areas in Sweden exploited for iron ores and, in fact, Europe’s oldest known blast furnace, Lapphyttan, is located in the Norberg district about 10 km from the mines in the village of Norberg (Norbergsby). Earlier archaeological excavations suggest the furnace was in operation as early as the 11th or 12th century (870 and 930 14C yr BP), and a number of other sites in the district have been dated to the 13th–15th centuries. Here, we have analyzed two lake sediment records (Kalven and Noren) from the village of Norberg and a peat record from Lapphyttan. The Lapphyttan peat record was radiocarbon dated, whereas the sediment from Kalven is annually laminated, which provides a fairly precise chronology. Our pollen data indicate that land use in the area began gradually as forest grazing by at least c. AD 1050, with indications of more widespread forest disturbance and cultivation from c. 1180 at Lapphyttan and 1250 at Kalven. Based on 206Pb/207Pb isotope ratios in Kalven’s varved sediment record, there is an indication of mining or metallurgy in the area c. 960, but likely not in immediate connection to our sites. Evidence of mining and metallurgy increases gradually from c. 1180 when there is a decline in 206Pb/207Pb ratios and an increase in charcoal particles at Lapphyttan, followed by increasing inputs of lithogenic elements in Noren’s sediment record indicating soil disturbance, which we attribute to the onset of mining the iron ore bodies surrounding Noren. From AD 1295 onwards evidence of mining and metallurgy are ubiquitous, and activities accelerate especially during the late 15th century; the maximum influence of Bergslagen ore lead (i.e., the minimum in 206Pb/207Pb isotope ratios) in both Kalven and Noren occurs c. 1490–1500, when also varve properties change in Kalven and in Noren sharp increases occur in the concentrations of a range of other ore-related metals (e.g., arsenic, cadmium, copper, iron, lead, mercury and zinc). From the 15th century onwards mining and metallurgy are the dominant feature of the sediment records.  相似文献   
822.
823.
824.
Abstract

Social norms surrounding women’s and men’s mobility in public spaces often differ. Here we discuss how gendered mobilities and immobilities influence women’s and men’s capacities to innovate in agriculture. We analyze four case studies from Western Kenya and Southwestern Nigeria that draw on 28 focus group discussions and 32 individual interviews with a total of 225 rural and peri-urban women, men and youth. Findings show that women in both sites are less mobile than men due to norms that delimit the spaces where they can go, the purpose, length of time and time of day of their travels. Overall, Kenyan women and Nigerian men have better access to agricultural services and farmer groups than their gendered counterparts. In Southwestern Nigeria this is linked to masculine roles of heading and providing for the household and in Western Kenya to the construction of women as the ‘developers’ of their households. Access and group participation may reflect norms and expectations to fulfill gender roles rather than an individual’s agency. This may (re)produce mobility pressures on time constrained gendered subjects. Frameworks to analyze factors that support women’s and men’s agency should be used to understand how gendered mobilities and immobilities are embedded in community contexts and affect engagement in agricultural innovation. This can inform the design of interventions to consider the ways in which norms and agency intersect and influence women’s and men’s mobilities, hence capacity to innovate in agriculture, thus supporting more gender transformative approaches.  相似文献   
825.
826.
ABSTRACT

Since the 1990s, numerous public investigations have been carried out around the world on the abuse of children in out-of-home care. In the case of Iceland, commissions were appointed by the Icelandic government in 2007 to examine the historical abuse of children and youth in institutions monitored by local or state authorities during the second half of the 20th century. All the institutions subject to national investigations in Iceland were created during the postwar era, the earliest one in 1947. This article addresses the discourse on institutions and out-of-home care from a long-time perspective. It is shown that ideas on those institutions came to the fore during the early 20th century and were closely linked to progressive ideas on child welfare at the time. World War II and the British occupation of Iceland shaped the views on institutional care, and the postwar era was a period of intensive institutionalization of children and youth. The study also shows that the rhetoric concerning disobedient youth was heavily gendered. Whereas boys were accused of petty larceny, truancy and vagrancy, the main evils of girls were related to their morals, promiscuity being their chief vice.  相似文献   
827.
ABSTRACT

Synesthesia is a rare neurological trait that causes unusual, often cross-sensory, experiences (e.g., seeing colors when listening to music). This article traces the history of synesthesia in the period 1876 to 1895. In this period, there was considerable debate over the nature of synesthesia, its causes, and how it should be named. The issue also attracted the leading thinkers of the time and, within a few years, the number of reported cases of synesthesia jumped from around ten to more than 100. For this reason, this period can be regarded as the “golden age” for synesthesia research in the nineteenth century. In this time, scientists debated whether synesthesia was a form of pathology or an alternative manifestation of intelligence. The differing roles of heredity and environment were contested, and there were several explanations proposed as to its neural basis. These enquiries went to the heart of the debate as to whether synesthetic experiences are special in any way or, instead, a more vivid manifestation of a more general capacity for forming associations.  相似文献   
828.
The discovery of 373 intact and broken tin‐bronze socketed axes accompanied by 404 fragments in four pits at Langton Matravers collectively represents one of the largest hoards found to date in prehistoric Britain and Ireland. They were very probably never meant to be used as axes as the very high levels of tin they contain would have made them brittle. Many were poorly finished, with the majority still containing their casting cores. The axes are typologically dated to the Llyn Fawr metalwork phase (c.800–600 BC) and span the Bronze Age/Iron Age transition, when the production, circulation and deposition of bronze appear to have been substantially reduced throughout north‐west Europe. By placing the Langton Matravers hoard(s) in a broader metallurgical, material and archaeological context, existing theories for this phenomenon, such as the preference for iron, a collapse in bronze supply, or the sharp devaluation of a social or ritual ‘bronze standard’, are evaluated. It is proposed that the Langton Matravers axes belong to a short phase in the centuries‐long processes underlying the changing roles of bronze and iron.  相似文献   
829.
830.
A tributary of the Banas, the Nagdi River flows through the old market town of Jahazpur in Bhilwara District, Rajasthan. Unlike India's major sacred waterways such as the Ganga and the Yamuna which have the status of goddesses, the Nagdi was never deified. However, it figures in Jahazpur's origin legend, reaching back to the epic Mahabharata. Due to a complex convergence of conditions unique to this place but resonant with ecological tragedies the world over, the Nagdi's flow has dwindled and its waters are badly polluted. Everyone in Jahazpur with whom the authors spoke during fieldwork in 2010–11 mourned the end of their river. Once proud of the Nagdi's beauty and miraculous properties, Jahazpur residents were aware of having lost an important part of their environmental and cultural heritage. This article explores the complex causalities of the Nagdi's deterioration and emergent possibilities for its restoration.  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