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   217篇
  免费   29篇
  2024年   3篇
  2023年   9篇
  2021年   3篇
  2020年   8篇
  2019年   5篇
  2018年   32篇
  2017年   25篇
  2016年   24篇
  2015年   14篇
  2014年   11篇
  2013年   43篇
  2012年   8篇
  2011年   16篇
  2010年   10篇
  2009年   11篇
  2008年   6篇
  2007年   5篇
  2006年   1篇
  2003年   1篇
  2002年   1篇
  1999年   3篇
  1998年   2篇
  1992年   1篇
  1977年   2篇
  1975年   1篇
  1966年   1篇
排序方式: 共有246条查询结果,搜索用时 15 毫秒
11.
The refining of silver ores in New Spain was defined by the chemical nature of the silver ore. Argentiferous galena (lead sulphide) could only be refined by smelting (36% silver produced), irrespective of silver content, and amalgamation (64%) could only be applied to the silver sulphide ores. Both processes were transferred from Europe, but amalgamation was transformed by local expertise from a recipe of limited application to an industrial-scale solution for refining sulphidic silver ores. Its implementation shaped the environmental history of colonial silver refining in the New World. Mercury was consumed mainly through its chemical conversion into calomel, with minimal emissions of volatile mercury. Waste silt and liquid mercury in the soil and waterways were its main legacy. Smelting created a greater impact on the environment of New Spain, via lead in lead fumes as the main heavy metal issued to the air, and its depletion of woodlands. This article argues that a technical analysis of period refining practices in New Spain reorients our understanding of Spain’s imperial relations with its New World colonies, of the role of local knowledge in a global economy of silver production, and of environmental issues in colonial history. It thus speaks to the problem of unpacking the complex web of relations that composed early European imperialism, in which were enmeshed commodities such as silver, cotton and sugar.  相似文献   
12.
13.
Research projects undertaken in the Cantabrian region since 1980 have produced new, high-quality information about the neolithisation process(es) in this area. It is now necessary to review this archaeological information and test the main hypotheses put forward to explain it. This paper presents an update on the archaeological evidence (sites, chronological dates, archaeozoological, archaeobotanical and technological information) for the early Neolithic in the Cantabrian region. It summarizes recent research on neolithisation in the region, and assesses the impact of this process during the early Neolithic, and its later consolidation. Although the available information is still incomplete, it is now possible to identify the focal point of the introduction of elements characteristic of the Neolithic way of life in the region. Current evidence suggests that it is in the eastern sector, where the earliest arrival of domesticates and new technologies such as pottery has been attested. The existence of continuities—such as sustained reliance on hunting and gathering and the coexistence of old and new funerary rites—suggests the persistence of native populations, which gradually participated in the neolithisation process after an ‘availability phase’.  相似文献   
14.
This article discusses how land-use planning and management can combine the aim of local development with the protection of mountain areas. The basis for this double approach comprises protected areas and the land-use element of the Municipal Master Plan according to the Nature Diversity Act and the Planning and Building Act (PBA), respectively. Case studies performed in six mountain municipalities show that the planning processes in general are performed by a combination of rationalistic and communicative rationality based on consensus and with little awareness of power structures. Today's two-part system is dominated by the interests backing protection, not only in the protected areas, but also in the buffer-zones. Though the conflicts are rather few, they nevertheless often seem deep-set and rooted in national–local power relations. We argue that a more agonistic and decentralized approach where the protection-area management is transferred to the PBA will, to a larger extent, be able to combine both use and protection and to stimulate local development in mountain municipalities.  相似文献   
15.
16.
17.
The benefits of urban open spaces for improving the quality of life and sustainability in cities are widely recognized. The functions they perform within the framework established by urban planning, as well as their metrics, are now more complex than in the past. It is convenient to develop methodologies for the evaluation of these spaces adapted to the present time to check their level of efficiency, which is useful in urban planning for the establishment of new urban open spaces. The aim of this study is to classify such spaces through a methodology that integrates spatial analysis, configuration analysis, and decision support so as to understand their complexity from a more advanced analytical perspective. In order to do this, a prior exploration of specific literature is carried out, which allows the characterization of the functions of urban open spaces by means of the corresponding analysis variables in a weighted manner. The integrated combination of these advanced tools is a step forward in achieving consistent and detailed results for urban open spaces. They perform their functions best in dense, central, equipped, accessible, connected, and easily walkable urban environments. In addition, future recommendations are provided.  相似文献   
18.
This work analyses the main Spanish legislative and urban planning instruments, highlighting some of the most important structural problems of the current Spanish urban realities. The survey on legislation runs from the first Land Use Act of 1956 to the decentralization of the administration and the culmination of the transfer processes to the respective Spanish regions. Later, we study the complete well-structured hierarchy of urban planning instruments in use at present. Finally, we analyse how these and other factors have an influence on the capacity to control housing prices and on a lack of sustainability characterized by the excessive urbanizing use of the land.  相似文献   
19.
Francis Bacon. By Perez Zagorin (Princeton, NJ: Princeton University Press, 1998) xvi + 286 pp. $29.95, £19.95

Francis Bacon: The History of the Reign of King Henry VII. Edited by Brian Vickers (Cambridge, UK: Cambridge University Press 1998) xlv + 284 pp. £40.00 cloth  相似文献   

20.
This paper evaluates the impact of accessibility on the productivity of Spanish manufacturing firms. We suggest the use of accessibility indicators of workers and commodities, integrating transport, land use, and individual components, computing real distances or traveling times using the Spanish full road network. Estimated firms’ total factor productivity is explained as a function of the accessibility indicators and additional control variables. Results evidence the crucial role on firms’ productivity to the accessibility of commodities and to a slightly lesser extent the workers.  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