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   496篇
  免费   10篇
  2024年   3篇
  2023年   8篇
  2022年   9篇
  2021年   9篇
  2020年   25篇
  2019年   18篇
  2018年   25篇
  2017年   23篇
  2016年   13篇
  2015年   8篇
  2014年   33篇
  2013年   126篇
  2012年   19篇
  2011年   36篇
  2010年   14篇
  2009年   26篇
  2008年   17篇
  2007年   13篇
  2006年   16篇
  2005年   13篇
  2004年   6篇
  2003年   6篇
  2002年   11篇
  2001年   9篇
  2000年   7篇
  1999年   1篇
  1998年   3篇
  1997年   2篇
  1996年   1篇
  1993年   2篇
  1992年   1篇
  1991年   3篇
排序方式: 共有506条查询结果,搜索用时 0 毫秒
51.
The noise level of the Romanian broadband stations operating since 2006 has been studied in order to identify the variations in background seismic noise as a function of time of day, season, and particular conditions at the stations. Power spectral densities and their corresponding probability density functions are used in this paper to characterize the background seismic noise. At high frequencies (> 1 Hz), seismic noise seems to have cultural origin, since significant variations (up to 55 dB) between daytime and nighttime noise levels are observed at almost all of the stations. However, this variability appears not to influence the detection capabilities of the Romanian Seismic Network in case of intermediate-depth earthquakes and earthquakes with magnitude over 3.0. For smaller magnitude events (Mw < 3), we showed that the number of stations detecting an event decreases during daytime. We studied the seasonal variation of the seismic noise for primary and secondary microseisms (with emphasize for the latter) and we demonstrated that the noise levels are higher in winter than in summer. We also observed a shift of the double-frequency peak from lower periods in summer to longer periods in winter. The polarization analysis indicated that the main sources of secondary microseisms for stations close to the Black Sea are coming from the Black Sea, while for the others the main sources are found in the Mediterranean Sea and Atlantic Ocean. Finally, the analysis of the probability density functions for stations located in different geologic conditions has pointed out that the noise level is higher for stations sited on softer formations than those sited on hard rocks.  相似文献   
52.
Abstract

It has recently been proposed that lowered lake levels after 4250 BP broadened opportunities for mobility and interaction patterns among hunter-gatherer populations in the Saginaw drainage and in Michigan more broadly (; ). Here, data are presented on chipped stone reduction strategies as reflected in two site assemblages in Bay City, Michigan (20BY28, 20BY387) that bridge this key point in time. The earliest Late Archaic components of these sites, occupied during the higher than modern post Nipissing recession ca. 3200 BP, are typified by on-site reduction of local cherts, often utilising a bipolar reduction strategy. Subsequent uses of the area largely shifted to lower elevations. The more recent site components contain both more diverse projectile styles, many of which can be linked with Ontario types, and higher occurrences of non-local raw materials, specifically Onondaga chert apparently arriving at the site as preforms. The last use of these sites occurred during the Late Woodland, also during lower water levels approaching modern, and reflecting the highest use of Onondaga chert. We suggest that these changes resulted from shifting mobility and exchange patterns, facilitated in part by lowered post Nipissing water levels.  相似文献   
53.
近年来,我国城乡建设取得了举世瞩目的成就,面貌为之一新。但在这个过程中,地下文物作为中华历史文化的物质载体的重要组成部分,遭遇了前所未有的严重破坏,造成了文物流失、文物遭毁等一系列严重后果。本文着眼干近年来城乡建设中地下文物屡遭破坏的现状,分析保护工作收效甚微的原因,说明加强和改进地下文物保护工作的重要性:并提出应以法律法规的建设完善和保护制度的健全为重点,从多方面制定应对措施,寻找当前形势下地下文物保护与城乡建设间的最佳平衡点。  相似文献   
54.
近现代文物缺失诸多,譬如,品类不全、难以一层分类、信息混交、价值无法量化、寿命短暂、赝品众多等。现将其揭示出来,并说明其存在形式及原因。  相似文献   
55.
琥珀制品在两汉时期风靡一时,琥珀印在琥珀制品中颇具特色。本文在对中国境内考古发现所见两汉琥珀印资料收集与整理的基础上,对其出土地域、自身特征、出土位置及伴出物品等问题进行了探讨。研究表明出土琥珀印的墓葬等级较高,且出土位置特殊,并伴随有水晶、玛瑙、海蓝宝等贵重宝石。这些宝石的产地可能源自南亚或东南亚地区,而这类随葬品在两汉墓葬中的流行亦体现了当时物质交流的成果。  相似文献   
56.
Abstract: Strategic management is a familiar concept in for-profit organisations but is relatively new to museums. This paper presents and discusses a model of strategic management for visitor-oriented museums that aims to be more comprehensive than current approaches. It shows how museums can overcome the tension between the strategic demand to develop visitor-oriented museum services and the duties and social mandate of museums as public institutions that are defined by cultural policy—enabling access to cultural heritage, promoting broad cultural participation and providing informal education. Visitor-oriented strategic museum management is concerned with attracting a variety of visitors as well as the development of museum services that are appropriate to diverse museum audiences. The model presented here emphasises the comprehensive strategic management concept. Audience research and evaluation are shown to be valuable analytic and revision tools for strategic management in visitor-oriented museums.  相似文献   
57.
Cultural policies and cultural projects in the United States have been reframed to emphasize their economic benefits to cities. New alliances between arts advocates and place promoters are apparent at all levels, but are most prominent locally. These new alliances are facilitated by the changing interests of local officials and business people, who have come to believe there is economic value in the arts and of arts administrators, for whom attracting broader public support has become imperative. In some cities, entirely new organizational structures have sprung up to plan and implement projects that serve cultural and economic development advocates simultaneously. Such new institutions are most prominent in more economically disadvantaged cities.  相似文献   
58.
Abstract: This paper explores the current discourse about arts policy and funding and its placement within an economic paradigm. The models of “cultural industry” and “creative industry” are explored and how they affect arts funding discourse. Similarly the impact of the introduction of the language of industry and business to the arts sector is considered. If bottom-line arguments are used by funders, governments and critics to argue the merits or otherwise of arts activity, how does this affect arts practice? In recent times arts funding agencies have been restructured to reflect a market-driven agenda rather than an arts-driven agenda. The impact of all these issues is considered in the context of Australian arts' models in particular, but with reference to examples in the United Kingdom and the United States of America. The paper concludes with suggestions for a reassertion of core cultural values in future discourse.  相似文献   
59.
Abstract

The discussion of the multicultural society has long been current in Danish social and educational policy, but it is only at the turn of the millennium that the issue has been placed on the agenda in a serious way in relation to the Danish national cultural policy. The transformation from a homogenous identity concept to the acceptance of a diversity of voices and interpretations is occurring only slowly in both the production and dissemination of art and culture. In the cultural policy discourse up through the 1980s there is an acute lack of discussion about the ethnic or multicultural. Far up into the 1990s, the cultural political contributions within the multicultural field are left to the social or humanitarian organs, with integration as the general goal. At the advent of the millennium we can identify greater openness and interest for the multicultural field. In the evaluation of The Ministry of Culture's Development Fund I have analysed the subsidized activities according to the strategies of ethnic revival , interculturalism and hybridisation , and in the article I discuss the problems of formulating criteria for artistic quality in an area new to members of the board. On this background I discuss the relation between multiculturalism and cultural diversity , where I find the concept of cultural diversity to be a better reflection of the new hybrid cultures, which not only transcend boundaries and traditional cultures but dissolve them and create new expressions across genres and cultural forms.  相似文献   
60.
This paper addresses the complexities involved in developing cultural policies in the Anglophone Caribbean. The first section examines the evolution of the cultural policy agenda in the 40‐odd years since the independence era. It traces and analyses the policy trajectory from one that sought to promote the intrinsic values of culture, to one that currently espouses the more instrumental value of the cultural industries. The next section analyses the efficacy of the policy path by examining a regional cultural policy initiative, the Caribbean Festival for the Arts (CARIFESTA). The paper suggests that the Caribbean cultural policies have under performed because of critical disjunctures. These generally involve the imposition of a nationalistic policy framework on the transnational structure of the Caribbean cultural sector. The paper concludes by suggesting a regional cultural approach to policy formulation can provide a more effective mechanism to encourage and harness the cultural wealth of the Anglophone Caribbean.  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