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   539篇
  免费   7篇
  2024年   2篇
  2023年   3篇
  2022年   15篇
  2021年   16篇
  2020年   21篇
  2019年   6篇
  2018年   15篇
  2017年   16篇
  2016年   23篇
  2015年   14篇
  2014年   18篇
  2013年   22篇
  2012年   28篇
  2011年   41篇
  2010年   34篇
  2009年   26篇
  2008年   31篇
  2007年   39篇
  2006年   33篇
  2005年   24篇
  2004年   20篇
  2003年   26篇
  2002年   22篇
  2001年   11篇
  2000年   13篇
  1999年   8篇
  1998年   7篇
  1996年   1篇
  1995年   2篇
  1994年   4篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1983年   1篇
  1982年   1篇
排序方式: 共有546条查询结果,搜索用时 15 毫秒
1.
古人发型是文化界长期关注的一个重要现象。发型不仅是时代的特征与时尚的符号,也是各个族群的辨识标志。从北朝到隋唐的中古社会,"剪头胡雏"的文物图像屡屡出现,一般来说,此类胡人形象是剪发而不是束发,在当时以"高髻为尚"的社会习俗中,"剪头胡雏"发型是有着"阶级感"的存在,是有关底层胡人的直观艺术产物。也说明当时入华胡人还没有彻底"汉化",仍然保留着本族群的发型特征。该发式是胡人与汉人的区别,也是其身份归属的象征。  相似文献   
2.
In recent years, bio-energy with carbon capture and storage (BECCS) has been awarded a key role in climate mitigation scenarios explored by integrated assessment models and referenced in reports by the Intergovernmental Panel on Climate Change. Because a majority of scenarios limiting global warming to 2 °C or 1,5 °C include vast deployment of BECCS, a critical discussion has emerged among experts about the moral implications of thus introducing an unproven technology into the policy realm.In this paper, we analyse this discussion as it has played out between 2013 and 2019, with a focus on how expert narratives are constructed in the mass media about the possibilities for decarbonisation within the current political-economic order. We find there are almost no narratives that support massive deployment of BECCS, and that all narratives presuppose limits to decarbonisation imposed by the current political-economic system. The perception of such limits lead some to argue, through deterministic and apolitical narratives, for the necessity of negative emissions technologies, while others argue instead that “degrowth” is the only solution. Thus, there is a distinct lack of positive narratives about how capitalism can bring about decarbonisation.  相似文献   
3.
浑仪、简仪(以下简称两仪)在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。  相似文献   
4.
南宁市房地产业经历了由沉寂、复苏、火爆到稳步发展的过程.各公司开发的房屋类型相近,但价格差异却很大,价格分布呈现明显的规律性:一是城市中心价格高,边缘与郊区价格低;二是东部城区价格高,西部城区价格低.主导价格分布规律的三大影响因子是地理位置、交通便捷程度和生态环境质量.南宁今后的房地产开发和城市规划建设一要顺应价格分布规律,优地优用、保障房地产开发的高效益;二要加强交通设施建设和环境保护.促进全市房地产的升值;三要因势利导,发展城市副中心,逐步形成多中心的城市建设格局。  相似文献   
5.
In this work, we apply a systemic approach to the analysis of a particular geographic territory, the industrial district. We are particularly interested in analysing the interaction between the productive-technological environment and the scientific environment by an examination of research contracts and patents. Our analysis shows that R&D activity in the Spanish ceramic tile District Innovation System was mainly conducted by suppliers. Final producers’ innovation efforts were related to non-technological aspects and differentiation.  相似文献   
6.
7.
岭南僻处南疆,地理复杂。隋末大乱之时,地方势力纷纷割据,唐初和平统一岭南后,采取羁縻政策,以原有势力为基础设管州的"都府"。而在都府之上,朝廷以广州、桂州、交州为中心置"统府",以点控面,有效地维护了岭南地区的稳定。但是这种层层管理的"统府三分格局",到高宗乾封二年发生突变,随着邕府和容府的建立,原统府消失,遂形成并立的"五府格局"。可是,最迟8世纪初,唐朝设立岭南五府经略使,统一管理整个岭南的军事。在此前后,岭南选补使、岭南按察使、岭南采访使等陆续出现,在人事、监察、民政等领域,对岭南道全境实施管辖权。因此,"盛唐"的岭南道,表现出明显的"归一"趋势。  相似文献   
8.
20世纪60年代,叙事学作为一门学科始于西方历史学、文学领域。直至20世纪末,叙事学开始转向空间领域研究形成空间叙事学,并被逐步应用到城乡规划中,尤其是城乡空间结构等领域。空间叙事学不仅关注城市发展中的物化要素,更加注重物化要素所代表的城市文化和城市记忆等非物化要素的深入挖掘,是探究场所本体与场所精神的重要研究思路。本文从空间叙事学出发,基于GIS平台运用核密度及K函数对古代、近代、现代三个时期沈阳旧城区人工叙事要素和人文事件叙事要素进行点模式量化分析,得出沈阳旧城区叙事空间的总体结构,以及叙事点核、叙事廊道、叙事簇群等叙事空间结构单元,指出沈阳旧城区叙事空间的动态发展性、功能多样性和历史传承性特点,探讨了叙事空间的经济驱动、自然要素、城市定位和交通发展四大演变机制。从人文地理学的视角出发,结合叙事空间理论对沈阳旧城区叙事空间进行分析,结果具有文化地理和城市地理双重属性,丰富了城市研究在该视角下的研究成果。  相似文献   
9.
This paper examines settlement density and settlement patterns in the Roman colonial territories of Venusia, Cosa and Aesernia, located in three different landscapes of central southern Italy (modern Basilicata, Tuscany and Molise). Using a series of GIS tools, we conducted a comparative analysis of the density and spatial distribution of sites dating to the Hellenistic period (ca. 350–50 b.c.). We used the legacy settlement data collected by previous large-scale, intensive, site-oriented field surveys to test the validity of two competing rural settlement models of early Roman colonization: the conventional model of neatly organized settlements regularly dispersed across the landscape and the recently proposed theory that colonists adopted a polynuclear settlement strategy. After calculating the extent to which the archaeological datasets conform to the regular or polynuclear model, we conclude that only a very small portion of the colonized areas actually meets traditional expectations regarding the organization of early colonial settlements. Our analyses show that the legacy survey data is more consistent with the polynuclear settlement theory, but the data also reveals some completely unexpected patterns, suggesting that early Roman colonial landscapes were more diverse than previously thought.  相似文献   
10.
The unique geographical environment and the historical waves of immigration of the northern Han Chinese to the Lingnan region have contributed to the development of a complex and unique culture in Guangdong Province. Four ancient ethnic groups, the Zhuang, Cantonese, Hoklo and Hakka, have resided in this area for centuries. As an important part of local culture, toponyms often survive changes in history and can reveal the temporal differences between the past and present in landforms and the spatial differences in the distribution of different ethnic group populations. In this study, two goals were sought: (1) the adoption of spatial smoothing and interpolation methods to reveal the spatial patterns of the Zhuang, Cantonese, Hoklo and Hakka toponyms based on comparisons among the proportions of those who speak various languages and (2) the investigation of the differences among toponymic layers under regional environmental conditions and the influences of geographic factors using an independent samples t-test and a binary logistic regression.  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