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   1945篇
  免费   152篇
  2024年   7篇
  2023年   46篇
  2022年   12篇
  2021年   12篇
  2020年   93篇
  2019年   68篇
  2018年   186篇
  2017年   179篇
  2016年   164篇
  2015年   102篇
  2014年   104篇
  2013年   460篇
  2012年   78篇
  2011年   72篇
  2010年   62篇
  2009年   47篇
  2008年   48篇
  2007年   31篇
  2006年   33篇
  2005年   22篇
  2004年   21篇
  2003年   14篇
  2002年   24篇
  2001年   19篇
  2000年   14篇
  1999年   14篇
  1998年   20篇
  1997年   10篇
  1996年   8篇
  1995年   10篇
  1994年   9篇
  1993年   12篇
  1992年   10篇
  1991年   9篇
  1990年   8篇
  1989年   10篇
  1988年   7篇
  1987年   8篇
  1986年   10篇
  1985年   4篇
  1982年   4篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1970年   1篇
  1969年   2篇
  1962年   1篇
  1959年   2篇
  1956年   1篇
  1950年   3篇
排序方式: 共有2097条查询结果,搜索用时 15 毫秒
41.
The original fineness of coins is very important information that can help us to understand the commercial situation in a wide historical context. This paper deals with a comparison of analytical methods suitable for the evaluation of the actual and original fineness of coins based on a detailed case study of a medieval coin sample. Both non‐destructive (i.e., scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, X‐ray fluorescence, atomic force microscopy and hydrostatic weighing) and destructive (i.e., inductively coupled plasma – mass spectrometry and the Volhard titration method) techniques were used. The original fineness can be also deduced from knowledge of the internal structure of the coin (limited miscibility of copper and silver). A new analytical method based on a combination of a micrograph of the metallographic cross‐section with consequent image analysis was developed for determination of the original fineness. The proposed approach is relatively simple and provides reliable values. Sample heterogeneity and its impact on the determination of fineness are also discussed.  相似文献   
42.
G. Hervé  P. Lanos 《Archaeometry》2018,60(4):870-883
We present a new curve of the directional secular variation of the geomagnetic field in Western Europe between 1500 bce and 200 ce . Its computation relies on a Bayesian framework. The fast secular variation during the Late Bronze and Early Iron Ages makes archaeomagnetic dating efficient with a respective precision of 150–200 and 60–100 years during these periods. The Bayesian method also provides posterior date distributions that refine the dating of reference data, especially during the period of the Hallstattian radiocarbon plateau. Archaeomagnetism becomes a valuable alternative to radiocarbon and will help to improve the archaeological chronologies.  相似文献   
43.
The period comprising the end of the Early Neolithic and the Middle Neolithic, dated broadly within the fifth millennium cal BC, corresponds to an interval that remains largely unknown in the extreme north-western tip of Africa. This situation contrasts with that of the Early Neolithic, a period characterised by the earliest evidence of the diffusion of a productive economy, cultivated plants and domestic animals. The paucity of data for these later phases can be explained in part by the lack of secure contexts and sequences based on radiocarbon datings of short-lived samples. The current study presents the results of the excavations of El-Khil Caves B and C that yield materials allowing re-evaluation of the chronology of a type of ceramic known as Ashakar ware. The study also identifies two traditions in the northern Moroccan Middle Neolithic. The first is heir to the so-called Impressa Mediterranean ware and rooted in the Cardial Neolithic, while the second is characterised by roulette cord impressions, red slip and tunnel lugs and probably rooted in the region of the Sahara, and has no technological precedents in the study area.  相似文献   
44.
45.
46.
47.
This paper investigates the function of beauty in David and Bathsheba’s encounter in 2 Sam 11,1-5. It argues that the female bather’s pleasant appearance, rather than simply kindling king David’s desire, focalizes the woman as sexually available (and vulnerable) and wraps the whole episode in a royal fantasy of shared intimacy. The focus on Bathsheba’s beautiful body—her wash, her motion towards the king, her self-sanctification and her pregnancy—frames the episode in a very erotic way, suggesting adultery. It conceals the sexual violence committed by the king who sends, takes and sleeps with the woman. David’s violent entitlement to Bathsheba reveals the beauty politics at play in his royal House.  相似文献   
48.
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   
49.
The defining element of island regions is their isolation, the separation of the islands from the mainland; there is an inherent notion of natural border. This condition has preserved ecosystems and protected against outside threats, stimulating ‘coevolution’ between man and the environment, a fundamental ingredient of sustainability. But insularity also means the evident added costs of access to markets which, together with territorial limits and the scarcity of basic resources, especially on small islands, hinders their socioeconomic development. These costs are even greater in the case of outlying islands, which suffer from a ‘double insularity’ in the form of both external and internal borders. For this reason, it is common for governments to establish various forms of support, from tax exemptions to the creation of permanent aid funds, like those implemented by the European Union for the outermost regions. This article discusses these aspects in the case of the Canary Islands, an example of a European outermost island region. The findings show that the support measures have not always been favourable for all the islands.  相似文献   
50.
The aim of this paper was to develop a social sustainability tool to clarify what social sustainability means in land use planning processes. The tool was developed through a robust research process covering a large amount of scientific literature and built environment sustainability assessment tools. To assess how the developed tool works in practice, we used it as a coding system for the assessment of social sustainability in a case study from Finland. The case study includes the master planning process of a medium-sized city and the legal framework guiding it. The theoretical contribution of the paper lies in creating a holistic tool for the assessment of social sustainability in planning processes. This study also provides a strong practical contribution, as it goes beyond theoretical definitions to the pragmatic level by providing exemplary measures to be used in designing and implementing processes. Therefore, this paper is a valuable source for those stakeholders (for example planners, developers and policymakers), who struggle with the issue of the successful implementation of social sustainability practices, and it will help them to benchmark their processes against the themes found in the tool.  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