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   83篇
  免费   2篇
  2023年   1篇
  2020年   3篇
  2019年   3篇
  2018年   8篇
  2017年   9篇
  2016年   4篇
  2015年   2篇
  2014年   5篇
  2013年   12篇
  2012年   3篇
  2011年   3篇
  2010年   1篇
  2009年   3篇
  2008年   4篇
  2007年   1篇
  2006年   3篇
  2005年   7篇
  2004年   1篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1997年   1篇
  1993年   1篇
  1992年   1篇
  1986年   1篇
  1977年   1篇
  1976年   1篇
排序方式: 共有85条查询结果,搜索用时 15 毫秒
71.
This article aims at illustrating the historical circumstances that led Julius Bernstein in 1902 Bernstein, J and Tschermak, A. 1902. Ueber die Beziehung der negativen Schwankung des Muskelstromes zur Arbeitsleistung des Muskels. Pflügers Arch, 89: 289331.  [Google Scholar] to formulate a membrane theory on resting current in muscle and nerve fibers. It was a truly paradigm shift in research into bioelectrical phenomena, if qualified by the observation that, besides Bernstein, many other electrophysiologists between 1890 and 1902 borrowed ideas from the recent ionistic approach in the physical-chemistry domain. But Bernstein's subjective perception of that paradigm shift was that it constituted a mere reinterpretation of the so-called preexistence theory advanced by his teacher Emil du Bois-Reymond in the first half of the nineteenth century.  相似文献   
72.
Urbanism in the Indian subcontinent occurred in three distinct time periods in which cultural cohesion over large regions is archaeologically demonstrated through the architecture and artifacts of social, ritual, and economic activity. In the Indus (2500–1900 B.C.) and Early Historic (3rd century B.C. to 4th century A.D.) periods, cities were not necessarily tied to political territories or guided by strong political leaders, but by the Medieval period (after the 9th century A.D.), urban zones were the base for political growth, warfare, and aggrandizement. The comparison of these three eras is undertaken within a framework for defining cities that balances quantitative criteria such as population size and areal extent with two types of qualitative criteria: internal specialization on the basis of materials found within archaeological sites, and external specialization on the basis of data recovered through regional analysis. Cities from the three eras also are evaluated from the perspective of the ordinary inhabitant through the examination of the social, religious, and economic factors that prompted and rewarded urban residence. While the Indus and Early Historic cities were attractive because of the networks of opportunity found there, Medieval cities additionally benefitted from a “push” factor as ordinary inhabitants allied themselves to urban areas in times of political stress and uncertainty.
Monica L. SmithEmail:
  相似文献   
73.
74.
At La Espiral cave, located in Bahia Honda municipality (Artemisa province, Cuba), there are several pictographs, including two of particular importance due to the design used: one of concentric circles and another of a spiral. We analyzed the pigments and binders used in one of these pictographs. The chemical ingredients of the paint are considered in this article, as well as the use of bat guano as a major pigment compound. The apparent presence of ellagic acid, ellagitannin, or anthocyanins would strengthen the hypothesis that artists used vegetable protein as a paint binder or solvent.  相似文献   
75.
Microfossil analysis of human dental calculus provides consumption‐specific and archaeologically relevant data for evaluating diet and subsistence in past populations. Calculus was extracted from 114 teeth representing 104 unique individuals from a late 16th to early 18th century skeletal series on Rapa Nui (Easter Island) to address questions of human–environment interactions and possible dietary preference. Scanning electron microscopy was used in lieu of optical microscopy for its superior depth of field and resolution of surface detail. The calculus microfossil recovery produced 16,377 total biogenic silica microfossils: 4733 phytoliths and 11,644 diatoms. The majority of phytoliths correspond with the Arecaceae or palm family (n = 4,456) and the minority corresponds to the Poaceae or grass family (n = 277). Because of the relatively large sample size, we were able to test hypotheses related to age cohort, sex, dental element and geographic region. Results indicate no significant difference in phytolith or diatom recovery based on age cohort or sex. The high frequency and proportion of Arecaceae phytoliths found in calculus extracted from the anterior dentition suggests consumption of soft or cooked foods containing palm phytoliths and the high frequency of diatoms recovered from the southern part of the island argue for different sources of drinking water. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
76.
ABSTRACT

Never before have the layout, the text format, and support been as important as they are today. Studies reflecting on the relationship between the meaning of the literary text and its form have rapidly increased. This kind of study has focused mostly on the history of the reading process and the history of the book as well as on the possibilities of new technologies in the literary field. However, none of these approaches has reached the point of creating a comprehensive methodology for the analysis of the relationship between the message and its channel. This work is intended to propose a methodology of analysis based on some concepts such as peritexts (Genette) and visuo-graphic zone (Cárdenas).  相似文献   
77.
The Coptic textile collection of the Museo Egizio in Torino (Italy) has been the object of a broad project aimed at investigating the production techniques, at documenting the conservation state and at reconsidering the attributed age. The collection was also analysed by non-invasive and micro-invasive techniques with the aim of detecting the dyes that have been employed to obtain the colours, in order to complete the set of technological information available for each textile. The data collected in the present work have been compared with published results from other Coptic textile collections, with the aim of highlighting a possible link between the age of the textile and the dyes that were employed. Moreover, the combined use of spectroscopic and chromatographic techniques allowed us to compare the results for the non-invasive and the micro-invasive approaches and to go deeper into the dyeing technology by detecting unexpected combinations of dyes. In particular, the use of a double dyeing with madder and Indian lac dye was revealed in some Roman-Byzantine and Byzantine textiles from the collection.  相似文献   
78.
79.
80.
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