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   297篇
  免费   8篇
  2024年   2篇
  2023年   3篇
  2022年   11篇
  2021年   3篇
  2020年   14篇
  2019年   14篇
  2018年   14篇
  2017年   11篇
  2016年   12篇
  2015年   11篇
  2014年   6篇
  2013年   37篇
  2012年   25篇
  2011年   24篇
  2010年   16篇
  2009年   24篇
  2008年   11篇
  2007年   14篇
  2006年   15篇
  2005年   14篇
  2004年   4篇
  2003年   6篇
  2002年   5篇
  2001年   1篇
  2000年   2篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1994年   1篇
排序方式: 共有305条查询结果,搜索用时 15 毫秒
1.
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   
2.
As social and cultural contexts change and globalization spreads, the number of transnational-marriage migrants mainly from Southeast Asia has increased in Taiwan. Using institutional ethnography, this article investigates the roles of local non-governmental organizations (NGOs) and projects aimed at helping foreign spouses to adapt to their new life. I mainly elaborate that NGOs emerge as important actors in assisting and empowering transnational spouses to ‘become locals’. In empowerment projects, foreign spouses are given a voice to elaborate themselves. However, this article elaborates that these projects are a scheme of education to shape each such migrant into a proper ‘Taiwanese wife/mother/daughter-in-law’. Also, these projects particularly promote ‘exoticism’ of migrants and become key sources of how local people understand the images of ‘foreign spouses’. As a result, though NGOs play positive roles in empowering foreign spouses, we need to be aware that NGOs’ efforts may ironically become a mechanism to strengthen transnational spouses’ gender roles and cultural stereotypes.  相似文献   
3.
This article analyses Conor O’Callaghan’s collection The Sun King as an expression of contemporary migration practices. It places the poet’s technological mobilities within larger global movements and argues that the collection reconfigures poetic versions of migration for the twenty-first century. The Sun King (2013) is located in explicitly transient spaces, while its formal innovations serve to mimeticise contemporary dislocation. In reinventing the dual demands of memory and migration in the postmodern society, The Sun King recognises and pursues alternative poetic possibilities. The article suggests that O’Callaghan’s Twitter-poem “The Pearl Works” can be read as indicative of an expansive impulse towards ephemeral online works. In particular, the article raises questions around composition, stability and memory practices in the digital era, and highlights how both migration and memory are complicated by technological innovations.  相似文献   
4.
The quick and accurate identification of post-earthquake rescue objects can minimize the casualties and property loss caused by earthquakes. With the rapid development of remote sensing technology, rescue objects can be identified through high-resolution remote sensing images. There are two main categories of approaches to identify rescue object through high-resolution images: automatic extraction by a computer and visual judgment by professionals. Although results can be obtained quickly by using automatic extraction, the accuracy of the results is unacceptably low. For visual judgment, the large demands for time and professionals restrict its wide practical application. In this study, we introduce crowdsourcing into the identification of post-earthquake rescue objects. First, we integrate the advantages of the computer and crowdsourcing, which means that the computer takes advantage of the speed of information processing, while crowdsourcing makes full use of human recognition capabilities. Second, we take visual judgment tasks out of the hands of professionals and entrust the tasks to workers in a crowdsourcing platform. Not only are the human resources infinite, but we can also improve the efficiency of identifying rescue objects. Third, we propose a crowdsourcing model that improves the quality of the results and saves human resources. Finally, experimental results demonstrate that our solution is feasible.  相似文献   
5.
扎什琍玛佛像因特征明确、像式丰富、工艺精细,在故宫珍藏的佛教造像中独树一帜。清宫的扎什琍玛像多附有皇家特有的黄条题记。本文从这些黄条所记内容入手,结合档案资料,对此类造像进行来源、类型及题材风格的细化探究,并进一步说明扎什琍玛对清宫佛教造像风格的深刻影响及其在促进西藏与内地政治、经济、文化联系方面曾经发挥的历史作用。  相似文献   
6.
The recording and 3D modelling of complex archaeological sites is usually associated with high capital and logistical costs, because the data acquisition must be performed by specialists using expensive surveying sensors (i.e., terrestrial laser scanners, robotic total stations and/or ground‐penetrating radar). This paper presents a novel, low‐cost, user‐friendly photogrammetric tool for generating high‐resolution and scaled 3D models of complex sites. The results obtained with unmanned aerial vehicle (UAV) photogrammetry of an archaeological site indicate that this approach is semi‐automatic, inexpensive and effective, and that it guarantees quality.  相似文献   
7.
In an era of rapid geographical data acquisition, interpretations of remote sensing products are an integral part of many undergraduate geography degree schemes but there are fewer opportunities for collection and processing of primary remote sensing data. Unmanned Aerial Vehicles (UAVs) provide a relatively inexpensive opportunity to introduce the principles and practice of airborne remote sensing into field courses, enabling students to learn about image acquisition, data processing and interpretation of derived products. Two case studies illustrate how a low-cost “DJI Phantom Vision+” UAV can be used by students to acquire images that can be processed using Structure-from-Motion photogrammetry software. Results from a student questionnaire and analysis of assessed student reports showed that using UAVs enhanced student engagement and equipped them with data processing skills. The derivation of bespoke orthophotos and Digital Elevation Models has the potential to provide students with opportunities to gain insight into various remote sensing data quality issues, although additional training is required to maximize this potential. Recognition of the successes and limitations of this teaching intervention provides scope for improving future UAV exercises. UAVs are enabling both a reconstruction of how we measure the Earth’s surface and a reconstruction of how students do fieldwork.  相似文献   
8.
Today’s trans youth grew up with the internet and online LGBTQ resources and spaces are important to these communities. This article focuses on conceptualising the digital cultural strategies that trans and gender questioning youth adopt both as social media users and producers in order to cope and thrive. Drawing on ethnographic data detailing a group of trans youth’s engagements with LGBTQ social media counterpublics and the wider web, and their movement between these spheres, in combination with close readings of online material identified as salient by the participants, this article argues that in the face of rampant transphobia and cis coded online paradigms, trans youth respond both critically and creatively. More specifically, I highlight how they resist prescribed user protocols of mainstream social networking sites as well as employ pragmatic strategies for navigating a binary gendered online world, staking out their own methods and aesthetics for self expression and community formation. Having examined the content and style of social media examples highlighted by the participants, the article contends that trans youth’s consumption and production of types of online and social media is significantly more diverse than research to date has recognised.  相似文献   
9.
古建筑三维重建已成为历史遗迹保护与修复的重要内容。为了探讨三维激光扫描数据的获取流程、数据处理方法,以三维激光扫描获取的大雁塔海量点云数据为例,研究了古建筑三维重建中点云数据获取与处理的详细过程。联合Cyclone、AutoCAD和3D-Max软件的优点构建了大雁塔真实的横面、剖面、立面模型,其中重点研究了海量点云数据在Cyclone软件中分块建模的方法。结果表明:将拼接好的大雁塔海量点云数据分块建模,不仅加快了数据处理的速度,而且符合精度要求。在点云数据拼接时采用标靶拼接和同名点拼接相结合及测站间两两拼接之后再整体拟合平差的方法,减少了拼接中的误差,使每站拼接误差都不超过3cm。在建模过程中的墙体拟合是上万个点云经过平差计算得到,精度高达2mm。最后在3D-Max软件中组合、渲染和贴图,真实地构建了大雁塔三维立体模型。为古建筑数字化存档和后期的修缮工作提供了重要的依据。  相似文献   
10.
Many questions remain about the effects of digital media use on citizens’ political engagement. This article argues that this is because such effects depend on the context in which digital media are used. Its findings are based on two cross-sectional sets from the 2010 and 2013 Australian Election Study and show that (1) political resources played different moderating roles in the association between digital media and offline participation, and (2) such a moderating role depended on different campaign contexts in the two elections, with context affecting political efficacy. The findings confirm that campaign context can function as leverage in motivating online news consumption and political participation, thereby emphasising the importance of political contexts in media use and political behaviour.  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