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《文物保护研究》2013,58(2):137-138
Abstract

Ancient bronzes in the collection of the J. Paul Getty Museum are maintained in low-humidity environments to eliminate the possibility of recurring chloride corrosion. A small, low-power, solid-state air drier was considered as an option to silica gel. This relatively new technology combines electrolytic dissociation of water molecules to hydrogen and oxygen with membrane separation. Hydrogen atoms formed on the anodic side penetrate the membrane and combine with oxygen on the cathodic side to form water. Oxygen atoms that remain on the anodic side recombine to form oxygen molecules. The process of water removal was found to be very efficient, but it is suggested that a portion of the oxygen atoms might react further to form ozone, a reactive molecule generally regarded as a deleterious pollutant in museum atmospheres. This was confirmed by passive sampling for ozone using diffusion tubes. While control levels after 60 days ranged from 0.43 to 1.25 parts per billion (ppb), samplers in the test environment recorded a level of 10.5 ppb, an increase of approximately 10 to 25 times. Developments in solid-state driers may overcome this problem in the future.  相似文献   

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In the developing world, a common trend is to have north–south collaborations constituting most of the continuous professional development (CPD) activities for librarians. The emerging drift highlighted in this article is a north–south–south initiative aimed at rebuilding the University of Juba Library through capacity-building of the library staff. This article will illuminate the process of equipping library staff with cataloging skills in the absence of previous library training. This endeavor is a result of the collaborative efforts of Makerere University Library (MakLib) in Uganda and the University of Bergen Library (UoBL) in Norway under the Juba Library Automation Project (JULAP). JULAP's main objective is to rebuild the University of Juba Library with the components of library automation and training of library staff. This article will concentrate on the practical training of the library staff in cataloging and the hands-on training on the Koha integrated library system to lay the groundwork for computerized library services for the University of Juba. This article will also highlight the challenges and lessons learned so far while articulating strategies for the future.  相似文献   

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Adopting the Orientation–Stimuli–Reasoning–Orientation–Response (O–S–R–O–R) model of political communication effects, this study examines the mediating roles of online/offline political discussion and political trust on the relationship between social media information seeking and online/offline political participation in China and Hong Kong. Findings through structural equation modeling showed that the relationship between information seeking and online participation was mediated by online discussion for both samples. Moreover, the relationship between information seeking and offline participation was mediated by offline discussion, and offline discussion mediated the relationship between information seeking and online participation. Political trust did not mediate any of the relationships in China and Hong Kong and all significant paths involving political trust were negative. Implications of the findings for youth political participation in China and Hong Kong are discussed.  相似文献   

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The information field continues to evolve rapidly as digital technology changes the very nature of information and how people interact with each other and with information. This article argues that the past 30 years have seen a shift from distinct emphases on information, individual people, and specific technologies to emphases on the interactions among more diverse forms and amounts of information, people, and technologies. Human–information interaction shifts the foci of all aspects of information work; blurs boundaries between information objects, technology, and people; and creates new forms of information. This article discusses changes in each of these components of information and trends and challenges surrounding the study of their interactions are presented.  相似文献   

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As is implicit in its name, the purpose of the Association for Professional Broadcasting Education is to work to continually improve the quality of education available for college students interested in joining the profession of broadcasting. The Journal of Broadcasting, as an agency of the APBE, has published some six dozen articles dealing with this subject in the eight years of its existence. However, the rapid growth of broadcast education, the normal turnover of teaching personnel, and the more‐than‐one‐generation span of this field of study have combined to make it difficult to see where we have been, and doubly hard to see where our present activities (as educators and broadcasters interested in broadcast education) are leading us. The following article attempts a broad survey of the first thirty‐five years of broadcast education. It is published for the benefit of the students in these curricula, the professors that teach them, the broadcasters who are called upon to test the “end product” and those in each category who recognize that one of the most important criteria for judging whether a body of activities is truly a profession is the quality of the education made available to the would‐be practitioner, and the traditions that lay behind it.  相似文献   

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The social impact of the “Digital Divide” in a Central–Eastern European country provides a comprehensive study of different “Digital Divides” existing between “emerging democracies” (or “emerging new market-oriented economies”) from Central and Eastern Europe, as well as between them and industrialized developed countries (Western Europe, USA, etc.). Former and actual influencing factors are analyzed and evaluated, basic facts and social impacts are presented, some solutions are issued. The United Nations' concerns and roles are emphasized.  相似文献   

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ABSTRACT

Wikipedia is a free online encyclopedia. The encyclopedia is openly edited by registered users. Wikipedia editors can edit their own and others' entries, and some abuse of this editorial power has been unveiled. Content authors have also been criticized for publishing less than accurate content. Educators and students acknowledge casual use of Wikipedia in spite of its perceived inaccuracies. Use of the online encyclopedia as a reference resource in scholarly papers is still debated. The increasing popularity of Wikipedia has led to an influx of research articles analyzing the validity and content of the encyclopedia. This study provides an analysis of relevant articles on academic use of Wikipedia. This analysis attempts to summarize the status of Wikipedia in relation to the scope (breadth) and depth of its contents and looks at content validity issues that are of concern to the use of Wikipedia for higher education. The study seeks to establish a reference point from which educators can make informed decisions about scholarly use of Wikipedia as a reference resource.  相似文献   

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This article compares 4 measurement models for the Watson–Barker Listening Test (WBLT)–Form C and constitutes the first confirmatory test of this listening comprehension measure. Results show that data does not conform to (a) a 5-factor correlated model, (b) a second-order model, or (c) a unidimensional model; and no model was sufficiently better than (d) the independence model. Exploratory analyses provide additional evidence that items are largely unrelated to one another. Given these findings, the use of the WBLT–Form C in assessments of listening comprehension is not recommended. The discussion explores what these findings imply for the conceptualization and measurement of listening and for potential revisions of the WBLT.  相似文献   

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