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The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy.  相似文献   
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The aim of the present study was to examine the movement patterns, ball skills, and the impressions of Swedish elite football players during competitive games on artificial turf and natural grass. Time - motion analyses (36 observations) and technical analyses (16 team observations) were performed and 72 male and 21 female players completed a questionnaire. No differences were observed between artificial turf and natural grass in terms of total distance covered (mean 10.19 km, s = 0.19 vs. 10.33 km, s = 0.23), high-intensity running (1.86 km, s = 0.10 vs. 1.87 km, s = 0.14), number of sprints (21, s = 1 vs. 22, s = 2), standing tackles (10, s = 1 vs. 11, s = 1) or headers per game (8, s = 1 vs. 8, s = 1), whereas there were fewer sliding tackles (P < 0.05) on artificial turf than natural grass (2.1, s = 0.5 vs. 4.3, s = 0.6). There were more short passes (218, s = 14 vs. 167, s = 12) and midfield-to-midfield passes (148, s = 11 vs. 107, s = 8) (both P < 0.05) on artificial turf than natural grass. On a scale of 0-10, where 0 = "better than", 5 = "equal to", and 10 = "worse than", the male players reported a negative overall impression (8.3, s = 0.2), poorer ball control (7.3, s = 0.3), and greater physical effort (7.2, s = 0.2) on artificial turf than natural grass. In conclusion, the running activities and technical standard were similar during games on artificial turf and natural grass. However, fewer sliding tackles and more short passes were performed during games on artificial turf. The observed change in playing style could partly explain the male players' negative impression of artificial turf.  相似文献   
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György Péteri 《Minerva》1996,34(4):367-380
Conclusions On the basis of these findings, I suggest that the structure and organisation of the field of Hungarian economics under state socialism should be described as a case of partitioned bureaucracy.9 The compromise between research economists and the political elite in the New Course era between 1953 and 195510 survived the post-1956 reaction in so far as political economy, with its predominantly legitimatory and ideological functions, remained partitioned from the other sectors in the field through the remainder of the state-socialist period. This secured considerable protection both for Marxist-Leninist political economy—which faced the destabilising effects of exposure to the findings of serious empirical research—and for the other sectors, which were professionally oriented and earnestly interested in the pursuit of unbiased empirical research, free from stifling agitprop interference. Our data concerning the reputational control of the field reflects only one, although very important, aspect of this partitioning. Another and much plainer aspect is that, from the early 1960s, the Agitation and Propaganda Department of the Central Committee no longer exercised control over the field, except in the political economy sector.The proposition about the mechanism paradigm should not be taken seriously as a statement of a Kuhnian type of intellectual organisation of Hungarian economics, with reform economics at its hard theoretical core. But it should certainly be taken seriously as a reflection of the sociopolitical structure which emerged and developed from the mid-1950s onwards. Neither the politicians nor the economists saw as necessary or even contemplated the integration of Hungarian economic research with Western mainstream economic thought. In exchange for the professional expertise and socio-economic intelligence necessary for the exercise of power, Hungary's state-socialist political class offered their economists relative autonomy and freedom from interference. The price the economists had to pay was partly to refrain from openly and systematically challenging the beliefs perpetuated by the political economy of socialism, and partly to accept in their research the paramountcy of policy orientation. But this burden they assumed willingly since it made them the only group within Hungary's academic intelligentsia—indeed, the only group in Hungarian society outside the political class—with the privilege of being coopted to the institutions with power over some restricted domains of policymaking. After 1989, especially under the conservative Antall government, this proved less than advantageous.11 Although the benevolence of many critics is open to question, it could greatly benefit the field if the economists' expulsion from contemporary politics went hand in hand with provision of the material, intellectual and institutional conditions for a new approach where a fundamentally scientific orientation is paramount.  相似文献   
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Librarians in Sweden are facing huge challenges in meeting the demands of their organisations and users. This article looks at four key areas: coping with open science/open access initiatives; increasing demands from researchers for support doing systematic reviews; understanding user experiences in Swedish health science libraries; and the consequences of expanding roles for recruitment and continuing professional development. With regard to changing roles, there is an increasing shift from the generalist towards the expert role. The authors raise the issue as to how to prepare those new to the profession to the changing environment of health science libraries.  相似文献   
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Around 1960, the politics of the emerging media society in Sweden tended to fixate the formative functions of mass communication. The monopoly of public service broadcast media, press subsidies and new tendencies in film policy were some of the issues around which uncertainty prevailed. New methods to provide reliable data were sought by politicians, since empirical facts were required as arguments for an updated media policy. This article examines the different ways that the field of media studies was introduced in Sweden between 1960 and 1980. We argue that Swedish academic media studies departed from, and emerged within, a rather diffuse borderland between industry, politics and academia. The formation of national media research in Sweden can partly be seen as an effect of politicians and the media industry wanting to be better informed on issues such as media influence, media ownership and the habits and composition of the media audience.  相似文献   
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The purpose of this study is to find a theoretically grounded, practically applicable and useful granularity level of an algorithmically constructed publication-level classification of research publications (ACPLC). The level addressed is the level of research topics. The methodology we propose uses synthesis papers and their reference articles to construct a baseline classification. A dataset of about 31 million publications, and their mutual citations relations, is used to obtain several ACPLCs of different granularity. Each ACPLC is compared to the baseline classification and the best performing ACPLC is identified. The results of two case studies show that the topics of the cases are closely associated with different classes of the identified ACPLC, and that these classes tend to treat only one topic. Further, the class size variation is moderate, and only a small proportion of the publications belong to very small classes. For these reasons, we conclude that the proposed methodology is suitable to determine the topic granularity level of an ACPLC and that the ACPLC identified by this methodology is useful for bibliometric analyses.  相似文献   
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In collaborative problem solving, children produce and evaluate arguments for proposals. We investigated whether 3- and 5-year-olds (N = 192) can produce and evaluate arguments against those arguments (i.e., counter-arguments). In Study 1, each child within a peer dyad was privately given a reason to prefer one over another solution to a task. One child, however, was given further information that would refute the reasoning of their partner. Five-year-olds, but not 3-year-olds, identified and produced valid and relevant counter-arguments. In Study 2, 3-year-olds were given discourse training (discourse that contrasted valid and invalid counter-arguments) and then given the same problem-solving tasks. After training, 3-year-olds could also identify and produce valid and relevant counter-arguments. Thus, participating in discourse about reasons facilitates children’s counter-argumentation.  相似文献   
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