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91.
In many countries choice of school is an increasing concern for families and governments. In Spain and Chile, it is also associated with a long‐standing political cleavage on the regulation of large sectors of private‐dependent schools. This article analyses both the micro‐ and the macro‐politics of choice in these two countries, where low‐status 15‐year‐old students record a significant segregation. At the micro level, some evidence is provided that not only middle‐class skilful choosers but also the political representatives of private‐dependent schools manage to pursue their interests drawing on economic, social and cultural capital. At the macro level, evidence also shows that the lobbies defending private‐dependent schools can use and maintain these power resources. However, in some episodes collective action is an effective power resource for those who campaign in favour of a stricter regulation of these schools, but its influence is much difficult to maintain for longer periods. 相似文献
92.
Carla A. Chase 《Educational gerontology》2013,39(1):27-37
Intergenerational interactions have demonstrated some success at improving attitudes of college students toward older adults. This quasiexperimental study involved undergraduate college students paired with older adults for a six-week e-mail exchange. Student attitudes toward older adults were measured pre- and posttest with Polizzi's revised version of the Aging Semantic Differential (ASD). Students were assigned to an intervention group (n = 23) or a control group (n = 20). The intervention group demonstrated significant improvement in attitude toward older adults as compared to the control group (F 14.694, p < .05). This educational approach holds promise for using readily accessible technology to connect the generations. 相似文献
93.
Skedsmo Guri Huber Stephan Gerhard 《Educational Assessment, Evaluation and Accountability》2019,31(2):151-153
Educational Assessment, Evaluation and Accountability - 相似文献
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ABSTRACTChalconatronite, Na2[Cu(CO3)]2·3H2O, is formed as a corrosion product when copper alloys are exposed to sodium carbonate solutions in the air. This also happens when metals come into contact with corroding soda glass which forms alkaline surface films in reaction with humidity from clean air. More often, substantial amounts of formaldehyde are present indoors which react to formate via the Cannizzarro reaction and accumulate over time in the films. Twenty cases of chalconatronite (including two mentioned in the literature) are reported as occurring on heritage objects with glass in contact with copper alloys: Baroque reliquaries with set glass gems, enamel on metal (sixteenth century and a modern replica of intentionally unstable composition), Christmas tree glass baubles with wires, glass buttons with metal shanks, a glass figure with a wire support, miners’ lamps, and a glass framed daguerreotype. These confirmed identifications might help conservators in investigating similar cases to shed more light on the formation conditions. 相似文献
97.
A sodium copper formate, first described in 2002, can also form on copper alloys with sodium originating from soda glass hydrolysis. The frequent occurrence (50% of 250 cases of glass-induced metal corrosion) is due to the presence of formaldehyde emissions in storage and its direct reaction to formate in the alkaline surface films. The compound can be produced without the presence of acetate when chalconatronite or metal coupons immersed in soda solution are exposed to formaldehyde vapours. The crystal structure, derived from X-ray powder diffraction, yielded the sum formula Cu4Na4O(HCOO)8(OH)2·4H2O. Except for the absence of acetate in the structure, this is in good agreement with the 2002 publication. To assess which kind of combined glass/metal objects are affected, a number of large museum collections were surveyed. Sodium copper formate was detected as a corrosion product using mainly micro-Raman spectroscopy, for instance, on 18 painted Limoges enamels, eight glass vessels with metal mountings, glass beads on metal wire from 11 bridal crowns, nine Christmas tree balls with wire decoration, 40 pieces of jewellery with glass gems, three daguerreotypes, and one miniature with cover glasses. 相似文献
98.
Carla S. Myers 《College & Undergraduate Libraries》2018,25(1):91-99
Plagiarism and copyright infringement are terms that most students are familiar with, and when asked, most students will readily express the sentiment that plagiarizing the work of others or committing copyright infringement is wrong. Despite students' basic understanding of these concepts, many struggle to put them into practice. Often this is a result of students not having enough knowledge about how to cite sources or how copyrighted works can legally be reused for scholarly purposes. This article identifies a way in which copyright and plagiarism can be taught as well as a process students can work through when addressing these issues. 相似文献
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Copper(II) hydroxide (as the rarely occurring mineral spertiniite) is formed under alkaline, oxidising conditions. It has been observed as a naturally occurring corrosion product of brass in sea water. But most occurrences on copper alloys are due to conservation treatments using basic solutions (sodium hydroxide or ammonia) or to intentional patination. Classical brass centrepieces (c. 1800), ‘cleaned’ with ammonia solution, developed a blue spertiniite patina in gaps, where evaporation was hindered. Additional to the danger of stress corrosion cracking this is another reason now outlawing this treatment. Copper pigment layers will transform to copper hydroxide when exposed to bases. The treatment of basic copper salts with bases has been used intentionally in the production of Bremen blue and similar pigments which can be composed of copper hydroxide as well. 相似文献
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