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Adams Edwin P. 《Journal of The Franklin Institute》1927,204(4):469-486
(I) Evidence has been given that the so-called permanent electrets of Eguchi are not permanent, but that their polarization decays with the time. At room temperatures this decay is too slow to be observed directly; but it is the decay of the polarization that, at least in part, accounts for the presence of the free charges that are always observed. At higher temperatures the results that have been obtained are consistent with the view that the rate of decay of the polarization increases very rapidly with the temperature; so much so that the polarization may be almost completely destroyed at a temperature which is not high enough to cause any appreciable softening of the waxes that form the substance of the electrets.(2) As is to be expected from Lord Kelvin's hypothesis as to the cause of pyro-electricity, these electrets have been shown to possess the pyro-electric property.(3) The piezo-electric effect, which always accompanies the pyro-electric property, has been shown to be exhibited by these electrets. 相似文献
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Dennis Adams 《Educational Media International》2013,50(3):158-163
Abstract The article discusses how sections of a video can best be used in the instructional process by activating the minds of students and using their reactions to viewing to produce intellectual action. It gives some suggested schemes for this activity and shows how technological forces can become energies of change. 相似文献
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Phyllis Bernt Lawrence WoodAuthor VitaeCarol TingAuthor Vitae 《Government Information Quarterly》2007
The role and continued relevance of state telecommunications regulators have been challenged by the development of competition, the introduction of new technologies, and the increasing dominance of federal authority. An important role that state utility commissions can play in the current telecommunications environment is to provide consumer education and information about consumer protection, competition, and universal service. Commissions can use their Web sites as effective tools in educating and informing consumers. This study analyzes the consumer-related telecommunications information included on the Web sites of the commissions in the 50 states and the District of Columbia to determine whether, and how well, state commissions are using their Web sites to educate and inform. 相似文献
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