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51.
I propose that educators construct pedagogical responses to youth in schools in ways that consider classrooms to be the result of and the boardroom for complex global flows. Youth's production of individual and collective identities wherein flows are apprehended, discarded, combined, and recombined, rages against purifying processes of neocolonial classrooms.  相似文献   
52.
The results of Del Rosario on cold emission are shown to result from the fact that, through the attainment of specially good vacuum conditions and freedom from contamination, the cold electron current from the wire was suppressed up to field strengths greater than those at which measurable current was obtained in the work of previous observers. It was in fact suppressed beyond the point at which discharge started from points on the welding of the support. The results of Del Rosario are thus probably characteristic of conditions other than those pertaining to the wire, a conclusion which accounts for his current voltage curves. The formula of Fowler and Nordheim is found to apply in the measurable regions in form directly and in magnitude only if irregularities of the surface are such as to raise the field at the surface to a sufficiently high value. Breakdowns after intense heat treatment are studied and found to be caused by immeasurably small currents of electrons knocking ions from the anode. The erratic original curves obtained by previous investigators are found to be caused by successive breakdowns similar to those found after intense heating.  相似文献   
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Hypertext is a computer technology for “nonsequential reading and writing” in which chunks or nodes of information are connected by fixed links. Users access hypertext by selecting cross-reference (or “buttons”) in the context of a given node that is connected via links to other nodes. Such an “associative” strategy for information storage and retrieval differs from the indexing and searching technology of conventional database management and text retrieval systems, and offers significant advantages when used instead of or in combination with search systems. Hypertext is an ideal medium for making job aids, reference materials, and ‘just in time training’ available online to information-based workers. This article reviews five commercially available hypertext systems, and discusses several key hypertext design issues. Among the most important of these issues are the critical role of navigational aids in preventing users from becoming “lost” in the hypertext, the application of structured writing techniques to hypertext development, and the potential contributions of the human performance technology approach to hypertext in the form of systematic analysis, design, and evaluation methods.  相似文献   
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