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41.
42.
为对18CrNi4A材料齿轮加工过程中出现的磨削烧伤现象进行有效控制与预防,从而达到改进工艺、延长寿命的目标,利用ABAQUS有限元仿真方法,建立了齿轮磨削仿真模型,研究了18CrNi4A材料齿轮磨削过程中砂轮线速度、磨削切深等工艺参数对磨削温度场的影响规律,确立了各工艺参数对磨削温度场影响的权重,为实现基于烧伤性能变化的磨削参数控制研究提供了参考.进行了18CrNi4A材料齿轮磨削加工试验,验证了有限元仿真分析的可信性,并得到了18CrNi4A材料的磨削烧伤临界温度,能够对18CrNi4A材料齿轮磨削加工工艺参数的确定提供一定的理论指导. 相似文献
43.
研究了高频气体放电等离子休对铁电体电滞特性的改性作用,并对其改性机现作了理论分析。研究表明:铁电体PZST经高频气体放电等离子体处理后,其电滞特性有明显改变,其中,矫顽电场强度Ee减小;自发极化强度Ps不变,其物理意义是铁电体电畴反转所需的能量降低;非线性增强。本文为铁电体电滞特性及其电光和光学非线性效应等的改变提供了一种新的物理实验方法。 相似文献
44.
Adelheid Voskuhl 《Studies in history and philosophy of science》2007,38(2):422-444
Using the famous android automata made by the Swiss clockmakers Jaquet-Droz as an example, this essay examines the relationship between the production of automata and the production of texts about them against the background of economic and cultural conditions of artisan production and of the emerging ‘media industry’ in the public sphere of the late eighteenth century on the European continent. It explores the artisan environment in which the automata came into being and develops readings of various types of texts on the automata, including analyses of the contexts and print media of which they were a part. The essay concludes by explaining two interrelated peculiarities about eighteenth-century texts on the Jaquet-Droz automata: the fact that none of the texts displayed any interest in the metaphysical or ethical consequences of artificial or mechanical humans, and that they were, on the contrary, often simply copied from each other and thus adhered to the customs and exigencies of the emerging media industry of the time. The pre-industrial, traditional, non-mass produced construction of the automata thus coincided with the emerging contemporary mass production of texts and media, and it makes these texts and their objects bring into focus a key paradox underlying the history of modernity, the mass production of individuals and of individuality. 相似文献
45.
高职教材建设的几点思考 总被引:1,自引:0,他引:1
孙燕华 《无锡职业技术学院学报》2005,4(1):31-33
通过《计算机绘图》教材的编写实践,思考高职教材建设如何与高职教育改革相适应,为高职人才培养服务,进一步体现高职教育特色。 相似文献
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48.
鉴于目前网络课程主要以章节或课时内容为基本单位进行管理的缺陷,本文提出了一种基于素材的网络课程管理模式,并对其原理及系统结构等作出了阐释和分析. 相似文献
49.
高金良 《嘉兴高等专科学校学报》1997,(2)
本文针对目前工程上在测定条件屈服强度中存在的问题,提出了用计算机进行辅助测定的方法,有效地提高了测定结果的准确性。 相似文献
50.
《Studies in history and philosophy of science》2013,44(4):683-689
In my paper I argue for mobilising recent material heritage at universities in teaching history of contemporary science. Getting your hands dirty in the messy worlds of the laboratory and the storage room, and getting entangled with the commemorative practices of scientists and technicians does not belong to the common experiences of students in history and philosophy of science. Despite the recent material turn in cultural studies, students’ engagement with the material world often remains a linguistic exercise, extending at most to an excursion to the sanitised and academically encultured world of the museum exhibit.I contrast this approach by drawing on experiences of taking students to the Atomei, Germany’s oldest research reactor at the Garching campus of the Munich University of Technology. Decommissioned since 2000, the installation and its history are still controlled by scientists. Studying contemporary laboratories and their materiality has so far been the domain of sociologists and ethnographers. I argue for opening these spaces to historians of science and engaging with the ‘unfinished’ material world of contemporary science. Taking the material seriously beyond the linguistic turn and asking students to explore laboratories and other sites of knowledge production challenges existing histories and historiographies. By exploring local university departments and their recent histories through their material heritage, we can observe everyday science and confront scientists and technicians’ cultures with those of historians’. By engaging with recent material heritage as historians and archivists, students can make an important contribution to enhancing the awareness about this heritage, its implications for history writing, as well as its documentation and preservation. 相似文献