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介绍TP6584AFNG芯片,研究了该芯片在变频空调用无刷直流电机控制中的应用。本系统使用三相半桥驱动电路,采用180度正弦波驱动技术,利用超前角设计,达到效率高、噪音低、转矩波动低的控制效果。实际生产制造中有很好的应用价值,产生很大的经济效益。 相似文献
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成军 《科技成果管理与研究》2008,(8):57-60
登机桥结构方案的评价就是典型的复杂对象多目标多层次综合评价问题,方案评价涉及很多影响因素,各因素的描述方式不同,而且普遍存在着模糊性现象,因此需要研究一种科学、合理的综合评价方法。本文开发了基于Windows环境的登机桥结构方案智能综合评价系统。该系统以模糊理论、神经网络理论和人工智能原理为基础,运用Visual Basic结构化程序设计语言、数据库技术和MATLAB工程技术软件实现了登机桥结构方案评价的智能化。 相似文献
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对互联网上传输信息内容进行检测的深度包检测技术,给传统互联网治理带来新的挑战和转变,在加强互联网治理的同时引发了关于网络中立性、技术部署的合法性、网络安全等规范性问题的激烈争论。 相似文献
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本文介绍了低渗透油气藏的地质特点,水平井完井开发方式的选择,分析讨论了目前低渗透油气藏完井的限流压裂技术,裸眼封隔器分段压裂技术,泵送桥塞套管固井分段压裂技术,连续油管喷砂射孔套管分段压裂技术,智能完井技术,并提出了低渗透油气田有效开发的建议。 相似文献
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水口电厂2台2X250T厂房桥机旧有的调速方法是转子回路串电阻调速,调速性能差,并车精度低,通过变频调速技术对其进行改造后,大大提高了桥机起吊作业的效率、可靠性、稳定性。 相似文献
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随着科学技术的快速发展,网络技术已经由3G技术向4G技术迈进,意味着LTE技术也处于快速发展的阶段。近年来,LTE室内分布系统虽然取得了很大的进步,但是建设过程中依然面临着诸多问题,需要采取有效措施解决。文章对LTE室内分布系统进行简要分析,并探讨该系统的规划、建设方案。 相似文献
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《中图法》是我国目前应用最为广泛的一部大型综合性分类法。该文比较分析了《中图法》第一至第五版之“G63 中等教育”类目的演变,研究了用于进一步复分的“专类复分表”变化。文章中对“总论复分表”中与教育有关的“-4 教育与普及”的演变进行了比较分析。经过不断修订的《中图法》之中等教育类目设置日趋成熟,随着社会的发展,能够及时增加反映新科技和新主题的类目。 相似文献
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英语是世界上使用最广泛的语言。如何利用英语原版电影学习英语是本文所论述的内容。英语原版电影语言真实地道,声像结合,图文并茂,能够激发学生的学习兴趣,丰富了英语学习的听说环境,提高了学生的听说能力,增强了学生的跨文化交际能力。英语原版电影越来越受到广大师生的欢迎,并利用这一资源更好地学习英语。 相似文献
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教改的关键是教材。《传感器与自动检测技术》(第二版)是一本好教材。该书简明精炼,理论和实践融为一体,使学生做学合一。它注重应用,把学生就业能力的培养贯穿于教材的始终。它前言中有编者的E—mail,读者反馈意见方便,能促进精品教材建设,值得提倡。 相似文献
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利用信息技术将校内的主要园林树种的图片与之相对应的树木分类学知识相结合,实现对树种数据的编辑、浏览、检索和维护等功能,大大方便了教学,提高了授课效率。 相似文献
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在企业办公系统中,常常有用户需要将报表直接用Excel打开或者是习惯于通过Excel对报表进行打印。Apache的POI项目,目标是处理OLE2对象,目前比较成熟的是HSSF接口,处理MS Excel(97-2003)对象,以及新开发的XSSF接口,处理MS Excel(2007)对象。它不像我们仅仅是用CSV生成的没有格式的,仅由Excel转换而来的东西,而是真正的Excel对象,你可以控制一些属性如shell、cell等等。 相似文献
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介绍《中国图书馆分类法》第五版S类(农业类)的修订情况,从文献保障、交叉类目列类的原理以及上下位类逻辑关系等角度,分析第五版S类下有关类目在分类上存在的不足,提出修改意见.根据数字林业的发展,提出新增设计算机技术在林业上应用和3S技术在林业上的应用二个类目的建议. 相似文献
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Radio Frequency Identification, or RFID, is a technology which has been receiving considerable attention as of late. It is
a fairly simple technology involving radio wave communication between a microchip and an electronic reader, in which an identification
number stored on the chip is transmitted and processed; it can frequently be found in inventory tracking and access control
systems. In this paper, we examine the current uses of RFID, as well as identifying potential future uses of the technology,
including item-level tagging, human implants and RFID-chipped passports, while discussing the impacts that each of these uses
could potentially have on personal privacy. Possible guidelines for RFID’s use, including Fair Information Principles and
the RFID Bill of Rights are then presented, as well as technological solutions to personal privacy problems, such as tag killing
and blocker tags, as well as simple aluminum foil shields for passports. It is then claimed, though, that guidelines and technological
solutions will be ineffective for privacy protection, and that legislation will be necessary to guard against the threats
posed by the RFID. Finally, we present what we believe to be the most important legislative points that must be addressed.
Vance Lockton has recently completed the M.Sc. program at the University of British Columbia, majoring in Computer Science.
Richard S. Rosenberg is a professor emeritus in the Department of Computer Science at the University of British Columbia;
the third edition of his book, “The Social Impact of Computers”, was published by Elsevier Academic Press in 2004. 相似文献
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This paper explores the complex relationship between scientific novelty and technological impact. We measure novel science as publications which make new combinations of prior knowledge, as reflected in new combinations of journals in their references, and trace links between science and technology by scientific references in patent applications. We draw on all the Web of Science SCIE journal articles published in 2001 and all the patents in PATSTAT (October 2013 edition). We find that the small proportion of scientific publications which score on novelty, particularly the 1% highly novel scientific publications in their field, are significantly and sizably more likely to have direct technological impact than comparable non-novel publications. In addition to this superior likelihood of direct impact, novel science also has a higher probability for indirect technological impact, being more likely to be cited by other scientific publications which have technological impact. Among the set of scientific publications cited at least once by patents, there are no additional significant differences in the speed or the intensity of the technological impact between novel and non-novel scientific prior art, but the technological impact from novel science is significantly broader and reaching new technology fields previously not impacted by its scientific discipline. Novel science is also more likely to lead to patents which are themselves novel. 相似文献
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将《中图法》第五版TP类的修订与第四版进行比较,认为第五版通过调整类目体系、规范类名、细分类目、更新术语、改进注释、停用过时类目等技术手段,实现了对类目的深度控制.通过实例分析了《中图法》第五版TP类的修订内容,指出修订后的TP类在类目设置、类目结构上仍存在的一些问题,并提出修改建议. 相似文献