共查询到20条相似文献，搜索用时 81 毫秒
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《实验室研究与探索》2018,(11)
作为继电保护的基础元件,高校继电保护教学实验普遍开设电流和电压继电器特性实验课程。实验过程中发现在调节电磁式继电器启动值和返回值时,电流继电器比电压继电器有更高稳定性,而且电压继电器更容易受使用年限的影响。收集当前本科实验室的两种电磁式继电器实测数据,通过统计方法归纳两种电磁式继电器实际特性情况。进一步结合两种电磁式继电器的原理,从理论上分析上述现象的原因,从而有助于帮助学生更深入掌握继电器特性。 相似文献
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巡检式数字温度监控仪能自动定时检测并显示8个检测点的地址编号及温度值，在温度异常时产生报警信号和控制继电器动作，避免事故的发生和损失。应用K型热电偶变换器MAX6675可以很好地实现这一控制，并且电路简单可靠。 相似文献
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通过对比串行送数和并行送数2种设计方案、硬件电路原理说明及软件设计流程,分析如何实现基于MCS51单片机的多位数码高亮静态显示,阐述利用数据锁存器件及单片机外部RAM地址控制来实现多位数码高亮静态显示技术的软件、硬件设计。 相似文献
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常辉 《兰州石化职业技术学院学报》2012,(3):10-12
石化厂丙烯腈变低压进线控制回路采用三相低压继电器,单触点触发的控制方式来实现备自投动作;时间继电器为断电延时。在全所失电时,会出现来电跳闸的情况,延误系统恢复时间,影响供电质量。基于对低压进线控制系统的分析,阐述了低电压继电器及时间继电器选取的重要意义,将进线柜内的三相低电压继电器更换为三个单相低电压继电器,时间继电器选为通电延时型。通过对控制系统的改进,缩短操作人员的系统恢复时间,提高了供电系统的稳定、可靠性。 相似文献
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白蕊 《化工职业技术教育》2007,(3)
作者根据电磁式继电器的工作原理提出了一个铁芯对应两组线圈的电磁式双绕组继电器设计构想,其独特的动作特性使得继电器的逻辑控制功能得到了扩展。另外还提出了双绕组继电器的设计构想中应注意的几个问题。 相似文献
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在汽车电气系统中,继电器用于启动、报警、灯光控制、刹车等操作,故对其寿命有特殊的要求,而继电器的寿命主要取决于电寿命．研究了以PLC为核心的汽车继电器电寿命试验装置．结果表明,该装置实现了继电器试验次数的显示、故障的监视和控制等功能,大大提高汽车继电器电寿命试验的可靠性和安全性． 相似文献
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Quiet students are sometimes misunderstood in the college classroom. Students may be quiet for reasons related to personality traits, learned behaviors, or situational factors, but regardless, their silences may be misinterpreted by their instructors as a lack of engagement in their courses. In fact, quiet students are often very engaged in the learning process but may need space to express their interest in ways that are suited to their quiet tendencies. This article describes how quiet students are perceived in the classroom, reviews the reasons why quiet students often serve as a source of uncertainty for college instructors, and explains a number of strategies that instructors can use to meet the learning needs of quiet students. 相似文献
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Margaret Hollingsworth 《Community College Journal of Research & Practice》2013,37(11):1070-1073
As electronic gadgets predominate a student’s life, there comes a need for silence. A quiet place free of electromagnetic spectrum waves, dirty and stray electricity, and the endless chirps, whistles, beeps, and customized signaling. A quiet place can offer solitude for meditation, inspiration, and spiritual awareness. Student involvement in the classroom and campus activities is of upmost importance for student retention and successful program completion; however, student veterans often face overwhelming transitioning barriers as they cross from combat to the community college environment. Whether student veterans need a place to calm themselves, compartmentalize traumatic memories, or concentrate on overcoming an educational challenge, the quiet place can offer sanctuary. The proposed quiet place will be designed inexpensively using furniture available on the host rural community college campus, the state surplus warehouse, and from employee donations. The labor to paint and refurbish will be provided by dedicated veteran college staff and members of the Student Veterans of America association on the community college campus. The quiet place will utilize a small room less than 10 feet squared, however with low earth sounds emanating from an MP3 player and speaker, soft comfortable seating, and a rug, the room will be free from all other electronics and electrical devices. This dedicated student-veteran space will be unstaffed, self-policed for quiet enforcement, although a Career Coach will be available to handle any situations and address messages left by student veterans. 相似文献
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罗运超 《毕节师范高等专科学校学报》2005,23(4):34-38
刘勰的虚静学说作为古典文艺美学范畴的一个重要概念，它直接本源于老子和庄子的虚静哲学观。刘勰的虚静学说不仅在文艺创作上有其重要理论意义，而且在审美观念上亦有其独特的理论价值。 相似文献
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刘勰的虚静学说作为古典文艺美学范畴的一个重要概念,它直接本源于老子和庄子的虚静哲学观.刘勰的虚静学说不仅在文艺创作上有其重要理论意义,而且在审美观念上亦有其独特的理论价值. 相似文献
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赵学存 《合肥师范学院学报》2010,28(2):84-87
宗白华中西美学比较的一个重要方面就是美感发生论比较,他认为中国古代的"移我情"是构成我们审美心理方面的积极因素和条件,而西方的"心理距离"、"静观",则构成审美心理的消极条件;中国古典美学里的"静照"是容纳了生命运动内容的美学范畴,不像西方"静观"理论那样绝对强调与世隔绝。宗白华的中西美感发生论比较留给后人深远的启发意义。 相似文献
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Maggie Woodrow 《Higher Education Quarterly》1993,47(3):207-220
The rapid spread affranchising activity by universities over the last few years has been a quiet revolution - revolutionary in its speed and radical nature, but so quiet that its significance has yet to be assessed. Publications on franchising, and there are only a few, are investigative and informative, rather than analytical or policy-oriented. This is perhaps because there has been no major national policy lead on franchising. Government departments and national bodies have contributed at best encouragement and recognition; at worst suspicion and obstruction. In the tradition of revolutionary activity, franchising has been a bottom-up initiative, institution-led, and at a speed which, 'In a sector not known as a quick-change artist is breathtaking'. This paper examines the origins, nature and implications of this quiet revolution. 相似文献
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2006年11月到2008年2月的所有XRT全日面数据中，筛选一些正好位于日面中心附近时的活动区、宁静区和冕洞区的Al-mesh和,Tj—poly全目面图像，利用Filter Ratio方法分别计算出这些活动区、宁静区和冕洞区的平均温度值．结果表明，活动区、宁静区和冕洞区的温度logT范围分别为6．7～6．85，6．2～6．45和6．1～6．2． 相似文献
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Greg Thompson James Bell 《Discourse: Studies in the Cultural Politics of Education》2011,32(3):399-413
Quiet students are a feature of the organisation of secondary schools. Using qualitative methods and Deleuzean conceptualisations of modern subjectivity, this paper explores the ways that quiet students negotiate the terrain of their school. These negotiations often seem to produce a self that is trapped rather than a subject who seizes opportunities to be inventive, creative and experimental of their self. Understanding the faciality of quiet students provides opportunities to advance debate on how schools could encourage freer selves. 相似文献
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高峰 《职教通讯(江苏技术师范学院学报)》2008,23(10)
较早形成的中国古代读书环境,以及明清时期独立的书房,与中国古代园林相融共生。古代书房清简古雅、自然恬静的氛围,与文人园林意求隐逸、描绘天人合一的理想色彩一脉相承,共同体现出古代文人淡泊宁静的旨趣和超尘脱俗、崇尚身心自由的精神追求。 相似文献
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Valerie Dagley 《Educational Action Research》2013,21(4):613-630
This article discusses the issue of ‘making the invisible visible’ from a methodological and a substantive viewpoint. The ideas emerged from a doctoral research study into individual target setting with middle ability students in an English secondary school. The students involved had been identified by assessments as ‘average’ and by their teachers as quiet, unnoticed children. It is suggested that the methods used by the researcher to elicit the students' perceptions could also be used by teachers in order to engage these quiet students in a learning discourse. 相似文献