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Jesper Haglund Emil Melander Matthias Weiszflog Staffan Andersson 《Research in Science & Technological Education》2017,35(3):349-367
Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations.Purpose: The purpose of the research was to explore students’ interactions with reformed thermodynamics laboratory activities. It was guided by the research question: How do university physics students make use of IR cameras in open-ended investigation of thermal radiation as a phenomenon?Sample: The study was conducted with a class of first-year university physics students in Sweden. The interaction with the activities of four of the students was selected for analysis. The four students are males.Design and methods: We used a qualitative, interpretive approach to the study of students’ interaction. The primary means of data collection was video recording of students’ work with the laboratory activities and their subsequent presentations. The analysis focused on how IR cameras helped students notice phenomena relating to thermal radiation, with comparison to previous research on students’ conceptions of thermal radiation.Results: When using the IR camera, students attended to the reflection of thermal radiation on shiny surfaces, such as polished metals, windows or a whiteboard and emissive properties of surfaces of different types. In this way, they went beyond using the technology as a temperature probe. Students were able to discuss merits and shortcomings of IR cameras in comparison with digital thermometers.Conclusions: With the help of IR cameras, university physics students attend to thermal phenomena that would otherwise easily go unnoticed. 相似文献
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结合三门峡职业技术学院沟槽式厕所冲水系统改造,提出了一种基于单片机控制的沟槽式厕所智能冲水系统设计方案,并给出了沟槽式厕所智能冲水系统根据人数多少冲水的处理方法,将系统用于各企事业单位及公共场所的沟槽式厕所,可大大节约水资源,节省单位财政支出。 相似文献
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近红外光谱是一种快速、无损、可实现多组分同时测定的分析技术。本文简要介绍了近红外光谱的发展、测量原理、技术特点．并对近年来近红外光谱技术在肥料成分分析中的应用及前景进行了总结。近红外光谱在肥料成分分析中的应用范围比较狭窄,主要集中在两个方面：一是利用近红外反射光谱（NIRS）分析技术快速测定各种畜禽粪便主要肥料成分含量;二是应用近红外光谱技术在土壤及土壤肥料学科中的应用;只有极少量的关于混合（复合）肥料的研究。随着近红外光谱技术的不断成熟,除了应用范围将不断拓宽之外,相信对于目前较为空白的应用机理的研究也将越来越深入、细致及严谨。 相似文献
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红外测温能在不接触、不停电情况下探明设备的发热程度,是当前变电运维工作中必不可少的技术手段。本文从红外测温的原理出发,阐述了该项技术在状态检修、故障处理中的应用情况,并给出具体实例,最后就红外测温的注意事项作归纳,以期更好地推广该项技术。 相似文献
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基于红外技术的机载高压线避障系统能有效保证直升机在低能见度条件下的低空飞行安全,避免直升机低空飞行撞击高压线。在分析红外成像原理的基础上,设计了红外光路系统和数字信号处理系统,结合霍夫变换算法,实现了高压线辨识与报警。该系统在某型直升机上挂载飞行表明：系统能较好地辨识500m范围内直径30～50mm的高压线,有效避免因高压线造成的直升机损失。 相似文献
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以单片机为控制芯片,设计了一种手动/遥控两用开关.该开关可以通过手动和遥控两种方式控制开关的开启和关闭,可实现定时、调压和延时等功能.遥控发射器用家用遥控器取代,成本低,安装和使用都很方便,能够给家庭和企业带来很大的便利和经济效益. 相似文献
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