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Discharge plasmas in air can be accompanied by ultraviolet(UV) radiation and electron impact,which can produce large numbers of reactive species such as hydroxyl radical(OH·),oxygen radical(O·),ozone(O3),and nitrogen oxides(NOx),etc.The composition and dosage of reactive species usually play an important role in the case of volatile organic compounds(VOCs) treatment with the discharge plasmas.In this paper,we propose a volume discharge setup used to purify formaldehyde in air,which is configured by a plate-to-plate dielectric barrier discharge(DBD) channel and excited by an AC high voltage source.The results show that the relative spectral-intensity from DBD cell without formaldehyde is stronger than the case with formaldehyde.The energy efficiency ratios(EERs) of both oxides yield and formaldehyde removal can be regulated by the gas flow velocity in DBD channel,and the most desirable processing effect is the gas flow velocity within the range from2.50 to 3.33 m s-1.Moreover,the EERs of both the generated dosages of oxides(O3 and NO2) and the amount of removed formaldehyde can also be regulated by both of the applied voltage and power density loaded on the DBD cell.Additionally,the EERs of both oxides generation and formaldehyde removal present as a function of normal distribution with increasing the applied power density,and the peak of the function is appeared in the range from 273.5 to 400.0 W l-1.This work clearly demonstrates the regulation characteristic of both the formaldehyde removal and oxides yield by using volume DBD,and it is helpful in the applications of VOCs removal by using discharge plasma. 相似文献
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传输线变压器具有频带宽、易于制作的特点,在通信领域得到了广泛的应用。但在超声换能器与超声信号源之间采用传输线变压器实现阻抗匹配的报道较少。文章对传输线变压器实现宽带阻抗匹配的机理进行了详细的分析,通过一个简单的等效电路阐明了传输线变压器如何巧妙地利用传输线间的分布电容,使其由影响高频能量传输的不利因素而转换为电磁能量转换必不可少的条件,从而达到宽频带传输的目的。以500kHz-2MHz范围内的超声换能器的阻抗匹配变压器的设计为例,具体给出了确定传输线变压器特性阻抗、线长、磁心、导线型号和匝数的方法。 相似文献
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基于CAN总线的网络智能液位传感器 总被引:3,自引:1,他引:2
介绍了以两个超声波换能器为检测探头的基于CAN总线的网络化智能液位传感器的实现,具有温度补偿和自诊断功能.传感器以PIC18F258单片机为核心,驱动超声波探头发出脉冲信号,回波信号被超声探头接收,转换成脉冲电压,利用单片机内嵌的捕捉功能测出时间,从而测得距离;通过两个探头获得数据的比较,实现系统的自诊断和校正功能;用单片机内嵌的CAN总线控制模块实现传感器的网络化,用软件保证传感器在网络上通信时有最大传输速率.软、硬件上采用了抗干扰措施,使传感器能在环境恶劣的工业现场长时间稳定运行.核心部分已申报发明专利(200610097403.8)和实用新型专利(200620124925.8). 相似文献
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"高频电子线路"课程教学改革探索 总被引:3,自引:0,他引:3
"高频电子线路"是电气信息学科的重要专业基础课。随着信息技术的迅猛发展,课程的结构和安排也应随之进行相应的调整。本文从课程内容、教学过程、授课手段等方面入手,详细论述了课程改革的基本构想,并在教学实践中取得了较好的效果。 相似文献
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