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介绍了使用LIN总线协议的89S52单片机主从收发系统,该设计包含两个模块,主单片机发送模块和从单片机LIN接收模块.设计中主要使用器件包括89S52两片,LIN收发器TJA1020,AD0809,液晶1602. 相似文献
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设计了一种粮仓无线监控系统,主要完成对粮食温度、湿度参数的采集、存储和向监控中心传送数据以及执行监控中心指令等功能。介绍了系统硬件组成及工作原理,无线传输电路、温湿度采集电路和辅助电路等硬件设计及软件设计。 相似文献
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Emission of methyl isothiocyanate (MITC) from fields treated with metam‐sodium (sodium N‐methyldithiocarbamate) is a potential environmental and human safety hazard. Concentrations of MITC at three heights above four arable fields were measured following the application of metam‐sodium at a rate of 480 litre ha−1 (166 kg AI ha−1). Two of these fields were treated by injection into a center‐pivot irrigation system (chemigation), while in the other two fields the fumigant was applied through injection directly into the soil. Generally, higher MITC air concentrations were observed above chemigated than above injected fields. Maximum MITC air concentrations were 11.2 and 7.4 µg m−3 recorded 10 cm above ground 6–8 h following application and the minimum concentrations were 0.7 and 0.2 µg m−3 observed at 200 cm 30–35 h after application above chemigated and injected fields, respectively. The estimated MITC respiratory exposure a worker might encounter during the re‐entry period ranged between 1.37 and 0.03 mg day−1 in chemigated fields and between 0.35 and 0.02 mg day−1 in the injected fields. These results suggest that application of the fumigant through injection reduced MITC volatilization losses in comparison with the chemigation method, thus posing a relatively lower risk of exposure to MITC emissions. © 2000 Society of Chemical Industry 相似文献
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介绍了使用LIN总线协议的89S52单片机主从收发系统,该设计包含两个模块,主单片机发送模块和从单片机LIN接收模块。设计中主要使用器件包括89S52两片,LIN收发器TJA1020,AD0809,液晶1602。 相似文献
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