<div style="text-align:justify;"> In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded p...<div style="text-align:justify;"> In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded places such as buses. A MEMS (Micro-Electro-Mechanical System) based thin film semiconductor was fabricated as the gas sensor. To obtain the target gas selective response, the surface of the sensitive film was modified with highly active metal catalytic nano-particles. Thus the anti-interference ability was improved and the false alarm rate was effectively reduced. Furthermore, the modular embedded system for information acquisition and transmission was developed. Supported by the Airflow Precision control system (APs), the rapid warning of volatile gas of flammable substances was realized. Experiments showed that RAs has satisfied selectivity to volatiles of usual flammable liquid, such as the output voltage reaches 3 V (0 - 3.3 V). With simulation about the actual installation state in bus, MWs sounds an alarm at 2 minutes after splashing 50 mL 92# petrol to the floor. For the last two years, FEVMEW has been integrated into more than 4000 buses in Hefei. This design has been proved feasible according to the actual operation. </div>展开更多
Due to its ability to broaden the transport channel of droplets within the plant canopy and enhance their penetration capacity,air-assisted spray technology is widely used in orchard pesticide application.To achieve u...Due to its ability to broaden the transport channel of droplets within the plant canopy and enhance their penetration capacity,air-assisted spray technology is widely used in orchard pesticide application.To achieve uniform distribution of pesticide droplets in the tree canopy and obtain a higher pesticide utilization rate,it is crucial to clarify the coupling mechanism of the airflow field and droplet field generated by the air-assisted sprayer.This paper introduces a three-dimensional modeling method of the fruit tree canopy based on CFD(Computational Fluid Dynamics),offering a theoretical basis for analyzing the airflow demand calculation during different growth periods of the canopy.It also examines the interaction between canopy modeling and airflow,highlighting advancements in airflow regulation equipment and the effects of airflow speed and volume on spraying.The study shows that the precise regulation of airflow velocity and discharge rate is of importance for improving spraying efficiency.It finally points out that future research should focus on developing intelligent regulation equipment for efficient airflow-droplet control,using biomass sensing,which involves measuring the growth characteristics of the tree canopy,to meet the needs of orchards with diverse growth stages and canopy structures.This article could provide guidance for the future study of precision air-assisted spraying technology in orchards.展开更多
文摘<div style="text-align:justify;"> In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded places such as buses. A MEMS (Micro-Electro-Mechanical System) based thin film semiconductor was fabricated as the gas sensor. To obtain the target gas selective response, the surface of the sensitive film was modified with highly active metal catalytic nano-particles. Thus the anti-interference ability was improved and the false alarm rate was effectively reduced. Furthermore, the modular embedded system for information acquisition and transmission was developed. Supported by the Airflow Precision control system (APs), the rapid warning of volatile gas of flammable substances was realized. Experiments showed that RAs has satisfied selectivity to volatiles of usual flammable liquid, such as the output voltage reaches 3 V (0 - 3.3 V). With simulation about the actual installation state in bus, MWs sounds an alarm at 2 minutes after splashing 50 mL 92# petrol to the floor. For the last two years, FEVMEW has been integrated into more than 4000 buses in Hefei. This design has been proved feasible according to the actual operation. </div>
基金supported by China Agriculture Research System of MOF and MARA(Grant No.CARS-28-21)Jiangsu Standard Orchard Intelligent Green Agricultural Machinery Research,Production and Application Integration Project(Grant No.JSYTH01).
文摘Due to its ability to broaden the transport channel of droplets within the plant canopy and enhance their penetration capacity,air-assisted spray technology is widely used in orchard pesticide application.To achieve uniform distribution of pesticide droplets in the tree canopy and obtain a higher pesticide utilization rate,it is crucial to clarify the coupling mechanism of the airflow field and droplet field generated by the air-assisted sprayer.This paper introduces a three-dimensional modeling method of the fruit tree canopy based on CFD(Computational Fluid Dynamics),offering a theoretical basis for analyzing the airflow demand calculation during different growth periods of the canopy.It also examines the interaction between canopy modeling and airflow,highlighting advancements in airflow regulation equipment and the effects of airflow speed and volume on spraying.The study shows that the precise regulation of airflow velocity and discharge rate is of importance for improving spraying efficiency.It finally points out that future research should focus on developing intelligent regulation equipment for efficient airflow-droplet control,using biomass sensing,which involves measuring the growth characteristics of the tree canopy,to meet the needs of orchards with diverse growth stages and canopy structures.This article could provide guidance for the future study of precision air-assisted spraying technology in orchards.
