针对中国水稻施肥机械化程度低,传统撒施肥料利用率低、施肥量大的现状,结合侧深施肥农艺特点,对风送式排肥方法进行了理论分析,研制了风送式水稻侧深精准施肥装置。该装置采用模块化设计与乘坐式插秧机配套使用,采用电机驱动排肥、风...针对中国水稻施肥机械化程度低,传统撒施肥料利用率低、施肥量大的现状,结合侧深施肥农艺特点,对风送式排肥方法进行了理论分析,研制了风送式水稻侧深精准施肥装置。该装置采用模块化设计与乘坐式插秧机配套使用,采用电机驱动排肥、风送肥料、全球定位系统(global position system,GPS)测速的工作原理,侧位深施化肥的施肥方式,采用车辆行驶速度与排肥驱动电机转速实时匹配的精准施肥控制方法。设备在黑龙江七星农场开展了田间实际作业试验。试验表明,该装置与插秧机配合使用时能一次性完成插秧与侧深精准施肥作业,当预置施肥量为300 kg/hm2,车辆稳定行驶速度为1 m/s时,施肥量偏差控制在5.82%以内,能够较好的满足实际生产需求。该研究为开展水稻变量施肥控制技术研究和水稻侧深施肥装置的研发提供了参考。展开更多
Pufferfish is prone to deterioration due to abundant nutrients and high moisture content.Drying technology can extend the shelf life and enhance the flavor quality of aquatic products.The study investigated the effect...Pufferfish is prone to deterioration due to abundant nutrients and high moisture content.Drying technology can extend the shelf life and enhance the flavor quality of aquatic products.The study investigated the effect of hot air drying(HAD),microwave vacuum drying(MVD)and hot air assisted radio frequency drying(HARFD)on the taste and volatile profiles of Takifugu obscurus.Different drying methods had significant influence on the color,rehydration,5’-nucleotides,free amino acids and volatile components(P<0.05).The results showed that HAD and HARFD could promote the flavor of T.obscurus by producing higher equivalent umami concentration(EUC)values,which were about two times of MVD group,and more pronounced pleasant odor according to sensory analysis.HAD is more appropriate for industrial application than HARFD and MVD considering the economic benefits.This study could provide a reference for the industrial application of drying T.obscurus.展开更多
In order to obtain nozzle droplet deposition characteristics for sprayer mechanical design and variable spraying control algorithms,a nozzle droplet deposition characteristics test system for air-assisted spraying was...In order to obtain nozzle droplet deposition characteristics for sprayer mechanical design and variable spraying control algorithms,a nozzle droplet deposition characteristics test system for air-assisted spraying was designed.The test system can supply a stable wind site with precisely controlled air speed whose speed control ranges from 2 m/s to 16 m/s with maximum relative error of 4.5%.It can spray out a certain amount of liquid pesticide with adjustable spraying pressure which can be controlled with high precision while the maximum relative error is only 1.33%.The distribution of droplet deposition can be collected and measured by using the acquisition device and a pesticide deposition optical measurement system.The experiment of two-dimensional nozzle flow measurement was carried out.The results show that nozzle flow distribution is uniform and symmetric with“double-hump”shape in the spray range.Multi-nozzle overlapped droplet deposition ranges from 85%to 116%relative to the average.The nozzle droplet deposition experiment was completed.The experiment results show that in air-assisted spraying,the higher the wind speed,the less droplet deposition is affected by gravity.When the wind speed is higher than 12 m/s and spraying distance is 0.80 m,droplet deposition is concentrated on the originally designated point and hardly affected by gravity.The horizontal spray width becomes smaller with higher wind speed.When the wind speed is high,it can be considered that nozzle deposition only focuses on the nozzle center,if the position requirement is not very high in orchard spraying.展开更多
文摘针对中国水稻施肥机械化程度低,传统撒施肥料利用率低、施肥量大的现状,结合侧深施肥农艺特点,对风送式排肥方法进行了理论分析,研制了风送式水稻侧深精准施肥装置。该装置采用模块化设计与乘坐式插秧机配套使用,采用电机驱动排肥、风送肥料、全球定位系统(global position system,GPS)测速的工作原理,侧位深施化肥的施肥方式,采用车辆行驶速度与排肥驱动电机转速实时匹配的精准施肥控制方法。设备在黑龙江七星农场开展了田间实际作业试验。试验表明,该装置与插秧机配合使用时能一次性完成插秧与侧深精准施肥作业,当预置施肥量为300 kg/hm2,车辆稳定行驶速度为1 m/s时,施肥量偏差控制在5.82%以内,能够较好的满足实际生产需求。该研究为开展水稻变量施肥控制技术研究和水稻侧深施肥装置的研发提供了参考。
基金supported by The National Natural Science Foundation of China (32001824, 31972198, 31901813, 31901816, 32001827)Startup Fund for Youngman Research at SJTU (SFYR at SJTU)
文摘Pufferfish is prone to deterioration due to abundant nutrients and high moisture content.Drying technology can extend the shelf life and enhance the flavor quality of aquatic products.The study investigated the effect of hot air drying(HAD),microwave vacuum drying(MVD)and hot air assisted radio frequency drying(HARFD)on the taste and volatile profiles of Takifugu obscurus.Different drying methods had significant influence on the color,rehydration,5’-nucleotides,free amino acids and volatile components(P<0.05).The results showed that HAD and HARFD could promote the flavor of T.obscurus by producing higher equivalent umami concentration(EUC)values,which were about two times of MVD group,and more pronounced pleasant odor according to sensory analysis.HAD is more appropriate for industrial application than HARFD and MVD considering the economic benefits.This study could provide a reference for the industrial application of drying T.obscurus.
基金China National 863 Project(2012AA101904)project 31201128 supported by NSFC,project KFZN2012W13-013IEA and project 2452013QN070 supported by Northwest A&F University.
文摘In order to obtain nozzle droplet deposition characteristics for sprayer mechanical design and variable spraying control algorithms,a nozzle droplet deposition characteristics test system for air-assisted spraying was designed.The test system can supply a stable wind site with precisely controlled air speed whose speed control ranges from 2 m/s to 16 m/s with maximum relative error of 4.5%.It can spray out a certain amount of liquid pesticide with adjustable spraying pressure which can be controlled with high precision while the maximum relative error is only 1.33%.The distribution of droplet deposition can be collected and measured by using the acquisition device and a pesticide deposition optical measurement system.The experiment of two-dimensional nozzle flow measurement was carried out.The results show that nozzle flow distribution is uniform and symmetric with“double-hump”shape in the spray range.Multi-nozzle overlapped droplet deposition ranges from 85%to 116%relative to the average.The nozzle droplet deposition experiment was completed.The experiment results show that in air-assisted spraying,the higher the wind speed,the less droplet deposition is affected by gravity.When the wind speed is higher than 12 m/s and spraying distance is 0.80 m,droplet deposition is concentrated on the originally designated point and hardly affected by gravity.The horizontal spray width becomes smaller with higher wind speed.When the wind speed is high,it can be considered that nozzle deposition only focuses on the nozzle center,if the position requirement is not very high in orchard spraying.
