With fresh winter jujube from the southern region of Xinjiang as the object of study, the method for detecting pesticide residues on winter jujube surface by near-infrared spectroscopy （NIR） combined with successive...With fresh winter jujube from the southern region of Xinjiang as the object of study, the method for detecting pesticide residues on winter jujube surface by near-infrared spectroscopy （NIR） combined with successive projections algorithm （SPA） and partial least squares （PLS） was investigated. The absorbance information of winter jujube sample surface was obtained through NIR technology, for the building of a full-wave band PLS model of fresh winter jujube sample sprayed with different concentrations of pesticide （taking chlorpyrifos as an example） as well as an SPA-PLS model which was built with the characteristic wavelengths extracted with SPA as the input variables for PLS, and the prediction precision of the two kinds of models was compared. The model built with the five characteristic waveslengths extected by SPA method only used the variables 0.32% of all the variables in the full wave band, but its accuracy and precision were better than the model built with the full wave band. It is feasible to build a model for different concentrations of chlorpyrifos on fresh winter jujube surfarce by NIR technology combined with SPA and PLS, and SPA method could simplify the complexity of the model and improve the precision and stablity of the model.展开更多
[Objectives]This study was conducted to study the variation laws and characteristics of stem sap flow rate in jujube under the injection irrigation mode,to improve the growth quality of jujube trees.[Methods]According...[Objectives]This study was conducted to study the variation laws and characteristics of stem sap flow rate in jujube under the injection irrigation mode,to improve the growth quality of jujube trees.[Methods]According to the characteristics of the growth environment and physiological characteristics of jujube Junzao trees in southern Xinjiang,eight different injection irrigation modes were designed.Through the variation of stem sap flow rate,the most suitable irrigation method for jujube Junzao trees in southern Xinjiang was explored.The variation law of stem sap flow rate of jujube and the effect of meteorological factors on stem sap flow rate of jujube were studied.The variation law of stem sap flow in jujube trees was analyzed,and multiple regression models and time series models were established to predict stem sap flow of jujube trees.[Results]The results showed that the simulation results of the time series model were closer to the actual data,and the model could accurately predict the stem sap flow rate of Junzao.[Conclusions]This study is suitable for the full utilization of water resources in the Tarim Basin in southern Xinjiang,and has important practical significance for analyzing the effect of water stress on the growth and development of jujube trees and precision irrigation.展开更多
基金Supported by Emergency Management Project of Natural Science Foundation of China(61640413)open project of Agricultural Information Research Center in Southern Region of Xinjiang,Agricultural Information Institute of CAAS(ZX2015005)Project of Key Laboratory of Crop Water Use and Regulation,Ministry of Agriculture(FIRI2018-05-03)
文摘With fresh winter jujube from the southern region of Xinjiang as the object of study, the method for detecting pesticide residues on winter jujube surface by near-infrared spectroscopy （NIR） combined with successive projections algorithm （SPA） and partial least squares （PLS） was investigated. The absorbance information of winter jujube sample surface was obtained through NIR technology, for the building of a full-wave band PLS model of fresh winter jujube sample sprayed with different concentrations of pesticide （taking chlorpyrifos as an example） as well as an SPA-PLS model which was built with the characteristic wavelengths extracted with SPA as the input variables for PLS, and the prediction precision of the two kinds of models was compared. The model built with the five characteristic waveslengths extected by SPA method only used the variables 0.32% of all the variables in the full wave band, but its accuracy and precision were better than the model built with the full wave band. It is feasible to build a model for different concentrations of chlorpyrifos on fresh winter jujube surfarce by NIR technology combined with SPA and PLS, and SPA method could simplify the complexity of the model and improve the precision and stablity of the model.
基金Supported by Principal Fund of Tarim University(TDZKQN201708).
文摘[Objectives]This study was conducted to study the variation laws and characteristics of stem sap flow rate in jujube under the injection irrigation mode,to improve the growth quality of jujube trees.[Methods]According to the characteristics of the growth environment and physiological characteristics of jujube Junzao trees in southern Xinjiang,eight different injection irrigation modes were designed.Through the variation of stem sap flow rate,the most suitable irrigation method for jujube Junzao trees in southern Xinjiang was explored.The variation law of stem sap flow rate of jujube and the effect of meteorological factors on stem sap flow rate of jujube were studied.The variation law of stem sap flow in jujube trees was analyzed,and multiple regression models and time series models were established to predict stem sap flow of jujube trees.[Results]The results showed that the simulation results of the time series model were closer to the actual data,and the model could accurately predict the stem sap flow rate of Junzao.[Conclusions]This study is suitable for the full utilization of water resources in the Tarim Basin in southern Xinjiang,and has important practical significance for analyzing the effect of water stress on the growth and development of jujube trees and precision irrigation.
