A Monte Carlo method to study the response of portable detector to terrestrial gamma ray is proposed. This method is based on two-stage Monte Carlo simulation.First, the probability distributions of the phase space co...A Monte Carlo method to study the response of portable detector to terrestrial gamma ray is proposed. This method is based on two-stage Monte Carlo simulation.First, the probability distributions of the phase space coordinates of the events that are most likely to be detected are reconstructed at the phase space shell level. The phase space shell is a closed surface enclosing the detector. The detector response to events originating from the phase space shell is then studied. The full absorption spectra as well as the partial absorption spectra are obtained for natural radionuclides uniformly distributed in the ground. For validation, this method is applied to a Hp Ge portable detector previously studied. The previous study is based on a semiempirical model. Good agreement is achieved when we compare the full-energy peak efficiencies and the total in situ spectra obtained by the two methods. As an application, the effective depth of the activity of the^(137) Cs artificial radionuclide in the soil is determined from the low-energy part of the total in situ spectrum.展开更多
Based on the analysis technology of visible/near infrared diffuse reflectance spectroscopy a portable and nondestructive detector was designed to test comprehensive quality of red globe grape bunches in the growth per...Based on the analysis technology of visible/near infrared diffuse reflectance spectroscopy a portable and nondestructive detector was designed to test comprehensive quality of red globe grape bunches in the growth period.The detector included spectrum acquisition probe,spectrometer,lithium battery,halogen lamp light source,advanced RISC machines(ARM)board and peripheral circuit.Based on microsoft foundation classes(MFC)development tool,the real-time analysis and processing software of the detector was written by C++language.The optimal partial least squares regression(PLSR)detection model of multi-quality parameters was implanted into the hardware device.This paper selected the red globe grapes bunches in the growth period as the research samples,collected the visible/near infrared diffuse reflectance spectrum information,and then used the established PLSR model to detect the soluble solid content(SSC),total acid(TA)and pH of the samples to generate comprehensive quality parameter.So as to realize the nondestructive detecting of comprehensive quality of red globe grapes bunches in the growth period.In conclusion,the detector could realize real-time and non-destructive detecting of red globe grapes bunches in growth period aiming at the comprehensive quality.展开更多
Sulfur dioxide and its derivative sulfite widely existed in air,water as the environment pollutant.Sulfite is also commonly used as preservative and additive in fresh fruits,vegetables,wines and pharmaceutical materia...Sulfur dioxide and its derivative sulfite widely existed in air,water as the environment pollutant.Sulfite is also commonly used as preservative and additive in fresh fruits,vegetables,wines and pharmaceutical materials.Due to sulfite is closely related with human diseases,it is very urgent for the sensitive and rapid quantification of sulfite in various samples.In our study,a turn-on near infrared(NIR)fluorescent probe(MDQ)was developed for sulfite detection based on a Michael addition reaction,with high sensitivity(LOD 4.16 nmol/L),selectivity and fast response time(400 s).Using MDQ,a quantify method for sulfite in traditional Chinese medicines(TCMs)was developed with the advantages of high precision,accuracy and convenient operation.Furthermore,according to the photophysical property of MDQ,a portable fluorescence detector is designed to quantify sulfite for TCMs and surface water in Dalian city of China.Therefore,the developed fluorescent probe MDQ and portable fluorescent detector as a rapid inspection instrument were successfully used to real-time monitor the sulfite in various complex samples.展开更多
文摘A Monte Carlo method to study the response of portable detector to terrestrial gamma ray is proposed. This method is based on two-stage Monte Carlo simulation.First, the probability distributions of the phase space coordinates of the events that are most likely to be detected are reconstructed at the phase space shell level. The phase space shell is a closed surface enclosing the detector. The detector response to events originating from the phase space shell is then studied. The full absorption spectra as well as the partial absorption spectra are obtained for natural radionuclides uniformly distributed in the ground. For validation, this method is applied to a Hp Ge portable detector previously studied. The previous study is based on a semiempirical model. Good agreement is achieved when we compare the full-energy peak efficiencies and the total in situ spectra obtained by the two methods. As an application, the effective depth of the activity of the^(137) Cs artificial radionuclide in the soil is determined from the low-energy part of the total in situ spectrum.
基金This study was funded by National Natural Science Foundation of China(32072302)Hubei Provincial(China)Natural Science Foundation(2012FKB02910)Hubei Research and Development Program(2011BHB016)。
文摘Based on the analysis technology of visible/near infrared diffuse reflectance spectroscopy a portable and nondestructive detector was designed to test comprehensive quality of red globe grape bunches in the growth period.The detector included spectrum acquisition probe,spectrometer,lithium battery,halogen lamp light source,advanced RISC machines(ARM)board and peripheral circuit.Based on microsoft foundation classes(MFC)development tool,the real-time analysis and processing software of the detector was written by C++language.The optimal partial least squares regression(PLSR)detection model of multi-quality parameters was implanted into the hardware device.This paper selected the red globe grapes bunches in the growth period as the research samples,collected the visible/near infrared diffuse reflectance spectrum information,and then used the established PLSR model to detect the soluble solid content(SSC),total acid(TA)and pH of the samples to generate comprehensive quality parameter.So as to realize the nondestructive detecting of comprehensive quality of red globe grapes bunches in the growth period.In conclusion,the detector could realize real-time and non-destructive detecting of red globe grapes bunches in growth period aiming at the comprehensive quality.
基金supported financially by Distinguished Professor Program of Liaoning Province(No.XLYC2002008)Dalian Science and Technology Leading Talents Project(Nos.2019RD15,2020RJ09 and 2020RQ076)+2 种基金Liaoning Provincial Natural Science Foundation(No.20180550761)Liaoning Revitalization Talents Program(No.XLYC1907017)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University(No.2021YB07).
文摘Sulfur dioxide and its derivative sulfite widely existed in air,water as the environment pollutant.Sulfite is also commonly used as preservative and additive in fresh fruits,vegetables,wines and pharmaceutical materials.Due to sulfite is closely related with human diseases,it is very urgent for the sensitive and rapid quantification of sulfite in various samples.In our study,a turn-on near infrared(NIR)fluorescent probe(MDQ)was developed for sulfite detection based on a Michael addition reaction,with high sensitivity(LOD 4.16 nmol/L),selectivity and fast response time(400 s).Using MDQ,a quantify method for sulfite in traditional Chinese medicines(TCMs)was developed with the advantages of high precision,accuracy and convenient operation.Furthermore,according to the photophysical property of MDQ,a portable fluorescence detector is designed to quantify sulfite for TCMs and surface water in Dalian city of China.Therefore,the developed fluorescent probe MDQ and portable fluorescent detector as a rapid inspection instrument were successfully used to real-time monitor the sulfite in various complex samples.
