Five new polyoxometalate(POM)-based compounds,namely[Cu_(4)^(Ⅱ)(btmc)(ctcm)4(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)]·H_(2)O(1),[Cu_(4)^(Ⅱ)(mct)2(ctcm)2(H_(2)O)6(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)](2),[Cu^...Five new polyoxometalate(POM)-based compounds,namely[Cu_(4)^(Ⅱ)(btmc)(ctcm)4(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)]·H_(2)O(1),[Cu_(4)^(Ⅱ)(mct)2(ctcm)2(H_(2)O)6(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)](2),[Cu^(Ⅱ)(dm4bt)(Mo_(3)O_(10))](3),[Co^(Ⅱ)(dm4bt)(Mo_(2)O_(7))](4)and[Co^(Ⅱ)(H2bdpm)(Mo_(2)O_(7))](5)(btmc=1,4-bis(1,2,4-triazol-1-methyl)cyclohexane,mct=4-(4-methyl-cyclohexylmethyl)-4H-[1,2,4]triazole,ctcm=C-(4-[1,2,4]triazol-4-ylmethyl-cyclohexyl)-methyl amine,dm4bt=2,2’-dimethyl-4,4’-bithiazole,and H2bdpm=1,1’-bis(3,5-dimethyl-1H-pyrazolate)methane),were obtained through traditional hydrothermal methods and fully characterized by single crystal X-ray diffraction analysis and IR spectroscopy.Compounds 1 and 2 show one-dimensional(1D)and two-dimensional(2D)structures,respectively,containing metal–organic chains.Compounds 3–5 are 1D,1D and 2D structures,respectively,including infinite Mo–O chains.The title compounds can act as bi functional electrochemical sensors to detect not only NO_(2)^(−)anions but also Cr(VI)cations,and especially compound 3 shows an excellent detection range and sensitivity for Cr(VI)and NO_(2)^(−).Compound 3 also can act as afluorescent sensor for the recognition of Hg^(2+).Thefluorescence intensities can be reduced 65%by adding the solution of Hg^(2+)ions.So this series of POM-based compounds can be used as multi functional photoelectric sensors for electrochemical sensing of NO_(2)^(−)and Cr(VI)andfluorescence sensing of Hg^(2+).Furthermore,the photocatalytic performances of compounds 1–5 were also studied.展开更多
Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low ...Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low cost and fast response time.This paper presents a Wolfberry tree dual-model detection method and the design of an orchard target-oriented variable-rate fertilization system based on photoelectric sensors.The dual-model detection method includes the Trunk Detection Model(TDM)and Canopy Detection Model(CDM),which can be applied for Wolfberry orchards at the green cluster and mature stages,respectively.A target-oriented fertilization system was designed using the dual-model method,and tested in the lab and Chinese Wolfberry orchard.The laboratory test results showed that the average center offset distances on the condition of detecting trunks,continuous canopies,and discontinuous canopies were 4.1 cm,9.1 cm and 13.1 cm,respectively.The system could ignore the signals from canes when their diameters were less than 16 mm,and also could determine the gaps within a tree when they were less than 21 cm.The orchard test results showed that the system accomplished target-oriented fertilization 95 times for 92 trees at the mature stage.The results indicated that the dual-model detection method could be used for Wolfberry trees or other trees with similar canopy changes at different growth stages.展开更多
A model of correcting the nonlinear error of photoelectric displacement sensor was established based on the least square support vector machine.The parameters of the correcting nonlinear model,such as penalty factor a...A model of correcting the nonlinear error of photoelectric displacement sensor was established based on the least square support vector machine.The parameters of the correcting nonlinear model,such as penalty factor and kernel parameter,were optimized by chaos genetic algorithm.And the nonlinear correction of photoelectric displacement sensor based on least square support vector machine was applied.The application results reveal that error of photoelectric displacement sensor is less than 1.5%,which is rather satisfactory for nonlinear correction of photoelectric displacement sensor.展开更多
In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure ...In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS.展开更多
Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected an...Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected and located through the local modulus maxima of wavelet transform.Simulation experiments are conducted with MATLAB software.The experimental results demonstrate that the method proposed in this paper is effective and feasible.展开更多
A pair of synchronous line-tracking robots based on STM32 are designed. Each robot is actually a small intelligent car with seven reflective infrared photoelectric sensors ST188 installed in the front to track the lin...A pair of synchronous line-tracking robots based on STM32 are designed. Each robot is actually a small intelligent car with seven reflective infrared photoelectric sensors ST188 installed in the front to track the line. Two rear wheels each driven by a moter are the driving wheels, while each rooter is driven by an H-bridge circuit. The running direction is con- trolled by the turning of a servo fastened to the front wheel and the adjustment of speed difference between the rear wheels. Besides, the light-adaptive line-tracking can be performed. The speeds of the motors are controlled by adjusting pulse-width modulation （PWM） values and an angular displacement transducer is used to detect the relative position of the cars in real time. Thus, the speeds of the cars can be adjusted in time so that the synchronism of the cars can be achieved. Through ex-periments, the fast and accurate synchronous tracking can be well realized.展开更多
This paper involves the systematic,integrated and unified design of an automatic apple grading system.Apples are placed on a constant-speed conveyor system and graded based on 2 parameters:weight and colour.For weight...This paper involves the systematic,integrated and unified design of an automatic apple grading system.Apples are placed on a constant-speed conveyor system and graded based on 2 parameters:weight and colour.For weight detection,a piezo-resistive load cell(ELAF-T1-M-10 L)is used.For colour detection,an RGB colour sensor(46 CLR-D5 LAC3-D5)is used.If the apples are equal to or above a pre-set weight threshold of 0.08 kg and if the colour of the apple is red,green or yellow,they are graded in to three bins(bin 1:red apples,bin 2:green apples,bin 3:yellow apples).If the weight is below the threshold and/or if the colour of the apple is not red,green or yellow,they are sent to a reject bin.Both weight and colour requirements have to be met to be successfully graded,otherwise the apple is rejected.Electric linear actuators(PA-15),actuated by combined signals from load cell,colour sensor and photoelectric sensors(OBR2000-R2)positioned very close to the actuators,are used to eject the apples to the correct bins.A digital magnetic speed sensor(DIGISPEC 0090/0091)is used to monitor the speed of the motor and maintain the required constant conveyor speed.Food grade conveyor belt(NS20 UFMT)is used to design the conveyor and direct drive DC motor(DMS07 G)is used to move the conveyor belt.In this paper,the functionality,operation,important parameters and justifications for choosing individual components have been provided as well as detailed explanations of the overall system operation,along with potential drawbacks of proposed system.Relevant calculations necessary for system design are also provided.展开更多
Photoelectric displacement sensors rarely possess a perfectly linear transfer characteristic, but always have some degree of non-linearity over their range of operation. If the sensor output is nonlinear, it will prod...Photoelectric displacement sensors rarely possess a perfectly linear transfer characteristic, but always have some degree of non-linearity over their range of operation. If the sensor output is nonlinear, it will produce a whole assortment of problems. This paper presents a method to compensate the nonlinearity of the photoelectric displacement sensor based on the extreme learning machine （ELM） method which significantly reduces the amount of time needed to train a neural network with the output voltage of the optical displacement sensor and the measured input displacement to eliminate the nonlinear errors in the training process. The use of this proposed method was demonstrated through computer simulation with the experimental data of the sensor. The results revealed that the proposed method compensated the presence of nonlinearity in the sensor with very low training time, lowest mean squared error （MSE） value, and better linearity. This research work involved less computational complexity, and it behaved a good performance for nonlinearity compensation for the photoelectric displacement sensor and has a good application prospect.展开更多
A novel fluorescent Cd-MOF probe [Cd_(2)(btec)(TPB)_(0.5)(H_(2)O)_(4)]·2H_(2)O (complex 1,TPB = 1,2,4,5-Tetra(4-pyridyl)benzene) has been rationally designed and synthesized,and its multipurpose sensing applicati...A novel fluorescent Cd-MOF probe [Cd_(2)(btec)(TPB)_(0.5)(H_(2)O)_(4)]·2H_(2)O (complex 1,TPB = 1,2,4,5-Tetra(4-pyridyl)benzene) has been rationally designed and synthesized,and its multipurpose sensing applications have been revealed.The thermo-sensitive property of complex 1 was investigated in a wide temperature range from 20 ℃ to 160 ℃.A good linear relationship was observed between the fluorescence quenching efficiency of complex 1 and the circumstance temperature,which suggested that complex 1 could be a promising material for application in fluorescent thermometers.Stable suspensions could be obtained after dispersion of complex 1 in various solvents,especially in water.A remarkable red shift (about 20 nm) in the fluorescence emission spectrum of complex 1 was observed when H_(2)O was used as the dispersion medium compared with that in D2O,which could be used for distinguishing D2O from H_(2)O.Furthermore,based on the strong inner filtering effect (IFE),the fluorescence detection of acetone in water was carried out using complex 1-H_(2)O suspensions.Real-time fluorescence quenching was observed after the addition of acetone into complex 1-H_(2)O suspensions.Moreover,the fluorescence quenching efficiency vs.the concentration of acetone fitted well with a non-linear equation (R2 = 0.9929) with an experimental detection limit for acetone as 0.06% (vol%).In addition,the photoelectric responses study revealed that complex 1 might be modified and used as a photoelectric sensor.展开更多
基金supports of this research by the National Natural Science Foundation of China(No.21571023,21401010 and 21471021)LiaoNing Revitalization Talents Program(XLYC1807049)the supports of the General Program Fund for Education Department of Liaoning Province(LQ2020010 and LJ2019006).
文摘Five new polyoxometalate(POM)-based compounds,namely[Cu_(4)^(Ⅱ)(btmc)(ctcm)4(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)]·H_(2)O(1),[Cu_(4)^(Ⅱ)(mct)2(ctcm)2(H_(2)O)6(β-Mo_(8)O_(26))]·[β-Mo_(8)O_(26)](2),[Cu^(Ⅱ)(dm4bt)(Mo_(3)O_(10))](3),[Co^(Ⅱ)(dm4bt)(Mo_(2)O_(7))](4)and[Co^(Ⅱ)(H2bdpm)(Mo_(2)O_(7))](5)(btmc=1,4-bis(1,2,4-triazol-1-methyl)cyclohexane,mct=4-(4-methyl-cyclohexylmethyl)-4H-[1,2,4]triazole,ctcm=C-(4-[1,2,4]triazol-4-ylmethyl-cyclohexyl)-methyl amine,dm4bt=2,2’-dimethyl-4,4’-bithiazole,and H2bdpm=1,1’-bis(3,5-dimethyl-1H-pyrazolate)methane),were obtained through traditional hydrothermal methods and fully characterized by single crystal X-ray diffraction analysis and IR spectroscopy.Compounds 1 and 2 show one-dimensional(1D)and two-dimensional(2D)structures,respectively,containing metal–organic chains.Compounds 3–5 are 1D,1D and 2D structures,respectively,including infinite Mo–O chains.The title compounds can act as bi functional electrochemical sensors to detect not only NO_(2)^(−)anions but also Cr(VI)cations,and especially compound 3 shows an excellent detection range and sensitivity for Cr(VI)and NO_(2)^(−).Compound 3 also can act as afluorescent sensor for the recognition of Hg^(2+).Thefluorescence intensities can be reduced 65%by adding the solution of Hg^(2+)ions.So this series of POM-based compounds can be used as multi functional photoelectric sensors for electrochemical sensing of NO_(2)^(−)and Cr(VI)andfluorescence sensing of Hg^(2+).Furthermore,the photocatalytic performances of compounds 1–5 were also studied.
基金This work was supported by Shaanxi Science and Technology Projects(2017KJXX-54 and 2014KTCL02-15)Science and Technology Project of Northwest A&F University(Z222021560)the"Young Faculty Study Abroad Program"of Northwest A&F University Scholarship Fund.
文摘Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low cost and fast response time.This paper presents a Wolfberry tree dual-model detection method and the design of an orchard target-oriented variable-rate fertilization system based on photoelectric sensors.The dual-model detection method includes the Trunk Detection Model(TDM)and Canopy Detection Model(CDM),which can be applied for Wolfberry orchards at the green cluster and mature stages,respectively.A target-oriented fertilization system was designed using the dual-model method,and tested in the lab and Chinese Wolfberry orchard.The laboratory test results showed that the average center offset distances on the condition of detecting trunks,continuous canopies,and discontinuous canopies were 4.1 cm,9.1 cm and 13.1 cm,respectively.The system could ignore the signals from canes when their diameters were less than 16 mm,and also could determine the gaps within a tree when they were less than 21 cm.The orchard test results showed that the system accomplished target-oriented fertilization 95 times for 92 trees at the mature stage.The results indicated that the dual-model detection method could be used for Wolfberry trees or other trees with similar canopy changes at different growth stages.
基金Project(50925727) supported by the National Fund for Distinguish Young Scholars of ChinaProject(60876022) supported by the National Natural Science Foundation of China+1 种基金Project(2010FJ4141) supported by Hunan Provincial Science and Technology Foundation,ChinaProject supported by the Fund of the Key Construction Academic Subject (Optics) of Hunan Province,China
文摘A model of correcting the nonlinear error of photoelectric displacement sensor was established based on the least square support vector machine.The parameters of the correcting nonlinear model,such as penalty factor and kernel parameter,were optimized by chaos genetic algorithm.And the nonlinear correction of photoelectric displacement sensor based on least square support vector machine was applied.The application results reveal that error of photoelectric displacement sensor is less than 1.5%,which is rather satisfactory for nonlinear correction of photoelectric displacement sensor.
文摘In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS.
文摘Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected and located through the local modulus maxima of wavelet transform.Simulation experiments are conducted with MATLAB software.The experimental results demonstrate that the method proposed in this paper is effective and feasible.
文摘A pair of synchronous line-tracking robots based on STM32 are designed. Each robot is actually a small intelligent car with seven reflective infrared photoelectric sensors ST188 installed in the front to track the line. Two rear wheels each driven by a moter are the driving wheels, while each rooter is driven by an H-bridge circuit. The running direction is con- trolled by the turning of a servo fastened to the front wheel and the adjustment of speed difference between the rear wheels. Besides, the light-adaptive line-tracking can be performed. The speeds of the motors are controlled by adjusting pulse-width modulation （PWM） values and an angular displacement transducer is used to detect the relative position of the cars in real time. Thus, the speeds of the cars can be adjusted in time so that the synchronism of the cars can be achieved. Through ex-periments, the fast and accurate synchronous tracking can be well realized.
文摘This paper involves the systematic,integrated and unified design of an automatic apple grading system.Apples are placed on a constant-speed conveyor system and graded based on 2 parameters:weight and colour.For weight detection,a piezo-resistive load cell(ELAF-T1-M-10 L)is used.For colour detection,an RGB colour sensor(46 CLR-D5 LAC3-D5)is used.If the apples are equal to or above a pre-set weight threshold of 0.08 kg and if the colour of the apple is red,green or yellow,they are graded in to three bins(bin 1:red apples,bin 2:green apples,bin 3:yellow apples).If the weight is below the threshold and/or if the colour of the apple is not red,green or yellow,they are sent to a reject bin.Both weight and colour requirements have to be met to be successfully graded,otherwise the apple is rejected.Electric linear actuators(PA-15),actuated by combined signals from load cell,colour sensor and photoelectric sensors(OBR2000-R2)positioned very close to the actuators,are used to eject the apples to the correct bins.A digital magnetic speed sensor(DIGISPEC 0090/0091)is used to monitor the speed of the motor and maintain the required constant conveyor speed.Food grade conveyor belt(NS20 UFMT)is used to design the conveyor and direct drive DC motor(DMS07 G)is used to move the conveyor belt.In this paper,the functionality,operation,important parameters and justifications for choosing individual components have been provided as well as detailed explanations of the overall system operation,along with potential drawbacks of proposed system.Relevant calculations necessary for system design are also provided.
文摘Photoelectric displacement sensors rarely possess a perfectly linear transfer characteristic, but always have some degree of non-linearity over their range of operation. If the sensor output is nonlinear, it will produce a whole assortment of problems. This paper presents a method to compensate the nonlinearity of the photoelectric displacement sensor based on the extreme learning machine （ELM） method which significantly reduces the amount of time needed to train a neural network with the output voltage of the optical displacement sensor and the measured input displacement to eliminate the nonlinear errors in the training process. The use of this proposed method was demonstrated through computer simulation with the experimental data of the sensor. The results revealed that the proposed method compensated the presence of nonlinearity in the sensor with very low training time, lowest mean squared error （MSE） value, and better linearity. This research work involved less computational complexity, and it behaved a good performance for nonlinearity compensation for the photoelectric displacement sensor and has a good application prospect.
基金supported by the National Natural Science Foundation of China(22007055,21775089,22074080)Natural Science Foundation of Shandong Province of China(ZR2020QB156)+2 种基金Changjiang Scholar Program of the Ministry of Education of China(Q2019258)Taishan Scholar Program of Shandong Province(tsqn201909106)the Startup Foundation for Doctors of Qufu Normal University.
文摘A novel fluorescent Cd-MOF probe [Cd_(2)(btec)(TPB)_(0.5)(H_(2)O)_(4)]·2H_(2)O (complex 1,TPB = 1,2,4,5-Tetra(4-pyridyl)benzene) has been rationally designed and synthesized,and its multipurpose sensing applications have been revealed.The thermo-sensitive property of complex 1 was investigated in a wide temperature range from 20 ℃ to 160 ℃.A good linear relationship was observed between the fluorescence quenching efficiency of complex 1 and the circumstance temperature,which suggested that complex 1 could be a promising material for application in fluorescent thermometers.Stable suspensions could be obtained after dispersion of complex 1 in various solvents,especially in water.A remarkable red shift (about 20 nm) in the fluorescence emission spectrum of complex 1 was observed when H_(2)O was used as the dispersion medium compared with that in D2O,which could be used for distinguishing D2O from H_(2)O.Furthermore,based on the strong inner filtering effect (IFE),the fluorescence detection of acetone in water was carried out using complex 1-H_(2)O suspensions.Real-time fluorescence quenching was observed after the addition of acetone into complex 1-H_(2)O suspensions.Moreover,the fluorescence quenching efficiency vs.the concentration of acetone fitted well with a non-linear equation (R2 = 0.9929) with an experimental detection limit for acetone as 0.06% (vol%).In addition,the photoelectric responses study revealed that complex 1 might be modified and used as a photoelectric sensor.
