Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive mo...Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.展开更多
The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is man...The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is manipulated by off line Because the off line measuring reference is differen t from the machining reference,the measurement result is diverse from the act ual dimension A new method to measure the middle convex and varying ellipse p iston profile, which is known as on line measuring, is presented By using thi s kind of method,the high measurement accuracy can be gained,as well as meeting the production requirement.展开更多
Using the ideal gas state equation, an on-line measuring method for the shell chamber volume is studied in this paper. After analyzing how various measurement parameters affect the measurement accuracy, the system par...Using the ideal gas state equation, an on-line measuring method for the shell chamber volume is studied in this paper. After analyzing how various measurement parameters affect the measurement accuracy, the system parameters are optimized in this method. Because the shape and volume of the tested items are similar, the method of using "tamping" to raise the accuracy and speed of the measurement is put forward. Based on the work above, a prototype of the testing instrument for shell chamber volume was developed, automatically testing and controlling. Compared with the method of "water weight", this method is more accurate, quicker and more automotive, so it is adaptable for the use of on-line detection.展开更多
On-line measurement for dielectric loss angle can effectively monitor the insulation condition of capacitive equipment in power systems. Synthetic relative measuring methods not only markedly overcome the shortcomings...On-line measurement for dielectric loss angle can effectively monitor the insulation condition of capacitive equipment in power systems. Synthetic relative measuring methods not only markedly overcome the shortcomings of traditional absolute measuring methods but also greatly improve the accuracy of dielectric loss angle measurement. However, synthetic relative measuring methods based on two or three pieces of capacitive equipment do not have the characteristic of generality. In this paper, a principle of synthetic relative measuring method is presented. The example of application for synthetic relative methods based on three and four pieces of capacitive equipment running in the same phase is taken to present the failure judgment matrices for N pieces of equipment. According to these matrices, the fault condition of N pieces of capacitive equipment can be watched, which is more general. Then some problems needing to be concerned along with two diagnostic methods used in diagnostic system are introduced. Finally, two programmable flow charts for the two methods are given and corresponding examples demonstrate their feasibility in practice.展开更多
Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast...Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.展开更多
Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts...Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts to produce online predictions of the chemical oxygen demand (COD) in wastewater from a pulp and paper mill using NIR spectroscopy are described. The task was perceived as very challenging, but with a root mean square error of prediction of 149 mg/l, roughly corresponding to 1/10 of the studied concentration interval, this attempt was deemed as successful. This result was obtained by using partial least squares model regression, interpolated reference values for calibration purposes, and by evenly distributing the calibration data in the concentration space. This work may also represent the first industrial application of online COD measurements in wastewater using NIR spectroscopy.展开更多
Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-lin...Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.展开更多
On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real tim...On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).展开更多
A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field duri...A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field during operation such as demagnetization, field sweeping, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on disk. The magnetic hysteresis loop and Barkhausen noise data can be converted into important magnetic parameters: coecivity, remanence, and hysteresis loss, Barkhausen amplitude, and Barkhausen noise energy. This system incorporated with the magnetostriction, and magnetoacoustic emission, is then related with the nondestructive detection of material degradation.展开更多
In this paper,a method of multipoint pseudorandom combined excita-tion with the orthogonal reciprocal repeated sequences(ORRS)is presented on thebackground of the on-line identification of multivariate system.The capa...In this paper,a method of multipoint pseudorandom combined excita-tion with the orthogonal reciprocal repeated sequences(ORRS)is presented on thebackground of the on-line identification of multivariate system.The capacity of therestraint to the identification error caused by the non-random D.C.drift of the mul-ti-input excitation with the ORRS in the multivariate system is also discussed.Thevalidity of the method described in this paper is proved by the modelling tests of themulti-plate rotor system.展开更多
A new approach to the on-line temperature rise measurement of submersible pump's motors is presented. A new method of power supply and signed transmission for the measurement device in the pump well is also put fo...A new approach to the on-line temperature rise measurement of submersible pump's motors is presented. A new method of power supply and signed transmission for the measurement device in the pump well is also put forward here. The design and some experimental results are given.展开更多
The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling pro...The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling processes.Monitoring and analyzing tool wear during these processes is crucial to assess the tool’s life and optimize the tool’s performance under study;as such,standards detail procedures to measure and assess tool wear for various tools.Measuring wear in machining tools can be time-consuming,as the process is usually manual,requiring human interaction and judgment.In the present work,an automated offline flank wear measurement algorithm was developed in Python.The algorithm measures the flank wear of coated end-mills and slot drills from Scanning Electron Microscopy(SEM)images,according to the ISO 8688 standard,following the same wear measurement procedure.SEM images acquired with different magnifications and tools with varying machining parameters were analyzed using the developed algorithm.The flank wear measurements were then compared to the manually obtained,achieving relative errors for the most common magnifications of around 2.5%.Higher magnifications were also tested,yielding a maximum relative error of 13.4%.The algorithm can measure batches of images quickly on an ordinary personal computer,analyzing and measuring a 10-image batch in around 30 s,a process that would require around 30 min when performed manually by a skilled operator.Therefore,it can be a reliable alternative to measuring flank wear on many tools from SEM images,with the possibility of being adjusted for other wear measurements on different kinds of tools and different image types,for example,on images obtained by optical microscopy.展开更多
A measurement system for high power electrical variables with ultrasonic frequency was established. It can measure the effective values of the voltage and the current, the active power, the phase difference of voltage...A measurement system for high power electrical variables with ultrasonic frequency was established. It can measure the effective values of the voltage and the current, the active power, the phase difference of voltage and current, the frequency of the transducer during ultrasonic welding and cutting. In sampling circuits of the system, the measured current is sensed by using a no capacitance and no inductance precision resistor and is treated with a difference amplifier, the measured voltage is processed by using a proportional amplifier. For achieving good amplitude frequency characteristics and rapid measurement of high frequency signals, the resistors, capacitors and amplifiers used in the system are rationally selected. Calibrating experiments show that relative errors are less than 1% for voltage and current effective values and less than 2.5% for active power, and absolute errors are ±1 Hz for frequency and ±1.7° for phase difference of voltage and current in the range of 17～23 kHz .展开更多
The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-se...The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.展开更多
Standardization is necessary for the early industrialization of the new materials and technology.It is achieved by having agreed practices for the measurement of properties and other characteristics.The promising use ...Standardization is necessary for the early industrialization of the new materials and technology.It is achieved by having agreed practices for the measurement of properties and other characteristics.The promising use of graphene-based materials in fields like electronics,energy,and composites has resulted in standards for their nomenclature,the measurement of key characteristics,and their specification,etc.Among these,standards for measuring the key characteristics are crucial.The critical parameters are the number of layers,the type and concentration of defects and functional groups,elemental composition,sheet resistance,and carrier mobility.Standards for characterizing these have been analyzed by the International Organization for Standardization Technical Committee in ISO/TC229 and the International Electrotechnical Commission Technical Committee in IEC/TC113.These give details of applicable or preferred samples,the fundamental principles of the techniques,specific precautions,and points for attention in the relevant standards.The pivotal role of the ISO/TC229 and IEC/TC113 standards is considered and challenges and future trends are outlined.展开更多
Traditional automated guided vehicle(AGV)primarily relies on scheduling systems to manage warehouse locations and execute picking or placing tasks on fixedheight pallets.However,these conventional systems are illsuite...Traditional automated guided vehicle(AGV)primarily relies on scheduling systems to manage warehouse locations and execute picking or placing tasks on fixedheight pallets.However,these conventional systems are illsuited for scenarios involving variable heights,such as vehicle loading and unloading or the complex stacking of soft packages.To address the challenges of AGV endeffector operations in nonfixed height scenarios,this paper proposes an innovative solution leveraging lowcost depth camera sensors.By capturing image and depth data,and integrating deep learning,image processing,and spatial attitude calculation techniques,the method accurately determines the position of the endeffector center point relative to the upper plane of the fork.The approach effectively resolves a key issue in AGV operations within intelligent logistics scenarios that lack fixed heights.The proposed algorithm is deployed on a domestic embedded,lowcost ARM chip controller,and extensive experiments are conducted on a real AGV equipped with multiple stacked vehicles and nonstandard vehicles.The experimental results demonstrate that for diverse vehicles with different heights,the measurement error can be maintained within±10 mm,satisfying the requirements for highprecision measurement.The height measurement method developed in the paper not only enhances the AGV’s adaptability in nonfixed height scenarios but also significantly broadens its application potential across various industries.展开更多
Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measu...Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measurement is presented in this paper. In order to eliminate the noise, the ratio of the fundamental and second-harmonic signals is used. The mathematical model of gas concentration harmonic measurement is built up.The detection result of methane concentration is also shown. Experiments have proved a sensitivity of 28×10-6.展开更多
AIM:To evaluate the differences and consistency of vault measurements obtained by Scheimpflug tomography(Pentacam),anterior segment optical coherence tomography(AS-OCT,CASIA II),and ultrasound biomicroscopy(UBM)follow...AIM:To evaluate the differences and consistency of vault measurements obtained by Scheimpflug tomography(Pentacam),anterior segment optical coherence tomography(AS-OCT,CASIA II),and ultrasound biomicroscopy(UBM)following implantable collamer lens(ICL)V4c implantation.METHODS:Vault measurements were acquired using three modalities:Pentacam,CASIA II AS-OCT,and UBM.Repeated-measures analysis of variance was used to compare the vault values obtained by the three devices.The correlation and consistency of measurements among the three instruments were assessed using the Pearson correlation coefficient,intraclass correlation coefficient(ICC),and Bland-Altman plots.RESULTS:This retrospective study enrolled 210 myopic eyes of 210 patients(158 women and 52 men)who underwent ICL implantation:108 eyes had a myopic ICL V4c implanted,and 102 eyes had a toric ICL V4c implanted.The mean vault values measured by Pentacam,CASIA II,and UBM were 452.64±204.20μm,538.57±203.54μm,and 560.95±227.54μm,respectively,with statistically significant differences among the three groups(P<0.05).Pearson correlation analysis showed strong positive correlations between vault values measured by different instruments(all P<0.001).ICC results indicated good consistency among the three measurement modalities(all P<0.001).Stratified analysis revealed that when the vault value was≤250μm,the correlation and consistency of measurements across the three instruments were lower than those in the medium and high vault subgroups.CONCLUSION:Vault values measured by Pentacam are lower than those obtained by CASIA II and UBM,with UBM yielding the highest mean vault values.Measurements from the three instruments are not interchangeable but can serve as mutual references due to their significant correlation and good overall consistency.Pentacam and CASIA II demonstrate the highest consistency in vault measurement.Notably,when the vault value is≤250μm,the consistency between Pentacam and the other two instruments decreases significantly.展开更多
Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function....Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.展开更多
[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of ...[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of body morphometrics is critical for assessing growth performance and breeding value.Traditional manual measurements are inefficient,prone to human error,and may cause stress to sheep,limiting their suitability for precision sheep management.By summarizing the applications of sheep body size measurement technologies and analyzing their development directions,this paper provides theoretical references and practical guidance for the research and application of non contact sheep body size measurement.[Progress]This review synthesizes progress across three principal methodological paradigms:two-dimensional(2D)image-based techniques,three-dimensional(3D)point cloud-based approaches,and integrated 2D-3D fusion systems.2D methods,employing either handcrafted geometric features or deep learning-based keypoint detector algorithms,are cost-effective and operationally simple but sensitive to variation in imaging conditions and unable to capture critical circumference metrics.3D point-cloud approaches enable precise reconstruction of full animal morphology,supporting comprehensive body-size acquisition with higher accuracy,yet face challenges including high hardware costs,complex data workflows,and sensitivity to posture variability.Hybrid 2D-3D fusion systems combine semantic richness from RGB imagery with geometric completeness from point clouds.Having been effectively validated in other livestock specise,e.g.,cattle and pigs,these fusion systems have demonstrated excellent performance,providing important technical references and practical insights for sheep body size measurement.[Conclusions and Prospects]Firstly,future research should focus on constructing large-scale,high-quality datasets for sheep body size measurement that encompass diverse breeds,growth stages,and environmental conditions,thereby enhancing model robustness and generalization.Secondly,the development of lightweight artificial intelligence models is essential.Techniques such as model compression,quantization,and algorithmic optimization can substantially reduce computational complexity and storage requirements,facilitating deployment in resource-constrained environments.Thirdly,the 3D point cloud processing pipeline should be streamlined to improve the efficiency of data acquisition,filtering,registration,and segmentation,while promoting the integration of low-cost,high-resilience vision systems into practical farming scenarios.Fourthly,specific emphasis should be placed on improving the accuracy of curved-dimensional measurements,such as chest circumference,abdominal circumference,and shank circumference,through advances in pose standardization,refined 3D segmentation strategies,and multimodal data fusion.Finally,the cross-fertilization of sheep body size measurement technologies with analogous methods for other livestock species offers a promising pathway for mutual learning and collaborative innovation,accelerating the industrialization of automated sheep morphometric systems and supporting the development of intelligent,data-driven pasture management practices.展开更多
文摘Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.
基金This project is supported by National Natural Science Foundation of China(No.59675066).
文摘The middle convex and varying ellipse piston is th e key component of an internal combustion engine In general,the piston is mac hined by non circular section CNC lathe,but the measuring of piston profile is manipulated by off line Because the off line measuring reference is differen t from the machining reference,the measurement result is diverse from the act ual dimension A new method to measure the middle convex and varying ellipse p iston profile, which is known as on line measuring, is presented By using thi s kind of method,the high measurement accuracy can be gained,as well as meeting the production requirement.
文摘Using the ideal gas state equation, an on-line measuring method for the shell chamber volume is studied in this paper. After analyzing how various measurement parameters affect the measurement accuracy, the system parameters are optimized in this method. Because the shape and volume of the tested items are similar, the method of using "tamping" to raise the accuracy and speed of the measurement is put forward. Based on the work above, a prototype of the testing instrument for shell chamber volume was developed, automatically testing and controlling. Compared with the method of "water weight", this method is more accurate, quicker and more automotive, so it is adaptable for the use of on-line detection.
文摘On-line measurement for dielectric loss angle can effectively monitor the insulation condition of capacitive equipment in power systems. Synthetic relative measuring methods not only markedly overcome the shortcomings of traditional absolute measuring methods but also greatly improve the accuracy of dielectric loss angle measurement. However, synthetic relative measuring methods based on two or three pieces of capacitive equipment do not have the characteristic of generality. In this paper, a principle of synthetic relative measuring method is presented. The example of application for synthetic relative methods based on three and four pieces of capacitive equipment running in the same phase is taken to present the failure judgment matrices for N pieces of equipment. According to these matrices, the fault condition of N pieces of capacitive equipment can be watched, which is more general. Then some problems needing to be concerned along with two diagnostic methods used in diagnostic system are introduced. Finally, two programmable flow charts for the two methods are given and corresponding examples demonstrate their feasibility in practice.
基金supported by the National Natural Science Foundation of China(Nos.U1301234,21277003)the Ministry of Science and Technology of China(No.2014BAC21B03)the Science and Technology Plan of Shenzhen Municipality
文摘Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.
文摘Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts to produce online predictions of the chemical oxygen demand (COD) in wastewater from a pulp and paper mill using NIR spectroscopy are described. The task was perceived as very challenging, but with a root mean square error of prediction of 149 mg/l, roughly corresponding to 1/10 of the studied concentration interval, this attempt was deemed as successful. This result was obtained by using partial least squares model regression, interpolated reference values for calibration purposes, and by evenly distributing the calibration data in the concentration space. This work may also represent the first industrial application of online COD measurements in wastewater using NIR spectroscopy.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 40525016.
文摘Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.
基金supported by the National Natural Science Foundation of China(No.41805105)。
文摘On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).
基金Reactor Pressure Boundary Materials Project !under the Nuclear R & D Program by MOST in Korea.
文摘A portable microcomputer-controlled inspection system has been developed for detection of magnetic properties of soft magnetic materials. It incorporates custom designed software for control of the magnetic field during operation such as demagnetization, field sweeping, and for data logging and analysis. Results are recorded using a 12-bit analog to digital converter and are then stored on disk. The magnetic hysteresis loop and Barkhausen noise data can be converted into important magnetic parameters: coecivity, remanence, and hysteresis loss, Barkhausen amplitude, and Barkhausen noise energy. This system incorporated with the magnetostriction, and magnetoacoustic emission, is then related with the nondestructive detection of material degradation.
文摘In this paper,a method of multipoint pseudorandom combined excita-tion with the orthogonal reciprocal repeated sequences(ORRS)is presented on thebackground of the on-line identification of multivariate system.The capacity of therestraint to the identification error caused by the non-random D.C.drift of the mul-ti-input excitation with the ORRS in the multivariate system is also discussed.Thevalidity of the method described in this paper is proved by the modelling tests of themulti-plate rotor system.
文摘A new approach to the on-line temperature rise measurement of submersible pump's motors is presented. A new method of power supply and signed transmission for the measurement device in the pump well is also put forward here. The design and some experimental results are given.
文摘The machining process remains relevant for manufacturing high-quality and high-precision parts,which can be found in industries such as aerospace and aeronautical,with many produced by turning,drilling,and milling processes.Monitoring and analyzing tool wear during these processes is crucial to assess the tool’s life and optimize the tool’s performance under study;as such,standards detail procedures to measure and assess tool wear for various tools.Measuring wear in machining tools can be time-consuming,as the process is usually manual,requiring human interaction and judgment.In the present work,an automated offline flank wear measurement algorithm was developed in Python.The algorithm measures the flank wear of coated end-mills and slot drills from Scanning Electron Microscopy(SEM)images,according to the ISO 8688 standard,following the same wear measurement procedure.SEM images acquired with different magnifications and tools with varying machining parameters were analyzed using the developed algorithm.The flank wear measurements were then compared to the manually obtained,achieving relative errors for the most common magnifications of around 2.5%.Higher magnifications were also tested,yielding a maximum relative error of 13.4%.The algorithm can measure batches of images quickly on an ordinary personal computer,analyzing and measuring a 10-image batch in around 30 s,a process that would require around 30 min when performed manually by a skilled operator.Therefore,it can be a reliable alternative to measuring flank wear on many tools from SEM images,with the possibility of being adjusted for other wear measurements on different kinds of tools and different image types,for example,on images obtained by optical microscopy.
基金This work has been carried out with the support of National Natural Science Foundation(No.59675054)
文摘A measurement system for high power electrical variables with ultrasonic frequency was established. It can measure the effective values of the voltage and the current, the active power, the phase difference of voltage and current, the frequency of the transducer during ultrasonic welding and cutting. In sampling circuits of the system, the measured current is sensed by using a no capacitance and no inductance precision resistor and is treated with a difference amplifier, the measured voltage is processed by using a proportional amplifier. For achieving good amplitude frequency characteristics and rapid measurement of high frequency signals, the resistors, capacitors and amplifiers used in the system are rationally selected. Calibrating experiments show that relative errors are less than 1% for voltage and current effective values and less than 2.5% for active power, and absolute errors are ±1 Hz for frequency and ±1.7° for phase difference of voltage and current in the range of 17～23 kHz .
基金support from the National Natural Science Foundation of China(Grant Nos.12172332,11727803 and 12072009)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ23A020007)the Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-C2022003).
文摘The presence of residual stresses in materials or engineering structures can significantly influence their mechanical per-formance.Accurate measurement of residual stresses is of great importance to ensure their in-service reliability.Although numerous instrumented indentation methods have been proposed to evaluate residual stresses,the majority of them require a stress-free reference sample as a comparison benchmark,thereby limiting their applicability in scenarios where obtaining stress-free reference samples is challenging.In this work,through a number of finite element simulations,it was found that the loading exponent of the loading load-depth curve and the recovered depth during unloading are insensitive to residual stresses.The loading curve of the stress-free specimen was virtually reconstructed using such stress-insensitive parameters extracted from the load-depth curves of the stressed state,thus eliminating the requirement for stress-free reference samples.The residual stress was then correlated with the fractional change in loading work between stressed and stress-free loading curves through dimensional analysis and finite element simulations.Based on this correlation,an instrumented sharp indentation method for measuring equibiaxial residual stress without requiring a stress-free specimen was established.Both numerical and experimental verifications were carried out to demonstrate the accuracy and reliability of the newly proposed method.The maximum relative error and absolute error in measured residual stresses are typically within±20%and±20 MPa,respectively.
文摘Standardization is necessary for the early industrialization of the new materials and technology.It is achieved by having agreed practices for the measurement of properties and other characteristics.The promising use of graphene-based materials in fields like electronics,energy,and composites has resulted in standards for their nomenclature,the measurement of key characteristics,and their specification,etc.Among these,standards for measuring the key characteristics are crucial.The critical parameters are the number of layers,the type and concentration of defects and functional groups,elemental composition,sheet resistance,and carrier mobility.Standards for characterizing these have been analyzed by the International Organization for Standardization Technical Committee in ISO/TC229 and the International Electrotechnical Commission Technical Committee in IEC/TC113.These give details of applicable or preferred samples,the fundamental principles of the techniques,specific precautions,and points for attention in the relevant standards.The pivotal role of the ISO/TC229 and IEC/TC113 standards is considered and challenges and future trends are outlined.
基金Supported by the Key Research and Development Program of Anhui Province(No.201904a05020035)the Postdoctoral Research Initiative of Anhui Province(No.2024B804)the Hefei City Key Technology Research and Development‘Ranking’(No.2023SGJ017).
文摘Traditional automated guided vehicle(AGV)primarily relies on scheduling systems to manage warehouse locations and execute picking or placing tasks on fixedheight pallets.However,these conventional systems are illsuited for scenarios involving variable heights,such as vehicle loading and unloading or the complex stacking of soft packages.To address the challenges of AGV endeffector operations in nonfixed height scenarios,this paper proposes an innovative solution leveraging lowcost depth camera sensors.By capturing image and depth data,and integrating deep learning,image processing,and spatial attitude calculation techniques,the method accurately determines the position of the endeffector center point relative to the upper plane of the fork.The approach effectively resolves a key issue in AGV operations within intelligent logistics scenarios that lack fixed heights.The proposed algorithm is deployed on a domestic embedded,lowcost ARM chip controller,and extensive experiments are conducted on a real AGV equipped with multiple stacked vehicles and nonstandard vehicles.The experimental results demonstrate that for diverse vehicles with different heights,the measurement error can be maintained within±10 mm,satisfying the requirements for highprecision measurement.The height measurement method developed in the paper not only enhances the AGV’s adaptability in nonfixed height scenarios but also significantly broadens its application potential across various industries.
文摘Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measurement is presented in this paper. In order to eliminate the noise, the ratio of the fundamental and second-harmonic signals is used. The mathematical model of gas concentration harmonic measurement is built up.The detection result of methane concentration is also shown. Experiments have proved a sensitivity of 28×10-6.
基金Supported by the National Natural Science Foundation of China(No.82171095)the Project of Shanghai Science and Technology(No.23XD1400500)the Research Fund of Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital(No.24QNPY049).
文摘AIM:To evaluate the differences and consistency of vault measurements obtained by Scheimpflug tomography(Pentacam),anterior segment optical coherence tomography(AS-OCT,CASIA II),and ultrasound biomicroscopy(UBM)following implantable collamer lens(ICL)V4c implantation.METHODS:Vault measurements were acquired using three modalities:Pentacam,CASIA II AS-OCT,and UBM.Repeated-measures analysis of variance was used to compare the vault values obtained by the three devices.The correlation and consistency of measurements among the three instruments were assessed using the Pearson correlation coefficient,intraclass correlation coefficient(ICC),and Bland-Altman plots.RESULTS:This retrospective study enrolled 210 myopic eyes of 210 patients(158 women and 52 men)who underwent ICL implantation:108 eyes had a myopic ICL V4c implanted,and 102 eyes had a toric ICL V4c implanted.The mean vault values measured by Pentacam,CASIA II,and UBM were 452.64±204.20μm,538.57±203.54μm,and 560.95±227.54μm,respectively,with statistically significant differences among the three groups(P<0.05).Pearson correlation analysis showed strong positive correlations between vault values measured by different instruments(all P<0.001).ICC results indicated good consistency among the three measurement modalities(all P<0.001).Stratified analysis revealed that when the vault value was≤250μm,the correlation and consistency of measurements across the three instruments were lower than those in the medium and high vault subgroups.CONCLUSION:Vault values measured by Pentacam are lower than those obtained by CASIA II and UBM,with UBM yielding the highest mean vault values.Measurements from the three instruments are not interchangeable but can serve as mutual references due to their significant correlation and good overall consistency.Pentacam and CASIA II demonstrate the highest consistency in vault measurement.Notably,when the vault value is≤250μm,the consistency between Pentacam and the other two instruments decreases significantly.
基金the National Natural Science Foundation of China[62525301,62127811,62433019]the New Cornerstone Science Foundation through the XPLORER PRIZEthe financial support by the China Postdoctoral Science Foundation[GZB20240797].
文摘Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.
文摘[Significance]In alignment with the national germplasm security strategy,current research efforts are accelerating the adoption of precision breeding in sheep.Within the whole-genome selection,accurate phenotyping of body morphometrics is critical for assessing growth performance and breeding value.Traditional manual measurements are inefficient,prone to human error,and may cause stress to sheep,limiting their suitability for precision sheep management.By summarizing the applications of sheep body size measurement technologies and analyzing their development directions,this paper provides theoretical references and practical guidance for the research and application of non contact sheep body size measurement.[Progress]This review synthesizes progress across three principal methodological paradigms:two-dimensional(2D)image-based techniques,three-dimensional(3D)point cloud-based approaches,and integrated 2D-3D fusion systems.2D methods,employing either handcrafted geometric features or deep learning-based keypoint detector algorithms,are cost-effective and operationally simple but sensitive to variation in imaging conditions and unable to capture critical circumference metrics.3D point-cloud approaches enable precise reconstruction of full animal morphology,supporting comprehensive body-size acquisition with higher accuracy,yet face challenges including high hardware costs,complex data workflows,and sensitivity to posture variability.Hybrid 2D-3D fusion systems combine semantic richness from RGB imagery with geometric completeness from point clouds.Having been effectively validated in other livestock specise,e.g.,cattle and pigs,these fusion systems have demonstrated excellent performance,providing important technical references and practical insights for sheep body size measurement.[Conclusions and Prospects]Firstly,future research should focus on constructing large-scale,high-quality datasets for sheep body size measurement that encompass diverse breeds,growth stages,and environmental conditions,thereby enhancing model robustness and generalization.Secondly,the development of lightweight artificial intelligence models is essential.Techniques such as model compression,quantization,and algorithmic optimization can substantially reduce computational complexity and storage requirements,facilitating deployment in resource-constrained environments.Thirdly,the 3D point cloud processing pipeline should be streamlined to improve the efficiency of data acquisition,filtering,registration,and segmentation,while promoting the integration of low-cost,high-resilience vision systems into practical farming scenarios.Fourthly,specific emphasis should be placed on improving the accuracy of curved-dimensional measurements,such as chest circumference,abdominal circumference,and shank circumference,through advances in pose standardization,refined 3D segmentation strategies,and multimodal data fusion.Finally,the cross-fertilization of sheep body size measurement technologies with analogous methods for other livestock species offers a promising pathway for mutual learning and collaborative innovation,accelerating the industrialization of automated sheep morphometric systems and supporting the development of intelligent,data-driven pasture management practices.
