Complicated loads encountered by floating offshore wind turbines(FOWTs)in real sea conditions are crucial for future optimization of design,but obtaining data on them directly poses a challenge.To address this issue,w...Complicated loads encountered by floating offshore wind turbines(FOWTs)in real sea conditions are crucial for future optimization of design,but obtaining data on them directly poses a challenge.To address this issue,we applied machine learning techniques to obtain hydrodynamic and aerodynamic loads of FOWTs by measuring platform motion responses and wave-elevation sequences.First,a computational fluid dynamics(CFD)simulation model of the floating platform was established based on the dynamic fluid body interaction technique and overset grid technology.Then,a long short-term memory(LSTM)neural network model was constructed and trained to learn the nonlinear relationship between the waves,platform-motion inputs,and hydrodynamic-load outputs.The optimal model was determined after analyzing the sensitivity of parameters such as sample characteristics,network layers,and neuron numbers.Subsequently,the effectiveness of the hydrodynamic load model was validated under different simulation conditions,and the aerodynamic load calculation was completed based on the D'Alembert principle.Finally,we built a hybrid-scale FOWT model,based on the software in the loop strategy,in which the wind turbine was replaced by an actuation system.Model tests were carried out in a wave basin and the results demonstrated that the root mean square errors of the hydrodynamic and aerodynamic load measurements were 4.20%and 10.68%,respectively.展开更多
In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array...In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array components often encounters challenges due to the reduced scale and complex structures,either by contact or noncontact optical approaches.Among these microstructural arrays,there are still no optical measurement methods for micro corner-cube reflector arrays.To solve this problem,this study introduces a method for effectively eliminating coherent noise and achieving surface profile reconstruction in interference measurements of microstructural arrays.The proposed denoising method allows the calibration and inverse solving of system errors in the frequency domain by employing standard components with known surface types.This enables the effective compensation of the complex amplitude of non-sample coherent light within the interferometer optical path.The proposed surface reconstruction method enables the profile calculation within the situation that there is complex multi-reflection during the propagation of rays in microstructural arrays.Based on the measurement results,two novel metrics are defined to estimate diffraction errors at array junctions and comprehensive errors across multiple array elements,offering insights into other types of microstructure devices.This research not only addresses challenges of the coherent noise and multi-reflection,but also makes a breakthrough for quantitively optical interference measurement of microstructural array devices.展开更多
The fragility and stochastic behavior of quantum sources make it crucial to witness the topology of quantum networks.Most previous theoretical methods are based on perfect assumptions of quantum measurements.In this w...The fragility and stochastic behavior of quantum sources make it crucial to witness the topology of quantum networks.Most previous theoretical methods are based on perfect assumptions of quantum measurements.In this work,we propose a method to witness network topology under imperfect assumptions of quantum measurements.We show that the discrimination between star and triangle networks depends on the specific error tolerances of local measurements.This extends recent results for witnessing the triangle network[Phys.Rev.Lett.132240801(2024)].展开更多
Vector magnetic measurement is increasingly widely used.In order to improve the accuracy of vector magnetic measurement system on board a vehicle,researchers have proposed various calibration methods.Most of them requ...Vector magnetic measurement is increasingly widely used.In order to improve the accuracy of vector magnetic measurement system on board a vehicle,researchers have proposed various calibration methods.Most of them require altering the magnetic vector in the vehicle coordinate system.Exploring the use of geomagnetic variation to change the geomagnetic vector in the vehicle coordinate system,this paper proposes a novel vector magnetic measurement calibration method.In this method,a vector magnetometer mounted on a vehicle and an accurate vector magnetometer separately measure the geomagnetic field at diff erent locations within the same area.Based on the physical principle that the geomagnetic variation at two nearby locations is equal,the calibration parameters of the magnetometer on the vehicle can be determined through a set of equations containing the measurements from the two magnetometers.The theoretical derivation and simulation experiment results demonstrate the feasibility of this method.Therefore,it can serve as a new alternative calibration method,especially in scenarios where a high degree of accuracy in the estimation of calibration parameters is not required.展开更多
Magnetic tracking technologies have a promising application in detecting the real-time position andattitude of a capsule endoscope.However,most of them need to measure the magnetic moment of a permanentmagnet(PM)embed...Magnetic tracking technologies have a promising application in detecting the real-time position andattitude of a capsule endoscope.However,most of them need to measure the magnetic moment of a permanentmagnet(PM)embedded in the capsule accurately in advance,which can cause inconvenience to practical application.To solve this problem,this paper proposes a magnetic tracking system with the capability of measuring themagnetic moment of the PM automatically.The system is constructed based on a 4×4 magnetic sensor array,whose sensing data is analyzed to determine the magnetic moment by referring to a magnetic dipole model.Withthe determined magnetic moment,a method of fusing the linear calculation and Levenberg-Marquardt algorithmsis proposed to determine the 3D position and 2D attitude of the PM.The experiments verified that the proposedsystem can achieve localization errors of 0.48 mm,0.42 mm,and 0.83 mm and orientation errors of 0.66◦,0.64◦,and 0.87◦for a PM(∅10 mm×10 mm)at vertical heights of 5 cm,10 cm,and 15 cm from the magnetic sensorarray,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
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
The Circular Electron Positron Collider(CEPC)proposed in China is a dual-ring collider with electron and positron beams in the energy range of 45.5–180 GeV.The main dipole in the CEPC collider is a dual-aperture dipo...The Circular Electron Positron Collider(CEPC)proposed in China is a dual-ring collider with electron and positron beams in the energy range of 45.5–180 GeV.The main dipole in the CEPC collider is a dual-aperture dipole with a shared coil between the two apertures,forming an I-shaped structure that can reduce power consumption by 50%.Because of its long length and low field strength,the development of this dual-aperture magnet faces challenges regarding its mechanical design,field measurement accuracy,and field performance.Numerical simulations were performed to better understand the Earth's field and the effect of different BH curves on field performance.The field results of the prototype are presented herein,and the field quality satisfies the requirements.The remanent field accounts for 2%of the integral field at 140 Gs,and the hysteresis effect caused an increase in field strength of approximately 0.075%after a standardization cycle of the trim coils.Research on this prototype can provide useful insights for understanding low-field dipole magnets.展开更多
美国国家仪器有限公司（NI）近日推出Measurement Studio软件的升级版本Measurement Studio 8。该软件是一个类库和控件的完整集合，适用于在基于Microsoft Visual Studio建立起来的应用程序中采集、分析和显示数据。现在借助ASP．NET的...美国国家仪器有限公司（NI）近日推出Measurement Studio软件的升级版本Measurement Studio 8。该软件是一个类库和控件的完整集合，适用于在基于Microsoft Visual Studio建立起来的应用程序中采集、分析和显示数据。现在借助ASP．NET的Web控件，这一升级版本为工程师们提供了用来创建可以在各种浏览器或操作系统下显示的Web页面的工具，以此来对他们的测试测量应用进行远程监控。Measurement Studio 8还提供与Microsoft Visual Studio 2005软件的完美集成、全新的用户界面控件、80多种新的分析方法和附加的数据采集代码生成功能。展开更多
Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for so...Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for social networks due to significant limitations.Specifically,most approaches depend mainly on user-user structural links while overlooking service-centric,semantic,and multi-attribute drivers of community formation,and they also lack flexible filtering mechanisms for large-scale,service-oriented settings.Our proposed approach,called community discovery-based service(CDBS),leverages user profiles and their interactions with consulted web services.The method introduces a novel similarity measure,global similarity interaction profile(GSIP),which goes beyond typical similarity measures by unifying user and service profiles for all attributes types into a coherent representation,thereby clarifying its novelty and contribution.It applies multiple filtering criteria related to user attributes,accessed services,and interaction patterns.Experimental comparisons against Louvain,Hierarchical Agglomerative Clustering,Label Propagation and Infomap show that CDBS reveals the higher performance as it achieves 0.74 modularity,0.13 conductance,0.77 coverage,and significantly fast response time of 9.8 s,even with 10,000 users and 400 services.Moreover,community discoverybased service consistently detects a larger number of communities with distinct topics of interest,underscoring its capacity to generate detailed and efficient structures in complex networks.These results confirm both the efficiency and effectiveness of the proposed method.Beyond controlled evaluation,communities discovery based service is applicable to targeted recommendations,group-oriented marketing,access control,and service personalization,where communities are shaped not only by user links but also by service engagement.展开更多
Accurate temperature measurement is a crucial step in predicting and managing the aerodynamic heating during Mars entry and Earth reentry.These processes often occur at extremely high temperatures and pose challenges ...Accurate temperature measurement is a crucial step in predicting and managing the aerodynamic heating during Mars entry and Earth reentry.These processes often occur at extremely high temperatures and pose challenges for quantitative measurements.A 1-μs time-resolved laser absorption technique was developed for simultaneous and time-dependent temperature and CO-concentration measurements over 3000-6000 K by adopting the P(0,21)and P(2,15)lines.To achieve quantitative measurement,the line strengths and Ar-broadening parameters were calibrated within 3030-5980 K.A“W”-shaped path-amplified strategy was used to increase the absorption features of the two lines during the calibration process.Validation experiments were conducted at 3040-5970 K to verify the accuracy of the technique.The new technique was then applied for simultaneous and time-resolved temperature and CO-concentration measurements during the CO_(2)dissociation process to further demonstrate the feasibility of the developed technique.The temperature-dependent CO_(2)absorption cross-sections at line centers of the two lines were calibrated within 2040-5870 K.The CO_(2)absorption interferences were quantified and subtracted from the measured laser absorbances.The measured results(referring to temperature and CO concentration)were generally consistent with the predictions from the kinetics mechanisms in the literature,highlighting the applicability of the developed technique for temperature measurements and CO_(2)dissociation studies within the investigated temperature range.展开更多
Characterized by high accuracy and operational simplicity,oil-film interferometry(OFI)has served as an effective wall-shear stress(WSS)measurement technique over the past decades.It utilizes the monochromatic light in...Characterized by high accuracy and operational simplicity,oil-film interferometry(OFI)has served as an effective wall-shear stress(WSS)measurement technique over the past decades.It utilizes the monochromatic light interference principle to measure the temporal variation of oil-film thickness caused by WSS,and calculates time-averaged WSS based on the variation of interference fringe width.However,small-scale noise,which is caused by defects on the target surface,ambient dust,and local oil-film non-uniformity,contaminates the interference fringe patterns and directly increases the measurement uncertainty.One practical way is to apply denoising methods to improve the accuracy of identifying the centroids of fringes.In the present study,quasi-bivariate variational mode decomposition(QBVMD)is proposed as a self-adaptive denoising method to remove small-scale noise.Since no characteristic information of fringe patterns is required in the QBVMD-based denoising method,it has higher accuracy and lower uncertainty than the conventional OFI denoising methods,which need to pre-set the mask signal or the bandpass frequency,i.e.,cross-correlation or spectral filtering.Thus,it facilitates the automatic identification of time-varying inhomogeneous fringes.Two sets of experiments,i.e.,WSS measurement on either a canonical flat-plate turbulent boundary layer(TBL)or a TBL perturbed by micro vortex generators(MVG),were conducted to validate the applicability of this QBVMD-OFI method.The former experiment shows that the accuracy of QBVMD-OFI is equivalent to near-wall high-resolution particle image velocimetry,and is considerably higher than that of a dual hot-film sensor.As for the latter,QBVMD-OFI provides sufficient spatial resolution to resolve fine WSS structures generated by MVG.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
The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) ...The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.展开更多
基金This work is supported by the National Key Research and Development Program of China(No.2023YFB4203000)the National Natural Science Foundation of China(No.U22A20178)
文摘Complicated loads encountered by floating offshore wind turbines(FOWTs)in real sea conditions are crucial for future optimization of design,but obtaining data on them directly poses a challenge.To address this issue,we applied machine learning techniques to obtain hydrodynamic and aerodynamic loads of FOWTs by measuring platform motion responses and wave-elevation sequences.First,a computational fluid dynamics(CFD)simulation model of the floating platform was established based on the dynamic fluid body interaction technique and overset grid technology.Then,a long short-term memory(LSTM)neural network model was constructed and trained to learn the nonlinear relationship between the waves,platform-motion inputs,and hydrodynamic-load outputs.The optimal model was determined after analyzing the sensitivity of parameters such as sample characteristics,network layers,and neuron numbers.Subsequently,the effectiveness of the hydrodynamic load model was validated under different simulation conditions,and the aerodynamic load calculation was completed based on the D'Alembert principle.Finally,we built a hybrid-scale FOWT model,based on the software in the loop strategy,in which the wind turbine was replaced by an actuation system.Model tests were carried out in a wave basin and the results demonstrated that the root mean square errors of the hydrodynamic and aerodynamic load measurements were 4.20%and 10.68%,respectively.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375414,52075100)Shanghai Science and Technology Committee Innovation Grant of China(Grant No.23ZR1404200).
文摘In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array components often encounters challenges due to the reduced scale and complex structures,either by contact or noncontact optical approaches.Among these microstructural arrays,there are still no optical measurement methods for micro corner-cube reflector arrays.To solve this problem,this study introduces a method for effectively eliminating coherent noise and achieving surface profile reconstruction in interference measurements of microstructural arrays.The proposed denoising method allows the calibration and inverse solving of system errors in the frequency domain by employing standard components with known surface types.This enables the effective compensation of the complex amplitude of non-sample coherent light within the interferometer optical path.The proposed surface reconstruction method enables the profile calculation within the situation that there is complex multi-reflection during the propagation of rays in microstructural arrays.Based on the measurement results,two novel metrics are defined to estimate diffraction errors at array junctions and comprehensive errors across multiple array elements,offering insights into other types of microstructure devices.This research not only addresses challenges of the coherent noise and multi-reflection,but also makes a breakthrough for quantitively optical interference measurement of microstructural array devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12271394 and 62172341)the Sichuan Natural Science Foundation(Grant Nos.2024NSFSC1365 and 2024NSFSC1375)。
文摘The fragility and stochastic behavior of quantum sources make it crucial to witness the topology of quantum networks.Most previous theoretical methods are based on perfect assumptions of quantum measurements.In this work,we propose a method to witness network topology under imperfect assumptions of quantum measurements.We show that the discrimination between star and triangle networks depends on the specific error tolerances of local measurements.This extends recent results for witnessing the triangle network[Phys.Rev.Lett.132240801(2024)].
基金General Project of Basic Research Plan for Natural Sciences in Shaanxi Province,grant number 2023-JC-YB-244Youth Project of Basic Research Plan for Natural Sciences in Shaanxi Province,grant number 2024JC-YBQN-0253.
文摘Vector magnetic measurement is increasingly widely used.In order to improve the accuracy of vector magnetic measurement system on board a vehicle,researchers have proposed various calibration methods.Most of them require altering the magnetic vector in the vehicle coordinate system.Exploring the use of geomagnetic variation to change the geomagnetic vector in the vehicle coordinate system,this paper proposes a novel vector magnetic measurement calibration method.In this method,a vector magnetometer mounted on a vehicle and an accurate vector magnetometer separately measure the geomagnetic field at diff erent locations within the same area.Based on the physical principle that the geomagnetic variation at two nearby locations is equal,the calibration parameters of the magnetometer on the vehicle can be determined through a set of equations containing the measurements from the two magnetometers.The theoretical derivation and simulation experiment results demonstrate the feasibility of this method.Therefore,it can serve as a new alternative calibration method,especially in scenarios where a high degree of accuracy in the estimation of calibration parameters is not required.
基金the National Natural Science Foundation of China(Nos.52275038 and 61803347)the Shanxi Province Science Foundation for Excellent Youth(No.202203021224007)+1 种基金the Key Research and Development Plan of Shanxi Province(No.201903D321164)the Opening Foundation of Shanxi Key Laboratory of Advanced Manufacturing Technology(No.XJZZ202101)。
文摘Magnetic tracking technologies have a promising application in detecting the real-time position andattitude of a capsule endoscope.However,most of them need to measure the magnetic moment of a permanentmagnet(PM)embedded in the capsule accurately in advance,which can cause inconvenience to practical application.To solve this problem,this paper proposes a magnetic tracking system with the capability of measuring themagnetic moment of the PM automatically.The system is constructed based on a 4×4 magnetic sensor array,whose sensing data is analyzed to determine the magnetic moment by referring to a magnetic dipole model.Withthe determined magnetic moment,a method of fusing the linear calculation and Levenberg-Marquardt algorithmsis proposed to determine the 3D position and 2D attitude of the PM.The experiments verified that the proposedsystem can achieve localization errors of 0.48 mm,0.42 mm,and 0.83 mm and orientation errors of 0.66◦,0.64◦,and 0.87◦for a PM(∅10 mm×10 mm)at vertical heights of 5 cm,10 cm,and 15 cm from the magnetic sensorarray,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 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The Circular Electron Positron Collider(CEPC)proposed in China is a dual-ring collider with electron and positron beams in the energy range of 45.5–180 GeV.The main dipole in the CEPC collider is a dual-aperture dipole with a shared coil between the two apertures,forming an I-shaped structure that can reduce power consumption by 50%.Because of its long length and low field strength,the development of this dual-aperture magnet faces challenges regarding its mechanical design,field measurement accuracy,and field performance.Numerical simulations were performed to better understand the Earth's field and the effect of different BH curves on field performance.The field results of the prototype are presented herein,and the field quality satisfies the requirements.The remanent field accounts for 2%of the integral field at 140 Gs,and the hysteresis effect caused an increase in field strength of approximately 0.075%after a standardization cycle of the trim coils.Research on this prototype can provide useful insights for understanding low-field dipole magnets.
文摘美国国家仪器有限公司（NI）近日推出Measurement Studio软件的升级版本Measurement Studio 8。该软件是一个类库和控件的完整集合，适用于在基于Microsoft Visual Studio建立起来的应用程序中采集、分析和显示数据。现在借助ASP．NET的Web控件，这一升级版本为工程师们提供了用来创建可以在各种浏览器或操作系统下显示的Web页面的工具，以此来对他们的测试测量应用进行远程监控。Measurement Studio 8还提供与Microsoft Visual Studio 2005软件的完美集成、全新的用户界面控件、80多种新的分析方法和附加的数据采集代码生成功能。
文摘Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for social networks due to significant limitations.Specifically,most approaches depend mainly on user-user structural links while overlooking service-centric,semantic,and multi-attribute drivers of community formation,and they also lack flexible filtering mechanisms for large-scale,service-oriented settings.Our proposed approach,called community discovery-based service(CDBS),leverages user profiles and their interactions with consulted web services.The method introduces a novel similarity measure,global similarity interaction profile(GSIP),which goes beyond typical similarity measures by unifying user and service profiles for all attributes types into a coherent representation,thereby clarifying its novelty and contribution.It applies multiple filtering criteria related to user attributes,accessed services,and interaction patterns.Experimental comparisons against Louvain,Hierarchical Agglomerative Clustering,Label Propagation and Infomap show that CDBS reveals the higher performance as it achieves 0.74 modularity,0.13 conductance,0.77 coverage,and significantly fast response time of 9.8 s,even with 10,000 users and 400 services.Moreover,community discoverybased service consistently detects a larger number of communities with distinct topics of interest,underscoring its capacity to generate detailed and efficient structures in complex networks.These results confirm both the efficiency and effectiveness of the proposed method.Beyond controlled evaluation,communities discovery based service is applicable to targeted recommendations,group-oriented marketing,access control,and service personalization,where communities are shaped not only by user links but also by service engagement.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620201)the frontier scientific research program of Deep Space Exploration Laboratory(Grant No.2022-QYKYJH-HXYF-019)the National Natural Science Foundation of China(Grant Nos.12388101,12027801,12402274,and U2430202)。
文摘Accurate temperature measurement is a crucial step in predicting and managing the aerodynamic heating during Mars entry and Earth reentry.These processes often occur at extremely high temperatures and pose challenges for quantitative measurements.A 1-μs time-resolved laser absorption technique was developed for simultaneous and time-dependent temperature and CO-concentration measurements over 3000-6000 K by adopting the P(0,21)and P(2,15)lines.To achieve quantitative measurement,the line strengths and Ar-broadening parameters were calibrated within 3030-5980 K.A“W”-shaped path-amplified strategy was used to increase the absorption features of the two lines during the calibration process.Validation experiments were conducted at 3040-5970 K to verify the accuracy of the technique.The new technique was then applied for simultaneous and time-resolved temperature and CO-concentration measurements during the CO_(2)dissociation process to further demonstrate the feasibility of the developed technique.The temperature-dependent CO_(2)absorption cross-sections at line centers of the two lines were calibrated within 2040-5870 K.The CO_(2)absorption interferences were quantified and subtracted from the measured laser absorbances.The measured results(referring to temperature and CO concentration)were generally consistent with the predictions from the kinetics mechanisms in the literature,highlighting the applicability of the developed technique for temperature measurements and CO_(2)dissociation studies within the investigated temperature range.
文摘Characterized by high accuracy and operational simplicity,oil-film interferometry(OFI)has served as an effective wall-shear stress(WSS)measurement technique over the past decades.It utilizes the monochromatic light interference principle to measure the temporal variation of oil-film thickness caused by WSS,and calculates time-averaged WSS based on the variation of interference fringe width.However,small-scale noise,which is caused by defects on the target surface,ambient dust,and local oil-film non-uniformity,contaminates the interference fringe patterns and directly increases the measurement uncertainty.One practical way is to apply denoising methods to improve the accuracy of identifying the centroids of fringes.In the present study,quasi-bivariate variational mode decomposition(QBVMD)is proposed as a self-adaptive denoising method to remove small-scale noise.Since no characteristic information of fringe patterns is required in the QBVMD-based denoising method,it has higher accuracy and lower uncertainty than the conventional OFI denoising methods,which need to pre-set the mask signal or the bandpass frequency,i.e.,cross-correlation or spectral filtering.Thus,it facilitates the automatic identification of time-varying inhomogeneous fringes.Two sets of experiments,i.e.,WSS measurement on either a canonical flat-plate turbulent boundary layer(TBL)or a TBL perturbed by micro vortex generators(MVG),were conducted to validate the applicability of this QBVMD-OFI method.The former experiment shows that the accuracy of QBVMD-OFI is equivalent to near-wall high-resolution particle image velocimetry,and is considerably higher than that of a dual hot-film sensor.As for the latter,QBVMD-OFI provides sufficient spatial resolution to resolve fine WSS structures generated by MVG.
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.
基金supported by the National Key Research and Development Program of Chinathe National Natural Science Foundation of China (Grant Nos.2024YFA1408000,12474097,and2023YFA1406001)+2 种基金the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2201001)the Center for Computational Science and Engineering at Southern University of Science and Technology,the Major Science and Technology Infrastructure Project of Material Genome Big-science Facilities Platform supported by Municipal Development and Reform Commission of Shenzhen(for J.L.Z.and Y.L.)the Chinese funding sources applied via HPSTAR。
文摘The magnetic properties and Kondo effect in Ce_(3)TiBi_(5) with a quasi-one-dimensional structure were investigated using in situ high-pressure resistivity measurements up to 48 GPa.At ambient pressure,Ce_(3)TiBi_(5) undergoes an antiferromagnetic(AFM)transition at T_(N)∼5 K.Under high pressures within 8.9 GPa,we find that Kondo scattering contributes differently to the high-temperature resistance,R(T),depending on the applied current direction,demonstrating a significantly anisotropic Kondo effect.The complete P–T phase diagram has been constructed,in which the pressure dependence of T_(N) exhibits a dome-like shape.The AFM order remains robust under pressure,even when the coherence temperature T^(*) far exceeds 300 K.We attribute the observed anisotropic Kondo effect and the robust AFM to the underlying anisotropy in electronic hybridization under high pressure.
