The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in th...The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in the multi-physics sense,but involves other physical domains such as fluid and thermal.This paper summarizes the mechatronic approach to modeling.Linear graphs facilitate the development of state-space models of mechatronic systems,through this approach.The use of linear graphs in mechatronic modeling is outlined and an illustrative example of sound system modeling is given.Both time-domain and frequency-domain approaches are presented for the use of linear graphs.A mechatronic model of a multi-physics system may be simplified by converting all the physical domains into an equivalent single-domain system that is entirely in the output domain of the system.This approach of converting(transforming)physical domains is presented.An illustrative example of a pressure-controlled hydraulic actuator system that operates a mechanical load is given.展开更多
Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar F...Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar Fatahiasl2, Mahmoud Mohammadi-Sadr1, Masoud Heydari Kahkesh3, and Marziyeh Tahmasbi2(1.Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran;2.Department of Radiologic Technology, School of Allied Medical Sciences, Ahvaz, Jundishapur University of Medical Sciences, Ahvaz, Iran;3.Department of Radiology and Radiotherapy, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran)Abstract:Magnetic resonance imaging(MRI) has revolutionized disease diagnosis and treatment.However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers.展开更多
Ultrafast optical spectroscopy was successfully introduced decades ago.Its deep relationship with condensed matter physics profoundly enriched the scientific frontier of light–matter interactions.Previously,materials...Ultrafast optical spectroscopy was successfully introduced decades ago.Its deep relationship with condensed matter physics profoundly enriched the scientific frontier of light–matter interactions.Previously,materials such as metals,insulators,semiconductors,and superconductors were investigated,followed by magnetic materials,strongly correlated materials,complex oxides,nano-materials,topological materials,and metamaterials.展开更多
Among the charged leptons,theτelectric dipole moment dτis the least constrained.We show that the Im[d_(τ)]imposes strong constraints on new physics that have yet to be discussed.Motivated in particular by the Super...Among the charged leptons,theτelectric dipole moment dτis the least constrained.We show that the Im[d_(τ)]imposes strong constraints on new physics that have yet to be discussed.Motivated in particular by the Super Tau-Charm Facility(STCF),which will provide a uniquely clean environment for precisionτ-physics,we study the momentum-transfer dependence of d_(τ)(q^(2))and compare the projected sensitivities of STCF and BelleⅡ.Our analysis shows that an axion-like coupling of the τ lepton can induce sizable real and imaginary components of the EDM.The predicted EDM values may approach the present experimental sensitivities,making them accessible to future measurements at Belle II and the STCF.展开更多
Delineating sweet spots is critical for the exploration and production of oil and gas in deep and tight sand reservoirs.The lack of advanced and reliable methods makes this a challenge for geologists and geophysicists...Delineating sweet spots is critical for the exploration and production of oil and gas in deep and tight sand reservoirs.The lack of advanced and reliable methods makes this a challenge for geologists and geophysicists.This study introduces,for the first time,an integrated workflow that combines pre-stack seismic inversion with rock physics modeling to predict reservoir porosity and shale volume(V-shale)for sweet spot identification in tight sand reservoirs.A new elastic parameter,the density calculation index(DCI),is introduced which links acoustic and shear impedance for seismic density inversion,thereby addressing the long-standing problem of poor density inversion accuracy.A novel combined Sun–Walsh rock physics model,developed as part of this study,significantly improves V-shale evaluation from seismic data.The proposed three-step seismic inversion approach includes:(1)deriving acoustic and shear impedance from angle-stack seismic data using model-based inversion;(2)calculating density using shear impedance constrained by DCI,followed by porosity estimation from the density–porosity relation;and(3)evaluating V-shale using theα-parameter derived from the Sun–Walsh model and pre-stack inversion results.This integrated workflow provides an effective tool for building accurate 3D reservoir models,and is especially applicable to deep,low-porosity,tight sand reservoirs worldwide.展开更多
This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the pred...This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.展开更多
The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Num...The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Numerical simulations,such as exact diagonalization,density matrix renormalization groups,matrix product states,and Monte Carlo methods are essential for examining the properties of strongly correlated systems.Recently,density functional theory has been employed in this field within the framework of composite fermion theory.This paper systematically evaluates how density functional theory approaches have addressed fundamental challenges in fractional quantum Hall systems,including ground state and low-energy excitations.Special attention is given to the insights provided by density functional theory regarding composite fermion behavior,edge effects,and the nature of fractional charge and magnetoroton excitations.The discussion critically examines both the advantages and limitations of these approaches,while highlighting the productive interplay between numerical simulations and theoretical models.Future directions are explored,particularly the promising potential of time-dependent density functional theory for modeling non-equilibrium dynamics in quantum Hall systems.展开更多
Background Evidence on pre-operative physical activity before hip and knee arthroplasty is limited and heterogeneous.Intervention components and behavior change techniques remain underexplored.This review examined the...Background Evidence on pre-operative physical activity before hip and knee arthroplasty is limited and heterogeneous.Intervention components and behavior change techniques remain underexplored.This review examined the effectiveness of pre-operative physical activity interventions on patient and surgical outcomes in elective hip and knee arthroplasty up to 12 weeks post-surgery.Methods A systematic search of 8 databases up to August 8,2024 identified randomized controlled trials of physical activity interventions before total hip and knee arthroplasty.Quality of evidence was evaluated with Grading of Recommendations,Assessment,Development and Evaluation framework.Random-effects models were used for meta-analyses.The Template for Intervention Description and Replication(TIDieR)was used for detailing the included interventions.Results Forty trials were included.Significant mean differences in favor of the intervention groups were found at pre-and post-surgery in 4 outcomes:health-related quality of life(Knee pre-surgery standardized mean difference(SMD)=−0.5,95%confidence interval(95%CI):−1.0 to−0.1 and Hip and Knee post-surgery SMD=−0.4,95%CI:−0.6 to−0.1),pain(Hip and Knee pre-surgery SMD=−0.4,95%CI:−0.6 to−0.1 and Knee post-surgery SMD=−0.3,95%CI:−0.6 to−0.1),function(Hip and Knee pre-surgery SMD=−0.5,95%CI:−0.8 to−0.2 and Knee post-surgery SMD=−0.6,95%CI:−1.0 to−0.2),and timed-up-and-go(Hip and Knee MD=−1.2 s,95%CI:−2.0 to−0.3 and Hip and Knee MD=−1.3 s,95%CI:−1.7 to−0.8).Half of the interventions reported over 75%of the TIDieR items,while behavior change techniques reporting was limited.Conclusion Pre-operative exercise improves health-related quality of life,pain,and function pre-and post-surgery in elective hip and knee arthroplasty.Standardized reporting is needed for establishing effective intervention components.展开更多
The increasing complexity of intelligent sensing environments,driven by the growth of Internet of Things technologies,has created a strong demand for neuromorphic systems capable of real-time,low-power multisensory pe...The increasing complexity of intelligent sensing environments,driven by the growth of Internet of Things technologies,has created a strong demand for neuromorphic systems capable of real-time,low-power multisensory perception.Traditional sensory architectures,constrained by single-modal processing and centralized computing,struggle to meet the requirements of diverse and dynamic input conditions.Multisensory neuromorphic devices offer a promising solution by mimicking the distributed,event-driven processing of biological systems.Recent efforts have explored synaptic devices and material systems that respond to various input modalities,including visual,tactile,thermal,and chemical stimuli.However,challenges remain in signal conversion,encoding compatibility,and the fusion of heterogeneous inputs without loss of unisensory information.This review provides a comprehensive overview of the physical mechanisms,device behaviors,and integration strategies that underpin signal processing in neuromorphic hardware.We highlight synaptic mechanisms conducive to cross-modal interaction,analyze representative signal fusion approaches at the device level,and discuss future directions for constructing efficient,scalable,and biologically inspired multisensory neuromorphic systems.展开更多
This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained...This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained by saturation.Measurements are transmitted to nodes of a sensor network over unreliable wireless channels.We propose a linear coding mechanism,together with a distributed method for obtaining a state estimate at each node.These designs aim to minimize the state estimation error covariance.In addition,we derive a bound on this covariance,and accommodate the design parameters to minimize this bound.The resulting design depends on the packet loss probabilities of the wireless channels.This permits applying the proposed scheme to systems in which communications suffer from denial-of-service attacks,as such attacks typically affect those probabilities.Finally,we present a numerical example illustrating this application.展开更多
Background:Cardiorespiratory fitness(CRF)is a powerful predictor of mortality and chronic disease risk,yet global patterns and determinants of CRF remain poorly defined,particularly in females and underrepresented pop...Background:Cardiorespiratory fitness(CRF)is a powerful predictor of mortality and chronic disease risk,yet global patterns and determinants of CRF remain poorly defined,particularly in females and underrepresented populations.We conducted a systematic review and quantitative synthesis of directly measured peak oxygen uptake(VO_(2peak))internationally and examined its association with human development and gender ine quality.Methods:Studies were eligible if VO_(2peak)was assessed via direct gas analysis during maximal exercise testing,and if the countries had scores for the Human Development Index(HDI)and Gender Inequality Index(GII).Studies were identified through MEDLINE/PubMed,Embase,CINAHL,and Web of Science.Risks of bias were assessed by an adaptation of the Newcastle-Ottawa Scale.Multivariable linear regression models examined associations between VO_(2peak),age,sex,exercise modality,HDI,GII,and study year.Results:Data included 95 studies from 24 countries with HDI and GII scores,comprising 119,435 adults(42%females)with VO_(2peak)assessed via direct gas analysis during maximal exercise testing.The risk of bias was low.VO_(2peak)was positively associated with HDI(β=14.1)and negatively associated with GII(β=-3.6).Slightly stronger associations were observed in females than males(HDI:β=18.9 vs.β=13.9,GII:β=-4.6vs.β=-3.6).Young females in middle-HDI countries had higher VO_(2peak)than those in low-HDI countries(31.2mL/kg/min vs.28.5 mL/kg/min),with limited additional gams in high-HDI contexts.VO_(2peak)decreased with higher gender inequality,with the largest disparities observed in young females between high-and low-GII countries(26.3 mL/kg/min vs.32.8 mL/kg/min).Conclusion:Global variation in CRF is tied to national levels of human development and gender equality.These findings support prioritizing structural and policy-level interventions that address social and gender disparities in physical activity access and health promotion.Studies from countries with lower HDI and information on ethnicity and socioeconomic status will bridge crucial gaps in understanding factors involved in global CRF levels.展开更多
Background:Health benefits have been reported for many physical activity(PA)interventions for improving fundamental movement skills(FMS)and cognitive function(CF),but the most effective type of PA interventions for em...Background:Health benefits have been reported for many physical activity(PA)interventions for improving fundamental movement skills(FMS)and cognitive function(CF),but the most effective type of PA interventions for emhancing FMS and CF in early childhood remain unknown.Thus,the study aimed to determine the effects of PA interventions in enhancing FMS and CF among young children and to establish the optimal types of PA interventions.Methods:Six electronic databases(PubMed,OVID,SPORTDiscus,Scopus,Web of Science,and Cochrane)were searched for studies from inception to March 17,2024.Randomized controlled trials(RCTs)were included in this study if they reported outcomes related to FMS,CF,or both associated with PA interventions.Effect sizes were calculated and performed as Hedges'g.The hierarchy of competing interventions was established using the surface under the cumulative ranking curve(SUCRA).Risk of bias was independently assessed using the Cochrane Riskof-Bias 2.Results:This analysis included 38 studies with 5237 young children,with sample sizes ranging from 32 to 897 participants.The types of PA interventions analyzed included active play/free play/unstructured PA(AP),general structured PA(GSPA),FMS-targeted PA programs(FMSprograms),cognitively-engaging PA programs(CPA),multilevel PA interventions(MPA),and exergaming.PA interventions had a large,pooled effect size for total FMS(g=0.96;95%CI:0.45-1.46;p<0.01;I^(2)=94%).For CF,a small-to-moderate pooled effect size was found(g=0.39;95%CI:0.18-0.60;p<0.01;I^(2)=88%).PA interventions longer than 3 months showed fewer benefits for FMS(p<0.01).The network meta-analysis showed that FMS-programs(standardized mean difference((SMD)=1.55,95%CI:0.98-2.11,SUCRA=98.3%)and GSPA(SMD=0.94,95%CI:0.05-1.85,SUCRA=69.8%)significantly improved total FMS compared to AP.For locomotor skills(LMS),exergaming ranked highest(SUCRA=79.3%),followed by FMS-programs(75.9%)and GSPA(61.6%).However,despite its top ranking,exergaming's effect estimate was not statistically significant(SMD=1.38,95%CI:-0.08 to 2.85).For object control skills(OCS),exergaming again ranked highest(SUCRA=91.9%)and showed the largest significant effect(SMD=2.38,95%CI:0.96-3.80),followed by FMS-programs(SUCRA=78.5%)and GSPA(SUCRA=53.7%).FMS-programs,GSPA,MPA,and UC also significantly improved OCS compared to AP.While no significant differences were observed across PA interventions for most CF domains,exergaming had a significant positive effect on working memory(SMD=1.41,95%CI:0.07-2.75).The certainty of evidence varied from low to moderate.Conclusion:These findings emphasize the importance of PA interventions in improving FMS and CF in early childhood.FMS-programs and GSPA appear to be the most effective approaches for enhancing total FMS,while exergaming showed the highest ranking for LMS and OCS,with a significant impact on OCS but uncertainty in LMS improvements.Additionally,exergaming had a positive effect on working memory,suggesting its potential cognitive benefits.展开更多
The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical ex...The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical experiments with and without moist physics.Results show that the CNOP with moist physics identifies sensitive areas corresponding to both the lower-(850−700 hPa)and upper-level(300−100 hPa)weather systems,while the CNOP without moist physics fails to capture the sensitive areas at lower levels.The reasons for the CNOP peaking at different levels can be explained in both algorithm and physics aspects.Firstly,the gradient of the cost function with respect to initial perturbations peaks at the upper level without moist physics which results in the upper-level peak of the CNOP,while it peaks at both the upper and lower levels with moist physics which results in both the upper-and lower-level peaks of the CNOP.Secondly,the upper-level sensitive area is associated with high baroclinicity,and these dynamic features can be captured by both CNOPs with and without moist physics.The lower-level sensitive area is associated with moist processes,and this thermodynamic feature can be captured only by the CNOP with moist physics.This result demonstrates the important contribution of the initial error of lower-level systems that are related to water vapor transportation to the forecast error of heavy rainfall associated weather systems,which could be an important reference for heavy rainfall observation targeting.展开更多
Multi-place nonlocal systems have attracted attention from many scientists.In this paper,we mainly review the recent progresses on two-place nonlocal systems(Alice-Bob systems)and four-place nonlocal models.Multi-plac...Multi-place nonlocal systems have attracted attention from many scientists.In this paper,we mainly review the recent progresses on two-place nonlocal systems(Alice-Bob systems)and four-place nonlocal models.Multi-place systems can firstly be derived from many physical problems by using a multiple scaling method with a discrete symmetry group including parity,time reversal,charge conjugates,rotations,field reversal and exchange transformations.Multiplace nonlocal systems can also be derived from the symmetry reductions of coupled nonlinear systems via discrete symmetry reductions.On the other hand,to solve multi-place nonlocal systems,one can use the symmetry-antisymmetry separation approach related to a suitable discrete symmetry group,such that the separated systems are coupled local ones.By using the separation method,all the known powerful methods used in local systems can be applied to nonlocal cases.In this review article,we take two-place and four-place nonlocal nonlinear Schr?dinger(NLS)systems and Kadomtsev-Petviashvili(KP)equations as simple examples to explain how to derive and solve them.Some types of novel physical and mathematical points related to the nonlocal systems are especially emphasized.展开更多
Under the constrained condition induced by the eigenfunction expresson of the potential (u, v)T = (-[A2q, q], [A2p, p])T = f (q, p), the spatial part of the Lax pair of the Kaup-Newell equation is non linearized to be...Under the constrained condition induced by the eigenfunction expresson of the potential (u, v)T = (-[A2q, q], [A2p, p])T = f (q, p), the spatial part of the Lax pair of the Kaup-Newell equation is non linearized to be a completely integrable system (R2N, Adp AND dq, H = H-1) with the Hamiltonian H-1 = -[A3q, p]-1/2[A2p, p][A2q, q]. while the nonlinearization of the time part leads to its N-involutive system {H(m)}. The involutive solution of the compatible fsystem (H-1), (H(m)) is mapped by into the solution of the higher order Kaup-Newell equation.展开更多
This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual reali...This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.展开更多
Accurate estimation of mineralogy from geophysical well logs is crucial for characterizing geological formations,particularly in hydrocarbon exploration,CO_(2) sequestration,and geothermal energy development.Current t...Accurate estimation of mineralogy from geophysical well logs is crucial for characterizing geological formations,particularly in hydrocarbon exploration,CO_(2) sequestration,and geothermal energy development.Current techniques,such as multimineral petrophysical analysis,offer details into mineralogical distribution.However,it is inherently time-intensive and demands substantial geological expertise for accurate model evaluation.Furthermore,traditional machine learning techniques often struggle to predict mineralogy accurately and sometimes produce estimations that violate fundamental physical principles.To address this,we present a new approach using Physics-Integrated Neural Networks(PINNs),that combines data-driven learning with domain-specific physical constraints,embedding petrophysical relationships directly into the neural network architecture.This approach enforces that predictions adhere to physical laws.The methodology is applied to the Broom Creek Deep Saline aquifer,a CO_(2) sequestration site in the Williston Basin,to predict the volumes of key mineral constituents—quartz,dolomite,feldspar,anhydrite,illite—along with porosity.Compared to traditional artificial neural networks (ANN),the PINN approach demonstrates higher accuracy and better generalizability,significantly enhancing predictive performance on unseen well datasets.The average mean error across the three blind wells is 0.123 for ANN and 0.042 for PINN,highlighting the superior accuracy of the PINN approach.This method reduces uncertainties in reservoir characterization by improving the reliability of mineralogy and porosity predictions,providing a more robust tool for decision-making in various subsurface geoscience applications.展开更多
In response to the capabilities presented by the High-Intensity Heavy Ion Accelerator Facility(HIAF) and the Accelerator-Driven Subcritical System(Ci ADS), as well as the proposed Chinese Advanced Nuclear Physics Rese...In response to the capabilities presented by the High-Intensity Heavy Ion Accelerator Facility(HIAF) and the Accelerator-Driven Subcritical System(Ci ADS), as well as the proposed Chinese Advanced Nuclear Physics Research Facility(CNUF), we are assembling a consortium of experts in relevant disciplines, both domestically and internationally,to delineate high-precision physics experiments that leverage the state-of-the-art research environment afforded by CNUF.Our focus encompasses six primary domains of inquiry: hadron physics—including endeavors such as the super eta factory and investigations into light hadron structures;muon physics;neutrino physics;neutron physics;the testing of fundamental symmetries;and the exploration of quantum effects within nuclear physics, along with the utilization of vortex accelerators.We aim to foster a well-rounded portfolio of large, medium, and small-scale projects, thus unlocking new scientific avenues and optimizing the potential of the Huizhou large scientific facility. The aspiration for international leadership in scientific research will be a guiding principle in our strategic planning. This initiative will serve as a foundational reference for the Institute of Modern Physics in its strategic planning and goal-setting, ensuring alignment with its developmental objectives while striving to secure a competitive edge in technological advancement. Our ambition is to engage in substantive research within these realms of high-precision physics, to pursue groundbreaking discoveries, and to stimulate progress in China's nuclear physics landscape, positioning Huizhou as a preeminent global hub for advanced nuclear physics research.展开更多
A complex geological environment with faults can be encountered in the process of coal mining.Fault activation can cause instantaneous structure slipping,releasing a significant amount of elastic strain energy during ...A complex geological environment with faults can be encountered in the process of coal mining.Fault activation can cause instantaneous structure slipping,releasing a significant amount of elastic strain energy during underground coal mining.This would trigger strong rockburst disasters.To understand the occurrence of fault-slip induced rockbursts,we developed a physical model test system for fault-slip induced rockbursts in coal mine drifts.The boundary energy storage(BES)loading apparatus and bottom rapid retraction(BRR)apparatus are designed to realize energy compensation and continuous boundary stress transfer of the surrounding rocks for instantaneous fault slip,as well as to provide space for the potential fault slip.Taking the typical fault-slip induced rockburst in the Xinjulong Coal Mine,China,as the background,we conducted a model test using the test system.The deformation and stress in the rock surrounding the drift and the support unit force during fault slip are analyzed.The deformation and failure characteristics and dynamic responses of drifts under fault-slip induced rockbursts are obtained.The test results illustrate the rationality and effectiveness of the test system.Finally,corresponding recommendations and prospects are proposed based on our findings.展开更多
基金supported by research grants from the Natural Sciences and Engineering Research Council(NSERC)of Canada
文摘The enhanced definition of Mechatronics involves the four underlying characteristics of integrated,unified,unique,and systematic approaches.In this realm,Mechatronics is not limited to electro-mechanical systems,in the multi-physics sense,but involves other physical domains such as fluid and thermal.This paper summarizes the mechatronic approach to modeling.Linear graphs facilitate the development of state-space models of mechatronic systems,through this approach.The use of linear graphs in mechatronic modeling is outlined and an illustrative example of sound system modeling is given.Both time-domain and frequency-domain approaches are presented for the use of linear graphs.A mechatronic model of a multi-physics system may be simplified by converting all the physical domains into an equivalent single-domain system that is entirely in the output domain of the system.This approach of converting(transforming)physical domains is presented.An illustrative example of a pressure-controlled hydraulic actuator system that operates a mechanical load is given.
文摘Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar Fatahiasl2, Mahmoud Mohammadi-Sadr1, Masoud Heydari Kahkesh3, and Marziyeh Tahmasbi2(1.Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran;2.Department of Radiologic Technology, School of Allied Medical Sciences, Ahvaz, Jundishapur University of Medical Sciences, Ahvaz, Iran;3.Department of Radiology and Radiotherapy, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran)Abstract:Magnetic resonance imaging(MRI) has revolutionized disease diagnosis and treatment.However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers.
文摘Ultrafast optical spectroscopy was successfully introduced decades ago.Its deep relationship with condensed matter physics profoundly enriched the scientific frontier of light–matter interactions.Previously,materials such as metals,insulators,semiconductors,and superconductors were investigated,followed by magnetic materials,strongly correlated materials,complex oxides,nano-materials,topological materials,and metamaterials.
基金supported by the National Natural Science Foundation of China (Grant Nos.12090064,12205063,12375088,and W2441004)the Fundamental Research Funds for the Central Universitiesin part by the National Key Research and Development Program of China (Grant No.2020YFC2201501)。
文摘Among the charged leptons,theτelectric dipole moment dτis the least constrained.We show that the Im[d_(τ)]imposes strong constraints on new physics that have yet to be discussed.Motivated in particular by the Super Tau-Charm Facility(STCF),which will provide a uniquely clean environment for precisionτ-physics,we study the momentum-transfer dependence of d_(τ)(q^(2))and compare the projected sensitivities of STCF and BelleⅡ.Our analysis shows that an axion-like coupling of the τ lepton can induce sizable real and imaginary components of the EDM.The predicted EDM values may approach the present experimental sensitivities,making them accessible to future measurements at Belle II and the STCF.
文摘Delineating sweet spots is critical for the exploration and production of oil and gas in deep and tight sand reservoirs.The lack of advanced and reliable methods makes this a challenge for geologists and geophysicists.This study introduces,for the first time,an integrated workflow that combines pre-stack seismic inversion with rock physics modeling to predict reservoir porosity and shale volume(V-shale)for sweet spot identification in tight sand reservoirs.A new elastic parameter,the density calculation index(DCI),is introduced which links acoustic and shear impedance for seismic density inversion,thereby addressing the long-standing problem of poor density inversion accuracy.A novel combined Sun–Walsh rock physics model,developed as part of this study,significantly improves V-shale evaluation from seismic data.The proposed three-step seismic inversion approach includes:(1)deriving acoustic and shear impedance from angle-stack seismic data using model-based inversion;(2)calculating density using shear impedance constrained by DCI,followed by porosity estimation from the density–porosity relation;and(3)evaluating V-shale using theα-parameter derived from the Sun–Walsh model and pre-stack inversion results.This integrated workflow provides an effective tool for building accurate 3D reservoir models,and is especially applicable to deep,low-porosity,tight sand reservoirs worldwide.
基金supported by the National Key R&D Program of China[grant number 2023YFC3008004]。
文摘This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.
基金supported by National Natural Science Foundation of China under Grant Nos.12474140 and 12347101supported by National Natural Science Foundation of China under Grant No.12204432+1 种基金supported by the graduate research and innovation foundation of Chongqing,China under Grant No.CYB25066the inaugural Doctoral Student Special Project of the China Association for Science and Technology Young Talents Lifting Program(2024)。
文摘The fractional quantum Hall effect remains a captivating area in condensed matter physics,characterized by strongly correlated topological order,which manifests as fractionalized excitations and anyonic statistics.Numerical simulations,such as exact diagonalization,density matrix renormalization groups,matrix product states,and Monte Carlo methods are essential for examining the properties of strongly correlated systems.Recently,density functional theory has been employed in this field within the framework of composite fermion theory.This paper systematically evaluates how density functional theory approaches have addressed fundamental challenges in fractional quantum Hall systems,including ground state and low-energy excitations.Special attention is given to the insights provided by density functional theory regarding composite fermion behavior,edge effects,and the nature of fractional charge and magnetoroton excitations.The discussion critically examines both the advantages and limitations of these approaches,while highlighting the productive interplay between numerical simulations and theoretical models.Future directions are explored,particularly the promising potential of time-dependent density functional theory for modeling non-equilibrium dynamics in quantum Hall systems.
文摘Background Evidence on pre-operative physical activity before hip and knee arthroplasty is limited and heterogeneous.Intervention components and behavior change techniques remain underexplored.This review examined the effectiveness of pre-operative physical activity interventions on patient and surgical outcomes in elective hip and knee arthroplasty up to 12 weeks post-surgery.Methods A systematic search of 8 databases up to August 8,2024 identified randomized controlled trials of physical activity interventions before total hip and knee arthroplasty.Quality of evidence was evaluated with Grading of Recommendations,Assessment,Development and Evaluation framework.Random-effects models were used for meta-analyses.The Template for Intervention Description and Replication(TIDieR)was used for detailing the included interventions.Results Forty trials were included.Significant mean differences in favor of the intervention groups were found at pre-and post-surgery in 4 outcomes:health-related quality of life(Knee pre-surgery standardized mean difference(SMD)=−0.5,95%confidence interval(95%CI):−1.0 to−0.1 and Hip and Knee post-surgery SMD=−0.4,95%CI:−0.6 to−0.1),pain(Hip and Knee pre-surgery SMD=−0.4,95%CI:−0.6 to−0.1 and Knee post-surgery SMD=−0.3,95%CI:−0.6 to−0.1),function(Hip and Knee pre-surgery SMD=−0.5,95%CI:−0.8 to−0.2 and Knee post-surgery SMD=−0.6,95%CI:−1.0 to−0.2),and timed-up-and-go(Hip and Knee MD=−1.2 s,95%CI:−2.0 to−0.3 and Hip and Knee MD=−1.3 s,95%CI:−1.7 to−0.8).Half of the interventions reported over 75%of the TIDieR items,while behavior change techniques reporting was limited.Conclusion Pre-operative exercise improves health-related quality of life,pain,and function pre-and post-surgery in elective hip and knee arthroplasty.Standardized reporting is needed for establishing effective intervention components.
基金the financial support from the National Key Research and Development Program of China(Grant No.2022YFB4400100)the NSFC under Grant Nos.92477102 and 62122084the open research fund of Songshan Lake Materials Laboratory 2023SLABFK09。
文摘The increasing complexity of intelligent sensing environments,driven by the growth of Internet of Things technologies,has created a strong demand for neuromorphic systems capable of real-time,low-power multisensory perception.Traditional sensory architectures,constrained by single-modal processing and centralized computing,struggle to meet the requirements of diverse and dynamic input conditions.Multisensory neuromorphic devices offer a promising solution by mimicking the distributed,event-driven processing of biological systems.Recent efforts have explored synaptic devices and material systems that respond to various input modalities,including visual,tactile,thermal,and chemical stimuli.However,challenges remain in signal conversion,encoding compatibility,and the fusion of heterogeneous inputs without loss of unisensory information.This review provides a comprehensive overview of the physical mechanisms,device behaviors,and integration strategies that underpin signal processing in neuromorphic hardware.We highlight synaptic mechanisms conducive to cross-modal interaction,analyze representative signal fusion approaches at the device level,and discuss future directions for constructing efficient,scalable,and biologically inspired multisensory neuromorphic systems.
基金supported by the KGJ Basic Research Fund(JCKY2023110C080)the National Natural Science Foundation of China(62322306,62173057,62033006)+2 种基金Aviation Science Foundation Project(2022Z018063001)the Argentinean Agency for Scientific and Technological Promotion(PICT-2021-I-A-00730)the National Foreign Expert Individual Project(H20240983).
文摘This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained by saturation.Measurements are transmitted to nodes of a sensor network over unreliable wireless channels.We propose a linear coding mechanism,together with a distributed method for obtaining a state estimate at each node.These designs aim to minimize the state estimation error covariance.In addition,we derive a bound on this covariance,and accommodate the design parameters to minimize this bound.The resulting design depends on the packet loss probabilities of the wireless channels.This permits applying the proposed scheme to systems in which communications suffer from denial-of-service attacks,as such attacks typically affect those probabilities.Finally,we present a numerical example illustrating this application.
基金NJP holds a Future Leader Award from the Novo Nordisk Foundation and European Foundation for the Study of Diabetes(NNF/EFSD NNF21SA0072747)a grant from the Diabetes Wellness Network Sverige(PG21-6524)+5 种基金supported by the Swedish Research Council(2015-00165)the European Research Council(ERC-2023-Ad G 101142093)a Wallenberg Scholars Award from the Knut and Alice Wallenberg Foundation(KAW 2023.0312)the Swedish Research Council for Sport Science(P2023-0093)The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent research center at the Faculty of Health and Medical Sciences,University of Copenhagen,Denmark partially funded by an unrestricted donation from the Novo Nordisk Foundation(NNF18CC0034900,NNF23SA0084103)supported by a postdoctoral fellowship from the Strategic Research Program in Diabetes at Karolinska Institutet。
文摘Background:Cardiorespiratory fitness(CRF)is a powerful predictor of mortality and chronic disease risk,yet global patterns and determinants of CRF remain poorly defined,particularly in females and underrepresented populations.We conducted a systematic review and quantitative synthesis of directly measured peak oxygen uptake(VO_(2peak))internationally and examined its association with human development and gender ine quality.Methods:Studies were eligible if VO_(2peak)was assessed via direct gas analysis during maximal exercise testing,and if the countries had scores for the Human Development Index(HDI)and Gender Inequality Index(GII).Studies were identified through MEDLINE/PubMed,Embase,CINAHL,and Web of Science.Risks of bias were assessed by an adaptation of the Newcastle-Ottawa Scale.Multivariable linear regression models examined associations between VO_(2peak),age,sex,exercise modality,HDI,GII,and study year.Results:Data included 95 studies from 24 countries with HDI and GII scores,comprising 119,435 adults(42%females)with VO_(2peak)assessed via direct gas analysis during maximal exercise testing.The risk of bias was low.VO_(2peak)was positively associated with HDI(β=14.1)and negatively associated with GII(β=-3.6).Slightly stronger associations were observed in females than males(HDI:β=18.9 vs.β=13.9,GII:β=-4.6vs.β=-3.6).Young females in middle-HDI countries had higher VO_(2peak)than those in low-HDI countries(31.2mL/kg/min vs.28.5 mL/kg/min),with limited additional gams in high-HDI contexts.VO_(2peak)decreased with higher gender inequality,with the largest disparities observed in young females between high-and low-GII countries(26.3 mL/kg/min vs.32.8 mL/kg/min).Conclusion:Global variation in CRF is tied to national levels of human development and gender equality.These findings support prioritizing structural and policy-level interventions that address social and gender disparities in physical activity access and health promotion.Studies from countries with lower HDI and information on ethnicity and socioeconomic status will bridge crucial gaps in understanding factors involved in global CRF levels.
文摘Background:Health benefits have been reported for many physical activity(PA)interventions for improving fundamental movement skills(FMS)and cognitive function(CF),but the most effective type of PA interventions for emhancing FMS and CF in early childhood remain unknown.Thus,the study aimed to determine the effects of PA interventions in enhancing FMS and CF among young children and to establish the optimal types of PA interventions.Methods:Six electronic databases(PubMed,OVID,SPORTDiscus,Scopus,Web of Science,and Cochrane)were searched for studies from inception to March 17,2024.Randomized controlled trials(RCTs)were included in this study if they reported outcomes related to FMS,CF,or both associated with PA interventions.Effect sizes were calculated and performed as Hedges'g.The hierarchy of competing interventions was established using the surface under the cumulative ranking curve(SUCRA).Risk of bias was independently assessed using the Cochrane Riskof-Bias 2.Results:This analysis included 38 studies with 5237 young children,with sample sizes ranging from 32 to 897 participants.The types of PA interventions analyzed included active play/free play/unstructured PA(AP),general structured PA(GSPA),FMS-targeted PA programs(FMSprograms),cognitively-engaging PA programs(CPA),multilevel PA interventions(MPA),and exergaming.PA interventions had a large,pooled effect size for total FMS(g=0.96;95%CI:0.45-1.46;p<0.01;I^(2)=94%).For CF,a small-to-moderate pooled effect size was found(g=0.39;95%CI:0.18-0.60;p<0.01;I^(2)=88%).PA interventions longer than 3 months showed fewer benefits for FMS(p<0.01).The network meta-analysis showed that FMS-programs(standardized mean difference((SMD)=1.55,95%CI:0.98-2.11,SUCRA=98.3%)and GSPA(SMD=0.94,95%CI:0.05-1.85,SUCRA=69.8%)significantly improved total FMS compared to AP.For locomotor skills(LMS),exergaming ranked highest(SUCRA=79.3%),followed by FMS-programs(75.9%)and GSPA(61.6%).However,despite its top ranking,exergaming's effect estimate was not statistically significant(SMD=1.38,95%CI:-0.08 to 2.85).For object control skills(OCS),exergaming again ranked highest(SUCRA=91.9%)and showed the largest significant effect(SMD=2.38,95%CI:0.96-3.80),followed by FMS-programs(SUCRA=78.5%)and GSPA(SUCRA=53.7%).FMS-programs,GSPA,MPA,and UC also significantly improved OCS compared to AP.While no significant differences were observed across PA interventions for most CF domains,exergaming had a significant positive effect on working memory(SMD=1.41,95%CI:0.07-2.75).The certainty of evidence varied from low to moderate.Conclusion:These findings emphasize the importance of PA interventions in improving FMS and CF in early childhood.FMS-programs and GSPA appear to be the most effective approaches for enhancing total FMS,while exergaming showed the highest ranking for LMS and OCS,with a significant impact on OCS but uncertainty in LMS improvements.Additionally,exergaming had a positive effect on working memory,suggesting its potential cognitive benefits.
基金supported by the National Nat-ural Science Foundation of China(Grant Nos.42030604,41875051,and 41425018).
文摘The impact of moist physics on the sensitive areas identified by conditional nonlinear optimal perturbation(CNOP)is examined based on four typical heavy rainfall cases in northern China through performing numerical experiments with and without moist physics.Results show that the CNOP with moist physics identifies sensitive areas corresponding to both the lower-(850−700 hPa)and upper-level(300−100 hPa)weather systems,while the CNOP without moist physics fails to capture the sensitive areas at lower levels.The reasons for the CNOP peaking at different levels can be explained in both algorithm and physics aspects.Firstly,the gradient of the cost function with respect to initial perturbations peaks at the upper level without moist physics which results in the upper-level peak of the CNOP,while it peaks at both the upper and lower levels with moist physics which results in both the upper-and lower-level peaks of the CNOP.Secondly,the upper-level sensitive area is associated with high baroclinicity,and these dynamic features can be captured by both CNOPs with and without moist physics.The lower-level sensitive area is associated with moist processes,and this thermodynamic feature can be captured only by the CNOP with moist physics.This result demonstrates the important contribution of the initial error of lower-level systems that are related to water vapor transportation to the forecast error of heavy rainfall associated weather systems,which could be an important reference for heavy rainfall observation targeting.
基金sponsored by the National Natural Science Foundations of China(No.11975131,11435005)K C Wong Magna Fund in Ningbo University。
文摘Multi-place nonlocal systems have attracted attention from many scientists.In this paper,we mainly review the recent progresses on two-place nonlocal systems(Alice-Bob systems)and four-place nonlocal models.Multi-place systems can firstly be derived from many physical problems by using a multiple scaling method with a discrete symmetry group including parity,time reversal,charge conjugates,rotations,field reversal and exchange transformations.Multiplace nonlocal systems can also be derived from the symmetry reductions of coupled nonlinear systems via discrete symmetry reductions.On the other hand,to solve multi-place nonlocal systems,one can use the symmetry-antisymmetry separation approach related to a suitable discrete symmetry group,such that the separated systems are coupled local ones.By using the separation method,all the known powerful methods used in local systems can be applied to nonlocal cases.In this review article,we take two-place and four-place nonlocal nonlinear Schr?dinger(NLS)systems and Kadomtsev-Petviashvili(KP)equations as simple examples to explain how to derive and solve them.Some types of novel physical and mathematical points related to the nonlocal systems are especially emphasized.
文摘Under the constrained condition induced by the eigenfunction expresson of the potential (u, v)T = (-[A2q, q], [A2p, p])T = f (q, p), the spatial part of the Lax pair of the Kaup-Newell equation is non linearized to be a completely integrable system (R2N, Adp AND dq, H = H-1) with the Hamiltonian H-1 = -[A3q, p]-1/2[A2p, p][A2q, q]. while the nonlinearization of the time part leads to its N-involutive system {H(m)}. The involutive solution of the compatible fsystem (H-1), (H(m)) is mapped by into the solution of the higher order Kaup-Newell equation.
文摘This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.
基金the North Dakota Industrial Commission (NDIC) for their financial supportprovided by the University of North Dakota Computational Research Center。
文摘Accurate estimation of mineralogy from geophysical well logs is crucial for characterizing geological formations,particularly in hydrocarbon exploration,CO_(2) sequestration,and geothermal energy development.Current techniques,such as multimineral petrophysical analysis,offer details into mineralogical distribution.However,it is inherently time-intensive and demands substantial geological expertise for accurate model evaluation.Furthermore,traditional machine learning techniques often struggle to predict mineralogy accurately and sometimes produce estimations that violate fundamental physical principles.To address this,we present a new approach using Physics-Integrated Neural Networks(PINNs),that combines data-driven learning with domain-specific physical constraints,embedding petrophysical relationships directly into the neural network architecture.This approach enforces that predictions adhere to physical laws.The methodology is applied to the Broom Creek Deep Saline aquifer,a CO_(2) sequestration site in the Williston Basin,to predict the volumes of key mineral constituents—quartz,dolomite,feldspar,anhydrite,illite—along with porosity.Compared to traditional artificial neural networks (ANN),the PINN approach demonstrates higher accuracy and better generalizability,significantly enhancing predictive performance on unseen well datasets.The average mean error across the three blind wells is 0.123 for ANN and 0.042 for PINN,highlighting the superior accuracy of the PINN approach.This method reduces uncertainties in reservoir characterization by improving the reliability of mineralogy and porosity predictions,providing a more robust tool for decision-making in various subsurface geoscience applications.
基金supported by the National Natural Science Foundation of China (Grant No.12075326)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2025A1515010669)+2 种基金the Natural Science Foundation of Guangzhou (Grant No.2024A04J6243)the Fundamental Research Funds for the Central Universities in Sun Yat-sen University (No.23xkjc017)the Innovation Training Program for bachelor students in Sun Yat-sen University。
文摘In response to the capabilities presented by the High-Intensity Heavy Ion Accelerator Facility(HIAF) and the Accelerator-Driven Subcritical System(Ci ADS), as well as the proposed Chinese Advanced Nuclear Physics Research Facility(CNUF), we are assembling a consortium of experts in relevant disciplines, both domestically and internationally,to delineate high-precision physics experiments that leverage the state-of-the-art research environment afforded by CNUF.Our focus encompasses six primary domains of inquiry: hadron physics—including endeavors such as the super eta factory and investigations into light hadron structures;muon physics;neutrino physics;neutron physics;the testing of fundamental symmetries;and the exploration of quantum effects within nuclear physics, along with the utilization of vortex accelerators.We aim to foster a well-rounded portfolio of large, medium, and small-scale projects, thus unlocking new scientific avenues and optimizing the potential of the Huizhou large scientific facility. The aspiration for international leadership in scientific research will be a guiding principle in our strategic planning. This initiative will serve as a foundational reference for the Institute of Modern Physics in its strategic planning and goal-setting, ensuring alignment with its developmental objectives while striving to secure a competitive edge in technological advancement. Our ambition is to engage in substantive research within these realms of high-precision physics, to pursue groundbreaking discoveries, and to stimulate progress in China's nuclear physics landscape, positioning Huizhou as a preeminent global hub for advanced nuclear physics research.
基金support from the National Natural Science Foundation of China (Grant Nos.51927807,42077267 and 42277174).
文摘A complex geological environment with faults can be encountered in the process of coal mining.Fault activation can cause instantaneous structure slipping,releasing a significant amount of elastic strain energy during underground coal mining.This would trigger strong rockburst disasters.To understand the occurrence of fault-slip induced rockbursts,we developed a physical model test system for fault-slip induced rockbursts in coal mine drifts.The boundary energy storage(BES)loading apparatus and bottom rapid retraction(BRR)apparatus are designed to realize energy compensation and continuous boundary stress transfer of the surrounding rocks for instantaneous fault slip,as well as to provide space for the potential fault slip.Taking the typical fault-slip induced rockburst in the Xinjulong Coal Mine,China,as the background,we conducted a model test using the test system.The deformation and stress in the rock surrounding the drift and the support unit force during fault slip are analyzed.The deformation and failure characteristics and dynamic responses of drifts under fault-slip induced rockbursts are obtained.The test results illustrate the rationality and effectiveness of the test system.Finally,corresponding recommendations and prospects are proposed based on our findings.
