The modern TSs (total stations) have reached a very high level in the provided reading and reliability (accuracy and precision) of their measurements. The evolution of the digital technology has helped in this dir...The modern TSs (total stations) have reached a very high level in the provided reading and reliability (accuracy and precision) of their measurements. The evolution of the digital technology has helped in this direction. Thus, the TSs can support all requirements for the stake out and monitoring of modern survey engineering and constructions projects. Their complicated manufacturing process and the sensitivity of their components require gauging, adjusting and calibration at certain time intervals. This appears to be the only way in order to assure the precision of measurements provided by the manufacturer and the reliability of the works they are used for. The goal of this paper is to propose a method for the estimation of the gauging time interval for modern YSs. which could be used by any user. More specifically, the indispensable need for the TSs gauging is elevated and documented. All the parameters that influence their operation are registered. A model expressed by a scale of grades is defined, leading thus to an equation for the calculation of the time interval for the next needed gauging and calibration.展开更多
Extensive USGS data tables and detailed,1 m2 Li DAR surveys are used to determine the optimal power n that relates discharge(Q)to stage(h*)above channel bottom(ho)at 39 gauging stations on small streams in the St.Loui...Extensive USGS data tables and detailed,1 m2 Li DAR surveys are used to determine the optimal power n that relates discharge(Q)to stage(h*)above channel bottom(ho)at 39 gauging stations on small streams in the St.Louis,Missouri area,all of which have catchments of 0.6 to 220 km2.Four different methodologies are employed to determine both n and ho:(1)optimizing linearity in a plot of Q1/n vs.local stage(hL)using USGS field measurements at each site;(2)optimizing linearity in a plot of Q1/n vs.hL using USGS rating tables at each site;(3)a mathematical inverse method applied to the same USGS rating tables;(4)use of Li DAR data on channel geometry to determine the power dependences of channel area A and hydraulic radius H on h*,combined with the Manning and rational equations to predict n.Of these methods,only methods 2 and 3 compare favorably,and these values compare poorly with Method 1 based on field data,and with method 4 based on theoretical and empirical relationships.Because Method 4 is predictive,it provides a useful alternative to methods 1–3 that are based on USGS field measurements,which are heavily weighted toward low discharges.We conclude that the apparent values of n in the USGS rating tables are systematically too low for small streams.展开更多
Uniaxial strain is a powerful tuning parameter that can control symmetry and anisotropic electronic properties in iron-based superconductors.However,accurately characterizing anisotropic strain can be challenging and ...Uniaxial strain is a powerful tuning parameter that can control symmetry and anisotropic electronic properties in iron-based superconductors.However,accurately characterizing anisotropic strain can be challenging and complex.Here,we utilize a cryogenic optical system equipped with a high-spatial-resolution microscope to characterize surface strains in iron-based superconductors using the digital image correlation method.Compared with other methods such as high-resolution x-ray diffraction,strain gauge,and capacitive sensor,digital image correlation offers a non-contact full-field measurement approach,acting as an optical virtual strain gauge that provides high spatial resolution.The results measured on detwinned BaFe_(2)As_(2)are quantitatively consistent with the distortion measured by x-ray diffraction and neutron Larmor diffraction.These findings highlight the potential of cryogenic digital image correlation as an effective and accessible tool for probing the isotropic and anisotropic strains,facilitating applications of uniaxial strain tuning in research of quantum materials.展开更多
Recently,a new method has been proposed to compute parton distributions using boosted correlators fixed in the Coulomb gauge(CG)within the framework of large-momentum effective theory.This approach,which does not invo...Recently,a new method has been proposed to compute parton distributions using boosted correlators fixed in the Coulomb gauge(CG)within the framework of large-momentum effective theory.This approach,which does not involve Wilson lines,could greatly improve the efficiency and precision of lattice quantum chromodynamics calculations.However,concerns remain regarding whether systematic uncertainties from Gribov copies,which correspond to ambiguities in lattice gauge-fixing,are adequately controlled.This work assesses the effects of Gribov copies on Coulomb-gauge-fixed quark correlators.We utilize different strategies for Coulomb-gauge fixing,selecting two different groups of Gribov copies based on lattice gauge configurations.We examine the differences in the resulting spatial quark correlators in both vacuum and pion states.Our findings indicate that the statistical errors of the matrix elements from both Gribov copies,regardless of the correlation range,decrease proportionally to the square root of the number of gauge configurations.The difference between the strategies does not show statistical significance compared to the gauge noise,demonstrating that the effect of the Gribov copies can be neglected in practical lattice calculations of quark parton distributions.展开更多
Conservation law plays a very important role in many geometric variational problems and related elliptic systems.In this note,we refine the conservation law obtained by Lamm-Rivière for fourth order systems and d...Conservation law plays a very important role in many geometric variational problems and related elliptic systems.In this note,we refine the conservation law obtained by Lamm-Rivière for fourth order systems and de Longueville-Gastel for general even order systems.展开更多
In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as an...In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same locations.To verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good agreement.We obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/yr.The absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/yr.We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia.展开更多
Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/appro...Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system.展开更多
The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,ev...The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon.展开更多
We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms...We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms like the well-type potential where a particle behaves almost freely but is very hard to escape without external energy, which can be interpreted as local confinement and asymptotic freedom. By assuming a 2-dimensional metric tensor in 4-dimensional space-time, we suggest the existence of 3 kinds of particles that resemble QCD with 3 color charges. We also show that the mass term exists but comes to zero and derive the charge and spin values. We can regard the particle with this new potential as a gluon, and the interaction in this well-type potential as a strong interaction for the properties of mass, charge, spin, and its behavior. We suggest the eight-fold way with this new particle, which is similar to the existing method based on SU (3) symmetry. Even though the strong interaction has been analyzed in the standard model and string theory, we build a new consistent model based on the theory of relativity including Riemann geometry, and show the unification of gravitational and strong interactional field.展开更多
Objectives: As therapeutic modalities for rheumatoid arthritis (RA) advance, immediate and quantitative determination of RA disease status is becoming increasingly important. The purpose of this study was to validate ...Objectives: As therapeutic modalities for rheumatoid arthritis (RA) advance, immediate and quantitative determination of RA disease status is becoming increasingly important. The purpose of this study was to validate the usefulness of a ring gauge as a simple semiquantitative method for assessing hand swelling in patients with RA. Methods: We enrolled patients diagnosed with RA either initiated or switched to a biological therapeutic agent. The circumference of the interphalangeal (IP) joint and the proximal interphalangeal (PIP) joint was measured using a ring gauge. Assessments of the joint echocardiography, incorporating both Gray Scale (GS) and Power Doppler (PD) imaging, were conducted. These evaluations were performed both before the initiation of biological agent treatment and 28 days after the initial dose. Results: Following the treatment intervention, a significant reduction was observed in the circumference of the joint from the thumb to the little finger (p Conclusions: Our study demonstrated the effectiveness of using a ring gauge as a simple assessment tool for RA, revealing that a change in the ring gauge number by 2 or more corresponded to either improvement or deterioration in synovial thickening detected via joint echocardiography.展开更多
As the eventful year of 2023 drew to a close,China’s decisive economic rebound over the preceding 11 months continued to propel steady recovery of the flagging global economy.Last November,China’s retail sales of co...As the eventful year of 2023 drew to a close,China’s decisive economic rebound over the preceding 11 months continued to propel steady recovery of the flagging global economy.Last November,China’s retail sales of consumer goods-a major gauge of consumption strength-maintained accelerated growth,evident in a registered year-on-year increase of 10.1 percent,according to National Bureau of Statistics(NBS)data published on December 15.During the January-November period,moreover,total retail sales of the country’s consumer goods swelled to RMB 42.79 trillion-a 7.2 percent increase over the previous year.展开更多
Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transform...Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.展开更多
This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and i...This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams.展开更多
In rolling process, the rolling force is an important parameter. The precision of the predicted rolling force will directly affect the precision of the finished product. By using adaptive control theory and fusing the...In rolling process, the rolling force is an important parameter. The precision of the predicted rolling force will directly affect the precision of the finished product. By using adaptive control theory and fusing the measured and predicted data, the precision of the predicted rolling force is gradually improved. This system has been used in plant for more than one year, and the result of the application shows that the system has steady and reliable performance, and high precision.展开更多
Conventional techniques to control variations within one plate have been based on preset models and constant automatic position control (APC or pressure feedback automatic gauge control(PAGC).However.because of the r...Conventional techniques to control variations within one plate have been based on preset models and constant automatic position control (APC or pressure feedback automatic gauge control(PAGC).However.because of the rolling force prediction error in the preset models and of the inadequate response speed of dynamic system and of the eccentricity, etc.,the conventional method has not given satisfactory results, the statistics'variations within one plate are in range of 0.25-0.60 mm The authors have developed the techniques to control the variations, which are dynamic intelligent control of hydraulic screwdown system. synchronism control of hydraulic screwdown, eccentricity control method by rotary encoder and the curve of modulus of mill measured automatically, etc., The techniques were fully and successfully industrialized in The Plate Mill of Maanshan Iron and Steel Company and good results that variations are in range of 0.08-0.15min hare been obtained in that mill.展开更多
In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate t...In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.展开更多
In this study, trends of minimum, average and maximum flows were investigated in Porsuk basin, which is a sub-basin of Sakarya basin and then changes in flows were mapped using Geographical Information Systems (GIS). ...In this study, trends of minimum, average and maximum flows were investigated in Porsuk basin, which is a sub-basin of Sakarya basin and then changes in flows were mapped using Geographical Information Systems (GIS). In the study, in 10 flow gauging stations across the Porsuk basin, monthly average, maximum and minimum flow data is used covering the period 1961-2013 (53 years). When analyzing the distribution of observed trends in the basin, a trend has been observed in most of the river flows. A decreasing trend has been observed overall in the basin. Trends are generally decreasing over time except for a few stations. As a result, increasing trends are observed in the west part of the basin;while in the east part of the basin decreasing trends are observed. When average and maximum monthly flows are investigated, decreasing trends are observed in the stations except DSI-12182. Trend analysis of 10 flow gauging stations across the Porsuk basin is investigated by Mann-Kendall method. Trend distribution was made according to flow trends of basin by transferring Z values to GIS.展开更多
文摘The modern TSs (total stations) have reached a very high level in the provided reading and reliability (accuracy and precision) of their measurements. The evolution of the digital technology has helped in this direction. Thus, the TSs can support all requirements for the stake out and monitoring of modern survey engineering and constructions projects. Their complicated manufacturing process and the sensitivity of their components require gauging, adjusting and calibration at certain time intervals. This appears to be the only way in order to assure the precision of measurements provided by the manufacturer and the reliability of the works they are used for. The goal of this paper is to propose a method for the estimation of the gauging time interval for modern YSs. which could be used by any user. More specifically, the indispensable need for the TSs gauging is elevated and documented. All the parameters that influence their operation are registered. A model expressed by a scale of grades is defined, leading thus to an equation for the calculation of the time interval for the next needed gauging and calibration.
基金the Jet Propulsion Laboratory,California Institute of Technology。
文摘Extensive USGS data tables and detailed,1 m2 Li DAR surveys are used to determine the optimal power n that relates discharge(Q)to stage(h*)above channel bottom(ho)at 39 gauging stations on small streams in the St.Louis,Missouri area,all of which have catchments of 0.6 to 220 km2.Four different methodologies are employed to determine both n and ho:(1)optimizing linearity in a plot of Q1/n vs.local stage(hL)using USGS field measurements at each site;(2)optimizing linearity in a plot of Q1/n vs.hL using USGS rating tables at each site;(3)a mathematical inverse method applied to the same USGS rating tables;(4)use of Li DAR data on channel geometry to determine the power dependences of channel area A and hydraulic radius H on h*,combined with the Manning and rational equations to predict n.Of these methods,only methods 2 and 3 compare favorably,and these values compare poorly with Method 1 based on field data,and with method 4 based on theoretical and empirical relationships.Because Method 4 is predictive,it provides a useful alternative to methods 1–3 that are based on USGS field measurements,which are heavily weighted toward low discharges.We conclude that the apparent values of n in the USGS rating tables are systematically too low for small streams.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFA1400400)the Fundamental Research Funds for the Central Universities,and the National Natural Science Foundation of China(Grant Nos.12174029 and 11922402).
文摘Uniaxial strain is a powerful tuning parameter that can control symmetry and anisotropic electronic properties in iron-based superconductors.However,accurately characterizing anisotropic strain can be challenging and complex.Here,we utilize a cryogenic optical system equipped with a high-spatial-resolution microscope to characterize surface strains in iron-based superconductors using the digital image correlation method.Compared with other methods such as high-resolution x-ray diffraction,strain gauge,and capacitive sensor,digital image correlation offers a non-contact full-field measurement approach,acting as an optical virtual strain gauge that provides high spatial resolution.The results measured on detwinned BaFe_(2)As_(2)are quantitatively consistent with the distortion measured by x-ray diffraction and neutron Larmor diffraction.These findings highlight the potential of cryogenic digital image correlation as an effective and accessible tool for probing the isotropic and anisotropic strains,facilitating applications of uniaxial strain tuning in research of quantum materials.
文摘Recently,a new method has been proposed to compute parton distributions using boosted correlators fixed in the Coulomb gauge(CG)within the framework of large-momentum effective theory.This approach,which does not involve Wilson lines,could greatly improve the efficiency and precision of lattice quantum chromodynamics calculations.However,concerns remain regarding whether systematic uncertainties from Gribov copies,which correspond to ambiguities in lattice gauge-fixing,are adequately controlled.This work assesses the effects of Gribov copies on Coulomb-gauge-fixed quark correlators.We utilize different strategies for Coulomb-gauge fixing,selecting two different groups of Gribov copies based on lattice gauge configurations.We examine the differences in the resulting spatial quark correlators in both vacuum and pion states.Our findings indicate that the statistical errors of the matrix elements from both Gribov copies,regardless of the correlation range,decrease proportionally to the square root of the number of gauge configurations.The difference between the strategies does not show statistical significance compared to the gauge noise,demonstrating that the effect of the Gribov copies can be neglected in practical lattice calculations of quark parton distributions.
基金supported by the Young Scientist Program of the Ministry of Science and Technology of China(2021YFA1002200)the National Natural Science Foundation of China(12101362)+4 种基金the Natural Science Foundation of Shandong Province(ZR2021QA003)supported by the National Natural Science Foundation of China(12271296)the Natural Science Foundation of Hubei Province(2024AFA061)supported by the National Natural Science Foundation of China(11571131)the Open Research Fund of Key Laboratory of Nonlinear Analysis&Applications(Central China Normal University),Ministry of Education,P.R.China。
文摘Conservation law plays a very important role in many geometric variational problems and related elliptic systems.In this note,we refine the conservation law obtained by Lamm-Rivière for fourth order systems and de Longueville-Gastel for general even order systems.
基金the University of French Polynesiafunding by several successive“Decision Aide a la Recherche”(DAR)grants to the Geodesy Observatory of Tahiti from the French Space Agency(CNES)+2 种基金fundings from the local government of French Polynesia(Observatoire Polynesien du Rechauffement Climatique)funding by“National Natural Science Foundation of China”(Grand No.41931075)funding by“the Fundamental Research Funds for the Central Universities"(Grand No.2042022kf1198)。
文摘In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same locations.To verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good agreement.We obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/yr.The absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/yr.We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia.
基金funded by the Fund Project of China Academy of Railway Sciences Corporation Limited[Grant No.2022YJ194,2023YJ254].
文摘Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system.
文摘The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon.
文摘We propose the new field potential by maintaining both the symmetry of the scalar gauge and the conservation law keeping N?ether’s theorem, while disregarding the symmetry of the vector gauge. The new potential forms like the well-type potential where a particle behaves almost freely but is very hard to escape without external energy, which can be interpreted as local confinement and asymptotic freedom. By assuming a 2-dimensional metric tensor in 4-dimensional space-time, we suggest the existence of 3 kinds of particles that resemble QCD with 3 color charges. We also show that the mass term exists but comes to zero and derive the charge and spin values. We can regard the particle with this new potential as a gluon, and the interaction in this well-type potential as a strong interaction for the properties of mass, charge, spin, and its behavior. We suggest the eight-fold way with this new particle, which is similar to the existing method based on SU (3) symmetry. Even though the strong interaction has been analyzed in the standard model and string theory, we build a new consistent model based on the theory of relativity including Riemann geometry, and show the unification of gravitational and strong interactional field.
文摘Objectives: As therapeutic modalities for rheumatoid arthritis (RA) advance, immediate and quantitative determination of RA disease status is becoming increasingly important. The purpose of this study was to validate the usefulness of a ring gauge as a simple semiquantitative method for assessing hand swelling in patients with RA. Methods: We enrolled patients diagnosed with RA either initiated or switched to a biological therapeutic agent. The circumference of the interphalangeal (IP) joint and the proximal interphalangeal (PIP) joint was measured using a ring gauge. Assessments of the joint echocardiography, incorporating both Gray Scale (GS) and Power Doppler (PD) imaging, were conducted. These evaluations were performed both before the initiation of biological agent treatment and 28 days after the initial dose. Results: Following the treatment intervention, a significant reduction was observed in the circumference of the joint from the thumb to the little finger (p Conclusions: Our study demonstrated the effectiveness of using a ring gauge as a simple assessment tool for RA, revealing that a change in the ring gauge number by 2 or more corresponded to either improvement or deterioration in synovial thickening detected via joint echocardiography.
文摘As the eventful year of 2023 drew to a close,China’s decisive economic rebound over the preceding 11 months continued to propel steady recovery of the flagging global economy.Last November,China’s retail sales of consumer goods-a major gauge of consumption strength-maintained accelerated growth,evident in a registered year-on-year increase of 10.1 percent,according to National Bureau of Statistics(NBS)data published on December 15.During the January-November period,moreover,total retail sales of the country’s consumer goods swelled to RMB 42.79 trillion-a 7.2 percent increase over the previous year.
文摘Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.
文摘This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams.
文摘In rolling process, the rolling force is an important parameter. The precision of the predicted rolling force will directly affect the precision of the finished product. By using adaptive control theory and fusing the measured and predicted data, the precision of the predicted rolling force is gradually improved. This system has been used in plant for more than one year, and the result of the application shows that the system has steady and reliable performance, and high precision.
文摘Conventional techniques to control variations within one plate have been based on preset models and constant automatic position control (APC or pressure feedback automatic gauge control(PAGC).However.because of the rolling force prediction error in the preset models and of the inadequate response speed of dynamic system and of the eccentricity, etc.,the conventional method has not given satisfactory results, the statistics'variations within one plate are in range of 0.25-0.60 mm The authors have developed the techniques to control the variations, which are dynamic intelligent control of hydraulic screwdown system. synchronism control of hydraulic screwdown, eccentricity control method by rotary encoder and the curve of modulus of mill measured automatically, etc., The techniques were fully and successfully industrialized in The Plate Mill of Maanshan Iron and Steel Company and good results that variations are in range of 0.08-0.15min hare been obtained in that mill.
基金The National Natural Science Foundation of China(No.10947127)the Science Foundation of Southeast University(No.11047005)
文摘In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.
基金This study was supported by the project 1506F500 accepted by Anadolu University Scientific Research Projects Commission.
文摘In this study, trends of minimum, average and maximum flows were investigated in Porsuk basin, which is a sub-basin of Sakarya basin and then changes in flows were mapped using Geographical Information Systems (GIS). In the study, in 10 flow gauging stations across the Porsuk basin, monthly average, maximum and minimum flow data is used covering the period 1961-2013 (53 years). When analyzing the distribution of observed trends in the basin, a trend has been observed in most of the river flows. A decreasing trend has been observed overall in the basin. Trends are generally decreasing over time except for a few stations. As a result, increasing trends are observed in the west part of the basin;while in the east part of the basin decreasing trends are observed. When average and maximum monthly flows are investigated, decreasing trends are observed in the stations except DSI-12182. Trend analysis of 10 flow gauging stations across the Porsuk basin is investigated by Mann-Kendall method. Trend distribution was made according to flow trends of basin by transferring Z values to GIS.