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
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
Accurate precipitation estimation in semiarid,topographically complicated areas is critical for water resource management and climate risk monitoring.This work provides a detailed,multi-scale evaluation of four major ...Accurate precipitation estimation in semiarid,topographically complicated areas is critical for water resource management and climate risk monitoring.This work provides a detailed,multi-scale evaluation of four major satellite precipitation products(CHIRPS,PERSIANN-CDR,IMERG-F v07,and GSMaP)over Isfahan province,Iran,over a 9-year period(2015-2023).The performance of these products was benchmarked against a dense network of 98 rain gauges using a suite of continuous and categorical statistical metrics,following a two-stage quality control protocol to remove outliers and false alarms.The results revealed that the performance of all products improves with temporal aggregation.At the daily level,GSMaP performed marginally better,although all products were linked with considerable uncertainty.At the monthly and annual levels,the GPM-era products(IMERG and GSMaP)clearly beat the other two,establishing themselves as dependable tools for long-term hydro-climatological studies.Error analysis revealed that topography is the dominant regulating factor,creating a systematic elevationdependent bias,largely characterized by underestimation from most products in high-elevation areas,though the PERSIANN-CDR product exhibited a contrasting overestimation tendency.Finally,the findings highlight the importance of implementing local,elevation-dependent calibration before deploying these products in hydrological modeling.展开更多
In the lattice system,when the synthetic flux reaches aπphase along a closed loop under the synthetic gauge field,destructive interference occurs and gives rise to the localization phenomenon.This is known as the Aha...In the lattice system,when the synthetic flux reaches aπphase along a closed loop under the synthetic gauge field,destructive interference occurs and gives rise to the localization phenomenon.This is known as the Aharonov-Bohm(AB)caging effect.It provides a powerful tool for the study of quantum transport and dynamical effects.In the system where lattice sites possess internal structure and the underlying gauge field is non-Abelian,localization can also occur,forming the non-Abelian AB caging.Here,we propose an experimental scheme to synthesize non-Abelian gauge fields with a single trapped ion by coupling multiple internal levels and Fock states in its motion via laser fields.In contrast to the Abelian AB caging,we numerically observe that the non-Abelian AB caging occurs either when the interference matrix is nilpotent,or when the initial state is specifically set.Our experimental scheme broadens the study of localization phenomena and provides a novel tool for the study of non-Abelian physics.展开更多
Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional fram...Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional framework of Landau-Ginzburg-Wilson(LGW)theory.At the DQCP,the system exhibits emergent gauge fields,fractionalized excitations,and enhanced symmetries.展开更多
We have investigated the gauge dependence of physical observables in a quantum Rabi model under different potential fields arising from the Hilbert space truncation of the atomic degrees of freedom.In both the square-...We have investigated the gauge dependence of physical observables in a quantum Rabi model under different potential fields arising from the Hilbert space truncation of the atomic degrees of freedom.In both the square-well and harmonic potentials,the optimal gauge for the ground-state energy depends on the cavity frequency,which is optimal in the low-frequency limit,whereas the Coulomb gauge is optimal in the high-frequency limit.For a dynamic quantity,such as an out-of-time-order correlator,we have demonstrated the necessity of introducing an optimal dynamic gauge.This study provides deeper insight into the intricate relationship between gauge choice and the dynamics of quantum electrodynamics systems,resulting in more accurate theoretical frameworks.展开更多
In this paper, in Section 1, we have described some equations and theorems concerning the Lebesgue integral and the Lebesgue measure. In Section 2, we have described the possible mathematical applications, of Lebesgue...In this paper, in Section 1, we have described some equations and theorems concerning the Lebesgue integral and the Lebesgue measure. In Section 2, we have described the possible mathematical applications, of Lebesgue integration, in some equations concerning various sectors of Chern-Simons theory and Yang-Mills gauge theory, precisely the two dimensional quantum Yang-Mills theory. In conclusion, in Section 3, we have described also the possible mathematical connections with some sectors of String Theory and Number Theory, principally with some equations concerning the Ramanujan’s modular equations that are related to the physical vibrations of the bosonic strings and of the superstrings, some Ramanujan’s identities concerning π and the zeta strings.展开更多
The transverse-traceless gauge condition is an important concept in the theory of gravitational waves.It is well known that a vacuum is one of the key conditions to guarantee the existence of the transverse-traceless ...The transverse-traceless gauge condition is an important concept in the theory of gravitational waves.It is well known that a vacuum is one of the key conditions to guarantee the existence of the transverse-traceless gauge.Although it is thin,the interstellar medium is ubiquitous in the Universe.Therefore,it is important to understand the concept of gravitational waves when matter is presented.Bondi-Metzner-Sachs theory has solved the gauge problem related to gravitational waves.But it does not help with cases when the gravitational wave propagates in matter.This paper discusses possible extensions of the transverse-traceless gauge condition to Minkowski perturbation with matter presented.展开更多
This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1...This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1)-dimensional Heisenberg supermagnet model.Furthermore,by means of the gauge transformation,we investigate the gauge equivalent counterparts,which are the(1+1)-dimensional inhomogeneous nonlinear Schrodinger equation and the(2+1)-dimensional super nonlinear Schrodinger equation,respectively.展开更多
We obtain for the first time the analytic two-loop four-point MHV lightlike form factor of the stress-tensor supermultiplet in planar N 4=SYM where the momentum q carried by the operator is taken to be massless.Remark...We obtain for the first time the analytic two-loop four-point MHV lightlike form factor of the stress-tensor supermultiplet in planar N 4=SYM where the momentum q carried by the operator is taken to be massless.Remarkably,we find that the two-loop result can be constrained uniquely by the infrared divergences and the collinear limits using the master-bootstrap method.Moreover,the remainder function depends only on three dual conformal invariant variables,which can be understood from a hidden dual conformal symmetry of the form factor arising in the lightlike limit of q.The symbol alphabet of the remainder contains only nine letters,which are closed under the action of the dihedral group D_(4).Based on the dual description in terms of periodic Wilson lines(null-wrapped polygons),we also consider a new OPE picture for the lightlike form factors and introduce a new form factor transition that corresponds to the three-point lightlike form factor.With the form factor results up to two loops,we make some all-loop predictions using the OPE picture.展开更多
Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important...Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important role in soil stabilization and fixation,as they resist soil erosion and shallow landslides in this area.However,the biomechanical properties of the roots of dominant herbs and their influencing factors in this area remain poorly understood.Therefore,we selected two dominant herbs in this area,Stipa aliena Keng and Poa crymophila Keng,and carried out a series of uniaxial tensile tests on the roots of the two herbs under different treatments.Meanwhile,the effects of root diameter,plant species,gauge length,root water content,and loading rate on the biomechanical properties of the two herbs'roots were analyzed.The results showed that root diameter was the most significant factor affecting the root biomechanical properties(P<0.010),and root tensile force displayed a positive power law relationship with root diameter,whereas root tensile strength and Young's modulus followed negative power law correlations with root diameter,and fracture strain increased linearly with root diameter.Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater than those of P.crymophila(P<0.001),which was mainly due to the higher lignin content and lignin:cellulose ratio of S.aliena roots.During uniaxial tensile process,hydrated roots exhibited elastic-plastic-brittle behavior,whereas dried roots exhibited elastic-brittle behavior.Root fracture strain of the two herbs was significantly lower under 100 mm gauge length than under 50 mm gauge length(P<0.001),and the Young's modulus was significantly greater(P<0.050).Tensile strength and fracture strain of hydrated roots of the two herbs were significantly greater than those of dried roots(P<0.050),whereas the Young's modulus was significantly lower(P<0.001).Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater under 20 mm/min loading rate than under 200 mm/min loading rate(P<0.050),whereas loading rate had no significant effect on the root biomechanical properties of P.crymophila(P>0.050).Fibrous roots of the two herbs were well developed,with relatively high tensile strengths and Young's moduli of 78.498 and 837.901 MPa for S.aliena,and 67.541 and 901.184 MPa for P.crymophila,respectively.The two herbs can stabilize soil and prevent soil erosion and can be used as pioneer species for ecological restoration in the upper reaches of the Yellow River.These results provide a theoretical basis for soil erosion and shallow landslide control in the giant landslide area of the upper reaches of the Yellow River.展开更多
In this work,the phase structure of a holographic s+d model with quartic potential terms from 4D Einstein–Gauss–Bonnet gravity is studied in the probe limit.We first show the qd-μphase diagram with a very small val...In this work,the phase structure of a holographic s+d model with quartic potential terms from 4D Einstein–Gauss–Bonnet gravity is studied in the probe limit.We first show the qd-μphase diagram with a very small value of the Gauss–Bonnet coefficientα=1×10-7and in the absence of the quartic terms to locate the suitable choice of the value of qd,where the system admits coexistent s+d solutions.Then we consider the various values of the Gauss–Bonnet coefficientαand present theα-μphase diagram to show the influence of the Gauss–Bonnet term on the phase structure.We also give an example of the re-entrant phase transition which is also realized in the holographic s+s and s+p models.After that we confirm the universality of the influence of the quartic term with coefficientλdon the d-wave solutions,which is similar to the case of s-wave and p-wave solutions previously studied in the s+p model.Finally we give the dependence of the special values of the quartic term coefficientλdon the Gauss–Bonnet coefficientα,below which the d-wave condensate grows to an opposite direction at the(quasi-)critical point,which is useful in realizing first order phase transitions in further studies of the holographic d-wave superfluids.展开更多
A power splitter with a wideband arbitrary splitting ratio,which provides flexibility and adaptability in forming photonic devices such as microring resonators and Mach–Zehnder interferometers,proves to be essential ...A power splitter with a wideband arbitrary splitting ratio,which provides flexibility and adaptability in forming photonic devices such as microring resonators and Mach–Zehnder interferometers,proves to be essential in photonic integrated circuits(PICs).We designed and fabricated a directional coupler-based power splitter with a wideband arbitrary splitting ratio and a microring resonator with a wideband uniform extinction ratio(ER)based on artificial gauge field(AGF)optimization.The neural network-aided inverse design method is applied to complete the target.Less than 0.9 dB power splitting variation and 1.6 dB ER variation have been achieved experimentally over a 100-nm bandwidth.Wideband performance,design efficiency,and device compactness are obtained by utilizing this optimization,which indicates great potential and universality in PIC applications.展开更多
Quantum link models(QLMs)serve as experimentally accessible platforms for studying lattice gauge theories with finite-dimensional Hilbert spaces.In this work,we investigate information scrambling in the partially conf...Quantum link models(QLMs)serve as experimentally accessible platforms for studying lattice gauge theories with finite-dimensional Hilbert spaces.In this work,we investigate information scrambling in the partially confined phase of a spin-1 quantum link model by calculating the dynamics of out-of-time-ordered correlators(OTOCs)and entanglement entropy.We observe that,in the partially confined phase,information scrambling exhibits significant asymmetry,manifested as the unidirectional propagation of both OTOCs and entanglement entropy.This phenomenon stands in stark contrast to the isotropic spreading observed in the deconfined phase and the localization characteristic of the confined phase.Furthermore,the simultaneous occurrence of the unidirectional propagation of both OTOCs and entanglement entropy,together with the q-induced asymmetric excitation propagation,reveals a direct connection between information scrambling and charge confinement.展开更多
The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave func...The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave functional.In essence,p-form gauge symmetry can be realized as a special construction of generic zero-form gauge symmetry in the functional space of p-brane configurations.The non-abelian generalization is straightforward in the functional space language.To simplify the analysis,we further introduce a toy model where the infinite dimensional functional space of p-brane configurations is replaced by a finite dimensional matrix space.After taking the symmetric trace in the matrix model,the original discussions of the p-form gauge symmetry can be inherited by the toy model.展开更多
Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays...Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays. Within the experimentally accessible range, we find that the various aspects of the U(1) gauge theory can be well simulated, such as the emergence of topological sectors, incommensurability, and the Rokhsar–Kivelson point that hosts deconfined charge excitations and degenerate topological sectors. Our proposal is promising to implement experimentally and exhibits pronounced quantum dynamics.展开更多
In this work,we investigate the shear elasticity and the shear viscosity in a simple holographic axion model with broken translational symmetry and rotational symmetry in space via the perturbation computation.We find...In this work,we investigate the shear elasticity and the shear viscosity in a simple holographic axion model with broken translational symmetry and rotational symmetry in space via the perturbation computation.We find that,in the case of spontaneous symmetry breaking,the broken translations and anisotropy both enhance the shear elasticity of the system.While in all cases,the broken symmetries introduce a double suppression of the shear viscosity,which is in contrast to the result from the study of the p-wave holographic superfluid where the shear viscosity is enhanced when the rotational symmetry is broken spontaneously.展开更多
This paper proposes a model-based control framework for vehicle platooning systems with secondorder nonlinear dynamics operating over switching signed networks,time-varying delays,and deception attacks.The study inclu...This paper proposes a model-based control framework for vehicle platooning systems with secondorder nonlinear dynamics operating over switching signed networks,time-varying delays,and deception attacks.The study includes two configurations:a leaderless structure using Finite-Time Non-Singular Terminal Bipartite Consensus(FNTBC)and Fixed-Time Bipartite Consensus(FXTBC),and a leader—follower structure ensuring structural balance and robustness against deceptive signals.In the leaderless model,a bipartite controller based on impulsive control theory,gauge transformation,and Markovian switching Lyapunov functions ensures mean-square stability and coordination under deception attacks and communication delays.The FNTBC achieves finite-time convergence depending on initial conditions,while the FXTBC guarantees fixed-time convergence independent of them,providing adaptability to different operating states.In the leader—follower case,a discontinuous impulsive control law synchronizes all followers with the leader despite deceptive attacks and switching topologies,maintaining robust coordination through nonlinear corrective mechanisms.To validate the approach,simulations are conducted on systems of five and seventeen vehicles in both leaderless and leader—follower configurations.The results demonstrate that the proposed framework achieves rapid consensus,strong robustness,and high resistance to deception attacks,offering a secure and scalable model-based control solution for modern vehicular communication networks.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
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.
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.
文摘Accurate precipitation estimation in semiarid,topographically complicated areas is critical for water resource management and climate risk monitoring.This work provides a detailed,multi-scale evaluation of four major satellite precipitation products(CHIRPS,PERSIANN-CDR,IMERG-F v07,and GSMaP)over Isfahan province,Iran,over a 9-year period(2015-2023).The performance of these products was benchmarked against a dense network of 98 rain gauges using a suite of continuous and categorical statistical metrics,following a two-stage quality control protocol to remove outliers and false alarms.The results revealed that the performance of all products improves with temporal aggregation.At the daily level,GSMaP performed marginally better,although all products were linked with considerable uncertainty.At the monthly and annual levels,the GPM-era products(IMERG and GSMaP)clearly beat the other two,establishing themselves as dependable tools for long-term hydro-climatological studies.Error analysis revealed that topography is the dominant regulating factor,creating a systematic elevationdependent bias,largely characterized by underestimation from most products in high-elevation areas,though the PERSIANN-CDR product exhibited a contrasting overestimation tendency.Finally,the findings highlight the importance of implementing local,elevation-dependent calibration before deploying these products in hydrological modeling.
基金supported by the National Natural Science Foundation of China(Grant Nos.92165206,12275090,and 12304554)the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0301603 and 2021ZD0302303)。
文摘In the lattice system,when the synthetic flux reaches aπphase along a closed loop under the synthetic gauge field,destructive interference occurs and gives rise to the localization phenomenon.This is known as the Aharonov-Bohm(AB)caging effect.It provides a powerful tool for the study of quantum transport and dynamical effects.In the system where lattice sites possess internal structure and the underlying gauge field is non-Abelian,localization can also occur,forming the non-Abelian AB caging.Here,we propose an experimental scheme to synthesize non-Abelian gauge fields with a single trapped ion by coupling multiple internal levels and Fock states in its motion via laser fields.In contrast to the Abelian AB caging,we numerically observe that the non-Abelian AB caging occurs either when the interference matrix is nilpotent,or when the initial state is specifically set.Our experimental scheme broadens the study of localization phenomena and provides a novel tool for the study of non-Abelian physics.
基金supported by the National Natural Science Foundation of China(Grant Nos.12134020 and 12374156)the National Key Research and Development Program of China(Grant No.2023YFA1406500)。
文摘Deconfined quantum critical points(DQCPs)have been proposed as a class of continuous quantum phase transitions occurring between two ordered phases with distinct symmetry-breaking patterns,beyond the conventional framework of Landau-Ginzburg-Wilson(LGW)theory.At the DQCP,the system exhibits emergent gauge fields,fractionalized excitations,and enhanced symmetries.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174194 and 12475033)the Fundamental Research Funds for the Central Universities。
文摘We have investigated the gauge dependence of physical observables in a quantum Rabi model under different potential fields arising from the Hilbert space truncation of the atomic degrees of freedom.In both the square-well and harmonic potentials,the optimal gauge for the ground-state energy depends on the cavity frequency,which is optimal in the low-frequency limit,whereas the Coulomb gauge is optimal in the high-frequency limit.For a dynamic quantity,such as an out-of-time-order correlator,we have demonstrated the necessity of introducing an optimal dynamic gauge.This study provides deeper insight into the intricate relationship between gauge choice and the dynamics of quantum electrodynamics systems,resulting in more accurate theoretical frameworks.
文摘In this paper, in Section 1, we have described some equations and theorems concerning the Lebesgue integral and the Lebesgue measure. In Section 2, we have described the possible mathematical applications, of Lebesgue integration, in some equations concerning various sectors of Chern-Simons theory and Yang-Mills gauge theory, precisely the two dimensional quantum Yang-Mills theory. In conclusion, in Section 3, we have described also the possible mathematical connections with some sectors of String Theory and Number Theory, principally with some equations concerning the Ramanujan’s modular equations that are related to the physical vibrations of the bosonic strings and of the superstrings, some Ramanujan’s identities concerning π and the zeta strings.
基金supported in part by the National Key Research and Development Program of China Grant No.2021YFC2203001in part by the NSFC(Grant Nos.11920101003,12021003 and 12005016)+1 种基金supported by‘the Fundamental Research Funds for the Central Universities’of Beijing Normal Universitysupported by the NSF of Hunan province(Grant No.2023JJ30179)。
文摘The transverse-traceless gauge condition is an important concept in the theory of gravitational waves.It is well known that a vacuum is one of the key conditions to guarantee the existence of the transverse-traceless gauge.Although it is thin,the interstellar medium is ubiquitous in the Universe.Therefore,it is important to understand the concept of gravitational waves when matter is presented.Bondi-Metzner-Sachs theory has solved the gauge problem related to gravitational waves.But it does not help with cases when the gravitational wave propagates in matter.This paper discusses possible extensions of the transverse-traceless gauge condition to Minkowski perturbation with matter presented.
基金supported by the National Natural Science Foundation of China(Grant Nos.12461048 and 12061051)Natural Science Foundation of Inner Mongolia Autonomous Region(Grant No.2023MS01003)+2 种基金the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Grant No.NJYT23096)the financial support from the Program of China Scholarships Council(Grant No.202306810054)for one year's study at the University of Leedsthe support of Professor Ke Wu and Professor Weizhong Zhao at Capital Normal University,China。
文摘This paper is concerned with the construction of two types of generalized Heisenberg supermagnet model with the constraint S^(3)=S,including the inhomogeneous Heisenberg supermagnet model in(1+1)dimensions and the(2+1)-dimensional Heisenberg supermagnet model.Furthermore,by means of the gauge transformation,we investigate the gauge equivalent counterparts,which are the(1+1)-dimensional inhomogeneous nonlinear Schrodinger equation and the(2+1)-dimensional super nonlinear Schrodinger equation,respectively.
基金supported in part by the National Natural Science Foundation of China under Grant Nos. 12175291, 11935013, 12047503, 12247103by the CAS under Grant No. YSBR-101the HPC Cluster of ITP-CAS for the support
文摘We obtain for the first time the analytic two-loop four-point MHV lightlike form factor of the stress-tensor supermultiplet in planar N 4=SYM where the momentum q carried by the operator is taken to be massless.Remarkably,we find that the two-loop result can be constrained uniquely by the infrared divergences and the collinear limits using the master-bootstrap method.Moreover,the remainder function depends only on three dual conformal invariant variables,which can be understood from a hidden dual conformal symmetry of the form factor arising in the lightlike limit of q.The symbol alphabet of the remainder contains only nine letters,which are closed under the action of the dihedral group D_(4).Based on the dual description in terms of periodic Wilson lines(null-wrapped polygons),we also consider a new OPE picture for the lightlike form factors and introduce a new form factor transition that corresponds to the three-point lightlike form factor.With the form factor results up to two loops,we make some all-loop predictions using the OPE picture.
基金funded by the National Natural Science Foundation of China(42267024,42041006)the Youth Research Fund Project of Qinghai University,China(2023-QGY-10).
文摘Soil erosion and shallow landslides in the upper reaches of the Yellow River,China,are increasing due to extreme climate events and human disturbances.The biomechanical properties of vegetation roots play an important role in soil stabilization and fixation,as they resist soil erosion and shallow landslides in this area.However,the biomechanical properties of the roots of dominant herbs and their influencing factors in this area remain poorly understood.Therefore,we selected two dominant herbs in this area,Stipa aliena Keng and Poa crymophila Keng,and carried out a series of uniaxial tensile tests on the roots of the two herbs under different treatments.Meanwhile,the effects of root diameter,plant species,gauge length,root water content,and loading rate on the biomechanical properties of the two herbs'roots were analyzed.The results showed that root diameter was the most significant factor affecting the root biomechanical properties(P<0.010),and root tensile force displayed a positive power law relationship with root diameter,whereas root tensile strength and Young's modulus followed negative power law correlations with root diameter,and fracture strain increased linearly with root diameter.Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater than those of P.crymophila(P<0.001),which was mainly due to the higher lignin content and lignin:cellulose ratio of S.aliena roots.During uniaxial tensile process,hydrated roots exhibited elastic-plastic-brittle behavior,whereas dried roots exhibited elastic-brittle behavior.Root fracture strain of the two herbs was significantly lower under 100 mm gauge length than under 50 mm gauge length(P<0.001),and the Young's modulus was significantly greater(P<0.050).Tensile strength and fracture strain of hydrated roots of the two herbs were significantly greater than those of dried roots(P<0.050),whereas the Young's modulus was significantly lower(P<0.001).Root tensile force,tensile strength,and fracture strain of S.aliena were significantly greater under 20 mm/min loading rate than under 200 mm/min loading rate(P<0.050),whereas loading rate had no significant effect on the root biomechanical properties of P.crymophila(P>0.050).Fibrous roots of the two herbs were well developed,with relatively high tensile strengths and Young's moduli of 78.498 and 837.901 MPa for S.aliena,and 67.541 and 901.184 MPa for P.crymophila,respectively.The two herbs can stabilize soil and prevent soil erosion and can be used as pioneer species for ecological restoration in the upper reaches of the Yellow River.These results provide a theoretical basis for soil erosion and shallow landslide control in the giant landslide area of the upper reaches of the Yellow River.
基金supported by the National Natural Science Foundation of China(Grant No.11965013)supported by Yunnan High-level Talent Training Support Plan Young&Elite Talents Project(Grant No.YNWR-QNBJ-2018-181)。
文摘In this work,the phase structure of a holographic s+d model with quartic potential terms from 4D Einstein–Gauss–Bonnet gravity is studied in the probe limit.We first show the qd-μphase diagram with a very small value of the Gauss–Bonnet coefficientα=1×10-7and in the absence of the quartic terms to locate the suitable choice of the value of qd,where the system admits coexistent s+d solutions.Then we consider the various values of the Gauss–Bonnet coefficientαand present theα-μphase diagram to show the influence of the Gauss–Bonnet term on the phase structure.We also give an example of the re-entrant phase transition which is also realized in the holographic s+s and s+p models.After that we confirm the universality of the influence of the quartic term with coefficientλdon the d-wave solutions,which is similar to the case of s-wave and p-wave solutions previously studied in the s+p model.Finally we give the dependence of the special values of the quartic term coefficientλdon the Gauss–Bonnet coefficientα,below which the d-wave condensate grows to an opposite direction at the(quasi-)critical point,which is useful in realizing first order phase transitions in further studies of the holographic d-wave superfluids.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2905502)the National Natural Science Foundation of China(Grant Nos.62122047 and 61935011).
文摘A power splitter with a wideband arbitrary splitting ratio,which provides flexibility and adaptability in forming photonic devices such as microring resonators and Mach–Zehnder interferometers,proves to be essential in photonic integrated circuits(PICs).We designed and fabricated a directional coupler-based power splitter with a wideband arbitrary splitting ratio and a microring resonator with a wideband uniform extinction ratio(ER)based on artificial gauge field(AGF)optimization.The neural network-aided inverse design method is applied to complete the target.Less than 0.9 dB power splitting variation and 1.6 dB ER variation have been achieved experimentally over a 100-nm bandwidth.Wideband performance,design efficiency,and device compactness are obtained by utilizing this optimization,which indicates great potential and universality in PIC applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.GG2030007011 and GG2030040453)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302004)+1 种基金support from the National Natural Science Foundation of China(Grant No.12174236)the fund for the Shanxi 1331 Project.
文摘Quantum link models(QLMs)serve as experimentally accessible platforms for studying lattice gauge theories with finite-dimensional Hilbert spaces.In this work,we investigate information scrambling in the partially confined phase of a spin-1 quantum link model by calculating the dynamics of out-of-time-ordered correlators(OTOCs)and entanglement entropy.We observe that,in the partially confined phase,information scrambling exhibits significant asymmetry,manifested as the unidirectional propagation of both OTOCs and entanglement entropy.This phenomenon stands in stark contrast to the isotropic spreading observed in the deconfined phase and the localization characteristic of the confined phase.Furthermore,the simultaneous occurrence of the unidirectional propagation of both OTOCs and entanglement entropy,together with the q-induced asymmetric excitation propagation,reveals a direct connection between information scrambling and charge confinement.
基金supported by National Natural Science Foundation of China(Grants No.12275217,12247103).
文摘The abelian(p+1)-form gauge field is inherently coupled to the p-brane worldvolume.After quantization,the corresponding p-form gauge transformation is associated with the local phase ambiguity of the p-brane wave functional.In essence,p-form gauge symmetry can be realized as a special construction of generic zero-form gauge symmetry in the functional space of p-brane configurations.The non-abelian generalization is straightforward in the functional space language.To simplify the analysis,we further introduce a toy model where the infinite dimensional functional space of p-brane configurations is replaced by a finite dimensional matrix space.After taking the symmetric trace in the matrix model,the original discussions of the p-form gauge symmetry can be inherited by the toy model.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2022YFA1404204 and 2022YFA1403700)the National Natural Science Foundation of China (Grant Nos. 12274086, 11534001 and 11925402)+5 种基金funding from the National Science Foundation of China (Grant Nos. 12274046, 11874094, 12147102, and 12347101)Chongqing Natural Science Foundation (Grant No. CSTB2022NSCQ-JQX0018)the Fundamental Research Funds for the Central Universities (Grant No. 2021CDJZYJH-003)Xiaomi Foundation/Xiaomi Young Talents Programthe supports of the start-up funding of Westlake Universitysupport from the Natural Sciences and Engineering Research Council of Canada (NSERC) through Discovery Grants。
文摘Simulating U(1) quantum gauge theories with spatial dimensions greater than one is of great physical significance. Here we propose a simple realization of U(1) gauge theory with Rydberg and Rydberg-dressed atom arrays. Within the experimentally accessible range, we find that the various aspects of the U(1) gauge theory can be well simulated, such as the emergence of topological sectors, incommensurability, and the Rokhsar–Kivelson point that hosts deconfined charge excitations and degenerate topological sectors. Our proposal is promising to implement experimentally and exhibits pronounced quantum dynamics.
基金supported by the National Natural Science Foundation of China(NSFC)under Grants Nos.12275038 and 12375054。
文摘In this work,we investigate the shear elasticity and the shear viscosity in a simple holographic axion model with broken translational symmetry and rotational symmetry in space via the perturbation computation.We find that,in the case of spontaneous symmetry breaking,the broken translations and anisotropy both enhance the shear elasticity of the system.While in all cases,the broken symmetries introduce a double suppression of the shear viscosity,which is in contrast to the result from the study of the p-wave holographic superfluid where the shear viscosity is enhanced when the rotational symmetry is broken spontaneously.
基金Deanship of Research and Graduate Studies at King Khalid University for funding this work through Large Research Project under grant number RGP.2/103/46”Deanship of Scientific Research at Northern Border University,Arar,Saudi Arabia for funding this research work through project number“NBU-FFR-2025-871-15”funding from Prince Sattam bin Abdulaziz University project number(PSAU/2025/R/1447).
文摘This paper proposes a model-based control framework for vehicle platooning systems with secondorder nonlinear dynamics operating over switching signed networks,time-varying delays,and deception attacks.The study includes two configurations:a leaderless structure using Finite-Time Non-Singular Terminal Bipartite Consensus(FNTBC)and Fixed-Time Bipartite Consensus(FXTBC),and a leader—follower structure ensuring structural balance and robustness against deceptive signals.In the leaderless model,a bipartite controller based on impulsive control theory,gauge transformation,and Markovian switching Lyapunov functions ensures mean-square stability and coordination under deception attacks and communication delays.The FNTBC achieves finite-time convergence depending on initial conditions,while the FXTBC guarantees fixed-time convergence independent of them,providing adaptability to different operating states.In the leader—follower case,a discontinuous impulsive control law synchronizes all followers with the leader despite deceptive attacks and switching topologies,maintaining robust coordination through nonlinear corrective mechanisms.To validate the approach,simulations are conducted on systems of five and seventeen vehicles in both leaderless and leader—follower configurations.The results demonstrate that the proposed framework achieves rapid consensus,strong robustness,and high resistance to deception attacks,offering a secure and scalable model-based control solution for modern vehicular communication networks.
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.
