Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling ...Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling the automatic derivation of analytical expressions for the eigenmatrix elements via symbolic computation,eliminating the need for tedious manual calculations.Using this approach,we investigate the impact of magnetic hysteresis on magnon-magnon coupling in a system with interlayer Dzyaloshinskii-Moriya interaction(DMI).The magnetic hysteresis leads to an asymmetric magnetic field dependence of the resonance frequency and alters the number of degeneracy points between the pure optical and acoustic modes.Moreover,it can result in the coupling strength at the gap of the f–H phase diagram being nearly vanishing,contrary to the conventionally expected maximum.These results deepen the understanding of the effect of interlayer DMI on magnon–magnon coupling and the proposed universal method significantly streamlines the solving process of magnon–magnon coupling problems.展开更多
An integrated coupling element considering wheel-rail interface for analyzing the dynamic responses of vehicle-rail-bridge interaction system with a non-uniform continuous bridge is presented. The governing equations ...An integrated coupling element considering wheel-rail interface for analyzing the dynamic responses of vehicle-rail-bridge interaction system with a non-uniform continuous bridge is presented. The governing equations of the interaction system are established first, and the solution procedure and assembly method of the coupling element are demonstrated. Finally, the accuracy, efficiency and function of the integrated coupling element are tested using two numerical examples. The influences of different combinations of rail and bridge element length in the coupling element on the solution are investigated, and the effects of different rail irregularities on the dynamic responses are discussed.展开更多
The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric ...The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SACCI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ（C,H）6-311G？？（I）. The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.展开更多
The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations ...The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.展开更多
The influence of annealing time on the magnetic properties and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons was systematically investigated by the methods of vibrating sample magnetometer （VSM）, ...The influence of annealing time on the magnetic properties and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons was systematically investigated by the methods of vibrating sample magnetometer （VSM）, X-ray diffraction （XRD） and high resolution transmission electron microscopy （HRTEM）. Interaction domains derived from strong exchange coupling interactions between hard and soft magnetic grains were imaged using magnetic force microscopy （MFM）. Maximum remanence, intrinsic coercivity, and maximum energy product values were obtained in the ribbons annealed at 700℃ for 15 min, which were composed of Pr2（Fe, Co）14B, α-（Fe, Co）, and slight Pr2（Fe, CO）17 phases. Although Jr, Hci, and （Bn）max decreased gradually with further increase of annealing time, it is emphasized that comparatively high Jr and Hci and （BH）max were obtained in a wide annealing time period of 15 to 360 min. The shape of initial magnetization curves and hysteresis loops change as a function of annealing time, indicating different magnetization reversal routes, which can be fully explained by the corresponding microstructure.展开更多
The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous literature.The parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more ...The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous literature.The parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more complex than that of a single pipe.However,there are few reports about the dynamic characteristics of the PLFPs.Therefore,this paper proposes improved frequency modeling and solution for the PLFPs,involving the logical alignment principle and coupled matrix processing.The established model incorporates both the fluid-structure interaction(FSI)and the structural coupling of the PLFPs.The validity of the established model is verified by modal experiments.The effects of some unique parameters on the dynamic characteristics of the PLFPs are discussed.This work provides a feasible method for solving the FSI of multiple pipes in parallel and potential theoretical guidance for the dynamic analysis of the PLFPs in engineering.展开更多
The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon （GMR） waveguide is investigated by numerical calculations, where the emitter is...The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon （GMR） waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR, The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.展开更多
The development and rapid usage of numerical codes for fluid-structure interaction(FSI) problems are of great relevance to researchers in many engineering fields such as civil engineering and ocean engineering. This m...The development and rapid usage of numerical codes for fluid-structure interaction(FSI) problems are of great relevance to researchers in many engineering fields such as civil engineering and ocean engineering. This multidisciplinary field known as FSI has been expanded to engineering fields such as offshore structures, tall slender structures and other flexible structures applications. The motivation of this paper is to investigate the numerical model of two-way coupling FSI partitioned flexible plate structure under fluid flow. The adopted partitioned method and approach utilized the advantage of the existing numerical algorithms in solving the two-way coupling fluid and structural interactions. The flexible plate was subjected to a fluid flow which causes large deformation on the fluid domain from the oscillation of the flexible plate. Both fluid and flexible plate are subjected to the interaction of load transfer within two physics by using the strong and weak coupling methods of MFS and Load Transfer Physics Environment, respectively. The oscillation and deformation results have been validated which demonstrate the reliability of both strong and weak method in resolving the two-way coupling problem in contribution of knowledge to the feasibility field study of ocean engineering and civil engineering.展开更多
The scalar and vector running coupling constants are derived using the renormalization group method in the σ-ω model. The numerical values of the two running coupling constants are obtained and the physical meaning ...The scalar and vector running coupling constants are derived using the renormalization group method in the σ-ω model. The numerical values of the two running coupling constants are obtained and the physical meaning of the result is discussed.展开更多
In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result ...In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result in a strengthened depletion force. So the difference of the depletion forces of the three-sphere system and its corresponding two two-sphere systems is introduced to describe the coupling effect of the depletion interactions. The numerical results obtained by Monte- Carlo simulations show that this coupling effect is affected by both the concentration of small spheres and the geometrical confinement. Meanwhile, it is also found that the mechanisms of the coupling effect and the effect on the depletion force from the ~eometry factor are the same.展开更多
Diagnostic studies have been done of the seasonal and interdecadal variations of the coupling patterns for the air-sea interactions in the northern Pacific region, by using 500-hPa geopotential height field of the Nor...Diagnostic studies have been done of the seasonal and interdecadal variations of the coupling patterns for the air-sea interactions in the northern Pacific region, by using 500-hPa geopotential height field of the Northern Hemisphere and monthly mean SST field of northern Pacific Ocean (1951 ~ 1995) and with the aid of the Singular Value Decomposition (SVD) technique. The results show that: (1) The distribution patterns of SVD, which link with the El Ni駉 (or La Ni馻) events, are important in the interaction between the atmosphere and ocean while the atmosphere, coupling with it, varies like the PNA teleconnection does. The coupling of air-sea interactions is the highest in the winter (January), specifically linking the El Ni駉 event with the PNA pattern in the geopotential height field. Of the four seasons, summer has the poorest coupling when the 500-hPa geopotential height field corresponding to the La Ni馻 event displays patterns similar to the East Asian-Pacific one (PJ). The spring and autumn are both transitional and the coupling is less tight in the autumn than in the spring. (2) Significant changes have taken place around 1976 in the pattern of air-sea coupling, with the year抯 winter having intensified PNA pattern of 500-hPa winter geopotential height field, deepened Aleutian low that moves southeast and the summer following it having outstanding PJ pattern of 500-hPa geopotential height field, which is not so before 1976.展开更多
The multi-physics simulation of coupled fluid-structure interaction problems, with disjoint fluid and solid domains, requires one to choose a method for enforcing the fluid-structure coupling at the interface between ...The multi-physics simulation of coupled fluid-structure interaction problems, with disjoint fluid and solid domains, requires one to choose a method for enforcing the fluid-structure coupling at the interface between solid and fluid. While it is common knowledge that the choice of coupling technique can be very problem dependent, there exists no satisfactory coupling comparison methodology that allows for conclusions to be drawn with respect to the comparison of computational cost and solution accuracy for a given scenario. In this work, we develop a computational framework where all aspects of the computation can be held constant, save for the method in which the coupled nature of the fluid-structure equations is enforced. To enable a fair comparison of coupling methods, all simulations presented in this work are implemented within a single numerical framework within the deal.ii [1] finite element library. We have chosen the two-dimensional benchmark test problem of Turek and Hron [2] as an example to examine the relative accuracy of the coupling methods studied;however, the comparison technique is equally applicable to more complex problems. We show that for the specific case considered herein the monolithic approach outperforms partitioned and quasi-direct methods;however, this result is problem dependent and we discuss computational and modeling aspects which may affect other comparison studies.展开更多
The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was pr...The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was proved by the numerical result that the depletion interactions in the three-sphere system are larger than that of the corresponding two-sphere system. Furthermore, we find that the mechanisms of the coupling effect and the effect on depletion force from the geometry factor are the same. In addition, the numerical results also show that this coupling effect will be affected by both the volume fraction and separation of three-sphere system.展开更多
The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coup...The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coupling effect is affected by the size ratio of large- to small-sphere: the larger the size ratio is, the larger the coupling effect will be.展开更多
The influence of power-low long-range interactions （LRI） and helicoidal coupling （HC） on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase （RNAP） binds to it at the physio...The influence of power-low long-range interactions （LRI） and helicoidal coupling （HC） on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase （RNAP） binds to it at the physiological temperature is analytically and numerically investigated in this paper. We have made an analogy with the Heisenberg model Hamiltonian of an anisotropic spin ladder with ferromagnetic legs and anti-ferromagnetic rung coupling. When we limit ourselves to the second-order terms in the Taylor expansion, the DNA dynamics is found to be governed by a completely integrable nonlinear Schr？dinger （NLS） equation. In this case, results show that increasing the value of HC force or LRI parameter enhances the bubble height and reduces the number of base pairs which form the bubble. For the fourth-order terms in a Taylor expansion, results are closely resembling those of second-order terms, and are confirmed by numerical investigation. These results match with some experimental data and thus provide a better representation of the base pairs opening in DNA which is essential for the transcription process.展开更多
Taking α-Fe and Nd_2Fe_(14)B grains as example, the grain size dependence of the exchange-coupling interaction and effective anisotropy and also their variations depending on the ratio of magnetically soft and hard g...Taking α-Fe and Nd_2Fe_(14)B grains as example, the grain size dependence of the exchange-coupling interaction and effective anisotropy and also their variations depending on the ratio of magnetically soft and hard grain sizes, D_s∶D_h, were investigated. When grain size D>L_(ex), the grain’s anisotropy is the statistic value of the coupled and uncoupled part. The anisotropy constant of uncoupled part is the common value K_1 and that of coupled part varies with the distance to the grain surface. The effective anisotropy constant between magnetically soft and hard grains, K_(eff), can be expressed as the sum of the products of volume fractions for soft and hard grains, respectively, and the corresponding mean anisotropy constants. The calculation results indicate that the exchange-coupling interaction is enhanced with the reduction of grain size, and the effective anisotropy decreases with reducing grain size and increasing ratio of D_s∶D_h. In order to get high effective anisotropy constant, K_(eff), in composite magnetically soft-hard grains, the hard grain size should be larger than 30 nm and the soft grain size should be about 10 nm.展开更多
Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform s...Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform structure, interactive phenomena of solitons are discussed, especially in the two-soliton case. It is found that different interactive behaviours of solitary waves take place under different parameter conditions of overtaking collision in this system. It is verified that the elastic interaction phenomena exist in this （1＋1）-dimensional integrable coupled model.展开更多
Global urbanization is exerting severe stress and having far-reaching impacts on the eco-environment, and yet there exists a complex non-linear coupling relationship between the two. Research on the interactive coupli...Global urbanization is exerting severe stress and having far-reaching impacts on the eco-environment, and yet there exists a complex non-linear coupling relationship between the two. Research on the interactive coupling effect between urbanization and the eco-environment will be a popular area of study and frontier in international earth system science and sustainability science in the next 10 years, while also being a high-priority research topic of particular interest to international organizations. This paper systematically collates and summarizes the international progress made in research on interactive coupling theory, coupling relationships, coupling mechanisms, coupling laws, coupling thresholds, coupling models and coupling optimization decision support systems. The research shows that urbanization and eco-environment interactive coupling theories include the Kuznets curve theory, telecoupling theory, planetary boundaries theory, footprint family theory and urban metabolism theory; most research on interactive coupling relationships is concerned with single- element coupling relationships, such as those between urbanization and water, land, atmosphere, climate change, ecosystems and biodiversity; the majority of research on interactive coupling mechanisms and laws focuses on five research paradigms, including coupled human and nature systems, complex social-ecological systems, urban ecosystems, social-economic-natural complex ecosystems, and urbanization development and eco-environment constraint ring; the majority of interactive coupling simulations use STIRPAT models, coupling degree models, multi-agent system models and big data urban computer models; and research has been carried out on urbanization and eco-environment coupling thresholds, coercing risk and optimal decision support systems. An objective evaluation of progress in international research on interactive coupling between urbanization and the eco-environment suggests that there are six main research focal points and six areas lacking research： a lot of research exists on macroscopic coupling effects, with little research on urban agglomeration and scale coupling effects; considerable research exists on sin-gle-dimension coupling effects, with little on multiple-dimension coupling effects; a great deal exists on ＂one-to-one＂ dual- element coupling effects, with little on ＂many-to-many＂ multiple-element coupling effects; a lot exists on positive feedback coupling effects, and little on negative feedback coupling effects; a great deal exists on empirical coupling effects, and little on theoretical coupling effects; a great deal exists on the use of simple quantitative methods, and little on using integrated simulation methods. Future studies should focus on coupling effects between urbanization in urban agglomerations and the eco-environment, spatial scale coupling effects, multi-dimensional coupling effects, telecoupling effects, ＂one-to-many＂ and ＂many-to-many＂ element coupling effects, and positive and negative feedback coupling effects. There is also a need to strengthen the development and application of dynamic models for multi-element,-scale,-scenario,-module and-agent integrated spatiotemporal coupling systems and further improve theoretical innovations in coupling effect research and integrate and form complete and diverse coupling theoretical systems.展开更多
Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynam...Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynamic slamming on marine vessels,tsunami impact on onshore structures,and sloshing in liquid containers)have aroused huge challenges to ocean engineering fields.In this paper,the moving particle semi-implicit(MPS)method and finite element method(FEM)coupled method is proposed for use in numerical investigations of the interaction between a regular wave and a horizontal suspended structure.The fluid domain calculated by the MPS method is dispersed into fluid particles,and the structure domain solved by the FEM method is dispersed into beam elements.The generation of the 2D regular wave is firstly conducted,and convergence verification is performed to determine appropriate particle spacing for the simulation.Next,the regular wave interacting with a rigid structure is initially performed and verified through the comparison with the laboratory experiments.By verification,the MPS-FEM coupled method can be applied to fluid-structure interaction(FSI)problems with waves.On this basis,taking the flexibility of structure into consideration,the elastic dynamic response of the structure subjected to the wave slamming is investigated,including the evolutions of the free surface,the variation of the wave impact pressures,the velocity distribution,and the structural deformation response.By comparison with the rigid case,the effects of the structural flexibility on wave-elastic structure interaction can be obtained.展开更多
基金supported by the National Key Research and Development Program of China (MOST)(Grant No.2022YFA1402800)the Chinese Academy of Sciences (CAS) Presidents International Fellowship Initiative (PIFI)(Grant No.2025PG0006)+3 种基金the National Natural Science Foundation of China (NSFC)(Grant Nos.51831012,12274437,and 52161160334)the CAS Project for Young Scientists in Basic Research (Grant No.YSBR-084)the CAS Youth Interdisciplinary Teamthe China Postdoctoral Science Foundation (Grant No.2025M773402)。
文摘Based on the Smit-Suhl formula,we propose a universal approach for solving the magnon-magnon coupling problem in bilayer coupled systems(e.g.,antiferromagnets).This method requires only the energy expression,enabling the automatic derivation of analytical expressions for the eigenmatrix elements via symbolic computation,eliminating the need for tedious manual calculations.Using this approach,we investigate the impact of magnetic hysteresis on magnon-magnon coupling in a system with interlayer Dzyaloshinskii-Moriya interaction(DMI).The magnetic hysteresis leads to an asymmetric magnetic field dependence of the resonance frequency and alters the number of degeneracy points between the pure optical and acoustic modes.Moreover,it can result in the coupling strength at the gap of the f–H phase diagram being nearly vanishing,contrary to the conventionally expected maximum.These results deepen the understanding of the effect of interlayer DMI on magnon–magnon coupling and the proposed universal method significantly streamlines the solving process of magnon–magnon coupling problems.
基金Project supported by the National Natural Science Foundation of China(No.51078164)
文摘An integrated coupling element considering wheel-rail interface for analyzing the dynamic responses of vehicle-rail-bridge interaction system with a non-uniform continuous bridge is presented. The governing equations of the interaction system are established first, and the solution procedure and assembly method of the coupling element are demonstrated. Finally, the accuracy, efficiency and function of the integrated coupling element are tested using two numerical examples. The influences of different combinations of rail and bridge element length in the coupling element on the solution are investigated, and the effects of different rail irregularities on the dynamic responses are discussed.
文摘The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SACCI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ（C,H）6-311G？？（I）. The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604200)the National Natural Science Foundation of China(Grant No.12261131495)Institute of Systems Science,Beijing Wuzi University(Grant No.BWUISS21).
文摘The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.
基金This work was financially supported by the National Natural Science Foundation of China (No.10074005)
文摘The influence of annealing time on the magnetic properties and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons was systematically investigated by the methods of vibrating sample magnetometer （VSM）, X-ray diffraction （XRD） and high resolution transmission electron microscopy （HRTEM）. Interaction domains derived from strong exchange coupling interactions between hard and soft magnetic grains were imaged using magnetic force microscopy （MFM）. Maximum remanence, intrinsic coercivity, and maximum energy product values were obtained in the ribbons annealed at 700℃ for 15 min, which were composed of Pr2（Fe, Co）14B, α-（Fe, Co）, and slight Pr2（Fe, CO）17 phases. Although Jr, Hci, and （Bn）max decreased gradually with further increase of annealing time, it is emphasized that comparatively high Jr and Hci and （BH）max were obtained in a wide annealing time period of 15 to 360 min. The shape of initial magnetization curves and hysteresis loops change as a function of annealing time, indicating different magnetization reversal routes, which can be fully explained by the corresponding microstructure.
基金Project supported by the National Natural Science Foundation of China(No.11972112)the Fundamental Research Funds for the Central Universities of China(Nos.N2103024 and N2103002)the Major Projects of Aero-Engines and Gasturbines(No.J2019-I-0008-0008)。
文摘The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous literature.The parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more complex than that of a single pipe.However,there are few reports about the dynamic characteristics of the PLFPs.Therefore,this paper proposes improved frequency modeling and solution for the PLFPs,involving the logical alignment principle and coupled matrix processing.The established model incorporates both the fluid-structure interaction(FSI)and the structural coupling of the PLFPs.The validity of the established model is verified by modal experiments.The effects of some unique parameters on the dynamic characteristics of the PLFPs are discussed.This work provides a feasible method for solving the FSI of multiple pipes in parallel and potential theoretical guidance for the dynamic analysis of the PLFPs in engineering.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51172030,11274052,51102019,51172208,and 61274015)the National Basic Research Program of China(Grant No.2010CB923200)
文摘The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon （GMR） waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR, The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.
文摘The development and rapid usage of numerical codes for fluid-structure interaction(FSI) problems are of great relevance to researchers in many engineering fields such as civil engineering and ocean engineering. This multidisciplinary field known as FSI has been expanded to engineering fields such as offshore structures, tall slender structures and other flexible structures applications. The motivation of this paper is to investigate the numerical model of two-way coupling FSI partitioned flexible plate structure under fluid flow. The adopted partitioned method and approach utilized the advantage of the existing numerical algorithms in solving the two-way coupling fluid and structural interactions. The flexible plate was subjected to a fluid flow which causes large deformation on the fluid domain from the oscillation of the flexible plate. Both fluid and flexible plate are subjected to the interaction of load transfer within two physics by using the strong and weak coupling methods of MFS and Load Transfer Physics Environment, respectively. The oscillation and deformation results have been validated which demonstrate the reliability of both strong and weak method in resolving the two-way coupling problem in contribution of knowledge to the feasibility field study of ocean engineering and civil engineering.
文摘The scalar and vector running coupling constants are derived using the renormalization group method in the σ-ω model. The numerical values of the two running coupling constants are obtained and the physical meaning of the result is discussed.
基金Project supported by the Scientific Research Fund of Hunan Provincial Education Department, China (Grant Nos. 08B028 and 10A075)the Natural Science Foundation of Hunan Province, China (Grant No. 08jj6043)
文摘In a three-sphere system, the middle sphere is acted upon by two opposite depletion forces from the other two spheres. It is found that, in this system, the two depletion forces are coupled with each other and result in a strengthened depletion force. So the difference of the depletion forces of the three-sphere system and its corresponding two two-sphere systems is introduced to describe the coupling effect of the depletion interactions. The numerical results obtained by Monte- Carlo simulations show that this coupling effect is affected by both the concentration of small spheres and the geometrical confinement. Meanwhile, it is also found that the mechanisms of the coupling effect and the effect on the depletion force from the ~eometry factor are the same.
基金Research on the formation mechanism and prediction theories of major climatic calamities in China a first initiated project in the Development Plan for National Key Fundamental Research Natural Science Foundation of China (49575261) Natural Science Fo
文摘Diagnostic studies have been done of the seasonal and interdecadal variations of the coupling patterns for the air-sea interactions in the northern Pacific region, by using 500-hPa geopotential height field of the Northern Hemisphere and monthly mean SST field of northern Pacific Ocean (1951 ~ 1995) and with the aid of the Singular Value Decomposition (SVD) technique. The results show that: (1) The distribution patterns of SVD, which link with the El Ni駉 (or La Ni馻) events, are important in the interaction between the atmosphere and ocean while the atmosphere, coupling with it, varies like the PNA teleconnection does. The coupling of air-sea interactions is the highest in the winter (January), specifically linking the El Ni駉 event with the PNA pattern in the geopotential height field. Of the four seasons, summer has the poorest coupling when the 500-hPa geopotential height field corresponding to the La Ni馻 event displays patterns similar to the East Asian-Pacific one (PJ). The spring and autumn are both transitional and the coupling is less tight in the autumn than in the spring. (2) Significant changes have taken place around 1976 in the pattern of air-sea coupling, with the year抯 winter having intensified PNA pattern of 500-hPa winter geopotential height field, deepened Aleutian low that moves southeast and the summer following it having outstanding PJ pattern of 500-hPa geopotential height field, which is not so before 1976.
文摘The multi-physics simulation of coupled fluid-structure interaction problems, with disjoint fluid and solid domains, requires one to choose a method for enforcing the fluid-structure coupling at the interface between solid and fluid. While it is common knowledge that the choice of coupling technique can be very problem dependent, there exists no satisfactory coupling comparison methodology that allows for conclusions to be drawn with respect to the comparison of computational cost and solution accuracy for a given scenario. In this work, we develop a computational framework where all aspects of the computation can be held constant, save for the method in which the coupled nature of the fluid-structure equations is enforced. To enable a fair comparison of coupling methods, all simulations presented in this work are implemented within a single numerical framework within the deal.ii [1] finite element library. We have chosen the two-dimensional benchmark test problem of Turek and Hron [2] as an example to examine the relative accuracy of the coupling methods studied;however, the comparison technique is equally applicable to more complex problems. We show that for the specific case considered herein the monolithic approach outperforms partitioned and quasi-direct methods;however, this result is problem dependent and we discuss computational and modeling aspects which may affect other comparison studies.
文摘The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was proved by the numerical result that the depletion interactions in the three-sphere system are larger than that of the corresponding two-sphere system. Furthermore, we find that the mechanisms of the coupling effect and the effect on depletion force from the geometry factor are the same. In addition, the numerical results also show that this coupling effect will be affected by both the volume fraction and separation of three-sphere system.
文摘The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coupling effect is affected by the size ratio of large- to small-sphere: the larger the size ratio is, the larger the coupling effect will be.
文摘The influence of power-low long-range interactions （LRI） and helicoidal coupling （HC） on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase （RNAP） binds to it at the physiological temperature is analytically and numerically investigated in this paper. We have made an analogy with the Heisenberg model Hamiltonian of an anisotropic spin ladder with ferromagnetic legs and anti-ferromagnetic rung coupling. When we limit ourselves to the second-order terms in the Taylor expansion, the DNA dynamics is found to be governed by a completely integrable nonlinear Schr？dinger （NLS） equation. In this case, results show that increasing the value of HC force or LRI parameter enhances the bubble height and reduces the number of base pairs which form the bubble. For the fourth-order terms in a Taylor expansion, results are closely resembling those of second-order terms, and are confirmed by numerical investigation. These results match with some experimental data and thus provide a better representation of the base pairs opening in DNA which is essential for the transcription process.
文摘Taking α-Fe and Nd_2Fe_(14)B grains as example, the grain size dependence of the exchange-coupling interaction and effective anisotropy and also their variations depending on the ratio of magnetically soft and hard grain sizes, D_s∶D_h, were investigated. When grain size D>L_(ex), the grain’s anisotropy is the statistic value of the coupled and uncoupled part. The anisotropy constant of uncoupled part is the common value K_1 and that of coupled part varies with the distance to the grain surface. The effective anisotropy constant between magnetically soft and hard grains, K_(eff), can be expressed as the sum of the products of volume fractions for soft and hard grains, respectively, and the corresponding mean anisotropy constants. The calculation results indicate that the exchange-coupling interaction is enhanced with the reduction of grain size, and the effective anisotropy decreases with reducing grain size and increasing ratio of D_s∶D_h. In order to get high effective anisotropy constant, K_(eff), in composite magnetically soft-hard grains, the hard grain size should be larger than 30 nm and the soft grain size should be about 10 nm.
文摘Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform structure, interactive phenomena of solitons are discussed, especially in the two-soliton case. It is found that different interactive behaviours of solitary waves take place under different parameter conditions of overtaking collision in this system. It is verified that the elastic interaction phenomena exist in this （1＋1）-dimensional integrable coupled model.
基金Major Program of the National Natural Science Foundation of China,No.41590840,No.41590842
文摘Global urbanization is exerting severe stress and having far-reaching impacts on the eco-environment, and yet there exists a complex non-linear coupling relationship between the two. Research on the interactive coupling effect between urbanization and the eco-environment will be a popular area of study and frontier in international earth system science and sustainability science in the next 10 years, while also being a high-priority research topic of particular interest to international organizations. This paper systematically collates and summarizes the international progress made in research on interactive coupling theory, coupling relationships, coupling mechanisms, coupling laws, coupling thresholds, coupling models and coupling optimization decision support systems. The research shows that urbanization and eco-environment interactive coupling theories include the Kuznets curve theory, telecoupling theory, planetary boundaries theory, footprint family theory and urban metabolism theory; most research on interactive coupling relationships is concerned with single- element coupling relationships, such as those between urbanization and water, land, atmosphere, climate change, ecosystems and biodiversity; the majority of research on interactive coupling mechanisms and laws focuses on five research paradigms, including coupled human and nature systems, complex social-ecological systems, urban ecosystems, social-economic-natural complex ecosystems, and urbanization development and eco-environment constraint ring; the majority of interactive coupling simulations use STIRPAT models, coupling degree models, multi-agent system models and big data urban computer models; and research has been carried out on urbanization and eco-environment coupling thresholds, coercing risk and optimal decision support systems. An objective evaluation of progress in international research on interactive coupling between urbanization and the eco-environment suggests that there are six main research focal points and six areas lacking research： a lot of research exists on macroscopic coupling effects, with little research on urban agglomeration and scale coupling effects; considerable research exists on sin-gle-dimension coupling effects, with little on multiple-dimension coupling effects; a great deal exists on ＂one-to-one＂ dual- element coupling effects, with little on ＂many-to-many＂ multiple-element coupling effects; a lot exists on positive feedback coupling effects, and little on negative feedback coupling effects; a great deal exists on empirical coupling effects, and little on theoretical coupling effects; a great deal exists on the use of simple quantitative methods, and little on using integrated simulation methods. Future studies should focus on coupling effects between urbanization in urban agglomerations and the eco-environment, spatial scale coupling effects, multi-dimensional coupling effects, telecoupling effects, ＂one-to-many＂ and ＂many-to-many＂ element coupling effects, and positive and negative feedback coupling effects. There is also a need to strengthen the development and application of dynamic models for multi-element,-scale,-scenario,-module and-agent integrated spatiotemporal coupling systems and further improve theoretical innovations in coupling effect research and integrate and form complete and diverse coupling theoretical systems.
基金supported by the National Natural Science Foundation of China(51879159,51490675,11432009,and 51579145)Chang Jiang Scholars Program(T2014099)+3 种基金Shanghai Excellent Academic Leaders Program(17XD1402300)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(2013022)Innovative Special Project of Numerical Tank of Ministry of Industry and Information Technology of China(2016-23/09)Lloyd’s Register Foundation for doctoral student
文摘Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynamic slamming on marine vessels,tsunami impact on onshore structures,and sloshing in liquid containers)have aroused huge challenges to ocean engineering fields.In this paper,the moving particle semi-implicit(MPS)method and finite element method(FEM)coupled method is proposed for use in numerical investigations of the interaction between a regular wave and a horizontal suspended structure.The fluid domain calculated by the MPS method is dispersed into fluid particles,and the structure domain solved by the FEM method is dispersed into beam elements.The generation of the 2D regular wave is firstly conducted,and convergence verification is performed to determine appropriate particle spacing for the simulation.Next,the regular wave interacting with a rigid structure is initially performed and verified through the comparison with the laboratory experiments.By verification,the MPS-FEM coupled method can be applied to fluid-structure interaction(FSI)problems with waves.On this basis,taking the flexibility of structure into consideration,the elastic dynamic response of the structure subjected to the wave slamming is investigated,including the evolutions of the free surface,the variation of the wave impact pressures,the velocity distribution,and the structural deformation response.By comparison with the rigid case,the effects of the structural flexibility on wave-elastic structure interaction can be obtained.
