This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding verti...This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and stiffness.Testing involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the control.Failures typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.展开更多
This paper presents a new approach to synthesize admittance function polynomials and coupling matrices for coupled resonator filters. The N + 2 transversal network method is applied to study a coupled resonator f...This paper presents a new approach to synthesize admittance function polynomials and coupling matrices for coupled resonator filters. The N + 2 transversal network method is applied to study a coupled resonator filter. This method allowed us to determine the polynomials of the reflection and transmission coefficients. A study is made for a 4 poles filter with 2 transmission zeros between the N + 2 transversal network method and the one found in the literature. A MATLAB code was designed for the numerical simulation of these coefficients for the 6, 8, and 10 pole filter with 4 transmission zeros.展开更多
Background: Transversal competences are included in the United Nations Organization 2030 Agenda for the formation of staff professional in higher education, having disciplinary and transversal skills to develop indivi...Background: Transversal competences are included in the United Nations Organization 2030 Agenda for the formation of staff professional in higher education, having disciplinary and transversal skills to develop individual, professional, social, and entrepreneurship at present time, creative individuals being able to solve social problems via collaboration. The aim was to evaluate the transversal competences developed by graduates, specialists in nursing with the accompaniment of clinic tutorship. Methods: Qualitative, phenomenological, and interpretative research. The informants were seven graduates from the Unique Program of Nursing Specialties (UPNS), from the National Autonomous University of Mexico (UNAM), one participant from each knowledge field: Nursing in the Elderly, Public Health, Neurology, Physical and Sports Culture, Oncology, and two participants from Adult in Critical Condition. Information collection was through a focal group, and data analysis according to the principles of Souza Minayo. Signed informed consent was obtained previously. Results: Five categories with 24 sub-categories emerged. Category 1, Student’s perception on clinic tutorship specialty. Category 2, Competences promoted by clinic tutorship according to student’s experience. Category 3, Experiences about clinic tutorship planning. Category 4, Challenges faced by the student in the evaluation of clinic tutorship. Category 5, Opportunity fields in clinic tutorship from students’ experiences. Conclusion: Graduate students from the specialties describe transversal competences related with decision taking, collaborative work, and increase of population welfare, as well as generic disciplinary competences. The analogy of a social hinge between the clinic tutor and the student is highlighted, which allows to identify mobile and fixed components while the bolt that binds mentor with mentee is learning, by means of the accompaniment by an expert. .展开更多
Commensurate and incommensurate Haldane phases for a spin-1 bilinear-biquadratic model are investigated using an infinite matrix product state algorithm.The bipartite entanglement entropy can detect a transition point...Commensurate and incommensurate Haldane phases for a spin-1 bilinear-biquadratic model are investigated using an infinite matrix product state algorithm.The bipartite entanglement entropy can detect a transition point between the two phases.In both phases,the entanglement spectrum shows double degeneracy.We calculate the nonlocal order parameter of the bond-centered inversion in both phases,which rapidly approaches a saturation value of-1 as the segment length increases.The nonlocal order parameter of the bond-centered inversion with a saturation value-1 and the nonzero value string order indicate that the Haldane phase is a symmetry-protected topological phase.To distinguish the commensurate and incommensurate Haldane phases,the transversal spin correlation and corresponding momentum distribution of the structure factor are analyzed.As a result,the transversal spin correlations exhibit different decay forms in both phases.展开更多
Applying the theory of stratification, the solution space structure about a class of deformed Navier-Stokes equation is determined. It is proved that such kind of equation has no C-k( k greater than or equal to2) stab...Applying the theory of stratification, the solution space structure about a class of deformed Navier-Stokes equation is determined. It is proved that such kind of equation has no C-k( k greater than or equal to2) stable solution by the fact that the strate transversale is a null set.展开更多
Ditroid is a directed version of matroid. In this paper we investigate transversal theory of ditroids. Directed versions of Rado-Hall and Edmonds-Fulkerson theorems are obtained. Our results provide partial answers to...Ditroid is a directed version of matroid. In this paper we investigate transversal theory of ditroids. Directed versions of Rado-Hall and Edmonds-Fulkerson theorems are obtained. Our results provide partial answers to two questions raised by L. Qi.展开更多
Based on genetic algorithm and neural network algorithm,the finite element analyses on the temperature fields and stress fields of multi-track laser cladding were carried out by using the ANSYS software.The results sh...Based on genetic algorithm and neural network algorithm,the finite element analyses on the temperature fields and stress fields of multi-track laser cladding were carried out by using the ANSYS software.The results show that,in the multi-track cladding process,the temperature field ellipse leans to the cladding formed,and the front cladding has preheating function on the following cladding.During cladding,the longitudinal stress is the largest,the lateral stress is the second,and the thickness direction stress is the smallest.The center of the cladding is in the tensile stress condition.The longitudinal tensile stress is higher than the lateral or thickness direction stress by several times,and the tensile stress achieves the maximum at the area of joint between the cladding and substrate.Therefore,it is inferred that transversal crack is the most main crack form in multi-track laser cladding.Moreover,the joint between cladding and substrate is the crack sensitive area,and this is consistent with the actual experiments.展开更多
AIM:To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship b...AIM:To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship between postoperative endothelial cell loss and the phacoemulsification parameters, as well as the other factors in both groups.METHODS:This prospective observational study was comprised of consecutive eligible cataract patients operated with phacoemulsification technique performed by the same surgeon using either a WHITESTAR Signature Ellips FX(transversal, group 1) or Infiniti OZil IP(torsional, group 2) machine.RESULTS:The study included 86 patients. Baseline characteristics in the groups were similar. The median nuclear sclerosis grade was 3(2-4) in the first group and2(2-4) in the second group(P =0.265). Both groups had similar phacoemulsification needle times(group 1: 60.63±36 s; group 2: 55.98±30 s; P =0.789). The percentage of endothelial cell loss 30 d after surgery ranged from 3% to15% with a median of 7% in group 1, and from 2% to13% with a median of 6% in group 2; however, there was no statistically significant difference between the groups(P =0.407). Hexagonality(P =0.794) and the coefficient of variation(CV; P =0.142) did not differ significantly between the groups before and 30 d after surgery. Asignificant positive correlation was found between the endothelial cell loss and nuclear sclerosis grade(group1: P 【0.001; group 2: P 【0.001) and between the endothelial cell loss and average phacoemulsification power(group 1: P =0.007; group 2: P =0.008).CONCLUSION:Both of these machines were efficient,with similar endothelial cell loss. This endothelial cell loss was related to the increased nuclear sclerosis grade and increased phacoemulsification power.展开更多
The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to effici...The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to efficiently reduce the influence of CO2 spring-out.Moreover, collar insertion depth substantially affected soil respiration measurement, i.e. when collar was shallowly inserted into soil,transversal gas diffusion and the CO2 re-spring-out caused by unstable collars in the measurement could lead to overestimating soil respiration rate; however, when collar was deeply inserted into soil, root respiration decline caused by root-cut and the most active respiratory of the surface soil separated by the inserted collars could lead to underestimating soil respiration rate. Furthermore, an error less than 5% could be guaranteed in typical sunny day if the target [CO2] was set to the mean value of ambient [CO2] in most time of the day, but it should be carefully set in early morning and late afternoon according to changing ambient [CO2]. This protocol of measurement is useful in real measurement.展开更多
Finite volume schemes for the two-dimensional(2D) wave system are taken to demonstrate the role of the genuine dimensionality of Lax-Wendroff flow solvers for compressible fluid flows. When the finite volume schemes a...Finite volume schemes for the two-dimensional(2D) wave system are taken to demonstrate the role of the genuine dimensionality of Lax-Wendroff flow solvers for compressible fluid flows. When the finite volume schemes are applied, the transversal variation relative to the computational cell interfaces is neglected, and only the normal numerical flux is used, thanks to the Gauss-Green formula. In order to offset such defects, the Lax-Wendroff flow solvers or the generalized Riemann problem(GRP) solvers are adopted by substituting the time evolution of flows into the spatial variation. The numerical results show that even with the same convergence rate, the error by the GRP2D solver is almost one ninth of that by the multistage Runge-Kutta(RK) method.展开更多
The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connec...The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.展开更多
The topological characteristics for the basic system of equations of atmospheric motion were analyzed with the help of method provided by stratification theory. It was proved that in the local rectangular coordinate s...The topological characteristics for the basic system of equations of atmospheric motion were analyzed with the help of method provided by stratification theory. It was proved that in the local rectangular coordinate system the basic system of equations of atmospheric motion is stable in infinitely differentiable function class. In the sense of local solution, the necessary and sufficient conditions by which the typical problem for determining solution is well posed were also given. Such problems as something about "speculating future from past" in atmospheric dynamics and how to amend the conditions for determining solution as well as the choice of underlying surface when involving the practical application were further discussed. It is also pointed out that under the usual conditions, three motion equations and continuity equation in the basic system of equations determine entirely the property of this system of equations.展开更多
Based on the nonlocal nonlinear Schr6dinger equation, the propagation properties of anomalous hollow beams in strongly isotropic nonlocal media are investigated. The analytical expressions of the beam propagation, the...Based on the nonlocal nonlinear Schr6dinger equation, the propagation properties of anomalous hollow beams in strongly isotropic nonlocal media are investigated. The analytical expressions of the beam propagation, the on-axis intensity and the beam width are obt.ained. The results show that the evolution of the beam is periodical and the input power is the most important parameter. The input power determines the variation of the period. Furthermore, it is found that there exists a critical input power in the x direction and in the y direction separately when the initial beam widths in the two transversal directions are unequal. The beam width remains invariant in the corresponding transversal direction when the input power equals the critical power in one of the transversal directions. Selecting a properinput power, the beam can be broadened or compressed in the two transversal directions at the same time, In particular, the beam can be broadened (compressed) in one transversal direction, whereas in the other transversal direction, it is compressed (broadened), i.e., the transversal reverse transformation.展开更多
The double plate system with a discontinuity in the elastic bonding layer of Winker type is studied in this paper. When the discontinuity is small, it can be taken as an interface crack between the bi-materials or two...The double plate system with a discontinuity in the elastic bonding layer of Winker type is studied in this paper. When the discontinuity is small, it can be taken as an interface crack between the bi-materials or two bodies (plates or beams). By comparison between the number of multifrequencies of analytical solutions of the double plate system free transversal vibrations for the case when the system is with and without disconti- nuity in elastic layer we obtain a theory for experimental vibration method for identification of the presence of an interface crack in the double plate system. The analytical analysis of free transversal vibrations of an elastically connected double plate systems with discontinuity in the elastic layer of Winkler type is presented. The analytical solutions of the coupled partial differential equations for dynamical free and forced vibration processes are obtained by using method of Bernoulli's particular integral and Lagrange's method of variation constants. It is shown that one mode vibration corresponds an infinite or finite multi-frequency regime for free and forced vibrations induced by initial conditions and one- frequency or corresponding number of multi-frequency regime depending on external excitations. It is shown for every shape of vibrations. The analytical solutions show that the discontinuity affects the appearance of multi-frequency regime of time function corresponding to one eigen amplitude function of one mode, and also that time functions of different vibration basic modes are coupled. From final expression we can separate the newgeneralized eigen amplitude functions with correspon- ding time eigen functions of one frequency and multifrequency regime of vibrations.展开更多
In this paper,the concept of right adequate transversals of rpp semigroups is introduced.We establish the structure of rpp semigroups with multiplicative right adequate transversals in terms of right normal bands and ...In this paper,the concept of right adequate transversals of rpp semigroups is introduced.We establish the structure of rpp semigroups with multiplicative right adequate transversals in terms of right normal bands and right adequate semigroups.In particular, some special cases are considered.展开更多
In this paper, the completed stochastic web and incompleted stochastic web produced by the perturbed saddle separatrix net are given. The structural properties of two kinds of web are discussed by means of the dynamic...In this paper, the completed stochastic web and incompleted stochastic web produced by the perturbed saddle separatrix net are given. The structural properties of two kinds of web are discussed by means of the dynamical system theory.展开更多
In this paper, we discuss some properties about an abundant semigroup with a quasi-ideal adequate transversal. Moreover, we show that the product of two quasi-ideal adequate transversals of an abundant semigroup which...In this paper, we discuss some properties about an abundant semigroup with a quasi-ideal adequate transversal. Moreover, we show that the product of two quasi-ideal adequate transversals of an abundant semigroup which satisfies some conditions is a quasiideal adequate transversal.展开更多
In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to syn...In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to synthesize discrimination waveform,so the poles extractionprocedure is not required.Particularly,it can successfully operate on the case that the poles ofthe target are weakly dependent on the aspect angle.展开更多
The ground state of a generalized Frenkel–Kontorova model with a transversal degree of freedom is studied.When the coupling strength,K,and the frequency of a single−atom vibration in the transversal direction,ω0y,ar...The ground state of a generalized Frenkel–Kontorova model with a transversal degree of freedom is studied.When the coupling strength,K,and the frequency of a single−atom vibration in the transversal direction,ω0y,are increased,the ground state of the model undergoes a transition from a two−dimensional configuration to a one-dimensional one.This transition can manifest in different ways.Furthermore,we find that the prerequisite of a two-dimensional ground state isθ≠1/q.展开更多
文摘This article presents a study on the structural behavior of transversely prestressed laminated timber slabs,focusing on an innovative approach:vertically misaligned lamellae.This misalignment,achieved by sliding vertically the wooden lamellae rather than aligning them,enhances the slab’s cross-section moment of inertia,thereby improving load-bearing capacity and stiffness.Testing involved two groups of structural size specimens:one with vertically aligned lamellae(control group)and the other with misaligned lamellae(study group).Results showed the study group exhibited 42%superior stiffness and 10%less load capacity compared to the control.Failures typically occurred individually in the lamellae,particularly in those with defects or lower modulus of elasticity,concentrated in the middle third of the slabs’free span where tensile stresses peak.Despite a higher number of failed lamellae,the study group demonstrated promising performance.Analysis of prestressing bar indicated no damage at all in the thread,suggesting potential for reducing bar diameter.These findings offer crucial insights into applying these slabs in timber construction as well as to any kind of construction.
文摘This paper presents a new approach to synthesize admittance function polynomials and coupling matrices for coupled resonator filters. The N + 2 transversal network method is applied to study a coupled resonator filter. This method allowed us to determine the polynomials of the reflection and transmission coefficients. A study is made for a 4 poles filter with 2 transmission zeros between the N + 2 transversal network method and the one found in the literature. A MATLAB code was designed for the numerical simulation of these coefficients for the 6, 8, and 10 pole filter with 4 transmission zeros.
文摘Background: Transversal competences are included in the United Nations Organization 2030 Agenda for the formation of staff professional in higher education, having disciplinary and transversal skills to develop individual, professional, social, and entrepreneurship at present time, creative individuals being able to solve social problems via collaboration. The aim was to evaluate the transversal competences developed by graduates, specialists in nursing with the accompaniment of clinic tutorship. Methods: Qualitative, phenomenological, and interpretative research. The informants were seven graduates from the Unique Program of Nursing Specialties (UPNS), from the National Autonomous University of Mexico (UNAM), one participant from each knowledge field: Nursing in the Elderly, Public Health, Neurology, Physical and Sports Culture, Oncology, and two participants from Adult in Critical Condition. Information collection was through a focal group, and data analysis according to the principles of Souza Minayo. Signed informed consent was obtained previously. Results: Five categories with 24 sub-categories emerged. Category 1, Student’s perception on clinic tutorship specialty. Category 2, Competences promoted by clinic tutorship according to student’s experience. Category 3, Experiences about clinic tutorship planning. Category 4, Challenges faced by the student in the evaluation of clinic tutorship. Category 5, Opportunity fields in clinic tutorship from students’ experiences. Conclusion: Graduate students from the specialties describe transversal competences related with decision taking, collaborative work, and increase of population welfare, as well as generic disciplinary competences. The analogy of a social hinge between the clinic tutor and the student is highlighted, which allows to identify mobile and fixed components while the bolt that binds mentor with mentee is learning, by means of the accompaniment by an expert. .
基金the National Natural Science Foundation of China(Grant No.11805285)the Natural Science Foundation of Shaanxi Province of China(Grant No.2022JM-033)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN 201900703)。
文摘Commensurate and incommensurate Haldane phases for a spin-1 bilinear-biquadratic model are investigated using an infinite matrix product state algorithm.The bipartite entanglement entropy can detect a transition point between the two phases.In both phases,the entanglement spectrum shows double degeneracy.We calculate the nonlocal order parameter of the bond-centered inversion in both phases,which rapidly approaches a saturation value of-1 as the segment length increases.The nonlocal order parameter of the bond-centered inversion with a saturation value-1 and the nonzero value string order indicate that the Haldane phase is a symmetry-protected topological phase.To distinguish the commensurate and incommensurate Haldane phases,the transversal spin correlation and corresponding momentum distribution of the structure factor are analyzed.As a result,the transversal spin correlations exhibit different decay forms in both phases.
文摘Applying the theory of stratification, the solution space structure about a class of deformed Navier-Stokes equation is determined. It is proved that such kind of equation has no C-k( k greater than or equal to2) stable solution by the fact that the strate transversale is a null set.
文摘Ditroid is a directed version of matroid. In this paper we investigate transversal theory of ditroids. Directed versions of Rado-Hall and Edmonds-Fulkerson theorems are obtained. Our results provide partial answers to two questions raised by L. Qi.
基金Project(HIT(WH)200711)supported by the Study Fund of Harbin Institute of Technology at Weihai,China。
文摘Based on genetic algorithm and neural network algorithm,the finite element analyses on the temperature fields and stress fields of multi-track laser cladding were carried out by using the ANSYS software.The results show that,in the multi-track cladding process,the temperature field ellipse leans to the cladding formed,and the front cladding has preheating function on the following cladding.During cladding,the longitudinal stress is the largest,the lateral stress is the second,and the thickness direction stress is the smallest.The center of the cladding is in the tensile stress condition.The longitudinal tensile stress is higher than the lateral or thickness direction stress by several times,and the tensile stress achieves the maximum at the area of joint between the cladding and substrate.Therefore,it is inferred that transversal crack is the most main crack form in multi-track laser cladding.Moreover,the joint between cladding and substrate is the crack sensitive area,and this is consistent with the actual experiments.
文摘AIM:To compare and evaluate the phacoemulsification parameters and postoperative endothelial cell changes of two different phacoemulsification machines, each with different modes, but also to assess the relationship between postoperative endothelial cell loss and the phacoemulsification parameters, as well as the other factors in both groups.METHODS:This prospective observational study was comprised of consecutive eligible cataract patients operated with phacoemulsification technique performed by the same surgeon using either a WHITESTAR Signature Ellips FX(transversal, group 1) or Infiniti OZil IP(torsional, group 2) machine.RESULTS:The study included 86 patients. Baseline characteristics in the groups were similar. The median nuclear sclerosis grade was 3(2-4) in the first group and2(2-4) in the second group(P =0.265). Both groups had similar phacoemulsification needle times(group 1: 60.63±36 s; group 2: 55.98±30 s; P =0.789). The percentage of endothelial cell loss 30 d after surgery ranged from 3% to15% with a median of 7% in group 1, and from 2% to13% with a median of 6% in group 2; however, there was no statistically significant difference between the groups(P =0.407). Hexagonality(P =0.794) and the coefficient of variation(CV; P =0.142) did not differ significantly between the groups before and 30 d after surgery. Asignificant positive correlation was found between the endothelial cell loss and nuclear sclerosis grade(group1: P 【0.001; group 2: P 【0.001) and between the endothelial cell loss and average phacoemulsification power(group 1: P =0.007; group 2: P =0.008).CONCLUSION:Both of these machines were efficient,with similar endothelial cell loss. This endothelial cell loss was related to the increased nuclear sclerosis grade and increased phacoemulsification power.
基金National Natural Science Foundation of China (30300271),Program of Key Basic Research from Ministry of Science and Technology (2004CCA02700) and Sina-Japan cooperation project on larch forest study.
文摘The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to efficiently reduce the influence of CO2 spring-out.Moreover, collar insertion depth substantially affected soil respiration measurement, i.e. when collar was shallowly inserted into soil,transversal gas diffusion and the CO2 re-spring-out caused by unstable collars in the measurement could lead to overestimating soil respiration rate; however, when collar was deeply inserted into soil, root respiration decline caused by root-cut and the most active respiratory of the surface soil separated by the inserted collars could lead to underestimating soil respiration rate. Furthermore, an error less than 5% could be guaranteed in typical sunny day if the target [CO2] was set to the mean value of ambient [CO2] in most time of the day, but it should be carefully set in early morning and late afternoon according to changing ambient [CO2]. This protocol of measurement is useful in real measurement.
基金Project supported by the National Natural Science Foundation of China(Nos.11771054 and 91852207)
文摘Finite volume schemes for the two-dimensional(2D) wave system are taken to demonstrate the role of the genuine dimensionality of Lax-Wendroff flow solvers for compressible fluid flows. When the finite volume schemes are applied, the transversal variation relative to the computational cell interfaces is neglected, and only the normal numerical flux is used, thanks to the Gauss-Green formula. In order to offset such defects, the Lax-Wendroff flow solvers or the generalized Riemann problem(GRP) solvers are adopted by substituting the time evolution of flows into the spatial variation. The numerical results show that even with the same convergence rate, the error by the GRP2D solver is almost one ninth of that by the multistage Runge-Kutta(RK) method.
基金the Ministry of Sciences and Enviromental Protection of Republic Serbia through Mathematical Institute SANU Belgrade Grants No.ON144002
文摘The study of energy transfer between coupled subsystems in a hybrid system is very important for applications. This paper presents an analytical analysis of energy transfer between plates of a visco-elastically connected double-plate system in free transversal vibrations. The analytical analysis shows that the visco-elastic connection between plates is responsible for the appearance of two-frequency regime in the time function, which corresponds to one eigen amplitude function of one mode, and also that time functions of different vibration modes are uncoupled, but energy transfer between plates in one eigen mode appears. It was shown for each shape of vibrations. Series of the two Lyapunov exponents corresponding to the one eigen amplitude mode are expressed by using the energy of the corresponding eigen amplitude time component.
基金Project supported by the National Natural Science Foundation of China(Nos.40175014,90411006)
文摘The topological characteristics for the basic system of equations of atmospheric motion were analyzed with the help of method provided by stratification theory. It was proved that in the local rectangular coordinate system the basic system of equations of atmospheric motion is stable in infinitely differentiable function class. In the sense of local solution, the necessary and sufficient conditions by which the typical problem for determining solution is well posed were also given. Such problems as something about "speculating future from past" in atmospheric dynamics and how to amend the conditions for determining solution as well as the choice of underlying surface when involving the practical application were further discussed. It is also pointed out that under the usual conditions, three motion equations and continuity equation in the basic system of equations determine entirely the property of this system of equations.
基金supported by the National Natural Science Foundation of China(Grant Nos.61308016,11374089,and 11347121)the Natural Science Foundationof Hebei Province,China(Grant Nos.A2012205023,F2012205076,and A2012205085)+3 种基金the Natural Science Foundation of Hunan Province,China(GrantNo.13JJ4097)the China Postdoctoral Science Foundation(Grant No.2014M551041)the Research Foundation of Education Bureau of Hebei Province,China(Grant No.ZD20131014)Hebei Normal University Foundation,China(Grant No.L2011B06)
文摘Based on the nonlocal nonlinear Schr6dinger equation, the propagation properties of anomalous hollow beams in strongly isotropic nonlocal media are investigated. The analytical expressions of the beam propagation, the on-axis intensity and the beam width are obt.ained. The results show that the evolution of the beam is periodical and the input power is the most important parameter. The input power determines the variation of the period. Furthermore, it is found that there exists a critical input power in the x direction and in the y direction separately when the initial beam widths in the two transversal directions are unequal. The beam width remains invariant in the corresponding transversal direction when the input power equals the critical power in one of the transversal directions. Selecting a properinput power, the beam can be broadened or compressed in the two transversal directions at the same time, In particular, the beam can be broadened (compressed) in one transversal direction, whereas in the other transversal direction, it is compressed (broadened), i.e., the transversal reverse transformation.
文摘The double plate system with a discontinuity in the elastic bonding layer of Winker type is studied in this paper. When the discontinuity is small, it can be taken as an interface crack between the bi-materials or two bodies (plates or beams). By comparison between the number of multifrequencies of analytical solutions of the double plate system free transversal vibrations for the case when the system is with and without disconti- nuity in elastic layer we obtain a theory for experimental vibration method for identification of the presence of an interface crack in the double plate system. The analytical analysis of free transversal vibrations of an elastically connected double plate systems with discontinuity in the elastic layer of Winkler type is presented. The analytical solutions of the coupled partial differential equations for dynamical free and forced vibration processes are obtained by using method of Bernoulli's particular integral and Lagrange's method of variation constants. It is shown that one mode vibration corresponds an infinite or finite multi-frequency regime for free and forced vibrations induced by initial conditions and one- frequency or corresponding number of multi-frequency regime depending on external excitations. It is shown for every shape of vibrations. The analytical solutions show that the discontinuity affects the appearance of multi-frequency regime of time function corresponding to one eigen amplitude function of one mode, and also that time functions of different vibration basic modes are coupled. From final expression we can separate the newgeneralized eigen amplitude functions with correspon- ding time eigen functions of one frequency and multifrequency regime of vibrations.
基金Supported by the NNSF of China(10961014)Supported by the NSF of Jiangxi ProvinceSupported by the SF of Education Department of Jiangxi Province(GJJ11388)
文摘In this paper,the concept of right adequate transversals of rpp semigroups is introduced.We establish the structure of rpp semigroups with multiplicative right adequate transversals in terms of right normal bands and right adequate semigroups.In particular, some special cases are considered.
基金The Project supported by the National Natural Science Foundation of China
文摘In this paper, the completed stochastic web and incompleted stochastic web produced by the perturbed saddle separatrix net are given. The structural properties of two kinds of web are discussed by means of the dynamical system theory.
基金Supported by National Natural Science Foundation of China(90818020) Supported by Scientific Research Foundation of China Jiliang University(20060810)
文摘In this paper, we discuss some properties about an abundant semigroup with a quasi-ideal adequate transversal. Moreover, we show that the product of two quasi-ideal adequate transversals of an abundant semigroup which satisfies some conditions is a quasiideal adequate transversal.
文摘In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to synthesize discrimination waveform,so the poles extractionprocedure is not required.Particularly,it can successfully operate on the case that the poles ofthe target are weakly dependent on the aspect angle.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos.10875011 and 11075016the National Basic Research Program of China under Grant No.2007CB814805+2 种基金the Foundation of Doctoral Training(No.20100003110007)the Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation from the Educational Commission of Zhejiang Province(GK100801067).
文摘The ground state of a generalized Frenkel–Kontorova model with a transversal degree of freedom is studied.When the coupling strength,K,and the frequency of a single−atom vibration in the transversal direction,ω0y,are increased,the ground state of the model undergoes a transition from a two−dimensional configuration to a one-dimensional one.This transition can manifest in different ways.Furthermore,we find that the prerequisite of a two-dimensional ground state isθ≠1/q.