期刊文献+
共找到154,991篇文章
< 1 2 250 >
每页显示 20 50 100
Multi-Barycenter Mechanics, N-Body Problem and Rotation of Galaxies and Stars
1
作者 Honglai Zhu 《Journal of Applied Mathematics and Physics》 2023年第10期3251-3273,共23页
In the present paper, the establishment of a systematic multi-barycenter mechanics is based on the multi-particle mechanics. The new theory perfects the basic theoretical system of classical mechanics, which finds the... In the present paper, the establishment of a systematic multi-barycenter mechanics is based on the multi-particle mechanics. The new theory perfects the basic theoretical system of classical mechanics, which finds the law of mutual interaction between particle groups, reveals the limitations of Newton’s third law, discovers the principle of the intrinsic relationship between gravity and tidal force, reasonably interprets the origin and change laws for the rotation angular momentum of galaxies and stars and so on. By applying new theory, the multi-body problem can be transformed into a special two-body problem and for which an approximate solution method is proposed, the motion law of each particle can be roughly obtained. 展开更多
关键词 Multi-Barycenter Mechanics Translation Principle for a Vector System Variation Principle for a Vector Origin and Change Laws for the Rotation Angular Momentum of Galaxies and Stars Multi-Body problem
在线阅读 下载PDF
Solutions of three-body problem based on an equivalent system approach
2
作者 Jing Tang Xing 《Acta Mechanica Sinica》 2026年第1期292-309,共18页
Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fund... Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems. 展开更多
关键词 Three-body problem Equivalent system with solutions Orbit-equation of a conic section Generalised reduced mass Chaotic motions Generalised Kepler’s law n-body problem
原文传递
Centralized Circumcentered-Reflection Method for Solving the Convex Feasibility Problem in Sparse Signal Recovery
3
作者 Chunmei LI Bangjun CHEN Xuefeng DUAN 《Journal of Mathematical Research with Applications》 2026年第1期119-133,共15页
Convex feasibility problems are widely used in image reconstruction, sparse signal recovery, and other areas. This paper is devoted to considering a class of convex feasibility problem arising from sparse signal recov... Convex feasibility problems are widely used in image reconstruction, sparse signal recovery, and other areas. This paper is devoted to considering a class of convex feasibility problem arising from sparse signal recovery. We first derive the projection formulas for a vector onto the feasible sets. The centralized circumcentered-reflection method is designed to solve the convex feasibility problem. Some numerical experiments demonstrate the feasibility and effectiveness of the proposed algorithm, showing superior performance compared to conventional alternating projection methods. 展开更多
关键词 convex feasibility problem centralized circumcentered-re ection method sparse signal recovery compressed sensing
原文传递
Quality-guaranteed Dubins Path Planning for USV Based on Mixed-integer Piecewise linear Programming for Addressing the Extended Minimum-time Intercept Problem
4
作者 Xing Zhou Kelin Zhu +3 位作者 Shuang Liu Zhaoqing Li Wenxin Zhang Kang Du 《哈尔滨工程大学学报(英文版)》 2026年第1期216-227,共12页
During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive... During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h^(2)/(4√2),where h is the piecewise length. 展开更多
关键词 Minimum-time intercept problem Dubins vehicle Mixed-integer piecewise-linear program LINEARIZATION Approximate error trigonometric function USV
在线阅读 下载PDF
Cooperative Metaheuristics with Dynamic Dimension Reduction for High-Dimensional Optimization Problems
5
作者 Junxiang Li Zhipeng Dong +2 位作者 Ben Han Jianqiao Chen Xinxin Zhang 《Computers, Materials & Continua》 2026年第1期1484-1502,共19页
Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when ta... Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems. 展开更多
关键词 Dimension reduction modified principal components analysis high-dimensional optimization problems cooperative metaheuristics metaheuristic algorithms
在线阅读 下载PDF
Nested regular polygon solutions for planar 2N-body problems 被引量:3
6
作者 张世清 周青 《Science China Mathematics》 SCIE 2002年第8期1053-1058,共6页
In this paper we study the necessary conditions for the masses of the nested regular polygon solutions of the planar 2N-body problem.We prove that the masses at the vertices of each regular polygon must be equal to ea... In this paper we study the necessary conditions for the masses of the nested regular polygon solutions of the planar 2N-body problem.We prove that the masses at the vertices of each regular polygon must be equal to each other. 展开更多
关键词 2n-body problems nested regular polygon periodic solutions circulant matrices
原文传递
Geometric characterization for the least Lagrangian action of n-body problems
7
作者 张世清 周青 《Science China Mathematics》 SCIE 2001年第1期15-20,共6页
For n-body problems with quasihomogeneous potentials in ?k (2[ n/2] ? k) we prove that the minimum of the Lagrangian action integral defined on the zero mean loop space is exactly the circles with center at the origin... For n-body problems with quasihomogeneous potentials in ?k (2[ n/2] ? k) we prove that the minimum of the Lagrangian action integral defined on the zero mean loop space is exactly the circles with center at the origin and the configuration of the n-bodies is always a regular n - 1 simplex with fixed side length. 展开更多
关键词 n-body problems Lagrangian action integral homographic solutions
原文传递
Difference Equation for N-body Type Problem
8
作者 Xu LE-SHUN HAN YUE-CAI LIU BAI-FENG 《Communications in Mathematical Research》 CSCD 2009年第5期411-417,共7页
In this paper, the difference equation for N-body type problem is established, which can be used to find the generalized solutions by computing the critical points numerically. And its validity is testified by an exam... In this paper, the difference equation for N-body type problem is established, which can be used to find the generalized solutions by computing the critical points numerically. And its validity is testified by an example from Newtonian Threebody problem with unequal masses. 展开更多
关键词 Difference equation n-bodytype problem critical point
在线阅读 下载PDF
The Orlicz Minkowski Problem for Logarithmic Capacity 被引量:1
9
作者 HE Min LIU Lijuan ZENG Hui 《Wuhan University Journal of Natural Sciences》 2025年第5期471-478,共8页
The Orlicz Minkowski problem for logarithmic capacity seeks to determine the necessary and sufficient conditions for a given finite Borel measure,such that it is the Orlicz logarithmic capacitary measure of a convex b... The Orlicz Minkowski problem for logarithmic capacity seeks to determine the necessary and sufficient conditions for a given finite Borel measure,such that it is the Orlicz logarithmic capacitary measure of a convex body.The Orlicz Minkowski problem for loga-rithmic capacity includes the Minkowski problem for logarithmic capacity and the Lp Minkowski problem for logarithmic capacity as special cases.The discrete case has been solved by the researchers.In this paper,we solve the Orlicz Minkowski problem for logarithmic capacity with respect to general Borel measures by applying an approximation scheme. 展开更多
关键词 Orlicz Minkowski problem capacity convex body
原文传递
Pilot Study of a School-Based Parenting Intervention:Prevention of Emotional and Behavioral Problems among Chinese Children 被引量:1
10
作者 Jin Peng Jiabei He Na Li 《International Journal of Mental Health Promotion》 2025年第7期953-977,共25页
Background:Parenting exerts a profound influence on children’s mental health and behavioral development.Despite the high prevalence of children’s emotional and behavioral problems(CEBP)in China,evidence-based parent... Background:Parenting exerts a profound influence on children’s mental health and behavioral development.Despite the high prevalence of children’s emotional and behavioral problems(CEBP)in China,evidence-based parenting interventions remain scarcely investigated as preventive public health strategies.This pilot study evaluated a school-based intervention for preventing CEBP.Methods:We employed a quasi-experimental design with propensity score matching(PSM)to select 28 families(intervention:n=13;control:n=15)from two matched urban primary schools.Quantitative data from seven validated scales were analyzed using t-tests and ANCOVA.Qualitative insights were derived from 10 semi-structured interviews via thematic analysis.Results:Compared to the control group,the intervention group demonstrated significantly greater improvements in CEBP(p=0.020,Cohen’s d=0.92),parental adjustment(p=0.031,Cohen’s d=0.80),parenting confidence(p=0.003,Cohen’s d=1.04),and parentchild relationships(p=0.001,Cohen’s d=1.46).Non-significant effects were observed for parenting style,parental relationship,and parenting conflict(p>0.05).Qualitative analysis corroborated these findings and further identified contributing factors for non-significant outcomes,including challengeswithmeasurement adaptability and inconsistent co-parenting practices.Conclusions:This pilot study suggests that an authoritative parenting style may be effective and culturally adaptable in China.Positive parenting interventions appear to mitigate CEBP by reducing risk factors and enhancing protective factors.However,improving parental relationships and parenting conflict may require targeted strategies.Given the pilot nature of this PSM-matched study(n=28),the findings should be interpreted as exploratory and used primarily for intervention refinement. 展开更多
关键词 Parenting intervention CHILDREN SCHOOL-BASED China emotional and behavioral problems
暂未订购
THECHORD GAUSS CURVATURE FLOW AND ITS L_(p)CHORDMINKOWSKI PROBLEM 被引量:1
11
作者 Jinrong HU Yong HUANG +1 位作者 Jian LU Sinan WANG 《Acta Mathematica Scientia》 2025年第1期161-179,共19页
In this paper,the L_(p)chord Minkowski problem is concerned.Based on the results shown in[20],we obtain a new existence result of solutions to this problem in terms of smooth measures by using a nonlocal Gauss curvatu... In this paper,the L_(p)chord Minkowski problem is concerned.Based on the results shown in[20],we obtain a new existence result of solutions to this problem in terms of smooth measures by using a nonlocal Gauss curvature flow for p>−n with p≠0. 展开更多
关键词 L_(p)chord Minkowski problem new Monge-Ampere equation geometric fow
在线阅读 下载PDF
On Waring-Goldbach Problem for Two Squares, Two Cubes and Two Fifth Powers
12
作者 LI Jinjiang ZHAO Chenyang +1 位作者 LIU Zishun ZHANG Min 《数学进展》 北大核心 2025年第4期735-748,共14页
Let Pr denote an almost-prime with at most r prime factors,counted according to multiplicity.In this paper,it is proved that,for every sufficiently large even integer N,the equation N=x^(2)+p_(2)^(2)+p_(3)^(3)+p_(4)^(... Let Pr denote an almost-prime with at most r prime factors,counted according to multiplicity.In this paper,it is proved that,for every sufficiently large even integer N,the equation N=x^(2)+p_(2)^(2)+p_(3)^(3)+p_(4)^(3)+p_(5)^(5)+_6^(5)is solvable with being an almost-prime P_(6) and the other variables primes.This result constitutes an enhancement upon the previous result of Hooley[Recent Progress in Analytic Number Theory,Vol.1(Durham,1979),London:Academic Press,1981,127-191]. 展开更多
关键词 Waring-Goldbach problem Hardy-Littlewood method almost-prime sieve method
原文传递
On the Divisor Problem with Congruence Conditions
13
作者 JIA Lirui ZHAI Wenguang CAI Tianxin 《数学进展》 北大核心 2025年第1期1-17,共17页
Let d(n;r_(1),q_(1),r_(2),q_(2))be the number of factorization n=n_(1)n_(2)satisfying n_i≡r_i(mod q_i)(i=1,2)andΔ(x;r_(1),q_(1),r_(2),q_(2))be the error term of the summatory function of d(n;r_(1),q_(1),r_(2),q_(2))... Let d(n;r_(1),q_(1),r_(2),q_(2))be the number of factorization n=n_(1)n_(2)satisfying n_i≡r_i(mod q_i)(i=1,2)andΔ(x;r_(1),q_(1),r_(2),q_(2))be the error term of the summatory function of d(n;r_(1),q_(1),r_(2),q_(2)).Suppose x≥(q_(1)q_(2))^(1+ε),1≤r_i≤q_i,and(r_i,q_i)=1(i=1,2).This paper studies the power moments and sign changes ofΔ(x;r_(1),q_(1),r_(2),q_(2)).We prove that for sufficiently large constant C,Δ(q_(1)q_(2)x:r_(1),q_(1),r_(2),q_(2))changes sign in the interval[T,T+C√T]for any large T.Meanwhile,we show that for small constants c and c,there exist infinitely many subintervals of length c√log^(-7)T in[T,2T]where±Δ(q_(1)q_(2)x:r_(1),q_(1),r_(2),q_(2))>cx^(1/4)always holds. 展开更多
关键词 divisor problem sign change congruence condition
原文传递
A unified M-tree self-correction solver for math word problems
14
作者 Zhiyuan Ma Jiayu Liu Zhenya Huang 《中国科学技术大学学报》 北大核心 2025年第7期26-35,25,I0001,共12页
Automatically answer math word problems is a challenging task in artificial intelligence.Previous solvers constructed mathematical expressions in sequence or binary tree.However,these approaches may suffer from the fo... Automatically answer math word problems is a challenging task in artificial intelligence.Previous solvers constructed mathematical expressions in sequence or binary tree.However,these approaches may suffer from the following issues:Models relying on such structures exhibit fixed-order reasoning(e.g.,left-to-right),limiting flexibility and increasing error susceptibility;prior models rely on autoregressive reasoning in a single pass,accumulating minor errors(e.g.,incorrect math symbols)during generation,resulting in reduced accuracy.To address the above issues,we emulate the human“check and modify”process in reasoning and propose a unified M-tree self-correction solver(UTSCSolver)by iterative inference with self-correction mechanism.First,we use an iterative,non-autoregressive process for generating mathematical expressions,free from fixed generation orders to handle complex and diverse problems.Additionally,we design a self-correction mechanism based on alternating execution between a generator and a discriminator.This module iteratively detects and rectifies errors in generated expressions,leveraging previous iteration information for subsequent generation guidance.Experimental results show that our UTSC-Solver outperforms traditional models in accuracy on two popular datasets,while it improves the interpretability of mathematical reasoning. 展开更多
关键词 mathematical reasoning non-autoregressive generation math word problems
在线阅读 下载PDF
Efficacy of School-Based Interventions to Manage Psychosocial Problems of an Adolescent: A Clinical Case Study
15
作者 Dua Fatima Afzaal Farhan Hashmi 《Open Journal of Medical Psychology》 2025年第1期19-31,共13页
This case study explores the efficacy of school-based intervention to address psychosocial challenges faced by an 11-year-old adolescent. The case study aimed to decrease the agression and acting out behavior as resul... This case study explores the efficacy of school-based intervention to address psychosocial challenges faced by an 11-year-old adolescent. The case study aimed to decrease the agression and acting out behavior as result of being victimized at school by the peers. The aim was to assess and manage the child’s aggressive behavior and academic underperformance which played a significant role in the child’s low self-esteem and emotional regulation. A comprehensive assessment was conducted to rule out the difficulties and a multi-faceted intervention strategy was utilized including anger management and structured activity scheduling that helped that child to improve his academic performance as well as to learn to manage his emotional expression. Throughout 16 sessions, the intervention targeted key behavioural indicators such as emotional expression, and aggression;post-assessment results demonstrated a 22% improvement in the child’s behavioral and academic challenges. The findings suggest that a multi-faceted therapeutic approach can be effective in addressing complex issues of aggression and academic underperformance in children, highlighting the importance of integrated psychological and educational interventions. 展开更多
关键词 AGGRESSION School-Related problems BULLYING VICTIMIZATION Cognitive-Behavioral Therapy
暂未订购
Relationship between parenting stress and behavioral and emotional problems in preschool children: A mediation effect analysis
16
作者 Zhi-Wei Fu Yue-Jing Li +3 位作者 Ran Yu Rui-Qing Guo Li-Xia Gao Sheng-Xia Zhao 《World Journal of Psychiatry》 SCIE 2025年第1期128-136,共9页
BACKGROUND Emotional reactions,such as anxiety,irritability,and aggressive behavior,have attracted clinical attention as behavioral and emotional problems in preschool-age children.AIM To investigate the current statu... BACKGROUND Emotional reactions,such as anxiety,irritability,and aggressive behavior,have attracted clinical attention as behavioral and emotional problems in preschool-age children.AIM To investigate the current status of family rearing,parental stress,and behavioral and emotional problems of preschool children and to analyze the mediating effect of the current status of family rearing on parental stress and behavioral/emo-tional problems.METHODS We use convenience sampling to select 258 preschool children in the physical examination center of our hospital from October 2021 to September 2023.The children and their parents were evaluated using a questionnaire survey.Pearson's correlation was used to analyze the correlation between child behavioral and emotional problems and parental stress and family rearing,and the structural equation model was constructed to test the mediating effect.RESULTS The score for behavioral/emotional problems of 258 preschool children was(27.54±3.63),the score for parental stress was(87.64±11.34),and the score for parental family rearing was(31.54±5.24).There was a positive correlation between the behavioral and emotional problems of the children and the“hostile/mandatory”parenting style;meanwhile,showed a negative correlation with the“support/participation”parenting style(all P<0.05).The intermediary effect value between the family upbringing of parents in parental stress and children's behavior problems was 29.89%.CONCLUSION Parental family upbringing has a mediating effect between parental stress and behavioral and emotional problems of children.Despite paying attention to the behavioral and emotional problems of preschool-age children,clinical medical staff should provide correct and reasonable parenting advice to their parents to promote the mental health of preschool-age children. 展开更多
关键词 Preschool children Parenting stress Children's behavioral and emotional problems Family rearing Mediating effect
暂未订购
Information-Body Relation and Information as a Solution of the Consciousness Problem in the Biological Structures
17
作者 Florin Gaiseanu 《Journal of Philosophy Study》 2022年第5期287-303,共17页
This paper approaches two main philosophical questions concerning the biological structures,from unicellular to multicellular organisms:one of them(i),referred to the information-body relation,as an extension of the m... This paper approaches two main philosophical questions concerning the biological structures,from unicellular to multicellular organisms:one of them(i),referred to the information-body relation,as an extension of the mind-body relation at human,and another one(ii),to the consciousness problem,concerning the existence and nature of consciousness(if any),at the inferior organisms on the complexity scale,as this concept is known at humans.As philosophy benefits of the privilege to use data/concepts from other sciences to obtain philosophical conclusions,there were included detailed descriptions of some key biologic mechanisms,analyzed from informational perspective,necessary just to support/demonstrate/reinforce the informational nature/substrate of the mentioned relations.The analysis of the close relation between information and body,related to the structuration and functional properties of the biological organisms,from cells to multicellular structures,shows that all of them are able to“embody/disembody”information during/by structuration/destructuration processes of matter,in particular that of DNA/RNA/proteins,their functions appearing as a result of their informational capabilities to internally manage the inter-connection with environment,primarily due to their permanent dependence on the food resources and adaptation/survival needs.The experimental and theoretical studies,revealing/documenting on one hand the automatic management of maintenance metabolic processes,the reproduction,and growth/development,and on the other hand the adaptive decision-making/sentient processes as a responsive reaction to the environmental cues,show/support the consistency of the informational model of the human body and living structures on the entire biological scale,providing support to the informational solution of the stated problems(i)and(ii).A distinct attention is paid to plants,which are organisms without nervous system,but which show/manifest also informational capabilities to detect/react to information and to modulate their behavior accordingly.The question if the living organisms possess a pseudo/proto-consciousness level as a consequence of the informational activity of their body,distinct from human,but active in any biological structure under certain conditions is furthermore discussed,and a reliable definition of rudimentary pseudo/proto-consciousness level is given/described and compared with other empirical/theoretical concepts. 展开更多
关键词 information in biological structures informationally-driven processes structuration/destructuration growth/differentiation/maintenance functionality/informational structure info-intra/inter-communication cognitive centers proto/pseudo-consciousness problem
在线阅读 下载PDF
Programming guide for solving constraint satisfaction problems with tensor networks
18
作者 Xuanzhao Gao Xiaofeng Li Jinguo Liu 《Chinese Physics B》 2025年第5期71-90,共20页
Constraint satisfaction problems(CSPs)are a class of problems that are ubiquitous in science and engineering.They feature a collection of constraints specified over subsets of variables.A CSP can be solved either dire... Constraint satisfaction problems(CSPs)are a class of problems that are ubiquitous in science and engineering.They feature a collection of constraints specified over subsets of variables.A CSP can be solved either directly or by reducing it to other problems.This paper introduces the Julia ecosystem for solving and analyzing CSPs with a focus on the programming practices.We introduce some important CSPs and show how these problems are reduced to each other.We also show how to transform CSPs into tensor networks,how to optimize the tensor network contraction orders,and how to extract the solution space properties by contracting the tensor networks with generic element types.Examples are given,which include computing the entropy constant,analyzing the overlap gap property,and the reduction between CSPs. 展开更多
关键词 tensor networks constraint satisfaction problems problem reductions Julia
原文传递
Direct and Inverse Problems for a Third-order Differential Operator with Anti-periodic Boundary Conditions and a Non-local Potential
19
作者 ZHANG Mingming LIU Yixuan 《数学理论与应用》 2025年第1期62-80,共19页
This paper focuses on the direct and inverse problems for a third-order self-adjoint differential operator with non-local potential and anti-periodic boundary conditions.Firstly,we obtain the expressions for the chara... This paper focuses on the direct and inverse problems for a third-order self-adjoint differential operator with non-local potential and anti-periodic boundary conditions.Firstly,we obtain the expressions for the characteristic function and resolvent of this third-order differential operator.Secondly,by using the expression for the resolvent of the operator,we prove that the spectrum for this operator consists of simple eigenvalues and a finite number of eigenvalues with multiplicity 2.Finally,we solve the inverse problem for this operator,which states that the non-local potential function can be reconstructed from four spectra.Specially,we prove the Ambarzumyan theorem and indicate that odd or even potential functions can be reconstructed by three spectra. 展开更多
关键词 Direct problem Inverse problem Non-local potential Anti-periodic boundary condition
在线阅读 下载PDF
On the Riemann-Hilbert problem for the reverse space-time nonlocal Hirota equation with step-like initial data
20
作者 Bei-Bei Hu Ling Zhang +1 位作者 Zu-Yi Shen Ji Lin 《Communications in Theoretical Physics》 2025年第2期30-38,共9页
In this paper,we use the Riemann-Hilbert(RH)method to investigate the Cauchy problem of the reverse space-time nonlocal Hirota equation with step-like initial data:q(z,0)=o(1)as z→-∞and q(z,0)=δ+o(1)as z→∞,where... In this paper,we use the Riemann-Hilbert(RH)method to investigate the Cauchy problem of the reverse space-time nonlocal Hirota equation with step-like initial data:q(z,0)=o(1)as z→-∞and q(z,0)=δ+o(1)as z→∞,whereδis an arbitrary positive constant.We show that the solution of the Cauchy problem can be determined by the solution of the corresponding matrix RH problem established on the plane of complex spectral parameterλ.As an example,we construct an exact solution of the reverse space-time nonlocal Hirota equation in a special case via this RH problem. 展开更多
关键词 nonlocal Hirota equation Cauchy problem Riemann-Hilbert problem step-like initial data
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部