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Conformal invariance and integration of first-order differential equations 被引量:7
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作者 何光 梅凤翔 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期2764-2766,共3页
This paper studies a conformal invariance and an integration of first-order differential equations. It obtains the corresponding infinitesimal generators of conformal invariance by using the symmetry of the differenti... This paper studies a conformal invariance and an integration of first-order differential equations. It obtains the corresponding infinitesimal generators of conformal invariance by using the symmetry of the differential equations, and expresses the differential equations by the equations of a Birkhoff system or a generalized Birkhoff system. If the infinitesimal generators are those of a Noether symmetry, the conserved quantity can be obtained by using the Noether theory of the Birkhoff system or the generalized Birkhoff system. 展开更多
关键词 differential equation conformal invariance Noether theory INTEGRATION
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Lie symmetry and conserved quantity of a system of first-order differential equations 被引量:4
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作者 许学军 梅凤翔 张永发 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第1期19-21,共3页
This paper focuses on studying the Lie symmetry and a conserved quantity of a system of first-order differential equations. The determining equations of the Lie symmetry for a system of first-order differential equati... This paper focuses on studying the Lie symmetry and a conserved quantity of a system of first-order differential equations. The determining equations of the Lie symmetry for a system of first-order differential equations, from which a kind of conserved quantity is deduced, are presented. And their general conclusion is applied to a Hamilton system, a Birkhoff system and a generalized Hamilton system. Two examples are given to illustrate the application of the results. 展开更多
关键词 Lie symmetry conserved quantity differential equation mechanical system
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Finite Element Approach for the Solution of First-Order Differential Equations
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作者 André Schmidt Horst R. Beyer +1 位作者 Matthias Hinze Evangelos N. Vandoros 《Journal of Applied Mathematics and Physics》 2020年第10期2072-2090,共19页
The finite element method has established itself as an efficient numerical procedure for the solution of arbitrary-shaped field problems in space. Basically, the finite element method transforms the underlying differe... The finite element method has established itself as an efficient numerical procedure for the solution of arbitrary-shaped field problems in space. Basically, the finite element method transforms the underlying differential equation into a system of algebraic equations by application of the method of weighted residuals in conjunction with a finite element ansatz. However, this procedure is restricted to even-ordered differential equations and leads to symmetric system matrices as a key property of the finite element method. This paper aims in a generalization of the finite element method towards the solution of first-order differential equations. This is achieved by an approach which replaces the first-order derivative by fractional powers of operators making use of the square root of a Sturm-Liouville operator. The resulting procedure incorporates a finite element formulation and leads to a symmetric but dense system matrix. Finally, the scheme is applied to the barometric equation where the results are compared with the analytical solution and other numerical approaches. It turns out that the resulting numerical scheme shows excellent convergence properties. 展开更多
关键词 Finite Element Method first-order differential Equations Fractional Powers of Operators
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Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
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作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 Population balance equation CRYSTALLIZATION peridynamic differential operator Euler’s first-order explicit method
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A “Tonebusting” Technique to Build a DAC from a First-Order Digital ΣΔ Modulator
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作者 Yves Leduc Gilles Jacquemod +1 位作者 Yoann Charlon Fabrice Muller 《Journal of Electronic Research and Application》 2025年第4期8-13,共6页
In this paper,we present a novel first-order digitalΣΔconverter tailored for digital-to-analog applications,focusing on achieving both high yield and reduced silicon estate.Our approach incorporates a substantial le... In this paper,we present a novel first-order digitalΣΔconverter tailored for digital-to-analog applications,focusing on achieving both high yield and reduced silicon estate.Our approach incorporates a substantial level of dithering noise into the input signal,strategically aimed at mitigating the spurious frequencies commonly encountered in such converters.Validation of our design is performed through simulations using a high-level simulator specialized in mixed-signal circuit analysis.The results underscore the enhanced performance of our circuit,especially in reducing spurious frequencies,highlighting its efficiency and effectiveness.The final circuit exhibits an effective number of bits of 13. 展开更多
关键词 first-order digital SD modulator Digital to analog converter Spurious frequencies Dithering
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ON HYPER-ORDER OF MEROMORPHIC SOLUTIONS OF FIRST-ORDER ALGEBRAIC DIFFERENTIAL EQUATIONS
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作者 李叶舟 冯绍继 《Acta Mathematica Scientia》 SCIE CSCD 2001年第3期383-390,共8页
The authors give a precise estimate of the hyper-order of meromorphic solutions of general first-order algebraic differential equations.
关键词 algebraic differential equation meromorphic solution HYPER-ORDER ZERO POLE
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Improved Inverse First-Order Reliability Method for Analyzing Long-Term Response Extremes of Floating Structures
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作者 Junrong Wang Zhuolantai Bai +3 位作者 Botao Xie Jie Gui Haonan Gong Yantong Zhou 《哈尔滨工程大学学报(英文版)》 2025年第3期552-566,共15页
Long-term responses of floating structures pose a great concern in their design phase. Existing approaches for addressing long-term extreme responses are extremely cumbersome for adoption. This work aims to develop an... Long-term responses of floating structures pose a great concern in their design phase. Existing approaches for addressing long-term extreme responses are extremely cumbersome for adoption. This work aims to develop an approach for the long-term extreme-response analysis of floating structures. A modified gradient-based retrieval algorithm in conjunction with the inverse first-order reliability method(IFORM) is proposed to enable the use of convolution models in long-term extreme analysis of structures with an analytical formula of response amplitude operator(RAO). The proposed algorithm ensures convergence stability and iteration accuracy and exhibits a higher computational efficiency than the traditional backtracking method. However, when the RAO of general offshore structures cannot be analytically expressed, the convolutional integration method fails to function properly. A numerical discretization approach is further proposed for offshore structures in the case when the analytical expression of the RAO is not feasible. Through iterative discretization of environmental contours(ECs) and RAOs, a detailed procedure is proposed to calculate the long-term response extremes of offshore structures. The validity and accuracy of the proposed approach are tested using a floating offshore wind turbine as a numerical example. The long-term extreme heave responses of various return periods are calculated via the IFORM in conjunction with a numerical discretization approach. The environmental data corresponding to N-year structural responses are located inside the ECs, which indicates that the selection of design points directly along the ECs yields conservative design results. 展开更多
关键词 Long-term response analysis Floating structures Inverse first-order reliability method Convolution model Gradient-based retrieval algorithm Environmental contour method
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EXISTENCE OF HOMOCLINIC ORBITS FOR A CLASS OF FIRST-ORDER DIFFERENTIAL DIFFERENCE EQUATIONS
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作者 郭承军 Donal O’REGAN +1 位作者 徐远通 Ravi P.AGARWAL 《Acta Mathematica Scientia》 SCIE CSCD 2015年第5期1077-1094,共18页
In this article we consider via critical point theory the existence of homoclinic orbits of the first-order differential difference equation z(t)+B(t)z(t)+f(t,z(t+τ),z(t),z(t-τ))=0.
关键词 homoclinic solutions differential difference equation critical point theory
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Fuzzy Dynamic Optimal Model for COVID-19 Epidemic in India Based on Granular Differentiability
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作者 KHATUA Debnarayan DE Anupam +3 位作者 KAR Samarjit SAMANTA Eshan SEKH Arif Ahmed GUHA ADHYA Debashree 《Journal of Shanghai Jiaotong university(Science)》 2025年第3期545-560,共16页
The pandemic SARS-CoV-2 has become an undying virus to spread a sustainable disease named COVID-19 for upcoming few years.Mortality rates are rising rapidly as approved drugs are not yet available.Isolation from the i... The pandemic SARS-CoV-2 has become an undying virus to spread a sustainable disease named COVID-19 for upcoming few years.Mortality rates are rising rapidly as approved drugs are not yet available.Isolation from the infected person or community is the preferred choice to protect our health.Since humans are the only carriers,it might be possible to control the positive rate if the infected population or host carriers are isolated from each other.Isolation alone may not be a proper solution.These are the resolutions of previous research work carried out on COVID-19 throughout the world.The present scenario of the world and public health is knocking hard with a big question of critical uncertainty of COVID-19 because of its imprecise database as per daily positive cases recorded all over the world and in India as well.In this research work,we have pre-sented an optimal control model for COVID-19 using granular differentiability based on fuzzy dynamical systems.In the first step,we created a fuzzy Susceptible-Exposed-Infected-Asymptomatic-Hospitalized-Recovered-Death(SEIAHRD)model for COVID-19,analyzed it using granular differentiability,and reported disease dynamics for time-independent disease control parameters.In the second step,we upgraded the fuzzy dynamical system and granular differentiability model related to time-dependent disease control parameters as an optimal control problem invader.Theoretical studies have been validated with some practical data from the epidemic COVID-19 related to the Indian perspective during first wave and early second wave. 展开更多
关键词 COVID-19 ASYMPTOMATIC SUSCEPTIBLE fuzzy dynamical system granular differentiability
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Application of First-Order Differential Equation to Heat Convection in Fluid
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作者 Zahidullah Rehan 《Journal of Applied Mathematics and Physics》 2020年第8期1456-1462,共7页
Differential equation is very important in science and engineering, because it required the description of some measurable quantities (position, temperature, population, concentration, electrical current, etc.) in mat... Differential equation is very important in science and engineering, because it required the description of some measurable quantities (position, temperature, population, concentration, electrical current, etc.) in mathematical form of ordinary differential equations (ODEs). In this research, we determine heat transferred by convection in fluid problems by first-order ordinary differential equations. So in this research work first we discuss the solution of ordinary homogeneous and non-homogeneous differential equation and then apply the solution of first-order ODEs to heat transferring particularly in heat convection in fluid. 展开更多
关键词 differential Equation Heat Transfer Analysis Heat Convection in Fluid Newton Cooling Law
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McKean-Vlasov Backward Stochastic Differential Equations with Weak Monotonicity Coefficients
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作者 FU Zongkui FEI Dandan GUO Shanshan 《应用数学》 北大核心 2026年第1期98-107,共10页
This paper deals with Mckean-Vlasov backward stochastic differential equations with weak monotonicity coefficients.We first establish the existence and uniqueness of solutions to Mckean-Vlasov backward stochastic diff... This paper deals with Mckean-Vlasov backward stochastic differential equations with weak monotonicity coefficients.We first establish the existence and uniqueness of solutions to Mckean-Vlasov backward stochastic differential equations.Then we obtain a comparison theorem in one-dimensional situation. 展开更多
关键词 McKean-Vlasov backward stochastic differential equation Weak monotonicity condition Comparison theorem
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Existence and Uniqueness of Positive Periodic Solutions for First-order Functional Differential Equations
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作者 HAN Qian-qian ZHAI Cheng-bo 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第3期454-461,共8页
In this paper, we prove the existence and uniqueness of positive periodic solutions for first-order functional differential equation y'(t) = α(t)y(t) + f(t, y(t -τ-(t))) + g(t)by using two fixed poi... In this paper, we prove the existence and uniqueness of positive periodic solutions for first-order functional differential equation y'(t) = α(t)y(t) + f(t, y(t -τ-(t))) + g(t)by using two fixed point theorems of general α-concave operators and homogeneous operators in ordered Banach spaces. 展开更多
关键词 functional differential equation existence and uniqueness positive periodics olution~ general s-concave operator homogeneous operator
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DPIL-Traj: Differential Privacy Trajectory Generation Framework with Imitation Learning
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作者 Huaxiong Liao Xiangxuan Zhong +4 位作者 Xueqi Chen Yirui Huang Yuwei Lin Jing Zhang Bruce Gu 《Computers, Materials & Continua》 2026年第1期1530-1550,共21页
The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location re... The generation of synthetic trajectories has become essential in various fields for analyzing complex movement patterns.However,the use of real-world trajectory data poses significant privacy risks,such as location reidentification and correlation attacks.To address these challenges,privacy-preserving trajectory generation methods are critical for applications relying on sensitive location data.This paper introduces DPIL-Traj,an advanced framework designed to generate synthetic trajectories while achieving a superior balance between data utility and privacy preservation.Firstly,the framework incorporates Differential Privacy Clustering,which anonymizes trajectory data by applying differential privacy techniques that add noise,ensuring the protection of sensitive user information.Secondly,Imitation Learning is used to replicate decision-making behaviors observed in real-world trajectories.By learning from expert trajectories,this component generates synthetic data that closely mimics real-world decision-making processes while optimizing the quality of the generated trajectories.Finally,Markov-based Trajectory Generation is employed to capture and maintain the inherent temporal dynamics of movement patterns.Extensive experiments conducted on the GeoLife trajectory dataset show that DPIL-Traj improves utility performance by an average of 19.85%,and in terms of privacy performance by an average of 12.51%,compared to state-of-the-art approaches.Ablation studies further reveal that DP clustering effectively safeguards privacy,imitation learning enhances utility under noise,and the Markov module strengthens temporal coherence. 展开更多
关键词 PRIVACY-PRESERVING trajectory generation differential privacy imitation learning Markov chain
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GÂTEAUX DIRECTIONAL DIFFERENTIABILITY OF THE GENERALIZED METRIC PROJECTION IN BANACH SPACES
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作者 Jinlu LI 《Acta Mathematica Scientia》 2025年第4期1597-1618,共22页
Let X be a real uniformly convex and uniformly smooth Banach space and C a nonempty closed and convex subset of X.Let Π_(C):X→C denote the generalized metric projection operator introduced by Alber in[1].In this pap... Let X be a real uniformly convex and uniformly smooth Banach space and C a nonempty closed and convex subset of X.Let Π_(C):X→C denote the generalized metric projection operator introduced by Alber in[1].In this paper,we define the Gâteaux directional differentiability of Π_(C).We investigate some properties of the Gâteaux directional differentiability of Π_(C).In particular,if C is a closed ball,or a closed and convex cone(including proper closed subspaces),or a closed and convex cylinder,then,we give the exact representations of the directional derivatives of Π_(C).By comparing the results in[12]and this paper,we see the significant difference between the directional derivatives of the generalized metric projection operator Π_(C) and the Gâteaux directional derivatives of the standard metric projection operator PC. 展开更多
关键词 uniformly convex and uniformly smooth Banach space the generalized metric projection directional differentiability of the generalized metric projection directional derivative of the generalized metric projection
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Determination of Phenolic Hydroxyl Content in Poly(phenylene oxide)by Differential Ultraviolet Spectrophotometry
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作者 Qin-Yu Yan Shun-Gang Song +4 位作者 Bu-Jie Zhou Jing Hu Lian-Fang Feng Xue-Ping Gu Cai-Liang Zhang 《Chinese Journal of Polymer Science》 2026年第1期79-86,I0010,共9页
Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its... Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques. 展开更多
关键词 Poly(phenylene oxide) Phenolic hydroxyl Redistribution differential UV spectrophotometry
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Cedrol ameliorates ulcerative colitis via myeloid differentiation factor 2-mediated inflammation suppression,with barrier restoration and microbiota modulation
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作者 Yi-Qing Zhao Yu Zhang +2 位作者 Yan Qin Rui-Ya Zhang Jun-Ping Wang 《World Journal of Gastroenterology》 2026年第2期135-151,共17页
BACKGROUND Ulcerative colitis(UC)is a chronic and treatment-resistant disorder requiring potent therapeutics that are effective and safe.Cedrol(CE)is a bioactive natural product present in many traditional Chinese med... BACKGROUND Ulcerative colitis(UC)is a chronic and treatment-resistant disorder requiring potent therapeutics that are effective and safe.Cedrol(CE)is a bioactive natural product present in many traditional Chinese medicines.It is known for its suppression of inflammation and mitigation of oxidative stress.Its therapeutic efficacy and mechanistic underpinnings in UC remain uncharacterized.AIM To investigate the therapeutic potential and mechanisms of CE in UC.METHODS The anti-inflammatory activity and intestinal barrier-repairing effects of CE were assessed in a dextran sulfate sodium-induced murine colitis model.Network pharmacology was employed to predict potential targets and pathways.Then molecular docking and dynamics simulations were utilized to confirm a stable interaction between CE and the toll-like receptor 4(TLR4)/myeloid differentiation factor 2(MD2)complex.The anti-inflammatory mechanisms were further verified using in vitro assays.Additionally,the gut microbiota composition was analyzed via 16S rRNA gene sequencing.RESULTS CE significantly alleviated colitis symptoms,mitigated histopathological damage,and suppressed inflammation.Moreover,CE restored intestinal barrier integrity by enhancing mucus secretion and upregulating tight junction proteins(zonula occludens 1,occludin,claudin-1).Mechanistically,CE stably bound to MD2,inhibiting lipopolysaccharide-induced TLR4 signaling in RAW264.7 cells.This led to suppression of the downstream mitogen-activated protein kinase and nuclear factor kappa B signaling pathways,downregulating the expression of tumor necrosis factor-alpha,interleukin-1β,and interleukin-6.Gut microbiota analysis revealed that CE reversed dextran sulfate sodium-induced dysbiosis with significant enrichment of butyrogenic Christensenella minuta.CONCLUSION CE acted on MD2 to suppress proinflammatory cascades,promoting mucosal barrier reconstitution and microbiota remodeling and supporting its therapeutic use in UC. 展开更多
关键词 CEDROL Ulcerative colitis Toll-like receptor 4 Myeloid differentiation factor 2 Signaling pathways Gut microbiota
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Paraconsistent Differential Calculus(Part I):First-Order Paraconsistent Derivative
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作者 Joao Inácio Da Silva Filho 《Applied Mathematics》 2014年第6期904-916,共13页
A type of Inconsistent Mathematics structured on Paraconsistent Logic (PL) and that has, as the main purpose, the study of common mathematical objects such as sets, numbers and functions, where some contradictions are... A type of Inconsistent Mathematics structured on Paraconsistent Logic (PL) and that has, as the main purpose, the study of common mathematical objects such as sets, numbers and functions, where some contradictions are allowed, is called Paraconsistent Mathematics. The PL is a non-Classical logic and its main property is to present tolerance for contradiction in its fundamentals without the invalidation of the conclusions. In this paper (part 1), we use the PL in its annotated form, denominated Paraconsistent Annotated Logic with annotation of two values—PAL2v for present a first-order Paraconsistent Derivative. The PAL2v has, in its representation, an associated lattice FOUR based on Hasse Diagram. This PAL2v-Lattice allows development of a Para-consistent Differential Calculus based on fundamentals and equations obtained by geometric interpretations. In this first article it is presented some examples applying derivatives of first-order with the concepts of Paraconsistent Mathematics. In the second part of this work we will show the Paraconsistent Derivative of second-order with application examples. 展开更多
关键词 Paraconsistent Logic Paraconsistent Annotated Logic Paraconsistent Mathematics Paraconsistent differential Calculus
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PERIODIC BOUNDARY VALUE PROBLEMS FOR FIRST-ORDER INTEGRO-DIFFERENTIAL EQUATIONS OF MIXED TYPE
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作者 张福保 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第3期363-370,共8页
The existence of at feast one solution and the existence of extreme solutions of periodic boundary value problems for first-order integro-differential equations of mixed type are studied, in the presence of generalize... The existence of at feast one solution and the existence of extreme solutions of periodic boundary value problems for first-order integro-differential equations of mixed type are studied, in the presence of generalized upper and laver solutions. The discussion is based an new comparison theorems and coincidence degree and monotone iterative methods. 展开更多
关键词 generalized upper and lower solutions coincidence degree monotone iteration integro-differential equation of mixed type
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DIFFERENTIABILITY OF C_0-SEMIGROUPS WITH APPLICATION
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作者 金振东 喻文焕 +1 位作者 靳展 王辅敏 《Transactions of Tianjin University》 EI CAS 1999年第2期25-29,共5页
This paper considers the differentiability of C 0 semigroups with respect to (w.r.t.) parameters contained in their infinitesimal generators.It is proved that the generalized continuity and strong differentiability ... This paper considers the differentiability of C 0 semigroups with respect to (w.r.t.) parameters contained in their infinitesimal generators.It is proved that the generalized continuity and strong differentiability of their infinitesimal generators w.r.t.parameters imply the differentiability of the C 0 semigroups.The results are applied to the differentiability of the solution of a linear delay differential equation w.r.t.its delays. 展开更多
关键词 C 0 semigroup infinitesimal generator generalized continuity strongly Frechet differential dalay equation
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DIFFERENTIABILITY FOR THE HIGH DIMENSIONAL POLYNOMIAL-LIKE ITERATIVE EQUATION 被引量:9
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作者 李晓培 邓圣福 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期130-136,共7页
This paper studies the smoothness of solutions of the higher dimensional polynomial-like iterative equation. The methods given by Zhang Weinian([7]) and by Kulczvcki M, Tabor j.([3]) are improved by constructing a new... This paper studies the smoothness of solutions of the higher dimensional polynomial-like iterative equation. The methods given by Zhang Weinian([7]) and by Kulczvcki M, Tabor j.([3]) are improved by constructing a new operator for the structure of the equation in order to apply fixed point theorems. Existence, uniqueness and stability of continuously differentiable solutions are given. 展开更多
关键词 ITERATION fixed point theorem differentiable solutions existence UNIQUENESS stability
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