期刊文献+
共找到135篇文章
< 1 2 7 >
每页显示 20 50 100
Properties of Some Kind of Number Theoretical Function(Ⅱ)
1
作者 李怡君 刘华柯 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第3期402-405,共4页
For any given positive integer n ≥ 1, the Euler function φ(n) is defined to be the number of positive integers not exceeding n, which is relatively prime to n. o:(n) is defined to be the number of different pri... For any given positive integer n ≥ 1, the Euler function φ(n) is defined to be the number of positive integers not exceeding n, which is relatively prime to n. o:(n) is defined to be the number of different prime divisors of n. In order to know the solvability of the function of φ(φ(φ(n))) = 2^ω(n), properties of the number theoretical function φ(φ(n)) is studied in the paper. 展开更多
关键词 Euler function solutionS number of solutions divide exactly
下载PDF
Travelling Waves: Interplay of Low to High Reynolds Number and Tan-Cot Function Method to Solve Burger’s Equations
2
作者 Md. Kamrujjaman Asif Ahmed Jahrul Alam 《Journal of Applied Mathematics and Physics》 2019年第4期861-873,共13页
We study the nonlinear parabolic equations for travelling wave solutions of Burger’s equations. The purpose of the present work is to study various types of Burger’s equations describing waves and those are based on... We study the nonlinear parabolic equations for travelling wave solutions of Burger’s equations. The purpose of the present work is to study various types of Burger’s equations describing waves and those are based on nonlinear equations. We focus on to describe the analytic solution in the special pattern of travelling wave solutions using tan-cot function method. We discuss about inviscid and viscous version of Burger’s equation for fluid flow and investigate the effects of internal friction of a fluid via Reynolds number. By changing the velocity amplitude, the nature of flows with shock wave and disturbance are observed. For numerical solutions, the Crank-Nicolson scheme is introduced to establish the wave solutions. 展开更多
关键词 Nonlinear PDES Tan-Cot function Method TRAVELLING Wave solutions Burg-er’s Equation REYNOLDS number CRANK-NICOLSON Scheme
下载PDF
A New Fourth Order Difference Approximation for the Solution of Three-dimensional Non-linear Biharmonic Equations Using Coupled Approach
3
作者 Ranjan Kumar Mohanty Mahinder Kumar Jain Biranchi Narayan Mishra 《American Journal of Computational Mathematics》 2011年第4期318-327,共10页
This paper deals with a new higher order compact difference scheme, which is, O(h4) using coupled approach on the 19-point 3D stencil for the solution of three dimensional nonlinear biharmonic equations. At each inter... This paper deals with a new higher order compact difference scheme, which is, O(h4) using coupled approach on the 19-point 3D stencil for the solution of three dimensional nonlinear biharmonic equations. At each internal grid point, the solution u(x,y,z) and its Laplacian Δ4u are obtained. The resulting stencil algo-rithm is presented and hence this new algorithm can be easily incorporated to solve many problems. The present discretization allows us to use the Dirichlet boundary conditions only and there is no need to discretize the derivative boundary conditions near the boundary. We also show that special treatment is required to handle the boundary conditions. Convergence analysis for a model problem is briefly discussed. The method is tested on three problems and compares very favourably with the corresponding second order approximation which we also discuss using coupled approach. 展开更多
关键词 THREE-DIMENSIONAL NON-LINEAR BIHARMONIC Equation Finite Differences Fourth order Accuracy Compact Discretization Block-Block-Tridiagonal Tangential Derivatives Laplacian Stream function REYNOLDS number
下载PDF
Some Kind of Equations Involving Euler's Function 被引量:5
4
作者 LI Yi-jun LI Yu-sheng 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第4期605-608,共4页
For any given positive integer n ≥ 1, the Euler function φ(n) is defined to be the number of positive integers not exceeding n which are relatively prime to n. w(n) is defined to be the number of different prime... For any given positive integer n ≥ 1, the Euler function φ(n) is defined to be the number of positive integers not exceeding n which are relatively prime to n. w(n) is defined to be the number of different prime divisors of n. Some kind of equations involving Euler's function is studied in the paper. 展开更多
关键词 Euler's function EQUATION number of solutions
下载PDF
The Polynomial Function Model in Born-Infeld Theory
5
作者 DAI Bing-bing ZHANG Rui-feng 《Chinese Quarterly Journal of Mathematics》 2022年第3期221-236,共16页
Based on the Lagrangian action density under Born-Infeld type dynamics and motivated by the one-dimensional prescribed mean curvature equation,we investigate the polynomial function model in Born-Infeld theory in this... Based on the Lagrangian action density under Born-Infeld type dynamics and motivated by the one-dimensional prescribed mean curvature equation,we investigate the polynomial function model in Born-Infeld theory in this paper with the form of-([10α(φ′)^(2)]φ′)′=λf(φ(x)),whereλ>0 is a real parameter,f∈C 2(0,+∞)is a nonlinear function.We are interested in the exact number of positive solutions of the above nonlinear equation.We specifically develop for the problem combined with a careful analysis of a time-map method. 展开更多
关键词 Time-map analysis Exact number of solutions Lagrangian action density the polynomial function model Born-Infeld theory
下载PDF
The Global Stability Analysis of a Mathematical Cellular Model of Hepatitis C Virus Infection with Non-Cytolytic Process 被引量:1
6
作者 Alexis Nangue Cyprien Fokoue Raoue Poumeni 《Journal of Applied Mathematics and Physics》 2019年第7期1531-1546,共16页
The aim of this work is to analyse the global dynamics of an extended mathematical model of Hepatitis C virus (HCV) infection in vivo with cellular proliferation, spontaneous cure and hepatocyte homeostasis. We firstl... The aim of this work is to analyse the global dynamics of an extended mathematical model of Hepatitis C virus (HCV) infection in vivo with cellular proliferation, spontaneous cure and hepatocyte homeostasis. We firstly prove the existence of local and global solutions of the model and establish some properties of this solution as positivity and asymptotic behaviour. Secondly we show, by the construction of appropriate Lyapunov functions, that the uninfected equilibrium and the unique infected equilibrium of the mathematical model of HCV are globally asymptotically stable respectively when the threshold number and when . 展开更多
关键词 HCV Model Global solutions Non-Cytolytic PROCESS Invariant Set Lyapunov functions Basic REPRODUCTION number Equilibrium Points
下载PDF
Generalized Eulerian Numbers
7
作者 Alfred Wünsche 《Advances in Pure Mathematics》 2018年第3期335-361,共27页
We generalize the Eulerian numbers ?to sets of numbers Eμ(k,l), (μ=0,1,2,···) where the Eulerian numbers appear as the special case μ=1. This can be used for the evaluation of generalizations Eμ(k,Z... We generalize the Eulerian numbers ?to sets of numbers Eμ(k,l), (μ=0,1,2,···) where the Eulerian numbers appear as the special case μ=1. This can be used for the evaluation of generalizations Eμ(k,Z) of the Geometric series G0(k;Z)=G1(0;Z) by splitting an essential part (1-Z)-(μK+1) where the numbers Eμ(k,l) are then the coefficients of the remainder polynomial. This can be extended for non-integer parameter k to the approximative evaluation of generalized Geometric series. The recurrence relations and for the Generalized Eulerian numbers E1(k,l) are derived. The Eulerian numbers are related to the Stirling numbers of second kind S(k,l) and we give proofs for the explicit relations of Eulerian to Stirling numbers of second kind in both directions. We discuss some ordering relations for differentiation and multiplication operators which play a role in our derivations and collect this in Appendices. 展开更多
关键词 EULERIAN numberS EULERIAN Polynomials STIRLING numberS PERMUTATIONS Binomials HYPERGEOMETRIC functions Geometric Series Vandermonde’s Convolution Identity Recurrence Relations Operator orderINGS
下载PDF
Motoyosi Sugita—A “Widely Unknown” Japanese Thermodynamicist Who Explored the 4th Law of Thermodynamics for Creation of the Theory of Life
8
作者 Kazumoto Iguchi 《Open Journal of Biophysics》 2016年第4期125-232,共109页
The purpose of this paper is to introduce to you, the Western people, nowadays a “widely unknown” Japanese thermodynamicist by the name of Motoyosi Sugita and his study on the thermodynamics of transient phenomena a... The purpose of this paper is to introduce to you, the Western people, nowadays a “widely unknown” Japanese thermodynamicist by the name of Motoyosi Sugita and his study on the thermodynamics of transient phenomena and his theory of life. This is because although he was one of the top theoretical physicists in Japan before, during and after WWII and after WWII he promoted the establishment of the biophysical society of Japan as one of the founding members, he himself and his studies themselves have seemed to be totally forgotten nowadays in spite that his study was absolutely important for the study of life. Therefore, in this paper I would like to present what kind of person he was and what he studied in physics as a review on the physics work of Motoyosi Sugita for the first time. I will follow his past studies to introduce his ideas in theoretical physics as well as in biophysics as follows: He proposed the bright ideas such as the quasi-static change in the broad sense, the virtual heat, and the field of chemical potential etc. in order to establish his own theory of thermodynamics of transient phenomena, as the generalization of the Onsager-Prigogine’s theory of the irreversible processes. By the concept of the field of chemical potential that acquired the nonlinear transport, he was seemingly successful to exceed and go beyond the scope of Onsager and Prigogine. Once he established his thermodynamics, he explored the existence of the 4th law of thermodynamics for the foundation of theory of life. He applied it to broad categories of transient phenomena including life and life being such as the theory of metabolism. He regarded the 4th law of thermodynamics as the maximum principle in transient phenomena. He tried to prove it all life long. Since I have recently found that his maximum principle can be included in more general maximum principle, which was known as the Pontryagin’s maximum principle in the theory of optimal control, I would like to explain such theories produced by Motoyosi Sugita as detailed as possible. And also I have put short history of Motoyosi Sugita’s personal life in order for you to know him well. I hope that this article helps you to know this wonderful man and understand what he did in the past, which was totally forgotten in the world and even in Japan. 展开更多
关键词 Unknown Japanese thermodynamicist Motoyosi Sugita thermodynamics of Transient Phenomena Virtual Heat Broad Quasi-Static Change Chemical Potential Field of Chemical Potential Diffusion Phenomena number of Partition Dissipation function Onsager’s theory of Irreversible Processes Prigogine’s Least Production of Entropy 4th Law of thermodynamics maximum Principle Pontryagin’s maximum Principle Bellman’s Optimality Principle theory of Metabolism theory of Life CYBERNETICS
下载PDF
高层结构-混联Ⅱ型惯容阻尼耗能体系减震性分析
9
作者 王晓琳 王善库 +1 位作者 葛新广 王昌盛 《地震工程与工程振动》 CSCD 北大核心 2024年第5期176-187,共12页
针对高层结构中设置混联Ⅱ型惯容阻尼器组成耗能体系的随机响应分析复杂的问题,提出了结构位移及阻尼器阻尼力响应的封闭解,并基于所获得的封闭解探究了实模态振型数对分析精度的影响和在原结构层间位移超限楼层设置阻尼器能有效减震的... 针对高层结构中设置混联Ⅱ型惯容阻尼器组成耗能体系的随机响应分析复杂的问题,提出了结构位移及阻尼器阻尼力响应的封闭解,并基于所获得的封闭解探究了实模态振型数对分析精度的影响和在原结构层间位移超限楼层设置阻尼器能有效减震的布置策略。首先,根据混联Ⅱ型惯容阻尼器力学构造图及设置方式,建立阻尼器阻尼力与结构节点水平位移的微分型本构关系进而重构耗能体系的地震动方程。其次,利用实模态解耦法获得高层结构简明等效的动力学参数,运用功率谱二次式分解法推导出结构节点相对于地面的绝对位移、竖向构件层间位移及阻尼器阻尼力等响应的功率谱精确二次式解进而推导出耗能体系基于双过滤白噪声激励下系列响应的0~2阶谱矩简明封闭解。最后,通过算例,验证了所提封闭解的正确性;研究了实模态振型数对系列响应谱矩分析精度的影响和阻尼器设置位置对结构减震效果的影响。研究表明:对于多自由度结构响应分析时,建议采用原结构自由振动分析时质量参与系数累计达100%时所对应的振型数,可获得稳定的精度和提高大型复杂结构设置混联Ⅱ型惯容阻尼器的响应的分析效率;通过在原结构层间位移超限楼层或连续多层层间位移超限的楼层中间隔一层设置参数合适的混联Ⅱ型惯容阻尼器可有效降低结构的地震动响应,所提惯容阻尼器设置策略具有较好的经济性。所提解析解和惯容系统在高层结构的设置策略可为混联Ⅱ型惯容阻尼器在实际工程应用中提供有益的参考价值。 展开更多
关键词 混联Ⅱ型惯容阻尼器 功率谱二次式分解法 封闭解 实模态振型数 阻尼器设置策略
下载PDF
一个与五边形数相关的数论函数方程的可解性
10
作者 王霞 丁恒兰 柯翠菊 《辽宁师专学报(自然科学版)》 2024年第3期5-11,17,共8页
利用Smarandache函数S(n)、Smarandache LCM函数SL(n)、广义Euler函数φ_(2)(n)的定义、性质,研究了与五边形数相关的数论函数方程S(SL(n^(23))=kφ_(2)[n(3n-1)\2]的可解性问题,其中k∈Z^(+)(Z^(+)是正整数集).得到如下结果:数论函数方... 利用Smarandache函数S(n)、Smarandache LCM函数SL(n)、广义Euler函数φ_(2)(n)的定义、性质,研究了与五边形数相关的数论函数方程S(SL(n^(23))=kφ_(2)[n(3n-1)\2]的可解性问题,其中k∈Z^(+)(Z^(+)是正整数集).得到如下结果:数论函数方程S(SL(n^(23))=kφ_(2)[n(3n-1)\2]的全部正整数解为(k,n)=(13,2),(2,12),(1,27). 展开更多
关键词 Smarandache函数S(n) Smarandache LCM函数SL(n) 广义欧拉函数φ_(2)(n) 五边形数 正整数解
下载PDF
基于最大熵原理的卧罐爆炸碎片数量概率分布 被引量:4
11
作者 孙东亮 蒋军成 +1 位作者 张明广 王志荣 《化工学报》 EI CAS CSCD 北大核心 2011年第S1期219-224,共6页
分析了储罐爆炸碎片数量与罐形、事故类型、破坏机理的关联性,通过卧罐爆炸事故数据的汇总研究,基于较多的数据,通过统计分析获得了四类爆炸事故数量及碎片数量与分布比例。依据最大熵原理,并通过爆炸事故数据的分析获得可利用的已知信... 分析了储罐爆炸碎片数量与罐形、事故类型、破坏机理的关联性,通过卧罐爆炸事故数据的汇总研究,基于较多的数据,通过统计分析获得了四类爆炸事故数量及碎片数量与分布比例。依据最大熵原理,并通过爆炸事故数据的分析获得可利用的已知信息为碎片数量均值及方差,由此建立四类爆炸事故产生的碎片数量的概率分布模型。结果表明,各爆炸类型生成的碎片数量区间大体上均为[1,9],且各类事故中碎片数量1~4均占有较大比例,不同事故类型对应的碎片数量分布比例不同。利用建立的模型计算获得的碎片数量理论概率分布与实际数据的吻合性较好。碎片数量在统计区间[1,9]内均服从离散指数分布。 展开更多
关键词 卧罐爆炸 碎片数量 最大熵原理 概率分布模型
下载PDF
基于结构元理论的模糊非线性规划求解方法 被引量:4
12
作者 岳立柱 郭永升 +1 位作者 左瑞 马卫民 《辽宁工程技术大学学报(自然科学版)》 CAS 北大核心 2013年第2期233-236,共4页
针对目标函数与约束函数含有多个模糊数参数的非线性规划问题,应用模糊结构元理论优化求解.利用结构元理论研究模糊值函数问题,得到了多参数函数转换成单参数函数的方法,将多模糊数参数非线性规划问题化简为仅含有一个模糊数参数(即结构... 针对目标函数与约束函数含有多个模糊数参数的非线性规划问题,应用模糊结构元理论优化求解.利用结构元理论研究模糊值函数问题,得到了多参数函数转换成单参数函数的方法,将多模糊数参数非线性规划问题化简为仅含有一个模糊数参数(即结构元)的非线性规划问题.通过结构元方法构造的自然序,将该规划问题转换成经典的非线性规划问题,并且二者同解.实例分析验证了方法的有效性. 展开更多
关键词 结构元 模糊非线性规划 模糊数 轮换对称函数 模糊值函数 扩张原理 同序单调
下载PDF
井间电磁测量数据的模拟与处理解释 被引量:6
13
作者 沈金松 孙文博 +1 位作者 赵文杰 曾文冲 《测井技术》 CAS CSCD 2007年第5期417-424,共8页
用有限元法模拟了偶极子源在二维介质中的频率域井间电磁响应。针对测量区域的层状地层分布特征,沿构造走向(y-轴方向)作Fourier变换,将全三维电磁场问题转化为一系列二维问题在波数域求解,极大地减小了计算量,使实际测量数据的处理解... 用有限元法模拟了偶极子源在二维介质中的频率域井间电磁响应。针对测量区域的层状地层分布特征,沿构造走向(y-轴方向)作Fourier变换,将全三维电磁场问题转化为一系列二维问题在波数域求解,极大地减小了计算量,使实际测量数据的处理解释成为可能。针对波数域中波数取值对模拟结果的影响,采用三次样条插值加密波数域数据,用高斯积分实现Fourier逆变换将波数域解变换为空间域电磁场。采用具有一定面积的伪δ函数表示源电流分布,避开了源点的奇异性,使数值解精度得以提高。通过对中国东部某油田2口井的实测井间电磁数据的模拟与处理解释,验证了该算法的有效性,为井间电磁数据的反演解释奠定了基础。 展开更多
关键词 井间电磁数据处理解释 频率域 有限元法 波数域解 伪δ函数
下载PDF
含弹性约束的模糊线性规划求解 被引量:3
14
作者 危子青 吕金辉 《辽宁工程技术大学学报(自然科学版)》 CAS 北大核心 2013年第6期844-847,共4页
针对模糊线性规划模型清晰化处理,利用结构元理论,构建并讨论一类含弹性约束条件的新型模糊线性规划,通过引入模糊数的加权特征数,定义了一种序关系并应用Verdegay的模糊线性规划方法,将模糊线性规划转化成一类含参数约束条件的清晰线... 针对模糊线性规划模型清晰化处理,利用结构元理论,构建并讨论一类含弹性约束条件的新型模糊线性规划,通过引入模糊数的加权特征数,定义了一种序关系并应用Verdegay的模糊线性规划方法,将模糊线性规划转化成一类含参数约束条件的清晰线性规划模型.结果表明:此类线性规划模型最优可行解是可求的,通过此方法可以达到求解过程中优化模型及简化模型的目的. 展开更多
关键词 结构元 弹性约束 序函数 最优可行解 模糊数 隶属函数 加权函数 特征数
下载PDF
涉及高阶Apostol-Euler数、错排数与第一类Stirling数之间的几个恒等式 被引量:3
15
作者 李志荣 李映辉 《吉林大学学报(理学版)》 CAS CSCD 北大核心 2007年第4期515-518,共4页
使用发生函数方法,建立高阶Apostol-Euler数、错排数与第一类Stirling数之间的恒等式,得到关于高阶Apostol-Euler数、Apostol-Euler数、高阶Euler数及Euler数的计算公式.
关键词 高阶Apostol-Euler数 高阶EULER数 错排数 第一类STIRLING数 恒等式 发生函数
下载PDF
有关高阶的Genocchi数、Euler数与Bernoulli数的一些恒等式 被引量:3
16
作者 李志荣 劳汉生 《安徽大学学报(自然科学版)》 CAS 北大核心 2008年第2期12-14,共3页
根据高阶Euler数、高阶Bernoulli数及高阶Genocchi数定义,利用发生函数方法建立起高阶Euler数、高阶Bernoulli数与高阶Genocchi数之间的恒等式,得到这些高阶数分别用其他普通数表示的几组计算公式,推广了已有的相关结果.
关键词 高阶Genocchi数 高阶EULER数 高阶BERNOULLI数 恒等式 发生函数
下载PDF
一个包含Eu ler函数的方程 被引量:28
17
作者 吕志宏 《西北大学学报(自然科学版)》 CAS CSCD 北大核心 2006年第1期17-20,共4页
目的研究方程φ(φ(n))=2ω(n)的可解性。方法利用初等方法以及Euler函数的性质。结果给出了方程φ(φ(n))=2ω(n)的所有正整数解。结论确定该方程共有20个正整数解。
关键词 EULER函数 方程的解 解的个数
下载PDF
两个数论函数及其方程 被引量:25
18
作者 吕志宏 《纯粹数学与应用数学》 CSCD 北大核心 2006年第3期303-306,共4页
对于任意给定的自然数n,著名的Eu ler函数φ(n)定义为不大于n且与n互素的正整数的个数.ω(n)表示n的所有不同素因子的个数.本文研究了方程φ(n)=2ω(n)的可解性,并给出了该方程的所有正整数解.
关键词 EULER函数 方程的解 解的个数
下载PDF
一个包含Euler函数的方程 被引量:19
19
作者 陈国慧 《纯粹数学与应用数学》 CSCD 北大核心 2007年第4期439-445,457,共8页
对任意自然数n≥1,著名的Euler函数φ(n)定义为不大于n且与n互素的正整数的个数.本文的主要目的是研究方程φ(φ(φ(n)))=2ω(n)的可解性,其中ω(n)表示n的所有不同素因子的个数,并给出了该方程的所有正整数解.
关键词 EULER函数 方程的解 解的个数
下载PDF
基于集成算子的改进IITFN多属性群决策方法 被引量:3
20
作者 徐丹青 毛军军 付亚男 《计算机工程与应用》 CSCD 2013年第12期53-56,共4页
对区间直觉梯形模糊数决策方法进行研究。定义了区间直觉梯形模糊数期望值、得分函数和精确函数,进而给出了区间直觉梯形模糊数的一种新的排序方法。另一方面,给出了有序加权平均算子和混合集成算子。建立了基于区间直觉梯形模糊数的多... 对区间直觉梯形模糊数决策方法进行研究。定义了区间直觉梯形模糊数期望值、得分函数和精确函数,进而给出了区间直觉梯形模糊数的一种新的排序方法。另一方面,给出了有序加权平均算子和混合集成算子。建立了基于区间直觉梯形模糊数的多属性群决策方法,给出了相应的群决策方法。实例分析验证了所提出方法的有效性。 展开更多
关键词 区间直觉梯形模糊数 得分函数 有序加权平均算子 混合集成算子 多属性群决策
下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部