期刊文献+
共找到35篇文章
< 1 2 >
每页显示 20 50 100
印刷电路板式换热器传热与流动研究进展 被引量:23
1
作者 于改革 陈永东 +1 位作者 李雪 吴晓红 《流体机械》 CSCD 北大核心 2017年第12期73-79,共7页
印刷电路板式换热器是适用于高温高压等苛刻条件的高效紧凑式换热器,在新一代核电、光热发电、氢能领域呈现出潜在应用前景。本文综述了国内外印刷电路板式换热器传热与流动数值模拟研究、试验研究,列出并对比了相关研究中得到的传热与... 印刷电路板式换热器是适用于高温高压等苛刻条件的高效紧凑式换热器,在新一代核电、光热发电、氢能领域呈现出潜在应用前景。本文综述了国内外印刷电路板式换热器传热与流动数值模拟研究、试验研究,列出并对比了相关研究中得到的传热与流动准则方程。指出了目前印刷电路板式换热器数值模拟局限于设定恒定边界条件,单层通道传热与流动的试验局限于低雷诺数范围,样机传热与流动试验局限于单相工质。展望了印刷电路板式换热器传热与流动进一步研究方向。 展开更多
关键词 印刷电路板式换热器 传热 流动 准则方程
下载PDF
一类具有连续分布的偏差变元的双曲型方程的振动准则(英文) 被引量:16
2
作者 林诗仲 周正新 俞元洪 《数学杂志》 CSCD 北大核心 2005年第5期521-526,共6页
本文研究了连续分布偏差变元的双曲型方程,利用化多维振动问题为一维问题的方法,得到了某些边值问题的每一个解均为振动的充分条件。所得条件推广和改进了文献中的结果。
关键词 振动准则 双曲型方程 连续分布的偏差变元
下载PDF
Rank-dependent ppredictableforward performance processes
3
作者 Bahman Angoshtari Shida Duan 《Probability, Uncertainty and Quantitative Risk》 2024年第2期181-218,共38页
Predictable forward performance processes(PFPPs)are stochastic optimal control frameworks for an agent who controls a randomly evolving system but can only prescribe the system dynamics for a short period ahead.This i... Predictable forward performance processes(PFPPs)are stochastic optimal control frameworks for an agent who controls a randomly evolving system but can only prescribe the system dynamics for a short period ahead.This is a common scenario in which a controlling agent frequently re-calibrates her model.We introduce a new class of PFPPs based on rank-dependent utility,generalizing existing models that are based on expected utility theory(EUT).We establish existence of rank-dependent PFPPs under a conditionally complete market and exogenous probability distortion functions which are updated periodically.We show that their construction reduces to solving an integral equation that generalizes the integral equation obtained under EUT in previous studies.We then propose a new approach for solving the integral equation via theory of Volterra equations.We illustrate our result in the special case of conditionally complete Black-Scholes model. 展开更多
关键词 Forward performance criteria Rank dependent utility Probability distortion Time consistency Inverse investment problems Volterra integral equations Completely monotonic inverse marginals
原文传递
TBM支撑-推进-换步机构的拓扑结构及运动特性分析 被引量:4
4
作者 王凯 杨玉虎 +2 位作者 黄田 牛文文 贺飞 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2017年第6期1135-1142,共8页
简要介绍机构的拓扑结构与工作原理,分析机构的拓扑结构在不同工况下对整机性能的影响,建立机构拓扑结构设计应遵循的基本准则.针对机构的结构特征,建立机构在线调向工况下的运动方程.以某开敞式硬岩掘进装备(TBM)(刀盘直径为8m)支撑-推... 简要介绍机构的拓扑结构与工作原理,分析机构的拓扑结构在不同工况下对整机性能的影响,建立机构拓扑结构设计应遵循的基本准则.针对机构的结构特征,建立机构在线调向工况下的运动方程.以某开敞式硬岩掘进装备(TBM)(刀盘直径为8m)支撑-推进-换步机构样机为例,结合TBM在线调向作业的运动仿真,建立机构的推进油缸、调向油缸及作业参数间的运动方程,为深入开展支撑-推进-换步机构的创新设计以及精准在线调向提供有效的计算方法. 展开更多
关键词 硬岩掘进装备(TBM) 支撑-推进-换步机构 拓扑结构 设计准则 运动方程 在线调向
下载PDF
REGULARITY CRITERIA FOR WEAK SOLUTION TO THE 3D MAGNETOHYDRODYNAMIC EQUATIONS 被引量:2
5
作者 王玉柱 王书彬 王银霞 《Acta Mathematica Scientia》 SCIE CSCD 2012年第3期1063-1072,共10页
In this article, regularity criteria for the 3D magnetohydrodynamic equations are investigated. Some sufficient integrability conditions on two components or the gradient of two components of u + B and u - B in Morre... In this article, regularity criteria for the 3D magnetohydrodynamic equations are investigated. Some sufficient integrability conditions on two components or the gradient of two components of u + B and u - B in Morrey-Campanato spaces are obtained. 展开更多
关键词 Magnetohydrodynamic equations regularity criteria Morrey-Campanato space
下载PDF
PCHE型混合工质冷凝器热力性能试验研究 被引量:3
6
作者 于改革 陈永东 +2 位作者 闫永超 张明然 倪利刚 《流体机械》 CSCD 北大核心 2019年第9期63-66,共4页
PCHE(Printed Circuit Heat Exchanger)型混合工质冷凝器是浮式液化天然气装置中冷凝器的首选型式。本文通过构建混合工质冷凝试验系统,完成了PCHE混合工质冷凝器冷凝试验。以混合工质冷凝平衡模型理论为基础,采用Bell-Ghaly方法与Shah... PCHE(Printed Circuit Heat Exchanger)型混合工质冷凝器是浮式液化天然气装置中冷凝器的首选型式。本文通过构建混合工质冷凝试验系统,完成了PCHE混合工质冷凝器冷凝试验。以混合工质冷凝平衡模型理论为基础,采用Bell-Ghaly方法与Shah冷凝准则方程进行微通道内混合工质冷凝计算。对比分析理论计算与试验结果表明:在高雷诺数情况下,Bell-Ghaly-Shah方法计算的混合工质冷凝传热系数与试验结果偏差为3.11%。本文研究内容对PCHE型混合工质冷凝器热力设计具有重要借鉴意义。 展开更多
关键词 半圆形截面 冷凝 Bell-Ghaly法 准则方程
下载PDF
Remarks on the Regularity Criteria of Three-Dimensional Navier-Stokes Equations in Margin Case 被引量:1
7
作者 ZHANG Xingwei ZHANG Wenliang DONG Bo-Qing 《Journal of Partial Differential Equations》 2011年第1期70-82,共13页
In the study of the regularity criteria for Leray weak solutions to threedimensional Navier-Stokes equations, two sufficient conditions such that the horizontal velocity u satisfies u∈L2(0,T;BMO(R3)) or u∈L^2/1... In the study of the regularity criteria for Leray weak solutions to threedimensional Navier-Stokes equations, two sufficient conditions such that the horizontal velocity u satisfies u∈L2(0,T;BMO(R3)) or u∈L^2/1+r(0,T;B∞,∞(R3)) for 0 〈 r 〈 1 are considered. 展开更多
关键词 Regularity criteria Navier-Stokes equations BMO Besov space.
原文传递
一类最优无偏估计方程 被引量:1
8
作者 赵慧秀 马文卿 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2010年第2期7-10,共4页
基于估计函数的最优性准则理论,给出一类最优无偏估计方程及其性质.得到的结果为寻找最优估计方程提供一个很好的理论方法.该方法可以提高估计的效率,在实际理论应用中具有重要意义.
关键词 估计函数 最优性准则 估计方程
下载PDF
Interval Criteria for Oscillation of CertainSecond-order Nonlinear Differential Equations
9
作者 ZHANG Wei-peng ZHU De-ming 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第4期500-509,共10页
The main desire of this paper is to present several new interval oscillation criteria related to a generalized Riccati technique for certain second-order nonlinear differential equations.Our results extend some known ... The main desire of this paper is to present several new interval oscillation criteria related to a generalized Riccati technique for certain second-order nonlinear differential equations.Our results extend some known equations.Finally,several examples illustrate the effectiveness of our results. 展开更多
关键词 interval oscillation criteria nonlinear differential equations Riccati technique
下载PDF
一类高阶非线性泛函方程的振动准则
10
作者 戴丽娜 林全文 《肇庆学院学报》 2012年第2期13-18,共6页
研究了变系数高阶非线性泛函方程x(g(t))=P(t)x(t)+sum( )from i=1 to m Qi(t)x(gK+i(t))的解的振动性,得到了一些新的振动准则.所得结论推广了目前已有结果,此外,给出了新振动准则在差分方程中的一些应用.
关键词 振动准则 非线性 变系数 泛函方程
下载PDF
TYPES AND CRITERIA OF NONOSCILLATORY SOLUTIONS FOR A CLASS OF SECOND ORDER NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATIONS WITH NONPOSITIVE COEFFICIENTS
11
作者 阮炯 傅希林 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1992年第2期182-187,共3页
In this paper we discuss the types and criteria of nonoscillatory solutions for the fol-lowing second order neutral functional differential equation with nonpositive coefficients
关键词 LIM TYPES AND criteria OF NONOSCILLATORY SOLUTIONS FOR A CLASS OF SECOND ORDER NEUTRAL FUNCTIONAL DIFFERENTIAL equations WITH NONPOSITIVE COEFFICIENTS
全文增补中
REGULARITY OF WEAK SOLUTIONS TO MAGNETO-MICROPOLAR FLUID EQUATIONS 被引量:14
12
作者 原保全 《Acta Mathematica Scientia》 SCIE CSCD 2010年第5期1469-1480,共12页
In this article, we study the regularity of weak solutions and the blow-up criteria for smooth solutions to the magneto-micropolar fluid equations in R3. We obtain the classical blow-up criteria for smooth solutions ... In this article, we study the regularity of weak solutions and the blow-up criteria for smooth solutions to the magneto-micropolar fluid equations in R3. We obtain the classical blow-up criteria for smooth solutions (u,w, b), i.e., u ∈ Lq(0, T; LP(R3) for 2/q+3/P≤ 1with 3〈P≤∞,u∈C([0,T);L3(R3))or△u∈Lq(0,T,LP)for 3/2〈P≤∞ satisfying 2/q+3/P≤ 2. Moreover, our results indicate that the regularity of weak solutions is dominated by the velocity u of the fluid. In the end-point case p = ∞, the blow-up criteriacan be extended to more general spaces △u E L1 (0, T; B0∞,∞(R3). 展开更多
关键词 magneto-micropolar fluid equations regularity criteria blow-up criteria
下载PDF
二阶半线性常微分方程的区间振动准则 被引量:6
13
作者 李万同 《数学学报(中文版)》 SCIE CSCD 北大核心 2002年第3期509-516,共8页
通过利用平均函数及 Hardy ,Littlewood和 Polya不等式,对二阶半线性微分方程建立了一些新的区间振动准则,这些准则不同于已知的依赖于整个区间[t0,∞)的性质的结果,而是仅依赖于区间[t0,∞)的子区间... 通过利用平均函数及 Hardy ,Littlewood和 Polya不等式,对二阶半线性微分方程建立了一些新的区间振动准则,这些准则不同于已知的依赖于整个区间[t0,∞)的性质的结果,而是仅依赖于区间[t0,∞)的子区间列的性质.所得结果推广和改进了 Kamenev,Kong,Li和 Yeh及 Philos的振动准则,同时也可应用于以前所不能处理的某些情形,如特别,还给出了几个例子以说明本文所得结果优越性. 展开更多
关键词 区间振动准则 二阶 半线性微分方程
原文传递
三阶中立型半线性时滞微分方程的振动性 被引量:9
14
作者 惠远先 王俊杰 《井冈山大学学报(自然科学版)》 2017年第1期8-13,共6页
研究了一类三阶中立型半线性时滞微分方程的振动性质。通过广义Riccati变换和不等式技巧,建立了保证此方程的一切解振动或者收敛到零的若干新的振动准则,推广和改进了近期文献的相关结论并给出了具体例子。
关键词 振动准则 三阶中立型半线性时滞微分方程 广义Riccati变换
下载PDF
On The Cauchy Problem for A 1D Euler-Alignment System in Besov Spaces
15
作者 Yaojun Yang 《Journal of Applied Mathematics and Physics》 2024年第2期603-631,共29页
In this paper, we investigate a 1D pressureless Euler-alignment system with a non-local alignment term, describing a kind of self-organizing problem for flocking. As a result, by the transport equation theory and Lagr... In this paper, we investigate a 1D pressureless Euler-alignment system with a non-local alignment term, describing a kind of self-organizing problem for flocking. As a result, by the transport equation theory and Lagrange coordinate transformation, the local well-posedness of the solutions for the 1D pressureless Euler-alignment in Besov spaces  with 1≤p∞ is established. Next, the ill-posedness of the solutions for this model in Besov spaces  with 1≤p and  is also deduced. Finally, the precise blow-up criteria of the solutions for this system is presented in Besov spaces  with 1≤p . 展开更多
关键词 Euler-Alignment equations Local Well-Posedness Blow-Up criteria ILL-POSEDNESS
下载PDF
二阶非线性中立型时滞微分方程的振动准则 被引量:6
16
作者 何宏庆 仉志余 《数学的实践与认识》 CSCD 北大核心 2007年第23期130-134,共5页
文章考虑二阶非线性中立型微分方程a(t)x(t)+∑li=1ci(t)x(t-τi(t))″+∑mi=1pi(t)fi(x(t-δi(t)))-∑ni=1qi(t)gi(x(t-σi(t)))=0的振动性,获得了该方程所有解振动的充分条件,推广了有关文献的结果.
关键词 振动准则 中立型微分方程 时滞
原文传递
ON THE REGULARITY CRITERIA OF THE 3D NAVIER-STOKES EQUATIONS IN CRITICAL SPACES 被引量:3
17
作者 董柏青 Sadek Gala 陈志敏 《Acta Mathematica Scientia》 SCIE CSCD 2011年第2期591-600,共10页
Regularity criteria of Leray-Hopf weak solutions to the three-dimensional Navier-Stokes equations in some critical spaces such as Lorentz space, Morrey space and multiplier space are derived in terms of two partial de... Regularity criteria of Leray-Hopf weak solutions to the three-dimensional Navier-Stokes equations in some critical spaces such as Lorentz space, Morrey space and multiplier space are derived in terms of two partial derivatives, θ1u1, θ2u2, of velocity fields. 展开更多
关键词 Regularity criteria Navier-Stokes equations
下载PDF
A BLOW-UP CRITERION FOR COMPRESSIBLE VISCOUS HEAT-CONDUCTIVE FLOWS 被引量:3
18
作者 江松 欧耀彬 《Acta Mathematica Scientia》 SCIE CSCD 2010年第6期1851-1864,共14页
We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the lo... We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the local strong solutions in terms of the gradient of the velocity only, which coincides with the famous Beale-Kato-Majda criterion for ideal incompressible flows. 展开更多
关键词 blow-up criteria strong solutions compressible Navier-Stokes equations heat-conductive flows
下载PDF
一类二阶中立型Emden-Fowler阻尼方程的振动性
19
作者 杨吉英 惠远先 《井冈山大学学报(自然科学版)》 2023年第2期9-15,共7页
通过构造广义Riccati变换得到新的广义Riccati不等式,利用积分平均技巧,建立了确保该方程一切解都振动的若干新的振动准则,推广和改进了近期文献的相关结果并给出了若干例子。
关键词 振动准则 二阶 中立型 Emden-Fowler阻尼方程 RICCATI变换
下载PDF
Comparison on Sufficient Conditions for the Stability of Hill Equation: An Arnold’s Tongues Approach 被引量:1
20
作者 Carlos A. Franco Joaquin Collado 《Applied Mathematics》 2017年第10期1481-1514,共34页
It is known that the solutions of a second order linear differential equation with periodic coefficients are almost always analytically impossible to obtain and in order to study its properties we often require a comp... It is known that the solutions of a second order linear differential equation with periodic coefficients are almost always analytically impossible to obtain and in order to study its properties we often require a computational approach. In this paper we compare graphically, using the Arnold Tongues, some sufficient criteria for the stability of periodic differential equations. We also present a brief explanation on how the authors, of each criterion, obtained them. And a comparison between four sufficient stability criteria and the stability zones found by perturbation methods is presented. 展开更多
关键词 Periodic Differential equations Stability SUFFICIENT criteria HILL Equation HAMILTONIAN LYAPUNOV Characteristic Constant
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部