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两相泥石流的非恒定特性研究 被引量:3
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作者 吕立群 崔鹏 王兆印 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2015年第5期67-72,共6页
针对两相泥石流的非恒定运动过程展开试验,研究了间歇流动的形成发展过程,通过分析建立了相应的力学模型。结果发现:两相泥石流的运动过程具有明显的间歇特征,龙头的运动和停滞呈间歇式分布。泥石流在停滞过程中,水流或泥沙悬浮液携带... 针对两相泥石流的非恒定运动过程展开试验,研究了间歇流动的形成发展过程,通过分析建立了相应的力学模型。结果发现:两相泥石流的运动过程具有明显的间歇特征,龙头的运动和停滞呈间歇式分布。泥石流在停滞过程中,水流或泥沙悬浮液携带石块在前部堆积使得龙头高度和坡度逐渐增大,当坡度达到临界值时,泥石流向下游运移,龙头高度和坡度进而减小;当龙头坡度减小到一定值时,泥石流进入下一个停滞阶段,等待上游泥沙的补给和能量的聚集。两相泥石流龙头后部水流断面平均速度〉颗粒断面平均速度〉龙头速度,水流速度是颗粒速度的2~3倍,水流通过颗粒不断将能量传递给龙头用来克服龙头相对较大的阻力。 展开更多
关键词 两相泥石流 阵流 能量聚集 非恒定性
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非淹没丁坝附近的水流流态 被引量:10
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作者 周阳 郭维东 +1 位作者 梁岳 董延超 《中国农村水利水电》 北大核心 2006年第7期82-84,共3页
以水槽试验为基础,对非淹没丁坝附近的水流现象进行了定性描述。采用三维声学多普勒流速仪对丁坝附近的水流特性进行了系统的试验研究,较为全面地分析了弯道内丁坝附近水流的三维时均流速和水面形态等,进一步表明绕丁坝近场流动的强三... 以水槽试验为基础,对非淹没丁坝附近的水流现象进行了定性描述。采用三维声学多普勒流速仪对丁坝附近的水流特性进行了系统的试验研究,较为全面地分析了弯道内丁坝附近水流的三维时均流速和水面形态等,进一步表明绕丁坝近场流动的强三维非恒定性,为相关的工程实践提供理论依据。 展开更多
关键词 淹没丁坝 三维非恒定性 ADV
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弯道内非淹没丁坝附近水流流态的试验研究 被引量:3
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作者 周阳 郭维东 +1 位作者 梁岳 董延超 《安徽农业科学》 CAS 北大核心 2005年第11期2217-2219,共3页
以水槽试验为基础,对非淹没丁坝附近的水流现象进行了定性描述。采用三维声学多普勒流速仪对丁坝附近的水流特性进行了系统的试验研究,分析了弯道水流的三维时均流速和水面形态等,进一步表明绕丁坝近场流动的强三维非恒定性。
关键词 淹没丁坝 三维非恒定性 ADV
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淤滩与刷槽之间没有必然的联系 被引量:3
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作者 齐璞 高航 +1 位作者 孙赞盈 彭红 《人民黄河》 CAS 北大核心 2005年第10期16-18,73,共4页
实测资料与动床摸型试验均表明,在洪水过程中淤滩与刷槽虽然同时发生,但它们之间并没有必然的联系。在多沙河流上洪水漫滩必然会造成滩地淤积,并在滩唇形成自然堤,阻断滩槽水流交换;主槽的冲刷发生在涨水期,在落水期不管含沙量大小,河... 实测资料与动床摸型试验均表明,在洪水过程中淤滩与刷槽虽然同时发生,但它们之间并没有必然的联系。在多沙河流上洪水漫滩必然会造成滩地淤积,并在滩唇形成自然堤,阻断滩槽水流交换;主槽的冲刷发生在涨水期,在落水期不管含沙量大小,河床均处于淤积状态。漫滩后的清水在滩地上流动缓慢,远远小于主槽水流的运动速度,因此漫滩水往往在落水期才能汇入主槽,且只能起到减少主槽淤积的作用,无法改变由于洪水的非恒定性形成的落水期河床必然淤积的状态。实测资料表明,含沙量100~200 kg/m3的不漫滩洪水在涨水期仍可造成主槽的强烈冲刷。 展开更多
关键词 非恒定性 涨冲落淤 洪水 刷槽 淤滩 黄河
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两相泥石流龙头的非恒定运动过程及能量特征 被引量:3
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作者 吕立群 王兆印 崔鹏 《水利学报》 EI CSCD 北大核心 2016年第8期1035-1044,共10页
两相泥石流通常会出现高陡的龙头,其集中了大量的粗大卵石和砾石,呈现间歇性或波动性的运动。两相泥石流的运动除了取决于流体本身的流变特征外,液相和固相之间的能量传递也起到了重要作用,利用能量分析方法来研究两相泥石流固相、液相... 两相泥石流通常会出现高陡的龙头,其集中了大量的粗大卵石和砾石,呈现间歇性或波动性的运动。两相泥石流的运动除了取决于流体本身的流变特征外,液相和固相之间的能量传递也起到了重要作用,利用能量分析方法来研究两相泥石流固相、液相和龙头之间的能量转化机理是研究两相泥石流非恒定运动的有效途径。通过野外两相泥石流原型和水槽实验,研究其非恒定运动过程,结果表明,两相泥石流的龙头在泥石流起动初始阶段逐渐增长,当运动到一段距离后,趋于稳定。龙头高度和速度都有波动特征,通过能量分析建立了物理方程,分析证明两相泥石流龙头运动的平均速度正比于沟道的坡降和激发泥石流的洪水流量,反比于龙头的体积。 展开更多
关键词 两相泥石流 间歇运动 非恒定性 水流功 耗能
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外语学习动机的课堂调控策略 被引量:1
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作者 刘永志 李玉梅 《成都理工大学学报(社会科学版)》 2003年第3期101-103,共3页
文章先从调控的角度把动机分为恒定动机和非恒定动机 ,并提出了动机调控的定义。然后用大量的课堂教学事例从以下六个方面对学习动机的课堂调控策略作了论述 :让学生接受教师、让学生对所讲内容产生好奇和兴趣、让学生参与并体会到学习... 文章先从调控的角度把动机分为恒定动机和非恒定动机 ,并提出了动机调控的定义。然后用大量的课堂教学事例从以下六个方面对学习动机的课堂调控策略作了论述 :让学生接受教师、让学生对所讲内容产生好奇和兴趣、让学生参与并体会到学习的快乐、让学生产生成就感、任务动机、用正确的文化立场使学生对外语文化产生正确的认同感。 展开更多
关键词 学习动机 恒定性动机 非恒定性动机 外语 课堂教学
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A Hierarchy of Lax Integrable Lattice Equations, Liouville Integrability and a NewIntegrable Symplectic Map 被引量:6
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作者 XUXi-Xiang ZHANGYu-Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期321-328,共8页
A discrete matrix spectral problem and the associated hierarchy of Lax integrable lattice equations are presented, and it is shown that the resulting Lax integrable lattice equations are all Liouville integrable discr... A discrete matrix spectral problem and the associated hierarchy of Lax integrable lattice equations are presented, and it is shown that the resulting Lax integrable lattice equations are all Liouville integrable discrete Hamiltonian systems. A new integrable symplectic map is given by binary Bargmann constraint of the resulting hierarchy. Finally, an infinite set of conservation laws is given for the resulting hierarchy. 展开更多
关键词 lattice soliton equation discrete Hamiltonian system Liouville integrability NONLINEARIZATION symplctic map conservation law
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Approximate Noether-Type Symmetries and Conservation Laws via Partial Lagrangians for Nonlinear Wave Equation with Damping 被引量:2
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作者 苏敬蕊 张顺利 李吉娜 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第1期37-42,共6页
In terms of our new exact definition of partial Lagrangian and approximate Euler-Lagrange-type equation, we investigate the nonlinear wave equation with damping via approximate Noether-type symmetry operators associat... In terms of our new exact definition of partial Lagrangian and approximate Euler-Lagrange-type equation, we investigate the nonlinear wave equation with damping via approximate Noether-type symmetry operators associated with partial Lagrangians and construct its approximate conservation laws in general form. 展开更多
关键词 approximate Noether-type symmetry partial Lagrangian approximate conservation law
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Conservation Law Classification and Integrability of Generalized Nonlinear Second-Order Equation 被引量:2
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作者 刘汉泽 李继彬 刘磊 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第12期987-991,共5页
This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservatio... This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservation laws(CLs) of such equations are provided.Furthermore,the integrability of the equation is considered in terms of the conservation laws.In addition,the relationship of multipliers and symmetries of the equations is investigated. 展开更多
关键词 conservation law MULTIPLIER symmetry INTEGRABILITY direct construction method Klein-Gordonwave equation
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On New Invariant Solutions of Generalized Fokker-Planck Equation 被引量:1
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作者 YAORuo-Xia LIZhi-Bin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第5期665-668,共4页
The generalized one-dimensional Fokker-Planck equation is analyzed via potential symmetry method and the invariant solutions under potential symmetries are obtained. Among those solutions, some are new and first repor... The generalized one-dimensional Fokker-Planck equation is analyzed via potential symmetry method and the invariant solutions under potential symmetries are obtained. Among those solutions, some are new and first reported. 展开更多
关键词 Fokker-Planck equation potential symmetry invariant solutions symbolic computation
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A Maple Package on Symbolic Computation of Conserved Densities for (1+l)-Dimensional Nonlinear Evolution Systems 被引量:3
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作者 YANG Xu-Dong RUAN Hang-Yu LOU Sen-Yue 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第6期961-968,共8页
A new algorithm for symbolic computation of polynomial-type conserved densities for nonlinear evolution systems is presented. The algorithm is implemented in Maple. The improved algorithm is more efficient not only in... A new algorithm for symbolic computation of polynomial-type conserved densities for nonlinear evolution systems is presented. The algorithm is implemented in Maple. The improved algorithm is more efficient not only in removing the redundant terms of the genera/form of the conserved densities but also in solving the conserved densities with the associated flux synchronously without using Euler operator. Furthermore, the program conslaw.mpl can be used to determine the preferences for a given parameterized nonlinear evolution systems. The code is tested on several well-known nonlinear evolution equations from the soliton theory. 展开更多
关键词 conservation laws nonlinear evolution systems computer algebra
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Analytical Treatment of an Oldroyd 8-constant Fluid Between Coaxial Cylinders with Variable Viscosity
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作者 Muhammad Yousaf Malik Azad Hussain Sohail Nadeem 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期933-938,共6页
The flow of an Oldroyd 8-constant fluid between coaxial cylinders with variable viscosity is considered.The heat transfer analysis is also taken into account.An analytical solution of the non-linear problem is obtaine... The flow of an Oldroyd 8-constant fluid between coaxial cylinders with variable viscosity is considered.The heat transfer analysis is also taken into account.An analytical solution of the non-linear problem is obtained usinghomotopy analysis method.The behavior of pertinent parameters is analyzed and depicted through graphs. 展开更多
关键词 variable viscosity analytical solution heat transfer
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Extended Conservation Laws of Some Nonlinear Partial Differential Equations
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作者 宋朝晖 梅建琴 张鸿庆 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第4期693-697,共5页
Self-adjoint theorem is introduced to match the corresponding functional of the given differential equations,and then Noether's theorem is used to determine the extended conservation laws of the original equations. F... Self-adjoint theorem is introduced to match the corresponding functional of the given differential equations,and then Noether's theorem is used to determine the extended conservation laws of the original equations. Finally, as the application of the method, the conservation laws of Drinfel'd-Sokolov-Wilson equation and Benjamin-Bona-Mahony equation are constructed. 展开更多
关键词 extended conservation laws Lagrangian function NSether's theorem
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Noether-Type Symmetries and Associated Conservation Laws of Some Systems of Nonlinear PDEs
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作者 MEI Jian-Qin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第3期495-498,共4页
The algorithm for constructing conservation laws of Euler Lagvange type equations via Noether-type symmetry operators associated with partial Lagrangian has been presented. As applications, many new conservation laws ... The algorithm for constructing conservation laws of Euler Lagvange type equations via Noether-type symmetry operators associated with partial Lagrangian has been presented. As applications, many new conservation laws of some important systems of nonlinear partial differential equations have been obtained. 展开更多
关键词 Lie-Backlund Noether-type symmetries conservation law coupled integrable dispersionless equations coupled wave equations
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Qualitative Analysis on a Reaction-Diffusion Prey-Predator Model and the Corresponding Steady-States 被引量:3
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作者 Qunyi BIE Rui PENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2009年第2期207-220,共14页
The authors study a diffusive prey-predator model subject to the homogeneous Neumann boundary condition and give some qualitative descriptions of solutions to this reaction-diffusion system and its corresponding stead... The authors study a diffusive prey-predator model subject to the homogeneous Neumann boundary condition and give some qualitative descriptions of solutions to this reaction-diffusion system and its corresponding steady-state problem. The local and global stability of the positive constant steady-state are discussed, and then some results for non- existence of positive non-constant steady-states are derived. 展开更多
关键词 Prey-predator model Steady-state Global stability NON-EXISTENCE
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Non-linear and non-conservative quasi-variational principle of flexible body dynamics and application in spacecraft dynamics 被引量:10
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作者 LIANG LiFu SONG HaiYan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第11期2192-2199,共8页
The law of conservation of energy is one of the most fundamental laws of nature.According to the law of the conservation of energy,the non-linear and non-conservative quasi-variational principle of flexible body dynam... The law of conservation of energy is one of the most fundamental laws of nature.According to the law of the conservation of energy,the non-linear and non-conservative quasi-variational principle of flexible body dynamics is established.The physical meaning of the quasi-stationary value conditions has been explained in non-linear and non-conservative flexible body dynamics.In the case study,the application in spacecraft dynamics is researched. 展开更多
关键词 NON-LINEAR non-conservative variational principle spacecraft dynamics flexible body
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