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排序方式: 共有687条查询结果,搜索用时 15 毫秒
611.
Numerical models are often used to evaluate the potential impact of human alteration of natural water bodies and to help the design the alternation to mitigate its impacts. A vertical (laterally integrated) two-dimensional hydrodynamic model was expanded to include the capability of simulating river loops as well as tributaries. The model was performed and applied to the Danshuei River estuarine system in northern Taiwan which consists of three major tributaries: the Tahan Stream, Hsintien Stream, Keelung River, and one river loop under the Chung-Hsin Bridge. The expanded model was reverified with observational field data of 2000. The verified model was then used to hindcast the river hydrodynamic conditions with a loop connection between the Danshuei River and Keelung River, which existed prior to 1965. It was found that the configuration of river loop connection has significant impacts on the residual transport along the connecting channel and the salinities in the connected river branches. The results show that the model may provide an ideal tool for management decision. 相似文献
612.
A. V. Gavriliov 《Algebra and Logic》2008,47(5):321-329
A framed Lie algebra is an algebra with two operations which is a Lie algebra with respect to one of these operations. A basic
example is a Lie algebra of vector fields on a manifold with connection where the covariant derivative serves as an additional
operation. In a free framed Lie algebra, we distinguish a set of special polynomials that geometrically correspond to invariantly
defined tensors. A necessary condition of being special is derived, and we presume that this condition is also sufficient.
Translated from Algebra i Logika, Vol. 47, No. 5, pp. 571–583, September–October, 2008. 相似文献
613.
Synchronization of N different coupled chaotic systems with ring and chain Lorenz system, and the R(o)ssler system are used as examples in verifying effectiveness of the method. Based on the Lyapunov stability theory, the form of the controller is designed and the area of the coupling coefficients is determined. Simulations indicate that global synchronization of the N different chaotic systems can be realized by choosing appropriate coupling coefficients by using the controller. 相似文献
614.
An explicit formula for a strong connection form in a principal extension by a coseparable coalgebra is given.
相似文献
615.
We show that the Vrănceanu connection which was initially introduced on non-holonomic manifolds can be used to study the geometry
of foliated manifolds. We prove that a foliation is totally geodesic with bundle-like metric if and only if this connection
is a metric one. We introduce the notion of a foliated Riemannian manifold of constant transversal Vrănceanu curvature and
the notion of a transversal Einstein foliated Riemannian manifold. The geometry of these two classes of manifolds is studied
and the relationship between them is determined. 相似文献
616.
Paul Bracken 《International journal of quantum chemistry》2008,108(9):1528-1532
An introduction to several geometrical ideas which are of use to quantum mechanics is presented. The Aharonov‐Anandan phase is introduced and without reference to any dynamical equation, this phase is formulated by defining an appropriate connection on a specific fiber bundle. The holonomy element gives the phase. By introducing another connection, the Pancharatnam phase formula is derived following a different procedure. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 相似文献
617.
Zhang Rongye 《应用数学和力学(英文版)》2000,21(7):825-835
By the theory of Modern Geometry, the mechanical principle and advanced calculus, the dynamics in Newtonian-Galilean spacetime
is generalized to Newtonian-Riemannian Spacetime, and the dynamics in N-R spacetime is established. Being divided it into
some parts. This paper is one of them. The others are to be continued.
CLC number: 0313.1
Document code: A 相似文献
618.
R. David Kumar 《Proceedings Mathematical Sciences》2005,115(3):259-277
In this paper we define nth order Hessian structures on manifolds and study them. In particular, whenn = 3, we make a detailed study and establish a one-to-one correspondence betweenthird-order Hessian structures and acertain class of connections on the second-order tangent bundle of a manifold. Further, we show that a connection on the tangent bundle of a manifold
induces a connection on the second-order tangent bundle. Also we define second-order geodesics of special second-order connection
which gives a geometric characterization of symmetric third-order Hessian structures. 相似文献
619.
A simple model of Brownian motion of a colloidal particle attached to the flat surface by a polymer thread is presented.
The model results are discussed in terms of the measurability of the elastic properties of a linear polymer chain in the dispersion
medium by observation of the motion of a colloidal particle connected to a fixed point by the polymer.
Received: 11 November 1998 Accepted: 9 December 1998 相似文献
620.
国际经济交流与区域经济协同的深化加速了企业的外部技术获取。为避免外部技术的过度依赖,尤其是与技术内化不匹配的依赖,将模糊集与集对分析进行改进并运用到技术依赖预警的研究中。借助集对分析对我国各省份规模上工业企业技术依赖同一度计算,构建各省技术依赖预警集。利用模糊隶属度联系数化改进提取技术依赖联系数并对其进行演化测度,参照集对势表剖析和诠释技术依赖预警的风险排列与演化趋势。研究结果表明,模糊隶属度补数的改进及其联系数化在对成组数据进行联系数提取时简便有效,偏联系数对演化趋势的测度准确详尽;经技术依赖预警与演化趋势测度,发现现阶段外部技术对我国自主研发的挤出效应不明显,但由于企业外部技术创造性依赖能力不足导致的外部技术内化风险凸显。 相似文献