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81.
Sérgio H. Faria 《Continuum Mechanics and Thermodynamics》2003,15(2):147-159
Recently, there appeared in this journal a short review article by Müller ((2002), 14: 227–229), in which it was argued that
the internal energy of a reacting mixture of liquid crystals should not be an objective quantity (i.e., a quantity independent
of the referential frame). Such a paradoxical conclusion has revealed the urging necessity for a better comprehension of the
interactions taking place in structured mixtures, specially when referred to non-inertial observers. This work shows that
Müller's paradox is avoided when all inertial effects are carefully accounted for. Further, it predicts interesting phenomena
without analogue in reacting mixtures of structureless fluids: internal inertial effects, produced by a combination of mass exchanges (e.g. by chemical reactions or phase changes) with the extra degrees of freedom
posed by the microstructure. Such effects clarify the reasons why inertial forces and couples acting on a mixture do not always
coincide with the sum of the inertial forces and couples exerted upon its individual constituents. The present conclusions
establish a reinterpretation of some fundamental concepts of continuum mechanics and thermodynamics, including a deeper understanding
of the manner in which total energy and momenta are conserved in complex media.
Received: July 25, 2002 / Published online: February 17, 2003
Communicated by Kolumban Hutter, Darmstadt
e-mail: faria@mechanik.tu-darmstadt.de 相似文献
82.
工程力学矢量的规范表示与弹性力学的不变性 总被引:3,自引:0,他引:3
通过引入规范变换,消除了工程力学矢量数学表示上的物理缺陷,使规范化力学矢量与力学张量具有物理上的等价表示,从而奠定了不变性弹性力学的基础,为它在不同坐标下的具体应用提供了理论保障。 相似文献
83.
84.
针对欠驱动桥式吊车系统,提出了一种基于分段能量分析的桥式吊车镇定控制器没计方法.具体而言,首先通过对系统特性进行分段分析构造出一个新的能量函数;随后,在其基础上设计了一种新型的能量控制器,并借助Lyapunov方法和LaSalle不变性原理证明了闭环系统的渐近稳定性.利用数值仿真与实际实验验证了所提出的控制算法具有良好的控制性能,对外界干扰具有较强的鲁捧性.此外,实验结果进一步表明:相比常规的能量控制方法与时间最优控制方法,该控制方法可降低驱动能耗,保征台车的快速精确定位,同时负载的摆角被抑制在更小的范围内,几乎无残余摆动. 相似文献
85.
86.
证明了紧承下方图度量不是平移不变的.对紧承下方图度量的代数运算的连续性进行了讨论.证明了关于紧承下方图度量,模糊数空间只能是嵌入到拓扑向量空间当中,但不嵌入赋范线性空间当中.并与关于上确界度量的结果进行了比较.最后,给出了一个紧承下方图度量的下界. 相似文献
87.
Jesús T. Pastor 《Annals of Operations Research》1996,66(2):91-102
In this paper, we undertake a revision and a generalization of the results contained in the only paper so far published on the matter of translation invariance by allowing inputs and outputs to take not only zero but negative values. This broadens the field of application of the DEA methodology. 相似文献
88.
Markus Schlicht 《Annals of Global Analysis and Geometry》1995,13(1):19-22
In this paper we relate the group of automorphisms of a principal fibre bundle with the (second) Bianchi identity generalizing a result of Kazdan.During the preparation of this paper the author was supported by a fellowship of theGraduiertenkolleg Geometrie und Mathematische Physik at the Ruhr-Universität Bochum. 相似文献
89.
The scale invariance technique has been employed to discuss theη
i-driven turbulent transport under a new fluid model developed by Kimet al [1]. Our analysis reveals that the finite Larmour radius effect plays a decisive role to determine the scaling behaviour
of the energy transport under the new fluid model. However, the overall scaling of the transport coefficient remains unchanged
as compared to that derived by Connor [2] under the traditional fluid model. The approximations considered by Connor [2] are
qualified with additional requirements within the new fluid approach. In the dissipative case, which has not been discussed
earlier, additional constraints on the power scaling laws of the transport properties are imposed due to the dissipative mechanisms
in the basic governing equations. 相似文献
90.
In this paper, we extend the Hölderian invariance principle of Lamperti [6] to the case of partial-sum processes based on a triangular array of row-wise independent random variables. As an application, we obtain necessary and sufficient conditions for the almost sure (resp. in probability) weak Hölder convergence of partial-sum processes based on bootstrapped samples. 相似文献