共查询到19条相似文献,搜索用时 62 毫秒
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对现有连续统场论中存在若干有关兼容性问题进行了简略的评论.根据重建的极性的连续统基本定律阐述三类兼容性问题.第一类是讨论各基本定律间的兼容性问题.第二类是讨论微极连续统基本定律兼容一般连续统基本定律的问题.第三类是讨论微极连续统基本定律兼容刚体动力学基本方程的问题.推导出的结果有助于深刻理解各种连续统理论的基本定律体系的结构和它们之间的联系.明确地指出,在传统的连续统场论的基本均衡定律的框架下,相容性问题是不可能自然地得到解决. 相似文献
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在对现有微极连续统理论已进行过再研究的基础上重新建立较为完整的微极连续统理论的基本均衡定律和方程体系。在此重建的新体系中不但考虑了由于动量引起的附加动量矩、面力引起的附加面矩和体力引起的附加体矩,而且还考虑了微角速度引起的附加速度,从而可以建立起耦合型的动量、动量矩和能量的均衡定律。从这些新的基本均衡定律可以很自然地推导出相应的局部和非局部均衡方程。通过对比可以清楚地看到这些新结果较之现有的结果都完整。 相似文献
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极性连续统的增率型运动方程和边界条件 总被引:5,自引:3,他引:2
推导出了各种偶应力张量间和它们的变率间的关系,并建立起增率型角动量方程及其相应的边界条件。于是,把这些结果和匡震邦在“非线性连续介质力学基础”中给出的经典连续统力学的相应结果组合起来即得Cauchy形式和Piola形式以及Kirchhoff形式的极性连续统的增率型运动方程和边界条件。 相似文献
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本文研究一类具有种内竞争的三种群捕食者-食饵模型的强耦合交错扩散系统,发现当捕食者对食饵的捕获水平高于食饵的种内竞争水平时,捕食者的大的交错扩散系数能够导致Turing不稳定. 相似文献
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正交曲线坐标系下极性连续统的动力学方程组 总被引:1,自引:0,他引:1
应用非完整系物理标架给出正交曲线坐标系下Bousinesq型、Kirchhof型、Signorini型和Novozhilov型有限变形极性弹性介质动力学方程组的具体形式. 相似文献
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本文研究了Poincaré著名注记中"内束"观念的数学表述法问题,通过构建Poincaré连续统模型,得到了这一问题的一种解答.文中还论述了有关数理哲学及方法论问题;文末特别指出了须继续研究的数学问题. 相似文献
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拓扑群在连续统上的膨胀作用 总被引:3,自引:0,他引:3
本文把一个同胚的膨胀作用推广到拓扑群的情形,并研究了有限生成离散群 的膨胀作用,得到了如下结果:Z×Z不能膨胀地作用在单位闭区间I上,而自由积 Z★Z可以膨胀地作用在I上. 相似文献
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带有微结构的连续统中新的能量守恒定律和C-D不等式 总被引:7,自引:6,他引:1
对带有微结构的连续统中现有的基本定律、均衡方程和Clausius-Duhem不等式进行了系统的再研究,发现所有的能量均衡方程和相关的C-D不等式都是不完整的.本文对现有的结果进行了评注,并提出新的能量均衡方程和相关的C-D不等式. 相似文献
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Abstract
We prove that there are non-recursive r.e. sets
A and C with A <
T
C such that for every set
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Both authors are supported by “863” and the National
Science Foundation of China 相似文献
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In their classical papers, Lerman, Lachlan, and Lebeuf developed the embedding method, which provides constructions of initial segments of Turing degrees isomorphic to various partially ordered structures. We analyze this method and prove that there is a nonzero degree below each decreasing chain of degrees uniform in O'. This imposes restrictions on the application of the embedding method. 相似文献
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In this paper we study some statements similar to the Partition Principle and the Trichotomy. We prove some relationships between these statements, the Axiom of Choice, and the Generalized Continuum Hypothesis. We also prove some independence results. MSC: 03E25, 03E50, 04A25, 04A50. 相似文献
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M. A. Dabkowska M. K. Dabkowski V. S. Harizanov A. S. Sikora 《Proceedings of the American Mathematical Society》2007,135(10):3383-3391
For a countable structure , the (Turing) degree spectrum of is the set of all Turing degrees of its isomorphic copies. If the degree spectrum of has the least degree , then we say that is the (Turing) degree of the isomorphism type of . So far, degrees of the isomorphism types have been studied for abelian and metabelian groups. Here, we focus on highly nonabelian groups. We show that there are various centerless groups whose isomorphism types have arbitrary Turing degrees. We also show that there are various centerless groups whose isomorphism types do not have Turing degrees.
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Antoní n Kucera Theodore A. Slaman 《Proceedings of the American Mathematical Society》2007,135(11):3723-3731
For every Scott set and every nonrecursive set in , there is a such that and are Turing incomparable.
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Valeriy K. Bulitko 《Mathematical Logic Quarterly》1999,45(4):561-571
We apply complexity concepts to define a new sort of sub-Turing reducibilities ≤ ?? make the degree hierarchy thinner and to obtain some new specifications of the well known jump inversion theorem of Friedberg. We show that this theorem doesn't hold when ≤ T is replaced with ≤ ??, where ?? is any countable subset of the class ?? of all total increasing functions f : ? → ?. 相似文献
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A computably enumerable (c.e.) degree a is called nonbounding, if it bounds no minimal pair, and plus cupping, if every nonzero c.e. degree x below a is cuppable. Let NB and PC be the sets of all nonbounding and plus cupping c.e. degrees, respectively. Both NB and PC are well understood, but it has not been possible so far to distinguish between the two classes. In the present paper, we investigate the relationship between the classes NB and PC , and show that there exists a minimal pair which join to a plus cupping degree, so that PC ? NB . This gives a first known difference between NB and PC . (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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S. Barry Cooper 《Mathematical Logic Quarterly》1996,42(1):191-196
We prove that there exists a nonzero recursively enumerable Turing degree possessing a strong minimal cover. Mathematics Subject Classification: 03D30. 相似文献