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1.
关于循环子半群的结构与数量问题及拟环的特征与结构   总被引:1,自引:0,他引:1  
彻底解决了所有循环半群及其子群的结构和数量问题,并讨论了拟群分解问题,同时,对群论基本定理作了部分推广,并给出了定理的另一部分不可推广的反例,最后,建立了一类特殊环-拟环。  相似文献   

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Every vector measure μ factors uniquely by μ = \?gm ° χ where χ is a universal measure and \?gm is a linear map continuous on simple functions in the strict topology. The completion of χ describes the dual of the space of measures by uniform closure based on χ-measurable sets and also as the completion of the simple functions in the strict topology.  相似文献   

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We study rigidity and stability properties of the Leibniz and chain rule operator equations. We describe which non-degenerate operators V, T 1, T 2,A: C k (?) → C(?) satisfy equations of the generalized Leibniz and chain rule type for f, gC k (?), namely, V (f · g) = (T 1 f) · g + f · (T 2 g) for k = 1, V (f · g) = (T 1 f) · g + f · (T 2 g) + (Af) · (Ag) for k = 2, and V (fg) = (T 1 f) ○ g · (T 2 g) for k = 1. Moreover, for multiplicative maps A, we consider a more general version of the first equation, V (f · g) = (T 1 f) · (Ag) + (Af) · (T 2 g) for k = 1. In all these cases, we completely determine all solutions. It turns out that, in any of the equations, the operators V, T 1 and T 2 must be essentially equal. We also consider perturbations of the chain and the Leibniz rule, T (fg) = Tfg · Tg + B(fg, g) and T (f · g) = Tf · g + f · Tg + B(f, g), and show under suitable conditions on B in the first case that B = 0 and in the second case that the solution is a perturbation of the solution of the standard Leibniz rule equation.  相似文献   

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The author describes various effects which he has detected involving the reversal of the reinforcing action of fillers in polymers in different subregions of the glassy state. It is suggested that these effects can be explained in terms of, among other things, the flexibility of the macromolecules. The concept of an optimal flexibility at which the maximum value of a given mechanical property can be realized is introduced. It is shown that it is possible, in principle, to reinforce a polymer in any subregion of the glassy state and even below Tb, as well as to obtain equal-strength, equal-modulus, equally reinforced, etc., composites containing different (large and small) amounts of fillers and plasticizers.  相似文献   

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This paper provides an axiomatic framework to compare the D-core (the set of undominated imputations) and the core of a cooperative game with transferable utility. Theorem 1 states that the D-core is the only solution satisfying projection consistency, reasonableness (from above), (*)-antimonotonicity, and modularity. Theorem 2 characterizes the core replacing (*)-antimonotonicity by antimonotonicity. Moreover, these axioms also characterize the core on the domain of convex games, totally balanced games, balanced games, and superadditive games.   相似文献   

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A bounded operator between Hilbert spaces has an adjoint if and only if the image of the unit ball is located.

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矩阵特征值、特征向量的确定   总被引:4,自引:1,他引:3  
施劲松  刘剑平 《大学数学》2003,19(6):123-126
首先对由 A的特征值、特征向量求 A- 1 ,AT,A* ( A的伴随矩阵 )、P- 1 AP以及 A的多项式φ( A)的特征值和特征向量的结论作了个归纳 ;对相反的情形 ,我们给出了部分已有的结果 ,并通过四道例题着重讨论了如何由 φ( A)的特征值来求 A的特征值 .  相似文献   

11.
居民收入和消费预测的灰理论方法   总被引:4,自引:2,他引:2  
阐述灰色模型GM(1,1)建立及检验的基本理论和方法.并依据2000年—2005年浙江农村居民人均纯收入和人均生活消费数据,利用GM(1,1)模型建模方法,对“十一五”期间浙江农民的纯收入和生活消费进行了预测.  相似文献   

12.
鱼咀及丁坝对长江口航道分流分沙的影响   总被引:2,自引:0,他引:2  
利用水平二维水流、盐度、泥沙数学模型研究了长江口航道整治工程(一期)实施前后,航道的分水分沙特点,重点讨论了束水丁坝的长度、潜堤的方向对航道分流比、分沙比的影响.数值模拟结果表明,双导堤工程减少了航道的分沙量,这有利于维护航道的畅通,但同时也使航道的分流比减小.航道分流分沙比的改变可通过调整各水工建筑物的布置或尺寸来实现.与束水丁坝长度的影响相比,鱼咀工程潜堤方向的改变对航道分流分沙比的影响更大.  相似文献   

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LetT be a positive linear operator on the Banach latticeE and let (S n ) be a sequence of bounded linear operators onE which converge strongly toT. Our main results are concerned with the question under which additional assumptions onS n andT the peripheral spectra (S n ) ofS n converge to the peripheral spectrum (T) ofT. We are able to treat even the more general case of discretely convergent sequences of operators.  相似文献   

16.
An algebraic system is constructed from which establishes two isospectral problems. By solving the zero curvature equations, two resulting integrable couplings of the Li hierarchy and Tu hierarchy are obtained, respectively. By making use of the quadratic-form identity, the Hamiltonian structures of the above integrable couplings are generated, which are Liouville integrable.  相似文献   

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讨论了函数与其反函数图像交点的个数及位置.同时举例说明我们的结果是精确的.  相似文献   

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The long-term results of operations on the abdominal aorta and iliac arteries have been studied. It is shown that the use of arterial autografts after eversion endarterectomy does not have any particular advantages over the use of a prosthesis in relation to the prevention of postoperative thromboses. Eversion endarterectomy and autovenous shunting are the best methods for the plastic replacement of small and medium arteries.  相似文献   

20.
We examine some recent results of Bownik on density and connectivity of the wavelet frames. We use orthogonality (strong disjointness) properties of frame and Bessel sequences, and also properties of Bessel multipliers (operators that map wavelet Bessel functions to wavelet Bessel functions). In addition we obtain an asymptotically tight approximation result for wavelet frames.  相似文献   

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