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1.
In high temperature superconductors (HTSC), when magnetic relaxation approaches the equilibrium state and the superconductor is applied with current, theE × j relation is calculated by considering both forward and backward hopping of thermally activated flux (where backward hopping means hopping from the barriers with low energy to the ones with high energy). It is pointed out that the InE× Inj curve shows positive curvature. And the results are compared with other models. The discussion on the topic that whether p approaches zero asj → 0 is carried out.  相似文献   

2.
In high temperature superconductors (HTSC), when magnetic relaxation approaches the equilibrium state and the superconductor is applied with current, the E~j relation is calculated by considering both forward and backward hopping of thermally activated flux (where backward hopping means hopping from the barriers with low energy to the ones with high energy). It is pointed out that the lnE~lnj curve shows positive curvature. And the results are compared with other models. The discussion on the topic that whether ρ approaches zero as j →0 is carried out.  相似文献   

3.
4.
The paper studies the region of values Dm,n(T) of the system {f(z1), f(z2),..., f(zm), f(r1), f(r2),..., f(rn)}, where m ≥ 1; n > 1; zj, j = 1, ... m, are arbitrary fixed points of the disk U = {z: |z| < 1} with Im zj ≠ 0, j = 1, 2, ..., m; rj, 0 < rj < 1, j = 1, 2, ..., n, are fixed; f ∈ T, and the class T consists of functions f(z) = z + c2z2 + ... regular in the disk U and satisfying the condition Im f(z) · Im z > 0 for Im z ≠= 0, z ∈ U. An algebraic characterization of the set Dm,n(T) in terms of nonnegative-definite Hermitian forms is provided, and all the boundary functions are described. As an implication, the region of values of f(z1) in the subclass of functions f ∈ T with prescribed values f(rj) (j = 1, 2, 3) is determined. Bibliography: 12 titles. Dedicated to the 100th anniversary of my father’s birthday __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 337, 2006, pp. 23–34.  相似文献   

5.
N. Ghoraf  M. Boushaba 《TOP》2003,11(2):275-283
Anm-consecutive-k-out-of-n:F system is a system ofn linearly arranged components which fails if and only if at leastm non-overlapping sequences ofk components fail, when there arek distinct components with failure probabilitiesq i fori=1,...,k and where the failure probability of thej-th component (j=rk+i (1 ≤ik) isq j =q i , we call this system by anm-consecutive-k-out-of-n:F system with cycle (or period)k. In this paper we give a formula of the failure probability ofm-consecutive-k-out-of-n:F system with cyclek via the failure probability of consecutive-k-out-of-n:F system.  相似文献   

6.
Let E,F be two Banach spaces,B(E,F),B+(E,F),Φ(E,F),SΦ(E,F) and R(E,F) be bounded linear,double splitting,Fredholm,semi-Frdholm and finite rank operators from E into F,respectively. Let Σ be any one of the following sets:{T ∈Φ(E,F):Index T=constant and dim N(T)=constant},{T ∈ SΦ(E,F):either dim N(T)=constant< ∞ or codim R(T)=constant< ∞} and {T ∈ R(E,F):Rank T=constant< ∞}. Then it is known that Σ is a smooth submanifold of B(E,F) with the tangent space TAΣ={B ∈ B(E,F):BN(A)-R(A) } for any A ∈Σ. However,for ...  相似文献   

7.
The Rankin-Selberg method associates, to each local factorL(s, π v × π v ) of an automorphicL-function onGL(n) ×GL(n), a certain local integral of Whittaker functions for π v and v . In this paper we show that, if ν is archimedean, and π v and v are spherical principal series representations with trivial central character, then the localL-factor and local integral are, in fact, equal. This result verifies a conjecture of Bump, which predicts that the archimedean situation should, in the present context, parallel the nonarchimedean one. We also derive, as prerequisite to the above result, some identities for generalized Barnes integrals. In particular, we deduce a new transformation formula for certain single Barnes integrals, and a multiple-integral analog of the classical Barnes’ Lemma.  相似文献   

8.
In 1968 Cryer conjectured that the growth factor of an n × n Hadamard matrix is n. In 1988 Day and Peterson proved this only for the Hadamard–Sylvester class. In 1995 Edelman and Mascarenhas proved that the growth factor of a Hadamard matrix of order 12 is 12. In the present paper we demonstrate the pivot structures of a Hadamard matrix of order 16 and prove for the first time that its growth factor is 16. The study is divided in two parts: we calculate pivots from the beginning and pivots from the end of the pivot pattern. For the first part we develop counting techniques based on symbolic manipulation for specifying the existence or non‐existence of specific submatrices inside the first rows of a Hadamard matrix, and so we can calculate values of principal minors. For the second part we exploit sophisticated numerical techniques that facilitate the computations of all possible (n ? j) × (n ? j) minors of Hadamard matrices for various values of j. The pivot patterns are obtained by utilizing appropriately the fact that the pivots appearing after the application of Gaussian elimination on a completely pivoted matrix are given as quotients of principal minors of the matrix. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

9.
We use the representation theory of Lie algebras and computational linear algebra to determine the simplest non-constant invariant polynomial in the entries of a general 2?×?2?×?3 array. This polynomial is homogeneous of degree 6 and has 66 terms with coefficients ±1, ±2 in the 12 indeterminates x ijk where i, j?=?1,?2 and k?=?1,?2,?3. This invariant can be regarded as a natural generalization of Cayley's hyperdeterminant for 2?×?2?×?2 arrays.  相似文献   

10.
   Abstract. Let S be a finite set of points in general position in R d . We call a pair (A,B) of subsets of S an (i,j) -partition of S if |A|=i , |B|=j and there is an oriented hyperplane h with S
h=A and with B the set of points from S on the positive side of h . (i,j) -Partitions generalize the notions of k -sets (these are (0,k) -partitions) and j -facets ((d,j) -partitions) of point sets as well as the notion of i -faces of the convex hull of S ((i+1,0) -partitions). In oriented matroid terminology, (i,j) -partitions are covectors where the number of 0 's is i and the numbers of + 's is j . We obtain linear relations among the numbers of (i,j) -partitions, mainly by means of a correspondence between (i-1) -faces of so-called k -set polytopes on the one side and (i,j) -partitions for certain j 's on the other side. We also describe the changes of the numbers of (i,j) -partitions during continuous motion of the underlying point set. This allows us to demonstrate that in dimensions exceeding 3 , the vector of the numbers of k -sets does not determine the vector of the numbers of j -facets—nor vice versa. Finally, we provide formulas for the numbers of (i,j) -partitions of points on the moment curve in R d .  相似文献   

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