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101.
Crystal of Yb3+-doped Ba3Gd(BO3)3 has been grown by the Czochralski method. The spectroscopic characterizations have been investigated at room temperature. The Yb3+:Ba3Gd(BO3)3 crystal exhibits broad absorption at 976nm with FWHM of 7nm and large overall spitting of 2F7/2 manifold (823cm-1). The absorption and emission cross sections are 5.09×10-21cm2 at 976nm and 0.97×10-21cm2 at 1040nm,respectively. The fluorescence lifetime is 2.84 ms. 相似文献
102.
ON NONLINEAR DIFFERENTIAL GALOIS THEORY 总被引:5,自引:0,他引:5
B. MALGRANGE 《数学年刊B辑(英文版)》2002,23(2):219-226
This Is an accom ofa work In course ofprogress.The aim Is the following: 相似文献
103.
Let X be a closed, oriented Riemannian 4-manifold. Suppose that a cyclic group Z(
p
(p is prime) acts on X by an orientation preserving isometry with an embedded Riemann surface as fixed point set. We study the representation of Z
p
on the Spinc-bundles and the Z
p-invariant moduli space of the solutions of the Seiberg–Witten equations for a Spinc-structure X. When the Z
p
action on the determinant bundle det L acts non-trivially on the restriction L| over the fixed point set , we consider -twisted solutions of the Seiberg-Witten equations over a Spinc-structure ' on the quotient manifold X/Z
p
X', (0,1). We relate the Z
p
-invariant moduli space for the Spinc-structure on X and the -twisted moduli space for the Spinc-structure on X'. From this we induce a one-to-one correspondence between these moduli spaces and calculate the dimension of the -twisted moduli space. When Z
p
acts trivially on L|, we prove that there is a one-to-one correspondence between the Z
p
-invariant moduli space M(
Zp
and the moduli space M (") where ' is a Spinc-structure on X' associated to the quotient bundle L/Z
p
X'. vskip0pt When p = 2, we apply the above constructions to a Kahler surface X with b
2
+
(X) > 3 and H
2(X;Z) has no 2-torsion on which an anti-holomorphic involution acts with fixed point set , a Lagrangian surface with genus greater than 0 and []2H
2(H ;Z). If
K
X
2 > 0 or K
X
2
= 0 and the genus g()> 1, we have a vanishing theorem for Seiberg–Witten invariant of the quotient manifold X'. When K
X
2
= 0 and the genus g()= 1, if there is a Z
2-equivariant Spinc-structure on X whose virtual dimension of the Seiberg–Witten moduli space is zero then there is a Spinc-structure " on X' such that the Seiberg-Witten invariant is ±1. 相似文献
104.
Adler Roy L.; Dedieu Jean-Pierre; Margulies Joseph Y.; Martens Marco; Shub Mike 《IMA Journal of Numerical Analysis》2002,22(3):359-390
To study a geometric model of the human spine we are led tofinding a constrained minimum of a real valued function definedon a product of special orthogonal groups. To take advantgeof its Lie group structure we consider Newton's method on thismanifold. Comparisons between measured spines and computed spinesshow the pertinence of this approach. 相似文献
105.
Kazuo Kobayasi 《Proceedings of the American Mathematical Society》1999,127(4):1143-1150
We construct an inertial manifold for the evolution equation as a limit of the inertial manifolds for the difference approximations of the Trotter-Kato type and show that this limit is taken in a topology.
106.
107.
The asymptotic properties of maximum likelihood estimates of a vector ARMAX system are considered under general conditions, relating to the nature of the exogenous variables and the innovation sequence and to the form of the parameterization of the rational transfer functions, from exogenous variables and innovations to the output vector. The exogenous variables are assumed to be such that the sample serial covariances converge to limits. The innovations are assumed to be martingale differences and to be nondeterministic in a fairly weak sense. Stronger conditions ensure that the asymptotic distribution of the estimates has the same covariance matrix as for Gaussian innovations but these stronger conditions are somewhat implausible. With each ARMAX structure may be associated an integer (the McMillan degree) and all structures for a given value of this integer may be topologised as an analytic manifold. Other parameterizations and topologisations of spaces of structures as analytic manifolds may also be considered and the presentation is sufficiently general to cover a wide range of these. Greater generality is also achieved by allowing for general forms of constraints. 相似文献
108.
In this paper we study the nature of the singularity of the Kontsevichs solution of the WDVV equations of associativity. We prove that it corresponds to a singularity in the change of two coordinates systems of the Frobenius manifold given by the quantum cohomology of CP2.
Mathematics Subject Classifications (2000) 53C99, 32D99, 14N35, 88A99. 相似文献
109.
GAO Hongzhu GUO Ren Department of Mathematics Beijing Normal University Beijing China 《中国科学A辑(英文版)》2004,47(3):431-439
The problem of embedding spheres in rational surfaces CP~2#nCP~2 is studied.For homology classes u=(b_1+k, b_2,…, b_n) with positive self-intersection numbers, anecessary and sufficient condition to detect its representability is given when k≤5. 相似文献
110.
Special Lagrangian Submanifolds with Isolated Conical Singularities. II. Moduli spaces 总被引:1,自引:1,他引:0
This is the second in a series of five papers studying special Lagrangiansubmanifolds (SLV m-folds) X in (almost) Calabi–Yau m-folds
M with singularities x
1
, ..., x
n
locally modelled on specialLagrangian cones
C
1, ..., C
n
in
m
with isolated singularities at 0.Readers are advised to begin with Paper V.This paper studies the deformation theory of compact SL m-folds X in Mwith conical singularities. We define the moduli space
X
of deformations of X in M, and construct a natural topology on it. Then we show that
X
is locally homeomorphic to the zeroes of a smooth map :
X
X between finite-dimensional vector spaces.Here the infinitesimal deformation space
X depends only on the topology of X, and the obstruction space
X only on the cones C
1, ..., C
n
at x
1, ..., x
n
. If the cones C
i
are stable then
X is zero, and
X
is a smooth manifold. We also extend our results to families of almost Calabi–Yau structures on M. 相似文献