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111.
Recent measurements revealed that commercial magnesium standard solutions showed isotopic abundance variations, which cannot clearly be distinguished from each other by calibrating against the only available isotopic reference material, SRM 980, or reference materials made from SRM 980 like IRMM-009. Therefore new SI-traceable magnesium isotopic reference materials are required. 相似文献
112.
Greg Friedman 《Proceedings of the American Mathematical Society》2004,132(10):3103-3109
Frame-spun knots are constructed by spinning a knot of lower dimension about a framed submanifold of . We show that all frame-spun knots are slice (null-cobordant).
113.
We argue that the recently introduced statefinder parameters (Sahni et al., JETP Lett. 77, 201 (2003)), that include the third derivative of the cosmic scale factor, are useful tools to characterize interacting quintessence models. We specify the statefinder parameters for two classes of models that solve, or at least alleviate, the coincidence problem. 相似文献
114.
A -frame is a lattice in which countable joins exist and binary meets distribute over countable joins. In this paper, the category MFrm, of metric -frames, is introduced, and it is shown to be equivalent to the category MLFrm
u, of metric Lindelöf frames.Finally, it is shown that the complete metric -frames are exactly the cozero parts of complete metric Lindelöf frames. 相似文献
115.
Charles K. Chui Wenjie He Joachim Stöckler Qiyu Sun 《Advances in Computational Mathematics》2003,18(2-4):159-187
When a cardinal B-spline of order greater than 1 is used as the scaling function to generate a multiresolution approximation of L
2=L
2(R) with dilation integer factor M2, the standard matrix extension approach for constructing compactly supported tight frames has the limitation that at least one of the tight frame generators does not annihilate any polynomial except the constant. The notion of vanishing moment recovery (VMR) was introduced in our earlier work (and independently by Daubechies et al.) for dilation M=2 to increase the order of vanishing moments. This present paper extends the tight frame results in the above mentioned papers from dilation M=2 to arbitrary integer M2 for any compactly supported M-dilation scaling functions. It is shown, in particular, that M compactly supported tight frame generators suffice, but not M–1 in general. A complete characterization of the M-dilation polynomial symbol is derived for the existence of M–1 such frame generators. Linear spline examples are given for M=3,4 to demonstrate our constructive approach. 相似文献
116.
Inhomogeneous multidimensional cosmological models with a higher-dimensional space-time manifold
0
i=1
n Mi (n 1) are in stigated under dimensional reduction to a D
0-dimensional effective non-minimally coupled -model which generalizes the familiar Brans–Dicke model. The general form of the Einstein frame representation of multidimensional solutions known in the Brans–Dicke frame is given with respect to cosmic synchronous time. As an example, the transformation is demonstrated explicitly for the generalized Kasner solutions where it is shown that solutions in the Einstein frame show no inflation of the external space although they can undergo deflation after the cosmic synchronous time inversion. 相似文献
117.
A modified (k, λ)‐frame of type gu is a modified (k, λ)‐GDD whose blocks can be partitioned into holey parallel classes, each of which is with respect to some group. Modified frames can be used to construct some other resolvable designs such as resolvable group divisible designs and semiframes. In this article, we shall investigate the existence of modified frames with block size 3. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 351–363, 2008 相似文献
118.
119.
Young-Hwa Ha 《Journal of Mathematical Analysis and Applications》2008,347(1):90-95
We obtain a condition implying that the union of two frame sequences is also a frame sequence. Christensen found a condition for this in terms of orthogonal projections. We phrase our condition by use of the angle between closed subspaces. Also a lower bound formula is obtained. We then apply the results to find conditions for a frame containing a Riesz basis to be a Riesz frame. 相似文献
120.
在高斯光束传输理论的基础上,利用矩阵光学原理和高斯光束耦合理论,得出光学相干层析系统中参考反射镜的空间位置对系统耦合效率影响的表达式,并用计算机模拟系统的耦合效率与参考反射镜和棒透镜间的距离及参考反射镜偏转角度的关系曲线。实验结果和理论分析相符合。 相似文献