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641.
Protein structural class describes the overall folding type of a protein or its domain. A number of methods were developed to predict protein structural class based on its primary sequence. The homology of the predicted sequences with respect to the training sequences is a key attribute for the prediction performance. In this article we investigated the FDOD method developed by Jin et al. [Jin, L., Fang, W., Tang, H., 2003. Prediction of protein structural classes by a new measure of information discrepancy. Comput. Biol. Chem. 27, 373-380], which gave high prediction accuracy on a low homology dataset, and we empirically confirmed that the reported results were an artifact of improper implementation. 相似文献
642.
We prove that for n = 5, 6, 7 a nodal hypersurface of degree n in
is factorial if it has at most (n − 1)2 − 1 nodes.
相似文献
643.
For a simplicial complex X and a field K, let .It is shown that if X,Y are complexes on the same vertex set, then for k?0
644.
提出了中臂弯曲的多臂量子环模型,且是上臂最短和下臂最长的不等臂量子环.研究发现:总磁通为零时,持续电流随半导体环增大发生非周期性振荡,并与电极的磁矩方向及隧穿电子的自旋方向相关,下臂因为最长而获得最小的平均持续电流.AB磁通增强时,持续电流会发生周期性振荡,各臂之间明显出现相互制约的现象.各臂持续电流之间的差异与臂长和磁通分布相关,Rashba自旋轨道耦合具有改变持续电流相位和相位差的效应.在一定条件下,两种波函数所对应的持续电流是可分离的.
关键词:
多臂量子环
持续电流
Rashba自旋轨道耦合 相似文献
645.
646.
Fengmei Tang Yuwen Ni Haijun Zhang Yun Li Jing Jin Longxing Wang Jiping Chen 《Analytica chimica acta》2012
A new cleanup method was developed and validated for the determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in sediment. The sample extract was first treated with sulfuric acid and then cleaned up by a large volume injection gas chromatography online coupled with liquid chromatography (LVI-GC-LC) system. PCDD/Fs in the extract were separated by a GC column (DB-5), selected cut, cool trapped and transferred to a LC column (alumina). The fraction of PCDD/Fs eluted from the alumina column was collected and concentrated for the instrumental analysis. Under the optimized conditions, LVI-GC-LC method achieved the recoveries of 57–102% for 2,3,7,8-substituted PCDD/Fs, which met the requirements of US Environmental Protection Agency (EPA) Method 1613 and were better than those obtained using the conventional multistep column cleanup method. Meanwhile, compared with the conventional method, the limit of detection (LOD) values of 2,3,7,8-substituted PCDD/Fs cleaned up by LVI-GC-LC method were decreased due to the high-efficiency removal of interferents. These results suggested that the LVI-GC-LC cleanup method was a promising alternative to the multistep cleanup procedure for the determination of dioxins in environmental samples. 相似文献
647.
648.
Let K⊂S3, and let denote the preimage of K inside its double branched cover, Σ(S3,K). We prove, for each integer n>1, the existence of a spectral sequence whose E2 term is Khovanov's categorification of the reduced n-colored Jones polynomial of (mirror of K) and whose E∞ term is the knot Floer homology of (when n odd) and of (S3,K#Kr) (when n even). A corollary of our result is that Khovanov's categorification of the reduced n-colored Jones polynomial detects the unknot whenever n>1. 相似文献
649.
Quandles with involutions that satisfy certain conditions, called good involutions, can be used to color non-orientable surface-knots. We use subgroups of signed permutation matrices to construct non-trivial good involutions on extensions of odd order dihedral quandles.For the smallest example of order 6 that is an extension of the three-element dihedral quandle R3, various symmetric quandle homology groups are computed, and applications to the minimal triple point number of surface-knots are given. 相似文献
650.