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排序方式: 共有885条查询结果,搜索用时 31 毫秒
871.
This article extends our previous analysis Stránský et al. (2014) of Excited-State Quantum Phase Transitions (ESQPTs) in systems of dimension two. We focus on the oscillatory component of the quantum state density in connection with ESQPT structures accompanying a first-order ground-state transition. It is shown that a separable (integrable) system can develop rather strong finite-size precursors of ESQPT expressed as singularities in the oscillatory component of the state density. The singularities originate in effectively 1-dimensional dynamics and in some cases appear in multiple replicas with increasing excitation energy. Using a specific model example, we demonstrate that these precursors are rather resistant to proliferation of chaotic dynamics. 相似文献
872.
聂昌雄 《数学年刊A辑(中文版)》2015,36(1):59-68
[Nie C X,Wu C X,Regular submanifolds in the conformal space Q_p~n,ChinAnn Math,2012,33B(5):695-714]中研究了共形空间Q_s~n中的正则子流形,并引入了共形空间Q_s~n中的子流形理论.本文作者将分类共形空间Q_s~n中的Blaschke拟全脐子流形,证明伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形是共形空间中的Blaschke拟全脐子流形;反之,共形空间中的Blaschke拟全脐子流形共形等价于伪Riemann空间形式中具有常数量曲率和平行的平均曲率向量场的正则子流形.这一结论可看作是共形空间Q_s~n中共形迷向子流形分类定理的推广. 相似文献
873.
Jean-Luc Chabert 《代数通讯》2015,43(1):309-324
We first globalize some recent results about polynomials whose divided differences are integer-valued on subsets of discrete valuation domains. This allows us to describe explicit computations, in particular for polynomials which are integer-valued on the prime numbers. Then, we specialize other recent results about integer-valued polynomials on triangular matrices to matrices whose coefficients are in some subsets, and in particular, when the coefficients are primes. 相似文献
874.
Jie Xiao 《Journal of Differential Equations》2019,266(11):7124-7151
This paper addresses a well-posedness of the weak solution to the transport equation (describing how a scalar quantity is transported in a space) with an initial data in the scaling invariant Besov or Essén–Janson–Peng–Xiao space via the boundedness of the left and right compositions acting on each space. 相似文献
875.
V.D. Zhuravlev О.G. Reznitskikh Yu.А. Velikodnyi Т.А. Patrusheva О.V. Sivtsova 《Journal of solid state chemistry》2011,184(10):2785-2789
Mutual solubility of bivalent metal molybdates and tungstates with scheelite structure was theoretically estimated by calculating formation enthalpies and the maximal decomposition temperatures of solid solutions at different temperatures. The theoretical stability of continuous solid solutions in binary systems of bivalent metal molybdates and tungstates was found to be higher than reported literature data. After cooling down continuous substitution solid solution should remain in following systems: CaMoО4–CdMoО4, SrMoО4–MMoО4 (M=Ba, Pb), BaMoО4–PbMoО4, SrWO4–MWO4 (M=Ca, Pb), and BaWO4–PbWO4. There is a probability that at room temperature in systems CaMoО4–SrMoО4, CaWO4–PbWO4, and BaWO4–SrWO4 the single homogeneity region may decompose to limited solid solutions. It was shown experimentally that a continuous series of scheelite-structure solid solutions M1−xMIxТO4 can be formed via citrate synthesis at temperatures below 500°С. 相似文献
876.
Sang-Young Kim Chi-Bong Choi Hyun-Sung Lee Sung-Ho Lee Dong-Cheol Woo Hwi-Yool Kim Kwan-Soo Hong Chul-Hyun Lee Bo-Young Choe 《Magnetic resonance imaging》2010
The forced swimming test (FST) is a useful paradigm that is relatively quick and simple to perform and has been utilized to predict antidepressant activity based on learned helplessness as a model of depression. To date, few studies have used proton magnetic resonance spectroscopy (1H-MRS) to assess antidepressant effects in rats. The purpose of this study was to assess desipramine (DMI) effects on the left dorsolateral prefrontal cortex (DLPFC) of the rats, which were randomly assigned to three groups (control, n=10; FST+saline, n=10; FST+DMI, n=10), using single-voxel localization technique. All 1H-MRS experiments were performed on a Bruker 4.7-T scanner with 400 mm bore magnet, allowing for acquisition of in vivo 1H point-resolved spectroscopy spectra (TR/TE=3000/30 ms, number of data points=2048, NEX=512, voxel volume=27 μl, scan time=25 min). Proton metabolites were quantified automatically using LCModel software and were expressed as ratios to total creatine (Cr+PCr). Major target metabolites such as N-acetyl aspartate (NAA)+N-acetylaspartylglutamate (NAAG), glutamate+glutamine (Glu+Gln), glycerophosphorylcholine+phosphorylcholine (GPC+PCho), myo-inositol (mIns) and taurine (Tau) were successfully quantified with Cramer–Rao lower boundary ≤10%. There were significantly higher mIns/(Cr+PCr) and mIns/(NAA+NAAG) ratios in the FST+saline group compared to the control group. In the FST+DMI group, both mIns/(Cr+PCr) and mIns/(NAA+NAAG) ratios were significantly decreased to the level similar to those in the control group. No other metabolite ratios were significantly different among the three groups. Our findings suggest a possible role of altered mIns level within the left DLPFC of the rat model for depression. 相似文献
877.
Alessandro Michelangeli Alessandro Olgiati Raffaele Scandone 《Journal of Nonlinear Mathematical Physics》2018,25(4):558-588
We establish the local and global theory for the Cauchy problem of the singular Hartree equation in three dimensions, that is, the modification of the non-linear Schrödinger equation with Hartree non-linearity, where the linear part is now given by the Hamiltonian of point interaction. The latter is a singular, self-adjoint perturbation of the free Laplacian, modelling a contact interaction at a fixed point. The resulting non-linear equation is the typical effective equation for the dynamics of condensed Bose gases with fixed point-like impurities. We control the local solution theory in the perturbed Sobolev spaces of fractional order between the mass space and the operator domain. We then control the global solution theory both in the mass and in the energy space. 相似文献
878.
879.
拟连续Domain的若干拓扑性质 总被引:1,自引:1,他引:0
对拟连续Domain D证明了:(1)双拓扑空间(D,σ(D),(D))为两两完全正则空间;(2)若D有可数基,则(max(D),σ(D)max(D))为正则空间当且仅当它为Polish空间;(3)拓扑空间(D,σb(D))为零维Tychonoff空间,其中σb(D)为D上Scott拓扑的b-拓扑。 相似文献
880.
《Journal of Pure and Applied Algebra》2024,228(2):107462
The second cohomology group of a left skew brace with coefficients in a trivial left brace with non-trivial actions is defined, its connection with extensions of a left skew brace by a trivial brace is established and a Wells' like exact sequence relating the second cohomology group with inducible automorphisms of an extension of left skew braces is constructed. 相似文献