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排序方式: 共有1254条查询结果,搜索用时 9 毫秒
91.
We investigate how models for neutrino–nucleus cross sections based on different assumptions for the nuclear dynamics affect the forecasted sensitivities to neutrino oscillation parameters at future neutrino facilities. We limit ourselves to the quasi-elastic regime, where the neutrino cross sections can be evaluated with less uncertainties, and discuss the sensitivity reach to θ13 and δ at a prototype low-γ β-beam, mostly sensitive to the quasi-elastic regime. 相似文献
92.
93.
Jiawang Zhou Ljiljana Stojanovi Andrey A. Berezin Tommaso Battisti Abigail Gill Benson M. Kariuki Davide Bonifazi Rachel Crespo-Otero Michael R. Wasielewski Yi-Lin Wu 《Chemical science》2021,12(2):767
Development of purely organic materials displaying room-temperature phosphorescence (RTP) will expand the toolbox of inorganic phosphors for imaging, sensing or display applications. While molecular solids were found to suppress non-radiative energy dissipation and make the RTP process kinetically favourable, such an effect should be enhanced by the presence of multivalent directional non-covalent interactions. Here we report phosphorescence of a series of fast triplet-forming tetraethyl naphthalene-1,4,5,8-tetracarboxylates. Various numbers of bromo substituents were introduced to modulate intermolecular halogen-bonding interactions. Bright RTP with quantum yields up to 20% was observed when the molecule is surrounded by a Br⋯O halogen-bonded network. Spectroscopic and computational analyses revealed that judicious heavy-atom positioning suppresses non-radiative relaxation and enhances intersystem crossing at the same time. The latter effect was found to be facilitated by the orbital angular momentum change, in addition to the conventional heavy-atom effect. Our results suggest the potential of multivalent non-covalent interactions for excited-state conformation and electronic control.The number and position of halogen substituents in purely organic π–π* chromophores critically affect the efficiency of phosphorescence. 相似文献
94.
Davide Guzzetti 《Communications in Mathematical Physics》1999,207(2):341-383
In this paper we compute Stokes matrices and monodromy of the quantum cohomology of projective spaces. This problem can be
formulated in a “classical” framework, as the problem of computation of Stokes matrices and monodromy of differential equations
with regular and irregular singularities. We prove that the Stokes' matrix of the quantum cohomology coincides with the Gram
matrix in the theory of derived categories of coherent sheaves. We also study the monodromy group of the quantum cohomology
and we show that it is related to hyperbolic triangular groups.
Received: 24 October 1998 / Accepted: 27 April 1999 相似文献
95.
96.
97.
Davide Ascoli 《Mathematical Methods in the Applied Sciences》1995,18(10):773-787
Following the abstract setting of [8] and using the global results of [2], global wellposedness and regularity results are proved for the solutions of quasi-linear symmetric hyperbolic systems with bounded coefficients which are regularized by a convolution in the space variables with a regularizing function. In the case of unbounded regularized coefficients, local existence of classical solutions is proved, as well as uniqueness and regularity of (not necessarily existing) global weak solutions with initial value in a Sobolev space. As the regularizing function tends to Dirac's δ, local-in-time convergence to the classical solution of the non-regularized problem is proved. 相似文献
98.
Davide L. Ferrario 《Archive for Rational Mechanics and Analysis》2006,179(3):389-412
Periodic and quasi-periodic solutions of the n-body problem can be found as minimizers of the Lagrangian action functional restricted to suitable spaces of symmetric paths.
The main purpose of this paper is to develop a systematic approach to the equivariant minimization for the three-body problem
in three-dimensional space. First we give a finite complete list of symmetry groups fitting to the minimization of the action,
with the property that any other symmetry group can be reduced to be isomorphic to one of these representatives. A second
step is to prove that the resulting (local and global) symmetric action-minimizers are always collisionless (when they are
not already bound to collisions). Furthermore, we prove some results which address the question of whether minimizers are
planar or non-planar; as a consequence of our theory we will give general criteria for a symmetry group to yield planar or
homographic minimizers (either homographic or not, as in the Chenciner-Montgomery eight solution). On the other hand we will
provide a rigorous proof of the existence of some interesting one-parameter families of periodic and quasi-periodic non-planar
orbits. These include the choreographic Marchal's P12 family with equal masses – together with a less-symmetric choreographic family (which anyway probably coincides with the
P12 family). 相似文献
99.
We compare different notions of curvature on contact sub-Riemannian manifolds. In particular, we introduce canonical curvatures as the coefficients of the sub-Riemannian Jacobi equation. The main result is that all these coefficients are encoded in the asymptotic expansion of the horizontal derivatives of the sub-Riemannian distance. We explicitly compute their expressions in terms of the standard tensors of contact geometry. As an application of these results, we obtain a sub-Riemannian version of the Bonnet–Myers theorem that applies to any contact manifold. 相似文献
100.
Davide Giraudo 《Journal of Theoretical Probability》2017,30(1):196-211
We provide some sufficient mixing conditions on a strictly stationary sequence in order to guarantee the weak invariance principle in Hölder spaces. Strong mixing and \(\rho \)-mixing conditions are investigated as well as \(\tau \)-dependent sequences. The main tools are deviation inequalities for mixing sequences. 相似文献