排序方式: 共有66条查询结果,搜索用时 15 毫秒
1.
Caesium heptaiodo‐dititanate(III), CsTi2I7, is obtained from CsI, Ti and TiI4 at 250 °C in a sealed tantalum ampoule as dark red single crystals. The crystal structure (trigonal, R‐3, a = 1706.6(3), c = 2088.3(5) pm, Z = 12, R1 = 0.0619) contains [TiI4] tetrahedra sharing common vertices (with Ti—I—Ti angles of 180°) to isolated ditetrahedra [Ti2I7]—. It may also be described as a cubic closest packing of alternating CsI3 and I4 layers between which neighbouring tetrahedra are occupied in a way that [Ti2I7]— ditetrahedra are achieved. http://www.gerdmeyer.de 相似文献
2.
Dominik Dorsch Hubertus Th. Jongen Vladimir Shikhman 《Set-Valued and Variational Analysis》2011,19(2):237-253
We examine the topological structure of the upper-level set M
max given by a min-max function φ. It is motivated by recent progress in Generalized Semi-Infinite Programming (GSIP). Generically, M
max is proven to be the topological closure of the GSIP feasible set (see Guerra-Vázquez et al. 2009; Günzel et al., Cent Eur J Oper Res 15(3):271–280, 2007). We formulate two assumptions (Compactness Condition CC and Sym-MFCQ) which imply that M
max is a Lipschitz manifold (with boundary). The Compactness Condition is shown to be stable under C
0-perturbations of the defining functions of φ. Sym-MFCQ can be seen as a constraint qualification in terms of Clarke’s subdifferential of the min-max function φ. Moreover, Sym-MFCQ is proven to be generic and stable under C
1-perturbations of the defining functions which fulfill the Compactness Condition. Finally we apply our results to GSIP and
conclude that generically the closure of the GSIP feasible set is a Lipschitz manifold (with boundary). 相似文献
3.
We consider the maximum function f resulting from a finite number of smooth functions. The logarithmic barrier function of the epigraph of f gives rise to a smooth approximation g
of f itself, where >0 denotes the approximation parameter. The one-parametric family g
converges – relative to a compact subset – uniformly to the function f as tends to zero. Under nondegeneracy assumptions we show that the stationary points of g
and f correspond to each other, and that their respective Morse indices coincide. The latter correspondence is obtained by establishing smooth curves x() of stationary points for g
, where each x() converges to the corresponding stationary point of f as tends to zero. In case of a strongly unique local minimizer, we show that the nondegeneracy assumption may be relaxed in order to obtain a smooth curve x(). 相似文献
4.
Let f be a smooth nondegenerate real valued function on a finite dimensional, compact and connected Riemannian manifold. The bipartite min-max graph is defined as follows. Its nodes are formed by the set of local minima and the set of local maxima. Two nodes (a local minimum and a local maximum) are connected in by means of an edge if some trajectory of the corresponding gradient flow connects them. Given a natural number k, we construct a function f such that the length of the shortest path in between two specific local minima exceeds k. The latter construction is independent of the underlying Riemannian metric. 相似文献
5.
Y. Jongen M. Abs W. Kleeven S. Zaremba A. A. Glazov S. V. Gurskiy O. V. Karamyshev G. A. Karamysheva N. A. Morozov 《Physics of Particles and Nuclei Letters》2011,8(4):386-390
Compact superconducting isochronous cyclotron C400 [1] has been designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in
the world capable of delivering protons, carbon and helium ions for therapeutic use. 12C6+ and 4He2+ ions will be accelerated to 400 MeV/u energy and extracted by electrostatic deflector, H2+ ions will be accelerated to the energy of 265 MeV/u and extracted by stripping. It is planned to use two normal conducting
RF cavities for ion beam acceleration in the cyclotron C400. Computer model of the double gap delta RF cavity with 4 stems
was developed in the general-purpose simulation software CST STUDIO SUITE. Necessary resonant frequency and increase of the
voltage along the gaps were achieved. Optimization of the RF cavity parameters leads us to the cavity with quality factor
about 14000, RF power dissipation is equal to about 50 kW per cavity. 相似文献
6.
7.
Using a probabilistic approach, the parallel dynamics of fully connected Q-Ising neural networks is studied for arbitrary Q. A novel recursive scheme is set up to determine the time evolution of the order parameters through the evolution of the distribution of the local field, taking into account all feedback correlations. In contrast to extremely diluted and layered network architectures, the local field is no longer normally distributed but contains a discrete part. As an illustrative example, an explicit analysis is carried out for the first four time steps. For the case of the Q = 2 and Q = 3 model the results are compared with extensive numerical simulations and excellent agreement is found. Finally, equilibrium fixed-point equations are derived and compared with the thermodynamic approach based upon the replica-symmetric mean-field approximation. 相似文献
8.
9.
10.