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981.
Zhao Qiaoling Yan Guojun 《高校应用数学学报(英文版)》2007,22(3):343-352
In this paper,the stochastic flow of mappings generated by a Feller convolution semigroup on a compact metric space is studied.This kind of flow is the generalization of superprocesses of stochastic flows and stochastic diffeomorphism induced by the strong solutions of stochastic differential equations. 相似文献
982.
Myocardial infarction results from the rupture of an atherosclerotic plaque, which occurs in response to both mechanical stress
and inflammatory processes. In order experimentally observe flow into atherosclerotic coronary artery morphologies, a novel
technique for molding realistic compliant phantom featuring injection-molded inclusions and multiple layers has been developed.
This transparent phantom allows for particle image velocimetry (PIV) flow analysis and can supply experimental data to validate
computational fluid dynamics algorithms and hypothesis. 相似文献
983.
Background
The morphological development of neurons is a very complex process involving both genetic and environmental components. Mathematical modelling and numerical simulation are valuable tools in helping us unravel particular aspects of how individual neurons grow their characteristic morphologies and eventually form appropriate networks with each other.Methods
A variety of mathematical models that consider (1) neurite initiation (2) neurite elongation (3) axon pathfinding, and (4) neurite branching and dendritic shape formation are reviewed. The different mathematical techniques employed are also described.Results
Some comparison of modelling results with experimental data is made. A critique of different modelling techniques is given, leading to a proposal for a unified modelling environment for models of neuronal development.Conclusion
A unified mathematical and numerical simulation framework should lead to an expansion of work on models of neuronal development, as has occurred with compartmental models of neuronal electrical activity.984.
985.
986.
Jason Miller 《Communications in Mathematical Physics》2011,308(3):591-639
We study the massless field on \({D_n = D \cap \tfrac{1}{n} \mathbf{Z}^2}\), where \({D \subseteq \mathbf{R}^2}\) is a bounded domain with smooth boundary, with Hamiltonian \({\mathcal {H}(h) = \sum_{x \sim y} \mathcal {V}(h(x) - h(y))}\). The interaction \({\mathcal {V}}\) is assumed to be symmetric and uniformly convex. This is a general model for a (2 + 1)-dimensional effective interface where h represents the height. We take our boundary conditions to be a continuous perturbation of a macroscopic tilt: h(x) = n x · u + f(x) for \({x \in \partial D_n,\,u \in \mathbf{R}^2}\), and f : R 2 → R continuous. We prove that the fluctuations of linear functionals of h(x) about the tilt converge in the limit to a Gaussian free field on D, the standard Gaussian with respect to the weighted Dirichlet inner product \({(f,g)_\nabla^\beta = \int_D \sum_i \beta_i \partial_i f_i \partial_i g_i}\) for some explicit β = β(u). In a subsequent article, we will employ the tools developed here to resolve a conjecture of Sheffield that the zero contour lines of h are asymptotically described by SLE(4), a conformally invariant random curve. 相似文献
987.
Ansgar Jüngel José Luis López Jesús Montejo–Gámez 《Journal of statistical physics》2011,145(6):1661-1673
A quantum Navier–Stokes system for the particle, momentum, and energy densities is formally derived from the Wigner–Fokker–Planck
equation using a moment method. The viscosity term depends on the particle density with a shear viscosity coefficient which
equals the quantum diffusion coefficient of the Fokker–Planck collision operator. The main idea of the derivation is the use
of a so-called osmotic momentum operator, which is the sum of the phase-space momentum and the gradient operator. In this
way, a Chapman–Enskog expansion of the Wigner function, which typically leads to viscous approximations, is avoided. Moreover,
we show that the osmotic momentum emerges from local gauge theory. 相似文献
988.
Shi-Kuo Li Chuan-Hao Li Fang-Zhi Huang Yang Wang Yu-Hua Shen An-Jian Xie Qiong Wu 《Journal of nanoparticle research》2011,13(7):2865-2874
Uniform Cu2O hollow spheres fabricated by single-crystalline particles (smaller than 20 nm) are facile synthesized in ethylene glycol
(EG) solution by a simple solvothermal route without using pre-fabricated templates and reductive agents. EG in this protocol
is not only used as a solvent, complexing agent, and reducing agent, but also served as a structure-directing agent for the
formation of hollow structure. By control of reaction conditions, such as reaction time, temperature, and the anions, the
morphology and structure of the hollow spheres can be tuned. A coordination adsorption and oriented attachment and Ostwald
ripening mechanism is proposed for explaining the formation process of hollow Cu2O spheres in EG solution; and importantly, the hollow Cu2O spheres exhibit an excellent property for the electro-catalytic oxidization of ascorbic acid in acetic acid buffer solution.
Moreover, the hollow spherical Cu2O particles could be potentially applied in catalysis, sensor, and as model for fundamental research. 相似文献
989.
Haishan Liu Hui Luo Mingxing Luo Liucheng Wang 《The European Physical Journal C - Particles and Fields》2011,71(11):1793
This paper starts with a self-contained discussion of the so-called Akulov–Volkov action SAV\mathcal{S}_{\mathrm{AV}}, which is traditionally taken to be the leading-order action of the Goldstino field. Explicit expressions for SAV\mathcal{S}_{\mathrm{AV}} and its chiral version SAVch\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} are presented. We then turn to the issue on how these actions are related to the leading-order action SNL\mathcal{S}_{\mathrm{NL}} proposed in the newly proposed constrained superfield formalism. We show that SNL\mathcal{S}_{\mathrm{NL}} may yield SAV/SAVch\mathcal{S}_{\mathrm {AV}}/\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} or a totally different action SKS\mathcal{S}_{\mathrm{KS}}, depending on how the auxiliary field in the former is integrated out. However, SKS\mathcal{S}_{\mathrm{KS}} and SAV/SAVch\mathcal{S}_{\mathrm {AV}}/\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} always yield the same S-matrix elements, as one would have expected from general considerations in quantum field theory. 相似文献
990.
We derive symplectically invariant uncertainty relations for a set of canonically conjugated variables. The uncertainty relations obtained are multimode analogs of the Robertson–Schrödinger inequalities. Our uncertainty relations are equivalent to the necessary and sufficient conditions for a matrix to be a correlation matrix of some quantum state, obtained by R. Simon and coauthors. The advantage of our inequalities, compared to that suggested by Simon, consists in its simplicity and more obvious symplectic invariance. We derive our inequalities for the case of a two-mode system in explicit form. Particular cases of small and large degrees of correlation between the first and second modes are analyzed in detail. 相似文献