Recent experiment [S.G. Glendinning et al., Phys. Rev. Lett. 78, 3318 (1997)] showed that the measured growth rate of laser ablative Rayleigh-Taylor (RT) instability with preheating is about 50% of the classic value a...
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Recent experiment [S.G. Glendinning et al., Phys. Rev. Lett. 78, 3318 (1997)] showed that the measured growth rate of laser ablative Rayleigh-Taylor (RT) instability with preheating is about 50% of the classic value and is reduced by about 18% compared with the simulated value obtained with the computer code LASNEX. By changing the temperature variation of the electron thermal conductivity at low temperatures, the density profile from the Bhatnagar-Gross-Krook approximation is recovered in the simulation, and the simulated RT growth rate is in good agreement with the experimental value from Glendinning et al. The preheated density profile on ablative RT stablization is studied numerically. A change of the Atwood number in the preheating case also leads to RT stabilization. The RT growth formula γ=Akg/(1+AkL)−2kVa agrees well with experiment and simulation, and is appropriate for the preheating case.
Thin cylindrical tethers are common lipid bilayer membrane structures, arising in situations ranging from micromanipulation experiments on artificial vesicles to the dynamic structure of the Golgi apparatus. We study ...
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Thin cylindrical tethers are common lipid bilayer membrane structures, arising in situations ranging from micromanipulation experiments on artificial vesicles to the dynamic structure of the Golgi apparatus. We study the shape and formation of a tether in terms of the classical soap-film problem, which is applied to the case of a membrane disk under tension subject to a point force. A tether forms from the elastic boundary layer near the point of application of the force, for sufficiently large displacement. Analytic results for various aspects of the membrane shape are given.
Composite materials are ideally suited to achieve multifunctionality since the best features of different materials can be combined to form a new material that has a broad spectrum of desired properties. Nature’s ult...
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Composite materials are ideally suited to achieve multifunctionality since the best features of different materials can be combined to form a new material that has a broad spectrum of desired properties. Nature’s ultimate multifunctional composites are biological materials. There are presently no simple examples that rigorously demonstrate the effect of competing property demands on composite microstructures. To illustrate the fascinating types of microstructures that can arise in multifunctional optimization, we maximize the simultaneous transport of heat and electricity in three-dimensional, two-phase composites using rigorous optimization techniques. Interestingly, we discover that the optimal three-dimensional structures are bicontinuous triply periodic minimal surfaces.
In a recent paper [D. A. Meyer, Phys. Rev. Lett. 82, 1052 (1999)], it has been shown that a classical zero-sum strategic game can become a winning quantum game for the player with a quantum device. Nevertheless, it is...
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In a recent paper [D. A. Meyer, Phys. Rev. Lett. 82, 1052 (1999)], it has been shown that a classical zero-sum strategic game can become a winning quantum game for the player with a quantum device. Nevertheless, it is well known that quantum systems easily decohere in noisy environments. In this paper, we show that if the handicapped player with classical means can delay his action for a sufficiently long time, the quantum version reverts to the classical zero-sum game under decoherence.
We investigate the dynamics of two interacting electrons in coupled quantum dots driven by an ac field. We find that the two electrons can be trapped in one of the dots by the ac field, in spite of the strong Coulomb ...
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We investigate the dynamics of two interacting electrons in coupled quantum dots driven by an ac field. We find that the two electrons can be trapped in one of the dots by the ac field, in spite of the strong Coulomb repulsion. In particular, we find that the interaction may enhance the localization effect. We also demonstrate the field excitation procedure to generate the maximally entangled Bell states. The generation time is determined by both analytic and numerical solutions of the time-dependent Schrödinger equation.
When a helical bacterial flagellum, clamped at one end, is placed in an external flow, it has been observed that regions of the flagellum transform to the opposite chirality, and travel as pulses down the length of th...
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When a helical bacterial flagellum, clamped at one end, is placed in an external flow, it has been observed that regions of the flagellum transform to the opposite chirality, and travel as pulses down the length of the filament, the process repeating periodically [H. Hotani, J. Mol. Biol. 156, 791 (1982)]. We propose a theory for this phenomenon based on a treatment of the flagellum as an elastic object with multiple stable configurations. The simplest possible implementation of the model accurately reproduces key features seen in experiment.
We investigate the quantum tunneling of Bose-Einstein condensates in optical lattices under gravity in the “Wannier-Stark localization” regime and “Landau-Zener tunneling” regime. Our results agree with experiment...
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We investigate the quantum tunneling of Bose-Einstein condensates in optical lattices under gravity in the “Wannier-Stark localization” regime and “Landau-Zener tunneling” regime. Our results agree with experimental data [B. P. Anderson et al., Science 282, 1686 (1998); F. S. Cataliotti et al., Science 293, 843 (2001)]. We obtain the total decay rate which is valid over the entire range of temperatures, and show how it reduces to the appropriate results for the classical thermal activation at high temperatures, the thermally assisted tunneling at intermediate temperatures, and the pure quantum tunneling at low temperatures. We design an experimental protocol to observe this new phenomenon in further experiments.
We introduce a new architecture for pipelined (and also algorithmic) A/D converters that give exponentially accurate conversion using inaccurate comparators. An error analysis of a sigma-delta converter with an imperf...
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We introduce a new architecture for pipelined (and also algorithmic) A/D converters that give exponentially accurate conversion using inaccurate comparators. An error analysis of a sigma-delta converter with an imperfect comparator and a constant input reveals a self-correction property that is not inherited by the successive refinement quantization algorithm that underlies both pipelined multistage A/D converters and algorithmic A/D converters. Motivated by this example, we introduce a new A/D converter, the beta converter, which has the same self-correction property as a sigma-delta converter but which exhibits higher order (exponential) accuracy with respect to the bit rate as compared to a sigma-delta converter, which exhibits only polynomial accuracy.
In this paper, the semi-discrete and fully discrete Fourier spectral schemes for the Ginzburg-Landau coupled with BBM equations with periodic initial value problem are proposed, and the convergence and stabilities for...
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In this paper, the semi-discrete and fully discrete Fourier spectral schemes for the Ginzburg-Landau coupled with BBM equations with periodic initial value problem are proposed, and the convergence and stabilities for the schemes are proved.
In this paper we study a class of nonlinear integro-differential equations which correspond to a fractional-order time derivative and interpolate nonlinear heat and wave equations. For this purpose we first establish ...
In this paper we study a class of nonlinear integro-differential equations which correspond to a fractional-order time derivative and interpolate nonlinear heat and wave equations. For this purpose we first establish some space-time estimates of the linear flow which is produced by Mittag-Leffler's functions based on Mihlin-Hörmander's multiplier estimates and other harmonic analysis tools. Using these space-time estimates we prove the well-posedness of a local mild solution of the Cauchy problem for the nonlinear integro-differential equation in C([0, T);Lp(Rn)) or Lq(0, T;Lp(Rn)).
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