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21.
原子与单模场相互作用中克尔效应与斯塔克效应的统一处理 总被引:11,自引:0,他引:11
处理了包含克尔效应和斯塔克效应的原子与场相互作用模型。由于在其有效哈密顿中作了旋转波近似,两种效应的影响可以归结为对原子与场失谐的改变,这种失谐变化依赖于一个系统的守恒量。研究表明,克尔效应和斯塔克效应在一定条件下是等价的。研究了当场的初态为宏观可区分量子迭加态时,光子的反聚束效应。探讨了在广义的克尔介质中原子与场相互作用模型的求解。 相似文献
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Rasika Prabhu Rasmus Klitkou Grigori A. Medvedev James M. Caruthers 《Journal of Polymer Science.Polymer Physics》2013,51(8):687-697
The linear viscoelastic behavior in dynamic shear and tensile creep at temperatures from −30 to 70 °C is measured for an styrene–butadiene rubber (SBR) elastomer cured with dicumyl peroxide to crosslinking densities between 0 and 23.5 × 10−5 mol/cm3. The G′, G″, and tan δ isotherms are analyzed by time–temperature superposition (TTS), where the tan δ master curves are consistent with those of Mancke and Ferry. However, to achieve the TTS in the lightly crosslinked SBR systems, an anomalous vertical shift is required in the narrow temperature region from 10 to 30 °C. The vertical shift factor in this temperature region is not the standard from rubber elasticity. No anomalous behavior is detected in the equilibrium modulus, which is a linear function of temperature in accordance with the classical theory of rubber elasticity. In contrast to SBR, standard vertical shifts are required to effect TTS for uncrosslinked polybutadiene and an ethylene propylene diene monomer elastomer. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
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Two main issues are essential nowadays for practitioners in the field of polymeric materials: how a polymer will behave under dynamic loading conditions and for how long a polymer is reliable. In this sense, the time-temperature superposition principle was applied to the main viscoelastic properties (E′, E″ and tan δ) of a series of polyurethane coatings (PU-DEG-TMP) tested for mechatronic devices. Polyurethanes are derived from an ester glycol (poly(ethylene adipate) glycol), an aromatic diisocyanate (4,4′-dibenzyldiisocyanate) and di/trifunctional chain extenders - diethylene glycol (DEG) and trimethylol propane (TMP). Despite polyurethane intrinsic rheologic complexity, the moduli/loss factor curves superimpose well over several decades of reduced frequency at the glass transition temperature (Tg), 0 °C and 15 °C, the last temperature being considered the midpoint of the practical testing range. Three criteria were for checking the applicability of the time-temperature superposition: the Cole-Cole plot, the similarity between the aT calculated from both moduli (E′, E″) and the visual appearance of the final master curve. The presence of both hydrogen bonding and chemical joint points, along with some dangling chains put in a broader context the discussion of the microstructural features resulted from the application of the William-Landell-Ferry (WLF) equation. 相似文献
25.
《Physics letters. A》2020,384(15):126307
We introduce a procedure for separating periodic oscillations superposed on a stochastic signal. The procedure combines empirical mode decomposition (EMD) of a signal with tools of data analysis based on stochastic differential equations, namely nonlinear Langevin equations. Taking the set of modes retrieved from the EMD of the signal, our procedure is able to separate them into two groups, one composing the periodic signal and another composing the stochastic signal. The framework is robust for a broad family of localized oscillations, in the range of large frequencies. In particular, we show that, in this context, the EMD method outperforms a low-pass filter and is robust for a wide interval of different frequency ranges and amplitudes of the periodic oscillation, as well as for a broad family of different non-linear Langevin processes. 相似文献
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Ichiro Tsuda Hiroshi Watanabe Hiromichi Tsukada Yutaka Yamaguti 《Entropy (Basel, Switzerland)》2022,24(2)
The focus of this article is the self-organization of neural systems under constraints. In 2016, we proposed a theory for self-organization with constraints to clarify the neural mechanism of functional differentiation. As a typical application of the theory, we developed evolutionary reservoir computers that exhibit functional differentiation of neurons. Regarding the self-organized structure of neural systems, Warren McCulloch described the neural networks of the brain as being “heterarchical”, rather than hierarchical, in structure. Unlike the fixed boundary conditions in conventional self-organization theory, where stationary phenomena are the target for study, the neural networks of the brain change their functional structure via synaptic learning and neural differentiation to exhibit specific functions, thereby adapting to nonstationary environmental changes. Thus, the neural network structure is altered dynamically among possible network structures. We refer to such changes as a dynamic heterarchy. Through the dynamic changes of the network structure under constraints, such as physical, chemical, and informational factors, which act on the whole system, neural systems realize functional differentiation or functional parcellation. Based on the computation results of our model for functional differentiation, we propose hypotheses on the neuronal mechanism of functional differentiation. Finally, using the Kolmogorov–Arnold–Sprecher superposition theorem, which can be realized by a layered deep neural network, we propose a possible scenario of functional (including cell) differentiation. 相似文献
27.
We propose a two-color scheme of atom waveguides and one-dimensional (1D) optical lattices using evanescent wave fields of different transverse modes around an optical micro/nano-fiber. The atom guide potential can be produced when the optical fiber carries a red-detuned light with TE01 mode and a blue-detuned light with HEll mode, and the 1D optical lattice potential can be produced when the red-detuned light is transformed to the superposition of the TE01 mode and HE11 mode. The two trapping potentials can be transformed to each other for accurately controlling mode transformation for the red-detuned light. This might provide a new approach to realize flexible transition between the guiding and trapping states of atoms. 相似文献
28.
第Ⅰ种非对称两态叠加多模叠加态光场的偶数阶等阶N次方Y压缩 总被引:18,自引:1,他引:17
本文利用多模压缩态理论,研究了第Ⅰ种非对称两态叠加多模叠加态光场|ΨⅠ(ab)Ⅰ>q的偶数阶等阶N次方Y压缩特性.结果发现:在压缩阶数N取偶数情况下,只要构成态|ΨⅠ(ab)Ⅰ>q的两个量子光场态的强度(即平均光子数)不相等,则当各模的初始相位φj(a)、φj(b)(j=1,2,3,…,q)、态间的初始相位差(θpq(bI)-θnq(aR))以及与上述的两个量子光场态相对应的各单模相干态光场的光子干涉项之和 =[Rj(a)Rj(b)cos(φj(a)-φj(b))]等满足一定条件时,态|ΨⅠ(ab)Ⅰ>q可呈现出周期性变化的、任意偶数阶的等阶N次方Y压缩效应.这一结果与现有文献报道的结果截然不同. 相似文献
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