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31.
本文在无生命、物质和科学三个限制的前提下讨论“信息”到底是什么.依次论证:(1)自然科学没有能力度量信息的“质”,只能讨论信息的“量”;(2)“信息熵”只是度量信息“量”的概念;(3)在无生命的物质科学领域内,信息熵完全等价于Boltzmann熵,对应于实验中的热熵;(4)运用Occam剃刀原理,信息熵和Boltzmann熵两个名词只能留下其中的任意一个;(5)“熵”取决于体系的微观状态总数,即最终取决于热运动引起的分子核骨架的动态变化.于是,在无生命、物质和科学三个限制的领域内“信息”只是望文生义的产物. 相似文献
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磁场对非对称量子点中极化子性质的影响 总被引:3,自引:1,他引:3
采用线性组合算符和幺正变换方法研究磁场对非对称量子点中弱耦合磁极化子性质的影响.导出了非对称量子点中弱耦合磁极化子的振动频率、基态能量和基态结合能随量子点的横向和纵向有效受限长度、磁场和电子-声子耦合强度的变化关系.数值计算结果表明:非对称量子点中弱耦合磁极化子的基态能量和基态结合能随量子点的横向和纵向有效受限长度的增加而迅速增大.随回旋频率的增加而增大,随电子-声子耦合强度的增加而减小. 相似文献
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用振幅比之方法计算了中性粲介子衰变到CP本征态的CP不对称性. 计算了时间相关和时间积分的CP不对称性. 结果表明, 时间积分的CP不对称参数约为千分之一的量级. 还讨论了在BESⅢ和B工厂上实验检验的可能性. 相似文献
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I. Grabec 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,22(1):129-135
A physical law is represented by the probability distribution of a measured variable. The probability density is described
by measured data using an estimator whose kernel is the instrument scattering function. The experimental information and data
redundancy are defined in terms of information entropy. The model cost function, comprised of data redundancy and estimation
error, is minimized by the creation-annihilation process.
Received 24 February 2000 and Received in final form 21 February 2001 相似文献
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The pre-scission neutrons measured in the reactions 16O 181Ta and 19F 178Hf are studied via a Langevin equation coupled with a statistical decay model. We find that because of the mass asymmetry of different entrance channels, the spin distributions of compound nuclei would be different, consequently, the measured neutrons in these two reactions would also different. This means that the entrance channel will affect the particle emission in the fission process of hot nuclei. 相似文献
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How, in the face of both intrinsic and extrinsic volatility, can unconventional computing fabrics store information over arbitrarily long periods? Here, we argue that the predictable structure of many realistic environments, both natural and artificial, can be used to maintain useful categorical boundaries even when the computational fabric itself is inherently volatile and the inputs and outputs are partially stochastic. As a concrete example, we consider the storage of binary classifications in connectionist networks, although the underlying principles should be applicable to other unconventional computing paradigms. Specifically, we demonstrate that an unsupervised, activity dependent plasticity rule, AHAH (Anti-Hebbian-And-Hebbian), allows binary classifications to remain stable even when the underlying synaptic weights are subject to random noise. When embedded in environments composed of separable features, the weight vector is restricted by the AHAH rule to local attractors representing stable partitions of the input space, allowing unsupervised recovery of stored binary classifications following random perturbations that leave the system in the same basin of attraction. We conclude that the stability of long-term memories may depend not so much on the reliability of the underlying substrate, but rather on the reproducible structure of the environment itself, suggesting a new paradigm for reliable computing with unreliable components. 相似文献
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Juan Colmenero 《Journal of Polymer Science.Polymer Physics》2019,57(18):1239-1245
The diffusion of polymer chains in miscible polymer blends with large dynamic asymmetry—those where the two blend components display very different segmental mobility—is not well understood yet. In the extreme case of the blend system of poly(ethylene oxide) (PEO) and poly(methyl methacrylate)(PMMA), the diffusion coefficient of PEO chains in the blend can change by more than five orders of magnitude while the segmental time scale hardly changes with respect to that of pure PEO. This behavior is not observed in blend systems with small or moderate dynamic asymmetry as, for instance, polyisoprene/poly(vinyl ethylene) blends. These two very different behaviors can be understood and quantitatively explained in a unified way in the framework of a memory function formalism, which takes into account the effect of the collective dynamics on the chain dynamics of a tagged chain. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1239–1245 相似文献