Uncertainty and Certainty Relations for Pauli Observables in Terms of Renyi Entropies of Order α∈ （0; 1]

We obtain uncertainty and certainty relations of state-independent form for the three Paufi observables with use of the Renyi entropies of order α∈ （0; 1]. It is shown that these entropic bounds are tight in the sense that they are always reached with certain pure states. A new result is the condition for equality in Renyi-entropy uncertainty relations for the Pauli observables. Upper entropic bounds in the pure-state case are also novel. Combining the presented bounds leads to a band, in which the rescaled average Renyi a-entropy ranges for a pure measured state. A width of this band is compared with the Tsallis formulation derived previously.     

轴承自供能监测的径向电磁式能量俘获建模与实验研究

无线网络和低功耗微电子技术的进步推动着设备健康监测技术的网联化和智能化发展。轴承作为旋转设备的关键部件，对国防、轨道交通、风电等重大装备的健康状态起到了非常重要的作用，实现轴承状态监测的微型化和自供能是装备智能化的重要技术基础。本文针对于轴承无线传感器网络的供能问题，提出了一种用于轴承自供能监测的径向电磁式旋转能量俘获建模方法，并通过引入环形Halbach永磁阵列增强了线圈中的磁场强度，提高了能量俘获系统的输出性能。基于磁荷理论和空间坐标变换给出了环形Halbach永磁阵列的径向磁场计算方法，进而利用电磁感应原理建立了电磁式旋转能量俘获系统的输出电压模型，仿真分析了不同参数对系统输出电压的影响。有限元仿真和不同转速下的实验结果验证了所建立模型预测输出电压的准确性，同时功率测试实验表明设计的俘能系统在1000rpm转速下可实现81.2mW的输出功率。     

负反馈诱发神经电振荡的反常现象的复杂动力学

传统观念认为,负反馈容易使系统达到稳定平衡点而正反馈容易引起振荡.本研究基于神经元理论模型,提出了负反馈可以诱发稳定平衡点、也就是静息、变为振荡、也就是放电的新观点.在Hopf分岔点附近,作用在静息上的一次足够大的负向脉冲电流的抑制性刺激,能够引起一个动作电位及随后的衰减振荡的后电位;而能够在后电位上诱发出动作电位的负脉冲电流强度阈值也是衰减振荡的.在模型中,引入具有时滞($\tau$)的负反馈来模拟抑制性自突触,一个动作电位诱发的负反馈自突触电流会作用到比动作电位延迟$\tau$的后电位上.随时滞增加,能够诱发出放电的负反馈增益强度阈值呈现出具有衰减振荡特点的类似多重相干共振的特性,衰减振荡的周期与电流阈值曲线的周期以及分岔点附近的放电周期相关.另外,负反馈还能诱发出放电与静息共存的复杂行为.本研究的结果不仅揭示了负反馈的新的反常调控作用,还有助于理解在现实神经系统中存在的慢抑制性自突触的潜在功能.      

A corresponding-state approach to quark-cluster matter

The state of super-dense matter is essential for us to understand the nature of pulsars; however, non- perturbative quantum chromodynamics makes it very difficult to make direct calculations of the state of cold matter at realistic baryon number densities inside compact stars. Nevertheless, from an observational point of view, it is conjectured that pulsars could be made up of quark clusters since the strong coupling between quarks might render the quarks to be grouped in clusters. In this paper, we attempt to find an equation of state of condensed quark-cluster matter in a phenomenological way. Supposing that the quark-clusters could be analogized to inert gases, we apply here the corresponding-state approach to derive the equation of state of quark-cluster matter, as was similarly demonstrated for nuclear and neutron-star matter in the 1970s. According to the calculations that we have presented, the quark-cluster stars, which are composed of quark-cluster matter, could have a high maximum mass that is consistent with observations and, in turn, further observations of pulsar mass could also place a constraint on the properties of quark-cluster matter. We will also briefly discuss the melting heat during the solid-liquid phase conversion and its related astrophysical consequences.     

具有复合幂函数和共存吸引子的新混沌系统的动力学分析与电路仿真

构造一个具有复合幂函数的三维连续自治混沌系统。系统的状态方程仅有5项，其中一项是指数小于1的复合幂函数。该系统具有结构简单、非双曲平衡点、吸引子共存的性质，展现出了复杂的动力学行为。首先，对系统的动力学行为进行分析，包括李雅普诺夫（Lyapunov）指数谱、分岔图以及庞加莱映射等，结果表明此系统具有混沌特性。然后进行混沌系统的电路设计，电路仿真结果验证了理论分析的正确性。     

可观测度的探讨及其在捷联惯导系统可观测性分析中的应用

可观测度是为了分析线性系统中组合状态的可观测程度而提出来的,在卡尔曼滤波的滤波效果分析中得到了应用。文中先对已有的两种可观测度分析方法进行了简述,并且分析了两种方法的等价性;然后从理论上分析了此描述方法的不全面性。通过典型例子说明了理论分析的结果,给出了一种更全面的描述系统可观测组合状态可观测度的方法,并且用新的描述方式分析了捷联惯导系统的各状态可观测度。结果表明,该数值刻画方式能够定量的给出系统状态可观测的程度,是解析分析方法的很好的补充。     

The MAP/PH/N retrial queue in a random environment

We consider the MAP/PH/N retrial queue with a finite number of sources operating in a finite state Markovian random environment. Two different types of multi-dimensional Markov chains are investigated describing the behavior of the system based on state space arrangements. The special features of the two formulations are discussed. The algorithms for calculating the stationary state probabilities are elaborated, based on which the main performance measures are obtained, and numerical examples are presented as well.     

别轻易下结论

正1.统计资料表明,大多数汽车事故发生在中等速度的行驶状态下,极少事故是发生在大于150千米/小时的行驶速度状态下。这是否意味着高速行驶比较安全?2.绝不是这样。统计关系往往不能表明因果关系。由于多数人是以中等速度开车,所以自然大多数事故是出在中等速度的行驶中。3.如果统计数字表明某市死于肺结核的人数比其他地区多,这是否意味着该市的气候容易生肺病?4.正好相反。该市的气候对害肺病的人有好处,所以数以千计的肺病患者纷纷前来。自然,该市死于肺结核的平均数就升高了。     

材料力学 教学中的编程实践1)——————应力状态分析

介绍了利用Excel中的VBA语言进行材料力学教学中的编程实践,制作交互式的动画,让抽象的概念和枯燥的理论知识变得形象和生动化。 通过动画及其工程应用展示,能够帮助学生培养解决复杂工程问题的能力。 此外,由于该编程入门简单,也可以通过实践性的大作业帮助学生提升编程能力和计算机的应用水平,从而能够更好地适应科技的发展和复合型工科人才培养的需求。     

MARKOV SKELETON PROCESS IN PERT NETWORKS

In this article, we investigate Programming Evaluation and Review Technique networks with independently and generally distributed activity durations. For any path in this network, we select all the activities related to this path such that the completion time of the sub-network （only consisting of all the related activities） is equal to the completion time of this path. We use the elapsed time as the supplementary variables and model this sub-network as a Markov skeleton process, the state space is related to the subnetwork structure. Then use the backward equation to compute the distribution of the sub-network＇s completion time, which is an important rule in project management and scheduling.