Analysis of one-dimensional Fibonacci-class quasicrystals using perturbation theory

In this work, we present a new and semi-analytical method to investigate one-dimensional Fibonacci-class photonic quasicrystals from waveguiding properties point of view. Usually, the exact treatment for obtaining band diagram in these situations is very hard and the numerical methods are used. In this paper, we investigate the waveguiding properties of one-dimensional quasicrystals by using perturbation method. In this direction, the band diagram and field distribution of this structure are investigated.     

Neutrino helicity flip in a curved space-time

In Minkowskian spaces, the helicity of a massless fermion is a conserved quantity. In principle, this property may not hold when gravitational effects are not neglected. In this context, this work proves that the helicity of a massless neutrino is not conserved in curved spaces. In order to show this fact, the time variation of the helicity in the Heisenberg picture is calculated. Also, we verify that the differential cross-section due to helicity flip of a massless neutrino in a curved space does not vanish as a result of the coupling between the spin and the curvature of space-time.     

The Franson experiment revisited

Previously, the Franson experiment was challenged as a true test of local realism. In this Letter we review this situation and show that this experiment reveals a peculiar behavior when we try to, simultaneously, explain second and fourth order interferences. In order to enhance this idea, a proposed local model is discussed.     

APPROACH FOR THE STUDY OF SOLITON IN OPTICAL FIBER

In the anomalous group velocity dispersion regime, under the influence of optical Kerr nonlinearity, the monomode optical fiber supports stable propagation of an initial soliton pulse. In this paper, we present a singular perturbation approach for the study of various perturbations acting on this initial soliton pulse, In contrast with the previous perturbation theory for this subject, this approach gets rid of dependence on any tool of the sophisticated inverse scattering transform.     

混沌神经网络的控制

提出了一种针对混沌神经网络的钉扎控制方法.利用此方法对混沌神经网络进行控制,使网络的输出稳定在网络的一个存储的模式上.实现了混沌神经网络的信息搜索,并对影响混沌神经网络控制效果的几个因素进行了讨论. 关键词： 混沌控制 混沌神经网络 钉扎控制方法     

The Young Julian Schwinger. I. A New York City Childhood

In this series of articles the early life and work of the young Julian Schwinger are explored. In this first article, Schwinger's childhood, growing-up, and early education are discussed.     

Design study of a L-band photocathode RF injector

In the proposal of the Beijing Advanced Light Source, a compact combination of XERL and XFEL using a common SC linac is being considered. In the meantime, an ERL-FEL test facility is being proposed and will be used for THz radiation. In this test facility, a L-band photocathode RF injector is needed. In this paper, we give the physical design of the L-band photocathode RF injector for the test facility.     

Preparation of In2S3 nanopraricle by ultrasonic dispersion and its tribology property

In this paper, we describe a facile and rapid method for preparing In2S3 nanoparticles via ultrasound dispersion. This method allows us to prepare In2S3 nanoparticles from bulk indium and sulfur with ease and without using expensive agents and in a short time. The possible growing mechanism of the In2S3 nanoparticles was presented. In addition, we provide detailed characterizations including TEM, XRD, TG-DTA, and XPS to study the shape, composition and structure of In2S3 nanoparticles. We also studied the tribology property of In2S3 nanoparticles made using this novel recipe.     

基于动力学同步的复杂网络结构识别速度研究

基于动力学同步的复杂网络结构识别是探测复杂网络拓扑性质的重要方面, 其中识别速度是一个重要但鲜有讨论问题. 首先对弱耦合条件下耦合非线性振子网络结构识别速度的问题进行了研究. 发现识别速度随耦合强度成正比增长. 通过解析讨论, 肯定了这一关系是普适的. 之后基于我们最近提出的反复驱动识别方法, 将处于同步稳定态的耦合区域也纳入研究范围. 在这种情形下存在一个最佳的时间片段的长度使识别速度达到极值. 这些结论加深了对时间序列中蕴含的拓扑结构信息量的理解.     

Design study of a L-band photocathode RF injector

In the proposal of the Beijing Advanced Light Source, a compact combination of XERL and XFEL using a common SC linac is being considered. In the meantime, an ERL-FEL test facility is being proposed and will be used for THz radiation. In this test facility, a L-band photocathode RF injector is needed. In this paper, we give the physical design of the L-band photocathode RF injector for the test facility.     

Spectral Determination of the Structure of 5-Hydroxymethylfurfurylidene Barbituric Acid

5-hydroxymethylfurfural reacts with barbituric acid and forms a product with maximum absorbance at 395nm. Via UV-VIS and IR-spectra it becomes evident that in acidic conditions this compound has a conjugated system of bonds with a chynoide-like chromophore. In alkali conditions this chromophore breaks out and the solution is colorless. In this paper is reported a mechanism which is an attempt to explain the stages of this reaction.     

血糖检测中建模方法和温度引入的偶然相关研究

近红外光谱分析技术应用在血糖检测中,需要借助化学计量学方法建立模型来实现对未知样品的定量分析。在模型建立和验证的过程中通常会引入一定程度的偶然相关,从而影响模型的稳健性。采用随机数模拟光谱数据及参考浓度的研究方式,从建模波长数的选择和交互验证方法两方面考察了不同建模方法在建模的过程中存在偶然相关的概率水平,并给出了最佳的建模波长数以及最优的交互验证方法,以降低引入的偶然相关。此外通过离体实验,研究温度对葡萄糖浓度检测的影响并指导如何在实际血糖检测中降低温度引入的偶然相关。     

非线性中子输运问题的一个解法

本文推导了考虑中子之间碰撞的非线性中子输运方程,提出了求解该方程的n-n逐次碰撞展开法,并利用此方法把方程化为适于数值求解的线性输运方程组的形式,编制计算程序进行了数值计算,讨论了解的物理意义。     

应该重视感生（涡旋）电场的方向性教学

感生电场的计算在大学物理教科书中,一般都是以具有轴对称性磁场变化为特例.在那里,感生电场的方向是不证自明的,真的是这样吗？本文力图说明,对称性并不能取代方向性的说明,方向性问题严格说来需要解边值条件下的微分方程,但在大学物理教学层面上可以有简单的办法处理.     

New Receiving Mode of Extinction for Determining Particle Size and Density without Convex Lens

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New Receiving Mode of Extinction for Determining Particle Size and Density without Convex Lens

In this article a new receiving mode for scattering light by particle is theoretically discussed. Using this receiving mode the convex lens can be omitted during determining the extinction of particle. Therefore the extinction coefficient of sphere particles is redefined by extrapolating the conventional one. In terms of the calculation results of light scattering the definition of near-field extinction coefficient of a swarm particle is depicted. Through the error analysis it is proved that the error coming from the new definition of extinction coefficient is acceptable for engineering application. In addition, a technique for determining the particle size and density is presented in this article and the advantage using this receiving mode is described.     

Bestimmung des Abschirmtensors der magnetischen Kernresonanz und des Tensors der magnetischen Suszeptibilität durch numerische Berechnung der Stromdichte in der Ladungsverteilung diamagnetischer Moleküle

Determination of the NMR Shielding Tensor and of the Tensor of Magnetic Susceptibility by Numerical Calculation of the Current Density in the Chargedistribution of Diamagnetic Molecules In papers [1] and [2] a semiclassical approach for calculation of the NMR shielding tensor and of the tensor of magnetic susceptibility of diamagnetic molecules was represented by SCHMIEDEL. In this method the equation of continuity for the currents in the electronic cloud induced by an external magnetic field must be solved. In this paper a method of numerical solution of this partial differential equation is developed. The H₂-molecule serves as an example to present the possibilities of this method.     

关于超纲链方法中无规相近似的讨论

应用超纲链方法讨论均匀费密子系统的多体效应时常用无规相近似和选取原始波函数为费密球分布的波函数。本文讨论这种做法的适用性,给出其适用范围与势的性质和密度的关系。 关键词：     

Observations of the Ramsauer–Townsend effect in quaternionic quantum mechanics

In this article, one of the well-known effects in quantum mechanics is addressed and also the extended form of quantum mechanics which is based on quaternions is presented. In the presence of this version of quantum mechanics the Ramsauer–Townsend effect has been investigated and the existence of this phenomenon is studied according to quaternionic calculations; results are presented by graphs.     

Visible light wireless communications based on predistorted OFDM

OFDM scheme is considered to enhance the data rate of visible light communication using lighting LEDs. In implementing this system, the inherent nonlinearity of LEDs is one of the factors of performance degradation. In this study, this LED nonlinearity is compensated by predistortion and performance enhancement is shown. Characterization and predistortion procedures of LEDs are proposed and experimental results are provided.