Electrical charges and liquids motion

This paper is mainly a review paper. It presents some new results, but mainly summarizes already known phenomena concerning the electrical effect induced by liquid motion and as well liquid motion due to electrical phenomena. After an historical review of the phenomena, we describe some basic experiments and the electrokinetic phenomena, then the general equations of the double layer, and the flow electrification process is more precisely analyzed.     

Über die periodischen Vorgänge in einer Gleichstromgasentladung

The energy source which maintains the periodical phenomena in a d.c. glow discharge in rarefied gases and the determining factors of their characteristics is studied. Departing from the obtained experimental data an unitary explanation of these phenomena is given indicating the a.c. glow discharge circuit, the components of the d.c. gas discharge proper oscillator circuits which determine the oscillation form and frequency as well as the surface phenomena in the negative glow region which are responsable for the generation and maintenance of these phenomena. The periodical light phenomena which occur in the positive glow discharge parts are a result of the d.c. modulation by the alternating current, a.c. circuit including these parts of the d.c. glow discharge.     

Dynamics of a backlash chain

This paper studies the dynamical properties of a system with distributed backlash and impact phenomena. This means that it is considered a chain of masses that interact with each other solely by means of backlash and impact phenomena. It is observed the emergence of non-linear phenomena resembling those encountered in the Fermi-Pasta-Ulam problem.     

The influence of subglottal acoustics on laboratory models of phonation

Many previous laboratory investigations of phonation involving physical models, excised larynges, and in vivo canine larynges have failed to fully specify the subglottal system. Many of these same studies have reported a variety of nonlinear phenomena, including bifurcations (e.g., various classes of phonation onset and offset, register changes, frequency jumps), subharmonics, and chaos, and attributed such phenomena to the biomechanical properties of the larynx. However, such nonlinear phenomena may also be indicative of strong coupling between the voice source and the subglottal tract. Consequently, in such studies, it has not been clear whether the underlying mechanisms of such nonlinear phenomena were acoustical, biomechanical, or a coupling of the acoustical and biomechanical systems. Using a physical model of vocal fold vibration, and tracheal tube lengths which have been commonly reported in the literature, it is hypothesized and subsequently shown that such nonlinear phenomena may be replicated solely on the basis of laryngeal interactions with the acoustical resonances of the subglottal system. Recommendations are given for ruling out acoustical resonances as the source of nonlinear phenomena in future laboratory studies of phonation.     

基于GUI的干涉衍射的实验教学研究

将Matlab用于光学教学,可以更好的解释光学现象的实质.实现了基本的干涉、衍射现象的干涉条纹及光强分布,并利用Matlab的GUI功能将这些干涉和衍射结合起来.在教学中,利用直观的图样,由图释义,在一个界面中可以比较各种光学现象.方便学生进行比较学习.     

Some studies of the interaction between two two-level atoms and SU(1,1) quantum systems

Herein, we present an approach to look for the best phenomenon to measure quantum correlation. The system of two isolated qubits each interacting with a single-mode cavity was theoretically created to study the quantum correlation. Some of the phenomena, such as the quantum discord and concurrence, were generated through such a system. The influences of initial state purity, qubit motion, and detuning parameters were discussed for the phenomena. These parameters for a specific value show that the behavior of phenomena are analogous. It is interesting to mention that some values of detuning undergo a sudden death of phenomena, and the quantum discord still captures the qubits quantum correlation. We predict that the quantum discord may be a better measure of quantum correlation than concurrence.     

Two interface effects: Exchange bias and magnetic proximity

Exchange bias and magnetic proximity effects are two novel phenomena that are in the limelight because of their fundamental and technological importance. Since both phenomena are interfacial in origin, we review these together. In the first part of this review, we have discussed the basics of these two phenomena. Subsequently, we have described numerous experimental examples involving a variety of composite magnetic materials and heterostructures. The recent theoretical models of these two interface phenomena have also been described. Finally, we have shed light on an obvious question: can one expect both these phenomena to occur together in any magnetically coupled system? We conclude that one can enhance the operating temperature of an exchange biased device by exploiting the magnetic proximity effect.     

Non-Kolmogorovian Approach to the Context-Dependent Systems Breaking the Classical Probability Law

There exist several phenomena breaking the classical probability laws. The systems related to such phenomena are context-dependent, so that they are adaptive to other systems. In this paper, we present a new mathematical formalism to compute the joint probability distribution for two event-systems by using concepts of the adaptive dynamics and quantum information theory, e.g., quantum channels and liftings. In physics the basic example of the context-dependent phenomena is the famous double-slit experiment. Recently similar examples have been found in biological and psychological sciences. Our approach is an extension of traditional quantum probability theory, and it is general enough to describe aforementioned contextual phenomena outside of quantum physics.     

Threshold phenomena in R-matrix theory

An R-matrix treatment of threshold phenomena in nuclear reactions is developed. It results, in addition to cusp phenomena, in a class of threshold anomalies induced by a resonance located at the threshold of the opening channel. The influence of compound nucleus and single-particle resonances and of direct interaction on threshold phenomena is discussed for s- and p- waves.     

旋转过程中的超重与失重实验设计

本实验用简单的装置和易懂的原理清晰明了地演示旋转过程中的超重与失重现象．滚摆的旋转上升和下降其质心的平动速度也较自由落体慢，便于学生观察实验现象，实验装置简单。     

HL-1M装置中的离轴电子回旋加热实验

在HL-1M装置上进行了离轴电子回旋加热实验。研究了电子温度的变化，等离子体密度对加热效果的影响，离轴加热条件下MHD锯齿的变化，波对m/nk=1/1模的影响及在与低杂波电流驱动共同作用下的各种实验现象。 这些现象被认为与高能电子和它们的分布有关。     

Re-entrance phenomena in mesomorphic poly-γ-benzyl-l-glutamate (PBLG) solutions

We predict here, using a two-parameter polymer model and a mean field theory, isotropic-nematic-isotropic re-entrance phenomena in PBLG dissolved in denatured solvents, and propose experimental conditions under which the phenomena may be observed.     

Macroscopic spin and charge transport theory

According to the general principle of non-equilibrium thermodynamics, we propose a set of macroscopic transport equations for the spin transport and the charge transport. In particular, the spin torque is introduced as a generalized `current density' to describe the phenomena associated with the spin non-conservation in a unified framework. The Einstein relations and the Onsager relations between different transport phenomena are established. Specifically, the spin transport properties of the isotropic non-magnetic and the isotropic magnetic two-dimensional electron gases are fully described by using this theory, in which only the macroscopic-spin-related transport phenomena allowed by the symmetry of the system are taken into account.     

Extreme midinfrared nonlinear optics in semiconductors

We have observed extreme nonlinear optical phenomena produced by intense midinfrared (MIR) pulses in semiconductors. These phenomena include multiple off-resonance optical sidebands (up to +/-3 MIR photons interacting with a near-infrared photon), multiple MIR harmonics (up to the seventh harmonic), and significant broadening and modification of MIR harmonic spectra. The generation of these extreme MIR nonlinear optical phenomena is primarily aided by cross-phase modulation.     

Non-equilibrium phenomena and molecular reaction dynamics: mode space,energy space and conformer space

The ability to characterise and control matter far away from equilibrium is a frontier challenge facing modern science. In this article, we sketch out a heuristic structure for thinking about the different ways in which non-equilibrium phenomena can impact molecular reaction dynamics. Our analytical schema includes three different regimes, organised according to increasing dynamical resolution: at the lowest resolution, we have conformer phase space, at an intermediate resolution, we have energy space; and at the highest resolution, we have mode space. Within each regime, we discuss practical definitions of non-equilibrium phenomena, mostly in terms of the corresponding relaxation timescales. Using this analytical framework, we discuss some recent non-equilibrium reaction dynamics studies spanning isolated small-molecule ensembles, gas-phase ensembles and solution-phase ensembles. This includes new results that provide insight into how non-equilibrium phenomena impact the solution-phase alkene–hydroboration reaction. We emphasise that interesting non-equilibrium dynamical phenomena often occur when the relaxation timescales characterising each regime are similar. In closing, we reflect on outstanding challenges and future research directions to guide our understanding of how non-equilibrium phenomena impact reaction dynamics.     

New fractional derivative with sigmoid function as the kernel and its models

Based on the idea of the fractional derivative with respect to another function, a new fractional derivative operator with sigmoid function as the kernel in this article, is proposed for the first time. Then, we make use of this new fractional operator to model various nonlinear phenomena from different fields of applications in science, such as the population growth, the shallow water wave phenomena and reaction-diffusion processes, and so on. As a result, we hope that the new fractional operator can be used to discover more evolutionary mechanisms of these phenomena.     

Wave motion and dispersion phenomena: veering, locking and strong coupling effects

The dispersion curves describe wave propagation in a structure, each branch representing a wave mode. As frequency varies the wavenumbers change and a number of dispersion phenomena may occur. This paper characterizes, analyzes, and quantifies these phenomena in general terms and illustrates them with examples. Two classes of phenomena occur. Weak coupling phenomena-veering and locking-arise when branches of the dispersion curves interact. These occur in the vicinity of the frequency at which, for undamped waveguides, the dispersion curves in the uncoupled waveguides would cross: if two dispersion curves (representing either propagating or evanescent waves) come close together as frequency increases then the curves either veer apart or lock together, forming a pair of attenuating oscillatory waves, which may later unlock into a pair of either propagating or evanescent waves. Which phenomenon occurs depends on the product of the gradients of the dispersion curves. The wave mode shapes which describe the deformation of the structure under the passage of a wave change rapidly around this critical frequency. These phenomena also occur in damped systems unless the levels of damping of the uncoupled waveguides are sufficiently different. Other phenomena can be attributed to strong coupling effects, where arbitrarily light stiffness or gyroscopic coupling changes the qualitative nature of the dispersion curves.     

Quantum contact interactions

The existence of several exotic phenomena, such as duality and spectral anholonomy is pointed out in one-dimensional quantum wire with a single defect. The topological structure in the spectral space which is behind these phenomena is identified.