Gazeau–Klauder coherent states examined from the viewpoint of diagonal ordering operation technique

In this paper we investigate the Gazeau–Klauder coherent states using a newly introduced diagonal ordering operation technique, in order to examine some of the properties of these coherent states. The results coincide with those obtained from other purely algebraic methods, but the calculations are greatly simplified. We apply the general theory to two cases of Gazeau–Klauder coherent states： pseudoharmonic as well as the Morse oscillators.

Tianjin Automotive Test Center & National Passenger Car Quality Supervision and Inspection Center——A State Testing and Universality Techniques Research Base in China

Tianiin Automotive Test Center has a test capability as well as a capability of conducting universality techniques research. With fixed assets of around RMB 76.44 million yuan and an architectural area of 11,200 sqm, test labs mainly include: auto emission test lab, full-scale vehicle crash test lab, auto safety test lab, auto lighting and view field test lab, engine test lab,

Fixed-time constrained acceleration reconstruction scheme for robotic exoskeleton via neural networks

Accurate acceleration acquisition is a critical issue in the robotic exoskeleton system,but it is difficult to directly obtain the acceleration via the existing sensing systems.The existing algorithm-based acceleration acquisition methods put more attention on finite-time convergence and disturbance suppression but ignore the error constraint and initial state irrelevant techniques.To this end,a novel radical bias function neural network(RBFNN)based fixed-time reconstruction scheme with error constraints is designed to realize high-performance acceleration estimation.In this scheme,a novel exponential-type barrier Lyapunov function is proposed to handle the error constraints.It also provides a unified and concise Lyapunov stability-proof template for constrained and non-constrained systems.Moreover,a fractional power sliding mode control law is designed to realize fixed-time convergence,where the convergence time is irrelevant to initial states or external disturbance,and depends only on the chosen parameters.To further enhance observer robustness,an RBFNN with the adaptive weight matrix is proposed to approximate and attenuate the completely unknown disturbances.Numerical simulation and human sub ject experimental results validate the unique properties and practical robustness.

Interdependence between electrical and magnetic properties of polycrystalline cobalt-substituted tungsten bronze multiferroic ceramics

Polycrystalline cobalt-substituted tungsten bronze ferroelectric ceramics with chemical composition Ba_(5)CaTi_(2-x)Co_(X)Nb_(8)O_(30)(x=0.00,0.02,0.04 and 0.08)were synthesized by solid state reaction technique.X-ray diffraction(XRD)technique was used to confirm the phase formation and it revealed the formation of single phase tetragonal structure with space group P4bm.The surface morphology of the samples was studied by using the scanning electron microscopy(SEM)technique.The dielectric properties such as dielectric constant and dielectric loss have been investigated as a function of temperature and frequency.The P-E and M-H studies confirmed the coexistent of ferroelectricity and magnetism at room temperature.The P-E loop study indicated an increase in the coercive field while the M-H study depicted a decrease in the magnetization with the incorporation of cobalt ions.