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Wang P.,Xinjiang Normal University | Wang P.,Shanghai University
Nonlinear Dynamics | Year: 2012

Perturbation to Noether symmetries and adiabatic invariants of discrete nonholonomic nonconservative mechanical systems on an uniform lattice are investigated. Firstly, we review Noether symmetry and conservation laws of a nonholonomic nonconservative system. Secondly, we study continuous Noether symmetry of a discrete nonholonomic system, give the Noether symmetry criterion and theorem of discrete corresponding holonomic system and nonholonomic system. Thirdly, we study perturbation to Noether symmetry of the discrete nonholonomic nonconservative system, give the criterion of perturbation to Noether symmetry for this system, and based on the definition of adiabatic invariants, we construct the theorem under which can lead to Noether adiabatic invariants for this system, and the forms of discrete Noether adiabatic invariants are given. Finally, we give an example to illustrate our results. © 2011 Springer Science+Business Media B.V.


Gao Y.,Xinjiang Normal University | Wang Y.,Xinjiang Normal University | Cui W.,Soochow University of China
Marine Drugs | Year: 2016

A major goal of biomimetics is the development of chemical compositions and structures that simulate the extracellular matrix. In this study, gelatin-based electrospun composite fibrous membranes were prepared by electrospinning to generate bone scaffold materials. The gelatin-based multicomponent composite fibers were fabricated using co-electrospinning, and the composite fibers of chitosan (CS), gelatin (Gel), hydroxyapatite (HA), and graphene oxide (GO) were successfully fabricated for multi-function characteristics of biomimetic scaffolds. The effect of component concentration on composite fiber morphology, antibacterial properties, and protein adsorption were investigated. Composite fibers exhibited effective antibacterial activity against Staphylococcus aureus and Escherichia coli. The study observed that the composite fibers have higher adsorption capacities of bovine serum albumin (BSA) at pH 5.32-6.00 than at pH 3.90-4.50 or 7.35. The protein adsorption on the surface of the composite fiber increased as the initial BSA concentration increased. The surface of the composite reached adsorption equilibrium at 20 min. These results have specific applications for the development of bone scaffold materials, and broad implications in the field of tissue engineering. © 2016 by the authors.


Dai P.,Xinjiang Normal University
Materials Research Bulletin | Year: 2017

A series of Tb3+-doped europium-based molybdate red-emitting phosphors (LiEuMo2O8) were prepared by solid-state reaction method, their crystal structure and luminescence properties have been investigated by X-ray diffraction, micro-Raman spectra, diffuse reflectance spectra, photoluminescence and photoluminescence excitation spectra. Partial substitution of Li+ by Tb3+ slightly distorts the host lattice, red-shifts the absorption edge of host and improves Eu3+ red-emitting intensity in LiEuMo2O8 compound. The red-emitting intensity of LiEuMo2O8 powder is enhanced by 30% at the doping level of 0.02 under excitation at 395 nm. In present study, we found that the contribution of Tb3+ → Eu3+ energy transfer to the enhanced Eu3+ emission is little since the Tb3+ ions are not responsive to the near ultraviolet (∼395 nm), the enhanced red emission is tentatively ascribed to the relaxation of parity-forbidden selection rules of Eu3+ ions. White light-emitting diodes are fabricated by using near ultraviolet light-emitting diode chips (∼395 nm) and the blends of the commercial blue, green and as-prepared red Li0.98Tb0.02EuMo2O8 phosphor, the resulting white light-emitting diode shows a color-rendering index of 93.5, luminous efficacy of 14 lm/W and chromaticity coordinates of (0.292, 0.329). © 2017 Elsevier Ltd


Wen W.,Hohai University | Zhao C.,Hohai University | Ma X.,Xinjiang Normal University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We present an investigation of generation, dynamics, and stability of dark solitons in anisotropic Fermi gases for a range of particle numbers and trap aspect ratios within the framework of the order-parameter equation. We calculate the periods of dark solitons oscillating in a trap and find good agreement with the results based on the Bogoliubov-de Gennes equations. By studying the stability of initially off-center dark solitons under various tight transverse confinements in the unitarity limit, we not only give the criterion of dynamical stability, but also find that the soliton and a hybrid of solitons and vortex rings can be characterized by different oscillation periods. The stability criterion is not fulfilled by the parameters of the recent experiment of Yefsah. Therefore, instead of a very slow oscillation as observed experimentally, we find that the created dark soliton undergoes a transverse snake instability with a collapse into vortex rings, which propagate in solitonlike manner with a nearly 2 times larger period. © 2013 American Physical Society.


Li J.,South China Normal University | Shen L.,Xinjiang Normal University | Pan Y.,South China Normal University | Li R.,South China Normal University
Optics Express | Year: 2014

A method for optical image hiding and for optical image encryption and hiding in the Fresnel domain via completely optical means is proposed, which encodes original object image into the encrypted image and then embeds it into host image in our modified Mach-Zehnder interferometer architecture. The modified Mach-Zehnder interferometer not only provides phase shifts to record complex amplitude of final encrypted object image on CCD plane but also introduces host image into reference path of the interferometer to hide it. The final encrypted object image is registered as interference patterns, which resemble a Fresnel diffraction pattern of the host image, and thus the secure information is imperceptible to unauthorized receivers. The method can simultaneously realize image encryption and image hiding at a high speed in pure optical system. The validity of the method and its robustness against some common attacks are investigated by numerical simulations and experiments. © 2014 Optical Society of America.


In this paper, a class of stochastic impulsive high-order BAM neural networks with time-varying delays is considered. By using Lyapunov functional method, LMI method and mathematics induction, some sufficient conditions are derived for the globally exponential stability of the equilibrium point of the neural networks in mean square. It is believed that these results are significant and useful for the design and applications of impulsive stochastic high-order BAM neural networks. © 2010 Elsevier B.V.


Chang L.-X.,Nankai University | Chang L.-X.,Xinjiang Normal University | Xiong G.,Nankai University | Wang L.,Xinjiang Normal University | And 2 more authors.
Chemical Communications | Year: 2013

Two 24-nuclear lanthanide clusters, Gd24 and Dy24 were obtained and structurally characterized. Magnetic investigations reveal that Gd24 exhibits the largest entropy change (-ΔSm) of 46.12 J kg-1 K-1 for ΔH = 7 T in all reported molecular clusters, and single-molecule magnet behaviour is observed in Dy 24. © 2013 The Royal Society of Chemistry.


Lei X.-L.,Xinjiang Normal University
Journal of Cluster Science | Year: 2011

Successively substituted Al13 cluster by B atom both neutral and anionic AlnBm(n + m = 13) clusters have been investigated by the density functional theory (DFT) at B3LYP/6-31G (d) level, the aim is to understand the evolution of the structural and electronic properties as a function of composition. The results clearly show Al13 cluster as well as Al rich AlnBm clusters prefer the icosahedral geometries while increasing boron contents promote quasi-planar configurations. The geometrical structures of the optimized anionic AlnBm- clusters are very close to those of the neutral clusters with smaller structural modifications. Overall, the vertical ionization potential (VIP), the adiabatic electron affinity (AEA), and the energy gaps (Eg) of AlnBm clusters decrease with increasing of substitution. The largest values of second-order energy differences (Δ2E), VIP, and Eg of Al12B cluster indicate it possesses the most stability among all the investigated clusters, which accords to the experimental results. The simulated photoelectron spectroscopies (PES) of AlnBm- clusters have also been discussed in this article. © 2011 Springer Science+Business Media, LLC.


Ren Q.,Xinjiang Normal University | Li T.,Xinjiang Normal University
Advances in Information Sciences and Service Sciences | Year: 2012

The problem of evaluating the school physical education teaching with triangular intuitionistic fuzzy information is the multiple attribute decision making (MADM) problems. In this paper, we investigate the multiple attribute decision making (MADM) problems for evaluating the school physical education teaching with triangular intuitionistic fuzzy information. Some operational laws of triangular intuitionistic fuzzy numbers, score functions and accuracy function of triangular intuitionistic fuzzy numbers are introduced. Based on these operational laws, we used triangular intuitionistic fuzzy ordered weighted averaging (TIFOWA) operator to evaluate the school physical education teaching. Finally, an illustrative example is given to verify the developed approach.


Lei X.-L.,Xinjiang Normal University
Chinese Physics B | Year: 2010

This paper studies the small molybdenum clusters of Mon (n=2-8) and their adsorption of N2 molecule by using the density functional theory (DFT) with the generalized gradient approximation. The optimized structures of Mon clusters show the onset of a structural transition from a close-packed structure towards a body-centred cubic structure occurred at n = 7. An analysis of adsorption energies suggests that the Mo2 is of high inertness and Mo6 cluster is of high activity against the adsorption of N2. Calculated results indicate that the N2 molecule prefers end-on mode by forming a linear or quasi-linear structure Mo-N-N, and the adsorption of nitrogen on molybdenum clusters is molecular adsorption with slightly elongated N-N bond. The electron density of highest occupied molecular orbital and lowest unoccupied molecular orbital, and the partial density of states of representative cluster are also used to characterize the adsorption properties of N2 on the sized Mon clusters. © 2010 Chinese Physical Society and IOP Publishing Ltd.

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