Polyimide (PI) films filled with K sub(0.5)Na sub(0.5)NbO sub(3) (KNN50) particles at different weight 0, 5, 10, and 15 wt % had been prepared by in-situ dispersion polymerization process. The ...thermally stimulated current (TSDC) method was used to investigate the charge carrier trap levels and their distribution of the composite films. The TSDC spectra show that pure film has Formulaomitted-peaks and Formulaomitted-peak, but the composite films only have Formulaomitted-peaks and an extraordinary peak at high temperature region. The trap parameters were calculated by an approximate model, and the results indicate that charge released of the shallow traps show a nonlinear behavior. The trap energies decrease from 0.879-0.968 eV to 0.549-0.839 eV with the increase of the KNN50 content. The surface and interface between KNN50 and PI matrix was considered to the variation of the trap levels. The extraordinary peak of the composite films was correlated with the phase transition of the KNN50 particles. copy 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39828.
A thorough, self-contained and easily accessible treatment of the theory on the polynomial best approximation of functions with respect to maximum norms. The topics include Chebychev theory, ...Weierstraß theorems, smoothness of functions, and continuation of functions.
The phonon spectrum of cubic BaThO(3) with the perovskite structure is calculated from first principles within the density functional theory. The analysis of unstable modes in the phonon spectrum ...enables to determine the symmetry of all possible distorted phases, calculate their energies, and show that the ground-state structure of barium thorate is Pbnm. For this structure, the static and optical dielectric constants, elastic moduli, heat capacity, Raman spectra, and the energy band gap in the IDA and GW approximations are calculated. The possibility of the structural phase transitions in BaThO(3) is also discussed.
We consider the critical behavior of the O(n)-symmetric model of the ϕ4 type with an antisymmetric tensor order parameter. According to a previous study of the one-loop approximation in the quantum ...field theory renormalization group, there is an IR-attractive fixed point in the model, and IR scaling with universal indices hence applies. Using a more specific analysis based on three-loop calculations of the renormalization-group functions and Borel conformal summation, we show that the IR behavior is in fact governed by another fixed point of the renormalization-group equations and the model therefore belongs to a different universality class than the one suggested by the simplest one-loop approximation. Nevertheless, the validity of the obtained results remains a subject for discussion.
We study the boundary properties of u(x,y)=Kya mu (x), defined on the half-space Ra+ARN by the convolution of an approximate identity Ky(a)(y>0) and the AhlforsaDavid singular ss-measure mu mu on ...RNRN. The Poisson and the GaussaWeierstrass integral are unified as special cases in our setting. The sharp LpLp estimates of the function u(x,y)u(x,y) near the boundary are given. In particular, we show that
The problem of deducing, from the FAPGpplaVon KA!rmA!n energy functional, a sequence of reduced discrete models having few degrees of freedom is analyzed. Similar discrete models have been recently ...intensively studied to analyze the multistable behavior of shallow shells, the bifurcations of composite laminates under temperature loads or the wrinkling in soft tissues.
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