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Based on the Devonshire theory, the E-induced effects of polarization, dielectrics, hysteresis loop, and energy storage are investigated. Numerical simulations confirm that the ferroelectrics with ...

Based on the Devonshire theory, a ratio of two thermodynamic parameters, a polarization – temperature coefficient, is found as the crucial for pyroelectric and dielectric tunability effects. Smalle...

Reversible electrostrictive effect in ferroelectrics of double-well free energy is modeled using the Devonshire theory. The idea is developed that in tetrogonal phase 90° turnings of dipoles from four poling axises, isoenergetic minima, perpendicular to electrical field to the direction of electrical field cause electrostriction. Numerical simulation results exhibit that the exchanging coupling coefficient between dipoles results in a butterfly shaped electrostriction loop. Influences of temperature and the two parameters of materials on shape of electrostriction loop are discussed, and an empirical experimental law, about magnitude of electrostriction with the Curie constant, is confirmed.

Based on the dynamics of vitrification process driven by the configurational entropy, a novel expression of viscosity- temperature relation with the form of Fermi-type function is deduced below melting temperature by supposed an exponential function of average aggregation energy with temperature. The ‘molecular rearrangement’ to form aggregated regions at temperatures below the melting temperature is major contribution to the aggregation energies for describing vitrification process. The expression of relaxation time or viscosity is confirmed with several super-cooled liquids in broad temperature region. The expression contains the Vogel-Fulcher relation in limited temperature region and can avoid Kauzmenn paradox. The derived fragility shows that a reduced temperature may be a common structural variable in comparing various glassy liquids.

In this study, we reported the cloning and over expression of a gene coding for human collagen peptide (CP6) in Escherichia coli and investigated the protective effects of CP6 on UVA-irradiated human skin fibroblasts cells. The collagen peptide (CP6) was highly soluble and the expression level was approximately 10% of the total bacteria proteins. Also, we performed assays with 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT), Annexin V-fluorescein isothiocyanate/propidine iodide (Annexin V-FITC/PI) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) methods to investigate the cytoprotective effects of CP6 on the proliferation of UVA-damaged human skin fibroblasts cells. Radiation dosages (5 J/cm2) significantly decreased the proliferation activities of human skin fibroblasts cells (HSF). Compared with UVA irradiated group, in the given concentration, CP6 could improve the activities of cell’s proliferation (P