Fabrication and Phase-Transition Characteristic Investigation of Nanocrystalline VO2 Thin Film

In this paper, nanocrystalline VO2 thin film is fabricated by a kind method of two steps and its phase transition characteristics are investigated. The two-step method contains low-temperature reactive ion sputtering and post-annealing, and its process parameters determine the phase transition properties of fabricated VO2 thin film. With optimized process parameters, VO2 thin film with nanocrystalline structure can be successfully fabricated and has excellent phase transition performance for smart glass and optical switch.

Collective Threshold Model Based on Utility and Psychological Theories

In this paper the authors investigate critical phase transition characteristic of collective action by considering the mechanisms of both rational utility and psychological threshold based on the Granovetter (1978)'s threshold model. Numeric simulation is used to observe the collective dynamics with consideration of both spatial factor and social network friendship density. The authors observe that activation threshold model with both utility and psychological thresholds included shows more stable in phase transition than that in the classic model. The authors also find that spatial factor and friendship network density have trivial impact on final equilibrium of collective behavior.

The Liquid-Solid Phase Transition Characteristic and Protein Binding Property of Composite Cryogel with Embedded Cellulose Beads

Poly (hydroxyethyl methacrylate)-based composite cryogel with embedded macroporous cellulose beads (pHEMA-CB cryogel) could be of interest as chromatographic medium for bioseparation applications. In this work, liquid-solid phase transition characteristic of the suspension mixture containing HEMA, poly (ethylene glycol) diacrylate (PEGDA), ammonium persulfate (APS),N,N,N',N'-tetramethylethylenediamine (TEMED) and cellulose beads for the production of pHEMA-CB composite cryogel was investigated to reveal the solvent crystallization process occurring in the column. Freezing curves were obtained and the values of initial solvent crystallization temperatureTcand the freezing point temperatureTmcwere estimated. Protein binding property of the pHEMA-CB cryogel grafted with (vinylbenzyl) trimethylammonium chloride (VBTAC) was measured and discussed.

CROSSOVER FROM CHIRAL SUSCEPTIBILITY IN QED3

In the framework of truncated Dyson–Schwinger equation for fermion propagator, we investigate the chiral susceptibility with the rise of temperature in QED3, while it demonstrates a phase transition characteristic in the chiral limit and illustrates a crossover beyond chiral limit in this Abelian system.

Transport and Electrochemical Properties of LiyNixMn2-xO4 (0.1 ≤ x ≤ 0.5) Cathode Materials

In this paper structural, electrical, electrochemical and thermal (DSC) characterization of series of manganese spinel samples with manganese substituted to different degree (x = 0 – 0.5) with nickel are presented. The conductivity and thermoelectric power measurements were performed in wide temperature range also versus oxygen partial pressure and for deintercalated samples. Electrochemical studies of these cathode materials were conducted in Li / Li+ / LiyNixMn2−xO4 type cells. Substitution of manganese with nickel causes disappearance of the phase transition characteristic of LiMn2O4 spinel. Studies of electrical properties reveal that Ni ions do not participate in charge transport at low temperatures. In the charge curves of Li / Li+/ LiyNixMn2−xO4 cells there are two visible plateaux, separated with distinct potential jump (~0.5V), which position on Li content perfectly matches the Mn3+ content in the doped cathode material. The lower plateau is related to the Mn3+ → Mn4+ oxidation, while the next of higher voltage, of the dopant Ni2+ → Ni4+ oxidation. The schematic diagrams of relative Mn – Ni electronic levels alignment are proposed.