Band alignment and defect states in amorphous GaInZnO thin films grown on SiO2/Si substrates

The band alignment and defect states of GaInZnO thin films grown on SiO₂/Si via radio frequency (RF) magnetron sputtering were investigated by using X‐ray photoelectron spectroscopy, reflection electron energy loss spectroscopy, thermally stimulated exo‐electron emission and photo‐induced current transient spectroscopy.The band gap via reflection electron energy loss spectroscopy was 3.2 eV. The defect states via photo‐induced current transient spectroscopy and thermally stimulated exo‐electron emission were at 0.24, 0.53, 1.69 and 2.01 eV below the conduction band minimum of GIZO thin films, respectively. The defect states at 0.24 and 0.53 eV are related to the field‐effect mobility, and the defect stated at 1.69 and 2.01 eV is related to the oxygen vacancy defect. Copyright © 2016 John Wiley & Sons, Ltd.     

Thermal and electro-optical properties of cerium-oxide-doped liquid-crystal devices

Doping with cerium (IV) oxide (CeO₂) nanoparticles can significantly enhance the thermal stability and electro-optical (EO) properties of nematic liquid crystal (NLC) systems. Thermal stability was improved without aggregation and reduction of transmittance by adding CeO₂ nanoparticles in a liquid crystal medium. In particular, the EO properties greatly improved in CeO₂-dispersed NLC cells. The threshold voltage reduced from 3.027 to 2.279 V and the response time decreased from 13.097 to 9.970 ms with increased CeO₂ nanoparticles in the NLC cells. The improved properties of liquid crystals doped with CeO₂ nanoparticles depend on the anchoring energy and the electric field of the CeO₂-dispersed liquid crystal displays.     

Hydrogel-shelled biodegradable microspheres for sustained release of encapsulants

Biodegradable microparticles are promising for the sustained release of encapsulated lipophilic drugs. In particular, the microparticles with uniform size show excellent linearity of cumulated release over time with minimized initial burst. Here, we encapsulate the biodegradable microparticles with a hydrogel shell to improve the controllability over the sustained release and suspension stability. With a capillary microfluidic device, monodisperse oil-in-water-in-oil (O/W/O) double-emulsion droplets are produced to have a toluene solution of polylactic acid (PLA) in the core and sodium alginate and calcium-ethylenediaminetetraacetic acid (EDTA) complex in the shell, whereas the continuous oil phase contains acetic acid. As the toluene evaporates, PLA consolidates to form a microsphere in the core. At the same time, acetic acid diffuses from the continuous phase to the water layer, which causes the dissociation of the Ca-EDTA complex and the gelation of alginate. The hydrogel-shelled PLA microspheres are transferred from the oil to an aqueous solution of calcium chloride, which further tightens the gel shell. The resulting core-shell microspheres show sustained release of encapsulants for extended periods as the hydrogel shell serves as a diffusion barrier. Moreover, the hydrogel shells prevent interparticle agglomeration and adhesion to the solid walls, securing high suspension stability during the injection.     

Magnetic field effect and controlling of Li amounts of cathode material for high performance in LIC

Journal of Solid State Electrochemistry - Li-doped high surface area of activated carbon (LHSAC) for Li ion capacitor (LIC) has been prepared by controlling the LiOH amounts for surface...     

Domino tilings of the expanded Aztec diamond

The expanded Aztec diamond is a generalized version of the Aztec diamond, with an arbitrary number of long columns and long rows in the middle. In this paper, we count the number of domino tilings of the expanded Aztec diamond. The exact number of domino tilings is given by recurrence relations of state matrices by virtue of the state matrix recursion algorithm, recently developed by the author to solve various two-dimensional regular lattice model enumeration problems.     

Synthesis and new application of green and recyclable cyclic poly(L‐lactide)‐clay hybrid

We report on the application of biodegradable cyclic poly(L ‐lactide) (PLLA) as new stabilizer; synthesis and application of a cyclic PLLA‐clay hybrid material as recyclable catalyst support. Cyclic PLLAs were used to stabilize palladium nanoparticles synthesized by a wet chemical method. It was found that the palladium particles were smaller with cyclic PLLA stabilizer (～5–10 nm) than the particles obtained from linear PLLA. The cyclic PLLA‐clay hybrid was prepared by a zwitterionic ring‐opening polymerization catalyzed by in situ‐generated N‐heterocyclic carbene catalyst. Palladium (0) nanoparticles were supported and well dispersed on the cyclic PLLA‐clay hybrid to form a new nanocomposite. The nanocomposite was found to be a highly efficient and recyclable catalyst for the aminocarbonylation reactions of aryl halides with various amines. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4167–4174