Abstract: Porous silicon (PS) is usually prepared by means of the anodization under constant current density, and fabrication of PS is a key step towards the realization of all-silicon electronic devices. It is a general belief that the photoluminescent properties of electrochemically etched PS depend on the anodization current density. In this work, we electrochemically prepared a series of PS films in the electrolyte of hydrofluoric acid by varying anodizing current density in the range of 1-70 mA/cm2. In spite of the different anodizing current density, the peak wavelength of the photoluminescence spectrum of the electrochemically anodized PS does not depend on the anodization current density. SEM has been utilized to characterize the morphology of the prepared PS films, and the mechanism is discussed for the anodization current independent photoluminescence of PS.
Abstract: A finite element model with progressive damage material properties is proposed to study the mechanical behavior of Ni-8YSZ/8YSZ half-cell structures under Vickers indentation tests. The simulation results show that the simulated hardnesses of the as-received anode (NiO-8YSZ with 12% porosity) and the reduced anode (NiO-8YSZ with 36.68% porosity) samples were 2.54 GPa and 0.66 GPa, respectively, which are fairly in agreement with the experimental data. The interface delamination between the anode layer and the electrolyte layer was investigated by varying the mechanical properties of the interface between the two layers. The parametric study shows that a weak interfacial layer (with a low Young’s modulus) may cause potential failure due to delamination.
Abstract: Mesoporous silica nanoparticles (MSNs) have been employed as a versatile solid support for constructing a variety of hybrid materials for controlled drug delivery. Controlled release systems that integrate external stimuli with nanocarriers have attracted much attention for sensors and drug delivery applications. Mesoporous silica nanoparticles grafted with thermo-sensitive polymers on the surface were fabricated via “grafting to” approach through chemical coupling reaction. The encapsulation and release of drug based on the thermo-sensitive nanogated system were investigated. The thermo-sensitive nanogated system can be expected as one of the promising candidates for drug delivery and controlled release.
Abstract: Aluminum nitride (AlN) films were prepared by radio frequency (RF) sputtering technique with self-prepared AlN ceramic target. The influence of substrate type and working gas of different N2 concentration to performance of AlN films were discussed. Microstructures of the films have been studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). And, the optical properties have been revealed by diffuse reflection spectrum (DRS). The optimized process to prepare AlN film of single orientation (100) was as follows: deposited on Si (100) substrate and 25% N2 concentration, 250W-300W sputtering power and 90min sputtering time, respectively.
Abstract: Electromagnetic properties of the material with effective permittivity and permeability very near zero (double-near-zero, DNZ) have been simulated based on the finite element method and analyzed all-around. The results of simulation show that DNZ can be used to reshape the phase front of a wave perfectly. It can be used as an angular filter as well. Furthermore, The propagation direction and the shape of phase front of EM wave can be controlled by the device which is constructed by DNZ.
Abstract: The ferroelectric domain’s structure and its evolution processes induced by DC electric field in 0.92Pb（Zn1/3Nb2/3）O3-0.08PbTiO3（PZNT）crystal is observed using synchrotron radiation white-beam topography. Two organic plates with tinsels covering their surfaces are used as electrodes to employ DC electric field, and the characterizing sample is two PZNT crystal slices whose surface orientation is  and , respectively. This research results is considered to be useful for demonstrating the electric field induced phase transition in PZNT crystals.
Abstract: Sheet-shaped zinc oxide nano-particles were prepared by hydrothermal method. The zinc oxide nanosheets were characterized by X-ray diffraction (XRD)，scanning electron microscopy(SEM) and photoluminescence spectrum (PL) at room temperature. The strongest diffraction apex of the nanosheet-shaped zinc oxide is assigned to crystal planes and exhibits obvious preferred orientation which is different from that of the general zinc oxide. The results show that ZnO nanosheets with about 1000nm×600nm×60 nm are obtained. The growth mechanism of the ZnO nanosheets was discussed.
Abstract: Optical properties of thin films of vanadium thermally oxidized at air were studied by ellipsometric method using wavelength of He-Ne laser. Multipart composition of these films was revealed and method of optimization of technological conditions based on dynamic of changing optical constants near 68°C was developed.
Abstract: A monomer 4,4'-bis(β-hydroxyethyl)biphenyl (2BP) was synthesized by the Williamson reaction from 2-chloroethanol and 4,4'-biphenol. Then, the novel dendritic liquid crystal macromolecule (DLCM) containing biphenyl structure was synthesized with 2BP and 1,3,5-benzenetrimethylacylchloride as monomers by dispersion method. The structures of 2BP and the DLCM were characterized by FT-IR and 1H-NMR. The thermal stabilities of he DLCM were measured by TGA and DSC. The results showed that the DLCM had good thermal stability and the DLCM may have a higher phase inversion temperature.
Abstract: Yttria-stabilized zirconia (YSZ) is an important material in the area of energy and optical applications. In this study, the mechanical properties (Young’s modulus, Vickers hardness, flexural strength, and coefficient thermal expansion) and physical properties (phase transition) of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) was reported. The effect of thermal cycling on the mechanical properties and the stability was also evaluated.