Advanced Materials Research Vol. 813

Abstract: Core-shell nanoparticles Gd₂O₃:Tb³⁺/SiOx were obtained by encapsulating Gd₂O₃:Tb³⁺ in a polysiloxane shell. We studied the influence of two kinds of reagents (NaOH and Bu₄NOH) reacting with precursor solution on size and luminescent property of nanoparticles. The result showed that the reaction involving NaOH was more favorable to the growth of nanoparticles, thus enhanced the energy transfer between the core and the shell of particles and improved their luminescent intensities.

Abstract: Using chemical vapor deposition in this study to grow vertically aligned carbon nanotubes on Ni/Ti/Au/Si as electrodes for supercapacitor is simpler and reproducible than other methods. Nanoparticles on Ni/Ti/Au/Si substrate proceeded by e-beam evaporation were less than 15 nm, vertically aligned MWCNT are distributed uniformly on the substrate, and the number of nanotubes per square centimeter is 6.3×10¹⁰. Morphologies and structures of the composite electrode were examined by scanning electron microscopy, transmission electron microscopy and Raman spectrum. This straightforward process can fabricate high specific surface areas of other nanoparticles on the MWCNTs.

Abstract: In this study, we aimed at exploring a layer of radio frequency (RF) sputtered titanium dioxide (TiO₂) film on a sputtered ZnO film treated by hydrothermal reaction and then conducted characterization of the film. The main objective was to discuss characteristics of the fabricated TiO₂ films under conditions of different annealing temperature, film thickness, and oxygen flow rate. After measurement of four-point probe for the fabricated TiO₂ films under the same film thickness or oxygen flow rate, their sheet resistance all became smaller through high-temperature annealing at 500°C, and the thicker the TiO₂ film was, the higher the sheet resistance was. Under conditions of fixed TiO₂ film thickness and annealing temperature, with increasing oxygen flow rate, the sheet resistances of sample thin films increased initially and then decreased. The sheet resistances became highest at oxygen flow rate of 4 sccm. Results, measured from field emission scanning electron microscope (FE-SEM), showed that the structure arrangement of TiO₂ nanorods was affected by TiO₂ film thickness, oxygen flow rate and annealing temperature. The stacking and blending situations between nanorods became severer for higher oxygen flow rate and annealing temperature above 400°C. In addition, grains formed on film surface apparently spread more outwards as the film became thicker.

Abstract: Al-Si-Al₂O₃ composites were prepared by powder metallurgy with in-situ synthesis technology. The recovery and recrystallization behavior of Al-Si-Al₂O₃ composites which underwent compression and then heat-treatment under different temperature were studied using micro-hardness tester, optical microscope (OM) and scanning electron microscopy (SEM) . The results showed that the hardness of composites increased dramatically after compression, and the sample containing 5wt% Si was increasing more evidently than the sample including 10wt%Si. Heat treatment gradually eliminated work hardening; meanwhile the fact that the hardness of composites trended to decline greatly when subjected to annealing suggested occurrence of recovery and recrystallization inside the composites. Recrystallization nucleation preferentially took place in the region near the particle, while the growth of recrystallized grains can also be hindered owning to the pining effect of particles. Depending on the analysis of microstructure and microhardness, it can be concluded that the recrystallization temperature of Al-wt.5%Si-Al₂O₃ composites was 500°C and the Al-wt.10%Si-Al₂O₃ composites was 525°C.

Abstract: This paper used COMSOL Multiphysics software to simulate and design two kinds of new touch panels with chain and mountain-shaped ITO electrodes, respectively. These two touch panel electrodes were both designed using parallel and vertical capacitance configurations. Compared with traditional common rectangular and diamond-shaped electrodes, it was found in simulation results that parallel and vertical capacitive gains for chain and mountain-shaped electrodes were 30% and 6%, respectively, higher than those for traditional rectangular and diamond-shaped ones. In addition, when the ratio of glass thickness (H) to indium tin oxide (ITO) electrode thickness (h) was larger, the corresponding capacitive gain was smaller.

Abstract: In order to accurately describe the growth behavior of the micro-fracture under the action of the rock external load, this paper proposes the use of chaos theory to describe the fracture formation process, explains the chaotic characteristics of the fracture from the perspective of the growth of micro-fracture, the number of growth and fracture formation morphology, respectively. Selecting the practical block of an oilfield, the theoretical calculation and finite element software simulation results show that, theoretical calculations are accurate and reliable.

Abstract: In this paper, we study the 45Mn steel material forging performance, and the results show that: as long as choosing reasonable forging process parameters, such as the crack forging defects can be avoided. Through the forging of 45Mn material internal organizational performance in microscopic analysis, found that the microstructure and beginning the determination of forging closely related temperature range, so as to determine the 45Mn steel forging process, for 45Mn steel forging production provides the practical feasible forging process. Keywords: 45Mn, Forging performance, Microstructure, Microscopic analysis, Forging process

Abstract: Effect of LiCl·H₂O on sintering properties of MgO prepared from natural brine from Qarhan Salt Lake, crystalline bischofite and MgCl₂·6H₂O(AR) was studied. The results showed that LiCl·H₂O of addition exceeded 1 wt% had promoting effect on sintering of magnesia prepared from MgCl₂·6H₂O(AR). While 1.5 wt% LiCl·H₂O was added, the bulk density of magnesia was 3.40 g/cm³, and the relative density was 95.0%. With 0.5 wt% LiCl·H₂O, the bulk densities of magnesia prepared from crystalline bischofite and brine were 3.04 and 3.10 g/cm³, and the relative densities increased by 8.4% and 14.8%, respectively. The main mechanism for promoting MgO sintering with LiCl·H₂O was that Li₂O produced by hydrolysis solubilized in MgO to form solid solutions and oxygen vacancies which were favorable to sintering. The main reasons for promoting sintering of brine magnesia with LiCl·H₂O were solid solution and liquid phase sintering, while the main reason was solid solution for magnesia from crystalline bischofite and MgCl₂·6H₂O(AR).

Abstract: 0.65(K_0.5Bi_0.5)TiO₃0.35BaTiO₃ (KBT-BT3) ceramics were synthesized using a two-step calcination process that combined hydrothermal and conventional calcination processes. After sintered into ceramic target, KBT-BT3 films were deposited on Pt/Ti/Si and SiO₂/Si/Al substrates by radio frequency magnetron (RF) sputtering at various temperatures. The surface morphologies and thicknesses of KBT-BT3 films were characterized by field emission scanning electron microscopy, and the thickness increased with increasing deposition temperature. XRD patterns showed that all KBT-BT3 films were amorphous and higher deposition temperature had no apparent effects to improve the crystalline orientation. The effects of deposition temperatures on the properties of the current-electric filed, polarization-applied electric field, and capacitance-voltage curves were also investigated. As deposition temperatures of KBT-BT3 films increased from room temperature to 400°C, the leakage current density had no apparent variation but the threshold voltage was shifted to lower value. The theorems for the effects of deposition temperature on the properties of KBT-BT3 films were also investigated.

Abstract: protein was extracted from Antarctic krill (AK), then blended with sodium alginate (SA) , prepare the spinning solution, the rheological properties of spinning solution were studied by Brookfield DV-C digital viscosimeter. AKP/SA fibers were prepared via wet spinning with CaCl₂ and PEG as coagulator .The morphology, tensile strength and thermal property of AKP/SA fibers were characterized by polarized light microscopy, monofilament strength tester and thermal gravimetric analysis (TGA) instrument. The result shows that the shear viscosities of spinning solution decrease with the increasing of shear rate and decreasing of concentration. the optimal Preparation Process of AKP/SA fibers were 5% concentration of SA, proportion of 1: 9 for AKP solution to SA solution, and proportion of 5:1 for CaCl₂ to PEG. The cross-section of AKP/SA fiber is a jagged shape. Thermal property of AKP/SA fibers is similar to SA fibers.