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Nano-porous SiO2 insulation material was made from foamed aqueous slurry of nano-silica powder by filter-pressing. The foamed aqueous slurry mainly consists of hydrophobic SiO2 nano-particles, xonotlite whiskers and glass fiber. The latter two will enhance strength of the insulation material. Rheological properties of the foamed slurry with varying solid mass concentration were studied. The effect of forming pressure on the density and pore size distribution of the nano-porous silica material was investigated. It was found that the foamed slurry with solid concentration less than 17% behaves pseudoplastic as decreasing its apparent viscosity with increasing of shear rate during rheological testing. Homogeneous foamed slurry can be obtained when solid concentration in it is below 7%. Such slurry should be dewatered into solid concentration being of 10-15% before filter-pressing. Rigorously stirring of the concentrated slurry is required before pouring it into a mould, which leads to reducing the viscosity of the slurry and helps uniformly filling mould. During pressing the loading speed should be strictly controlled in order to reaching designed pore size distribution in SiO2 insulation material. The SiO2 insulation material with apparent density about 0.45g/cm3 and pore size mainly ranging from 10 to 50nm was obtained.

Porous Si3N4/SiO2/BN composite ceramics with high strength and low dielectric constant were prepared by dry-pressing process and pressureless sintering at 1750°C for 1.5 h in flow nitrogen. The influences of BN content on microstructure, porosity, mechanical and dielectric properties of the porous Si3N4/SiO2/BN composite ceramics were discussed. The results showed that the porous Si3N4/SiO2/BN composite ceramics with porosity ranging from 29% to 48% were fabricated by adjusting the content of BN. The flexural strength of the porous Si3N4/SiO2/BN composite ceramics was 78215 MPa. The dielectric constant of the porous Si3N4/SiO2/BN composite ceramics was 3.9~5 at 1 MHz.

The offshore outsourcing of IT services is more and more important in today’s IT industry. Applying a simple model with two countries, the “North” and the “South”, we analyze the optimal industrial competition policy which is set by a Competition Agency. During the interactions between the “North” and the “South”, a final IT product is provided by the northern oligopolistic firms, who utilize an input processed by the southern oligopolistic IT services providers with lower costs. In the paper, we focus on relations between IT services outsourcing and industrial competition policy. The Competition Agency plays an important role throughout the outsourcing process. The result shows that, by controlling the degree of competition, the IT services outsourcing rents can be appropriated perfectly.

regeneration silk fibroin particles prepared through the dissolving-regeneration route do not fulfill many desired requirements for bio-related applications, due to their partial solubility in water. So, Native silk fibroin powder (NSFP) was prepared by mechanical method to instead of regeneration silk fibroin particles. The goal of this paper is to evaluate the inflammatory response of polyurethane/NSFP composite membrane containing aspirin implanted in mice. The polyurethane/NSFP composite membranes containing aspirin were fabricated by coagulation technique at 30°C. The composite membranes were embedded in mice for 1 weeks and inflammatory response of composite membranes in mice was studied. Inflammatory cells accumulation occurred around implanted polyurethane/NSFP composite membrane, but was reduced significantly in composite membrane containing aspirin. The results indicated that the aspirin released from composite membrane of polyurethane and NSFP could suppress the replication of inflammatory cells and prevent the entering of cells into composite membrane.

The Bi2MnxV1-xO5.5- powders were synthesized by high temperature melting method. The effect of Mn dopant concentration on the crystal structure and chemical composition was studied. The crystal structure was determined by X-ray powder diffraction. The chemical composition was tested by X-ray fluorescence (XRF) and Energy Disperse Spectroscopy (EDS). When x < 0.2 the Aurivillius structure solid solution coexisted with few BiVO4. When 0.2 ≤ x ≤ 0.3 the γ-phase Bi2MnxV1-xO5.5- solid solution with tetragonal structure formed and the maximum Mn atomic content was 2.14%. When x ≥ 0.4 the manganese oxide secondary phase appeared. And when x = 0.8 the Bi7VO13 structure solid solution formed while the Aurivillius structure disappeared.

Porous SiO2 insulation material was made by wet process. Fibrous xonotlite crystal and glass fiber were used as reinforced fibers, and graphite, zirconia and titania powders were added as infrared scattering materials into the porous SiO2 insulation material. The density of the SiO2 insulation material was about 0.3g/cm3. The porosity was about 85%, and the pore size was mainly ranged from 20 to 60 nm in diameter. Heat transfer due to solid conduction and gas convection was reduced greatly because of the existence of larger amount of nano pores. Thermal radiation was partly blocked by the infrared scattering powders. Thermal conductivity of the porous SiO2 insulation material added with graphite powder as infrared scattering powder can reach as low as 0.04W/m.K at 700°C. The type and amount of added infrared scattering powders had important influence on the thermal performances of insulation materials.

BiFeO3-based single-phase multiferroics have been widely studied in both ceramics and films. However, the macroscopic magnetic properties of BiFeO3 ceramics were now most very weak. In this work, MnO2 and Co2O3 were used as B-site substitutes in BiFeO3 ceramics in order to the enhancement of magnetic properties. The change of magnetization was analyzed based on the phase composition and the microstructure of ceramics.

Extrusion gelation freeform fabrication (EGFF) is a new solid freeform fabrication technique to fabricate ceramic parts. The study of ceramic suspensions rheological behavior is essential to a better understanding of parts fabrication through EGFF process. In this paper, the effects of dispersant concentrations, solids loading and binder composition on the rheological behavior of alumina suspensions were examined. The optimal amount of dispersant was found to be about 0.1 wt.%. The suspensions with 50 vol.% alumina and 1wt.% sodium alginate show shear thickening behavior. Such behavior is unfavorable for extrusion gelation freeform fabrication. By addition of PVA or styrene-acrylic latex, the rheological behavior of suspensions was changed. The addition of PVA or latex has a great effect on the viscosity of the suspensions and the type of their rheological behavior. The ceramic suspensions with PVA or latex were found to be shear thinning more suitable for EGFF.

As a good binder for aqueous Al2O3 suspensions tape-casting process, a commercial styrene-acrylic latex binder had been investigated. This paper studied on the rheological behaviors of the suspensions and drying process of aqueous slurries with latex binder system, and the research results indicated the rheological behaviors was affected by pH value, solid loading and dispersant (PAA-NH4) additives; and the drying speed of slurries was most decided by drying temperature and slurry coating thickness.

Piezoelectricity of composite was simulated by employing Dilute Model and Limit Unit method. The analogizing results recommend that the particle stackers influence the properties of piezo-composite. While fabricating piezo-composite, particles stack different with different routine. For thermo-pressing proceeding, stackers trend to take on higher D33 than that processing from forging-membrane.

This paper focuses on the structural change and the thermochromism of the phase transition of the hybrid (C12H25NH3)2FeCl4. The temperature and the structures of the phase transition is investigated by a thermal gravimetry (TG) and differential scanning calorimetry (DSC), an infrared spectra (IR) and X-ray diffraction (XRD) patterns. The UV adsorption spectra account for the thermochromism. The results suggest that the reversible phase transition arises from the structural changes of the organic chains. The thermochromism is presumably due to the electrons redistribution on the levels and to the energy transition to translational and rotational motions of the organic chains.

This paper focuses on the influence of interactions between different species in hybrids (CnH2n+1NH3)2MCl4 (M = Mn, Cu; n =2,4,6,8,10) on the structural stabilities. DSC-TG curves were used to find out the onset and the end decomposition temperatures. The results show that the hybrids of M =Cu start to decompose at about 210 centigrade degrees, average 25 centigrade degrees lower than that of M=Mn. The end temperatures of M=Cu are also lower. This suggests that in this case the thermal stabilities of the hybrids would be governed by the interactions between the organic and inorganic species and are little affected by weak Van de Waals interactions between the organic and organic species.

A new method, which allowed lamination at room temperature without any additional adhesive, was described in this paper. A low Tg styrene-acrylic latex binder was used to forming the green tape via a water-based slurry. The green tapes could adhere to each other at room temperature under low or slight pressure. The density and deformation of laminated green parts depended significantly on lamination pressure, but the density of green parts did not increase after the lamination pressure exceeded a specific value of 4MPa. The interface between the tapes had been investigated in the green and sintered state by SEM. The experimental results showed that the microstructure of interface and density of lamination ceramics was a function of fraction of binder, plasticizer, and laminated pressure.

Extrusion gelation freeform fabrication process is an extrusion-based freeforming technique capable of fabricating complex shaped monolithic ceramic prototypes by the sequential deposition and solidification of ceramic suspensions from a computer aided design model. In this process, ceramic parts are produced using an extrusion nozzle suitable for extruding ceramic suspensions. In this study, the processing parameters influencing on manufacturing Al2O3 parts were discussed. Air pressure on top of suspensions, rotating speed of screw, nozzle diameter and scan speed are the main factors to influence the dimensional precision of ceramic bodies. By optimizing these processing parameters, the green bodies were fabricated with high precision. The sintered samples with homogenous microstructure and ~97.6% relative density could be prepared by sintering of these green bodies at 1600oC for 2 hours.

By means of a finite element method model, the effects of property parameters of refractory on thermal stress of injection lance have been studied. The results show that the maximum thermal stress increases with the improvement of thermal conductivity and elastic modulus of refractory, while it decreases at first and then increases with the improvement of the coefficient of expansion of refractory.