In the present paper, magnesium dititanate (MgTi2O5, M2T) was introduced into aluminum titanate (Al2TiO5, AT) to form AT-M2T solid solution so that the thermal shock resistance of Al 2TiO5 could be kept still good whi...
详细信息
In the present paper, magnesium dititanate (MgTi2O5, M2T) was introduced into aluminum titanate (Al2TiO5, AT) to form AT-M2T solid solution so that the thermal shock resistance of Al 2TiO5 could be kept still good while without any decomposition. The effect of MgTi2O5 addition on thermal shock resistance of Al2TiO5 was investigated. The experimental results showed that the thermal shock resistance of Al 2TiO5 began to decrease when a little amount of MgTi 2O5 was added and then rose with the continuous addition of MgTi2O5, even overrunning that of pure Al 2TiO5 when 30mol% MgTi2O5 was contained. It was found that fine solid solution was formed between Al 2TiO5 and MgTi2O5, which enhanced the thermal shock resistance of Al2TiO5.
Highly oriented plate-like rod/tube arrays of ZnO arc synthesized by a solution-based approach at low temperature. The ZnO rod/tube arrays grow oriented vertically on silicon substrate and the intersectant ZnO nanoshe...
详细信息
Calcium carbonate particles with different morphologies were fabricated by the precipitation reaction of sodium carbonate with calcium chloride in the absence and presence of the copolymer poly (styrene-alt-maleic aci...
详细信息
Calcium carbonate particles with different morphologies were fabricated by the precipitation reaction of sodium carbonate with calcium chloride in the absence and presence of the copolymer poly (styrene-alt-maleic acid) (PSMA) at 80°C, respectively. The as-prepared products were characterized with SEM, XRD, Infrared and BET surface areas. The results showed that the pH of solution and the concentration of PSMA and CaCO3 significantly influenced the morphologies of CaCO3 particles. Various crystal morphologies of calcium carbonate, such as plates, rhombohedras, rods, ellipsoids, dumbbells, peanuts, spheres etc., could be obtained depending on the experimental conditions.
As has been discussed, research on the electronic structure between organic and inorganic atoms in hybrid compounds has become important. In our study, DV—Xα method was employed to calculate the electronic structure...
As has been discussed, research on the electronic structure between organic and inorganic atoms in hybrid compounds has become important. In our study, DV—Xα method was employed to calculate the electronic structure of the hybrid compound. The information obtained from the calculation included orbit charge, bonding order, Fermi energy, density of the state, etc. The influence of organic and inorganic parts on the energy band structure of the hybrid compound was discussed based on the calculation results of Fermi energy and density of state. The chemical bonding between organic and inorganic parts in the hybrid compound was also analyzed in detail according to the orbital charges and bond orders.
With the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM),thermal gravimetry (TG) and differentia...
With the preparation of organic-inorganic layered perovskite-type compounds (C4H9NH3)2MCl4 (M = Mn, Cu) in solutions, X-ray diffraction (XRD), scanning electron microscopy (SEM),thermal gravimetry (TG) and differential scanning calorimetry (DSC) have been used to characterize the obtained powders. XRD patterns demonstrate that the two compounds have obvious layered structures and SEM pictures reveal that both (C4H9NH3)2MCl4 and (C4H9NH3)2CuCl4 take on obvious sheet-like microstructure. TG&DSC curves indicate that (C4H9NH3)2CuCl4 decomposes at much lower temperature than (C4H9NH3)*** is ascribed to weakening interactions between its organic and inorganic components, which is presumably due to the Jahn-Teller distortion of [CuCl6] octahedra.
In liquid composites molding (LCM) processes,a gap between the perform and the mold edge can create a preferential flow path for the resin, which is the so-called edge effect. The resin flow behaviors in different gap...
详细信息
In liquid composites molding (LCM) processes,a gap between the perform and the mold edge can create a preferential flow path for the resin, which is the so-called edge effect. The resin flow behaviors in different gaps were studied by the unidirectional flow method together with the equivalent permeability tensor of flow path computed by two geometric models. In addition, the filling process was simulated to predict the influences of edge effects on the flow pattern. It is found out that even small gaps would disturb the edge flow. The simulation shows good agreement with the experiments.
The influences of sintering temperature, soaking time and annealing time on the quality factor of Ba(Mg/13Nb2/3)O3 microwave dielectric ceramic were investigated. The result showed that Qf value increased as the sinte...
详细信息
The influences of sintering temperature, soaking time and annealing time on the quality factor of Ba(Mg/13Nb2/3)O3 microwave dielectric ceramic were investigated. The result showed that Qf value increased as the sintering temperature increasing. It was ascribed to the increasing of the relative density and ordering parameter S. The maximum value of Qf, 49500 GHz, was gained at 1550°C. With soaking time increasing, Qf value increased. The increasing of B-site 1:2 ordering degree and grain size should be responsible for the improvement of Qf value. When soaking time was 16 h, Qf value reached 58000 GHz. Annealing time had great effect on Qf value. With annealing time increasing, Qf value increased quickly. This was because of the improvement of B-site 1:2 ordering caused by annealing. A high Qf value, 71500 GHz, was acquired when annealing time was 48 h.
technology trends in today's cooperative design environments are making it more and more important to monitor the network performance and ensure the network security. This paper describes the design and implementa...
详细信息
ISBN:
(纸本)184000025
technology trends in today's cooperative design environments are making it more and more important to monitor the network performance and ensure the network security. This paper describes the design and implementation of a distributed network traffic monitoring system based on embedded NetFlow hardware and software engines. The system architecture and design principles were introduced in the paper, some discussions were also presented about the NetFlow-based network monitoring technologies. The system had been successfully used to monitor highspeed campus networks at full wire speed without packet sampling in scenarios where commercial NetFlow collectors could not be used due to their limitations. Results show that this is an effective mechanism to identify, diagnose, and determine controls for network activities in CSCW environments and other network-based applications.
In 2003, a joint research project entitled "Nano and graded thermoelectric materials/Photovoltaic-thermoelectric-wind power generation" is established in cooperation among research institutes from Japan and ...
详细信息
ISBN:
(纸本)0878499709
In 2003, a joint research project entitled "Nano and graded thermoelectric materials/Photovoltaic-thermoelectric-wind power generation" is established in cooperation among research institutes from Japan and China. The major research institutes include statekeylaboratory of advancedtechnology for materialssynthesis and processing (Wuhan University of technology, China), Shanghai Institute of Ceramics (Chinese Academy of Sciences, China), statekeylaboratory of New Ceramics and Fine processing (Tsinghua University, China), Japan Aerospace Exploration Agency (JAXA, Japan) and Foundation for Promotion of Japanese Aerospace technology (JAST, Japan). The main aim of this project is to develop a photovoltaic-thermoelectric-wind power generation system with high efficiency solar energy conversion. The key works of the project include: (1) fabrication of high efficiency nano thermoelectric materials with a maximum figure of merit Z≥ 1.3;(2) design and fabrication of nano graded thermoelectric material/component with efficiency conversion larger than 12% for wide temperature range and (3) design and construction of photovoltaic- thermoelectric coupled power generation system. The recent progress about the joint research project is reported in this paper. Emphasis is put on the mechanism, design and fabrication of high efficiency nano graded thermoelectric materials. The future research plan is also mentioned in brief.
In this paper, transparent Li2O-Al2O 3-SiO2 system glass-ceramic with low expansion was prepared by melting method, using SiO2, Al2O3 Li2CO3 as raw materials, a small amount of alkaline-earth metal oxide, clarify addi...
详细信息
In this paper, transparent Li2O-Al2O 3-SiO2 system glass-ceramic with low expansion was prepared by melting method, using SiO2, Al2O3 Li2CO3 as raw materials, a small amount of alkaline-earth metal oxide, clarify additive and nucleating agent (TiO2, ZrO 2). The glass-ceramic was nucleated and crystallized under different temperature and time, according to the DTA. The results show that the glass-ceramic of Li2O-Al2O2-SiO2 system could be obtained by being nucleated at 550°C for 2 hours and crystallized at 550°C for 1 hour. The system was fully compact. The crystal size in the glass-ceramics was small and homogenous, and its main crystalloid was β-quartz. The expansion coefficient of the glass-ceramics was 2.262×10-7/°C(0 [similar to] 900°C)and the density was 2.5 g/cm3.
暂无评论