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60wt%Fe2O3/Al2O3 oxygen carriers were prepared by different methods and characterized by means of XRD, H2-TPR, infrared gas analyzer. The effects of preparation methods on the structure and activity of Fe2O3/Al2O3 oxygen carriers for chemical looping combustion of methane were also investigated. The factors on the selectivity of CO2 in the chemical looping combustion process at different reaction temperatures were discussed. Methane can be quickly converted to CO2 and H2O with high selectivity at 850°C for 15 min. After redox cycling in alternant methane/air atmosphere for 30 times, the formation of CO2 was enhanced, indicating higher activity of oxygen carrier after the redox experiment.

Single-phase β-Sialon ceramic compacts with z=2 have been synthesized by reaction-bonded sintering using Si, Al and Al2O3 as raw materials. After post-sintering at 1550℃ for 2h, only β-Sialon ceramic compacts with z=2 was obtained. When the temperature up to 1650℃ and 1750℃, the decomposition reaction of samples was occurred.

The Si¬2ON2-SiC ceramic was fabricated by pressureless sintering method. In this paper we researched the effect of SiC content (50%, 70% and 90%) on the performance of silicon oxynitride bonded silicon carbide ceramics. Through testing and analyzing the SEM, XRD, density and porosity of the final silicon oxynitride bonded silicon carbide ceramic samples, the results show that: changes in SiC content not only affect the bulk density of the composites but also affect the phase composition and the microstructure of fracture surface. The most compactness experimental product is sintered at1500℃ containing 50wt% SiC.

In this paper, nano-Fe3O4 as sorbent was used to remove Congo red dye from aqueous solution, in order to investigate its adsorption properties. Fe3O4 nano-particles were synthesized by hydrothermal method, and were characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Powder Diffraction (XRD) to examine their size, morphology and property. The adsorption and removal of Congo red dye from aqueous solution on nano-Fe3O4 was studied in batch equilibrium experiments. These results showed an excellent adsorption capability for Congo red with a maximum adsorption capacity of 1395mg•g-1 at 20℃ and pH2.0. It indicates that Fe3O4 nano-particles can be effectively used to remove color from wastewater containing dyes.

(1-x)KNbO3-xBaGeO3 based PTCR ceramic materials are prepared using high purity K2CO3, Nb2O5, GeO2, Al2O3 and BaCO3 powders as starting materials, and the structural and electrical properties have been investigated. The results indicated that the samples doped with minute Ba as donor show excellent PTCR effect above the temperature of about 36℃. For the 0.40at% Ba-doped sample, the minimum resistance of 4.2×104Ω·cm, temperature coefficient (αk) of 24.37%/℃, PTCR anomaly lg(Rmax/Rmin) of 3.82 and transition temperature (Tmin) of 36℃ are obtained.

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 ℃, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 ℃ the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 ℃

In this paper, Nb-doped BaTiO3-(Na0.5Bi0.5)TiO3 (BBNT-Nb) based PTCR ceramic material has been prepared using high purity Nb2O5, Bi2O3, Na2CO3, TiO2 and BaTiO3 powders as starting materials, and its structural and electrical properties are investigated. The results indicated that the Nb2O5 dopant is helpful not only to promote the formation of tetragonal BBNT structure without any second phase, but also to decrease the room-temperature resistivity. For the 0.10at% Nb-doped BBNT material with BNT content 35mol%, the properties of room-temperature resistance of 104Ω·cm, temperature coefficient (αk) of 6.3%/℃, PTCR anomaly lg(Rmax/Rmin) of 3.6 and Curie temperature (Tc) of 193℃ are obtained.