Papers by Author: Gang Xue

Abstract: A series of rare-earth composite catalytic material LZ1,LZ2 and LZ3 that contains mixture of La_0.9Sr_0.1Co_0.5Mn_0.5O₃ and Ce_0.7Zr_0.3O₂ in different proportion (3:7, 5:5, 7:3) were prepared by a sol-gel method and characterized by X-ray diffraction (XRD), specific surface analysis (BET) , Transmission electron microscopy (TEM) and temperature programmed reduction (TPR). The results indicated that in LZ3, a perfect crystal structure of perovskite and a cubic fluorite structure were formed. Besides LZ3 presented scattered spherical granules with a particle size of about 30 nm and a specific surface area of 20.9870 m²/g. The temperature of reduction peak was lowest (490°C) and peak area was larger, so it had the best catalytic activity for methane combustion.

Abstract: The main properties of tourmaline are far infrared radiation, spontaneous polarization, widely used in the fields of saving energy and environment. Tourmaline as catalyst have extensive applications in the fields of environmental protection, fuel combustion, air purification, printing, deodorant, antibacterial, as well as wastewater treatment of dyeing and aquaculture.

Abstract: The tourmaline-based composite materials as an effective thermal coating of heat exchanger unit were prepared from natural mineral tourmaline, transition metal oxides and carbon nanotubes. The far infrared emission properties and heat emission performance were studied. The results indicated that thermal performance of materials can be adjusted with the chemical composition of materials, and when the mass percentage of carbon nanotubes is 10%, the fractional of 26.77% of energy saving efficiency can be achieved.

Abstract: A series of rare earth perovskite-type oxides La₀₉Sr_0.1Co_0.9Mn_0.1O₃La₀₈Sr_0.2Co_0.8Mn_0.2O₃ and La₀₅Sr_0.5Co_0.5Mn_0.5O₃ were prepared along the sol-gel method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy techniques (TEM) and catalytic activity measurement for combustion of CH₄. The results indicated that a perfect crystal structure of perovskite was formed and La³⁺ and Co³⁺ ions were partly replaced by Sr²⁺ and Mn³⁺ ions, respectively, and perovskite-type oxides were composed of nanocrystals with particle size of 20~50nm. The catalytic activity for the combustion of CH4 was evaluated and La₀₅Sr_0.5Co_0.5Mn_0.5O₃ exhibited best performance with the temperature of 50% and 90% conversion efficiency of 723K and 833K.

Abstract: A series of rare earth perovskite-type oxides La0.9Sr0.1CoO3, La0.9Sr0.1MnO3 and La0.9Sr0.1Co0.5Mn0.5O3 were prepared by sol-gel method and characterized by X-ray diffraction (XRD), specific surface analysis (BET), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) techniques. The results showed that for La0.9Sr0.1Co0.5Mn0.5O3 sample, Sr2+ and Mn3+ ions partly replaced La3+ and Co3+ ions and entered perovskite crystal lattice, and finally a perfect crystal structure of perovskite was formed. Moreover, these powders presented sphericity granules with particle size of about 20nm and satisfactory pore structure. With the doping of Sr2+ ions in a certain range, the coexisting system of Mn3+- Mn4+ and Co3+- Co4+ as well as the concentration of oxygen vacancies were increased, thus leading to the higher catalytic activity of the prepared catalysts.

Abstract: Experimental device and principle were proposed with the aim of giving a method to evaluate energy efficiency of heat emission coating in this paper. The formula for calculating energy saving efficiency of heat emission coating was given based on heat dissipating capacity obtained. The results showed that the method was effective for evaluation of energy efficiency of heat emission coating with an error of 0.32%.

Abstract: The far infrared radiance tourmaline composite materials have been successfully prepared. From the XRD results, the composite materials were composed of tourmaline and transition metal oxides（Fe2O3, MnO2, Co2O3）and cerium oxide. Under SEM, the spherical particles of transition metal oxides were adsorbed by the flake particles of tourmaline. The composite materials show relatively high far infrared radiance than tourmaline and the mineral composite materials with smaller unit cell volume exhibits higher infrared radiance

Abstract: The powders of mineral materials with far infrared radiation (CTTP) were prepared using rare earth cerium nitrate, tourmaline and transition metal oxide by coprecipitation, and calcination at 1073K for 3h. The inorganic-organic mineral composite materials with far infrared radiation (CTTR) were prepared from CTTP and resin according to the weight ratio of 4:6. It was found by characterization with scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscope (FTIR), that the infrared radiance of the CTTR was 93%. The effects of the CTTR on the surface tension and the kinematic viscosity of diesel oil as well as the effects of the CTTR on oil consumption and air pollutant emissions of oil-burning boiler were investigated in this paper. The results showed that the diesel oil dealted with the CTTR resulted in the strengthenty of molecular movement and the decrease of intermolecular contacts. In laboratory, the surface tension of diesel oil was reduced from 27.287 to 27.254 mN/m and the kinematic viscosity of diesel oil was reduced from 2.85 to 2.81 mm2s-1. The oil-saving rate of the RBS•VH-1.5 boiler treated with the CTTR could reach 4.57%, and the reducing rates of CO and NO in the exhaust gas were 1.30 and 4.08%, respectively.