Papers by Author: Ai Hong Guo

Abstract: In this paper, thermal barrier materials of mullite whiskers made by kyanite is studied, take -325~+400 mesh kyanite as raw material, the firing conditions is that nucleation temperature is 1150°C and crystallization temperature is 1250°C; the adding method of catalyst (AlF₃) is external additive. After the orthogonal experiment, it is determined that the effects order on products of raw material granularity, heating rate and catalyst addition is raw material granularity > catalyst addition > heating rate, and the best experimental conditions is obtained.

Abstract: Prepare TiO₂ doped with ZnO or Fe₂O₃ composite photocatalytic film by using sol-gel method and characterize its microstructure and light absorption performance with X-ray diffraction instrument (XRD), scanning electron microscopy (SEM) and UV-visible spectrophotometer. The results show that: particles of TiO₂ doped with Fe₂O₃ composite photocatalytic film are uniform and well dispersed; the rough surface of the film has a certain gap which is helpful for the adhesion of gas and liquid; the diameter of the particles is about 50 nm. The crystal grain size of TiO₂ film doped with ZnO is bigger, about 100 nm; the gap of the film is less and particles are nearly spherical and protruding, the shape of grain is structured. The absorption spectrum of TiO₂ doped with ZnO or Fe₂O₃ has a red shift and both of their absorption intensity is higher than that of pure TiO₂ film in the scope of the ultraviolet and visible region.

Abstract: In order to broaden the utilization of desulfurization gypsum in China and achieve the direct usage of desulfurization gypsum, in this paper, Polycarboxylic acid water-reducer (HC), Naphthalene sulfonate formaldehyde polycondensate (NF) and Sulfonated melamine formaldehyde resin (SM) were selected as water reducer to modify desulfurization gypsum. The experiment results are as follows: SM water reducer has little effect on setting time of desulfurization gypsum, although it is helpful to increase the strength of the gypsum-sample, however, compared with HC and NF, it has no obvious effect. About HC water reducer, it has obvious effect on setting time of desulfurization gypsum, so does it to desulfurization gypsum strength, but, higher water using of normal consistency will do adverse effect on the whole with the increase of the dosage. NF water reducer has the similar effect on setting time and sample's strength on desulfurization gypsum with HC, but the dominant changes have no discipline among different mixing amounts with these two water reducer. Lower water using of normal consistency benefits the retention of the sample's strengths.

Abstract: Lithium-ion secondary cell has high energy density, stable and high working voltage, wide working temperature and long working term. It is a safe and clean energy resource without pollution. At present, Lithium Hexafluorophosphate is used as conducting electrolyte lithium salt in lithium-ion secondary batteries. But Lithium Hexafluorophosphate as conducting electrolyte lithium salt has some disadvantages such as hydrolysis and instability. Lithium Bis (heptafluoroisopropyl) t-etrafluorophosphate Li [(C₃F₇)₂PF₄] was received by simons process from diisopropylchlorophosphane in this paper. As electrolyte of Li ion secondary cell, Li [(C₃F₇)₂PF₄] had lower vapor pressure than LiPF₆ in the solvent in the same temperature, comparable conductivity and oxidation stability in the same concentration in room temperature. It was worth mentioning that Li [(C₃F₇)₂PF₄] has excellent stability towards hydrolysis. The synthesis process is safe and easily controlled.

Abstract: The silica-alumina-pillared rectorite materials (SiAl-REC) were developed a novel method, which combined several techniques such as ion-exchange, intercalation and surfactant modification. The morphology, composite structure and pore properties of such composite materials, were investigated by X-ray powder diffraction (XRD), Fourier-transform infra-red (FTIR) spectra, as well as Nitrogen Adsorption-Desorption Isotherms. The layer structure of the prepared materials retained and their pore structures were found to be slit-shaped pores located between plate-like particles. The prepared SiAl-REC materials had a BJH pore volume of 0.65cm³ g-1, a remarkably high BET specific surface area940m² g^-1 and a narrow pore size distribution in the mesoporous region 4.3 nm after thermal treatment at 600 °C.

Abstract: The acid dipping-plating pretreatment was applied on iron substrate prior to no-cyanide copper plating process. After being pretreated in dipping solution, the thin copper film formed on iron substrate which could change the cathode electronic potential and enhance the copper plating rate in the follow-up copper electroplating. As a comparation, the iron substrate was directly electroplated in another copper plating bath without dipping-plating pretreatment (DPr). The effects of temperature and electric current density on the copper plating rate were investigated in both process with DPr and process without DPr. And the mechanism was discussed.

Abstract: Landscape characteristics and dynamics change are studied based on RS and GIS from 1993 to 2007. The results show that there is a big change in Tangshan Nanhu wetland subsidence in the last 15 years. Construction land, water bodies, woodland regional landscape pattern instead of the landscape of construction land and farmland. The change is caused by mining production and land reclamation activities mainly. Take the forest cover index, grass cover index, wetland index, index of landscape heterogeneity, landscape diversity, biological abundance index and Poor index of ecological as assessment index, use analytic hierarchy process to determine the weight of indexes, evaluate Nanhu area eco-environmental quality. The results show that: From 1993 to 2000, there is a slight decline in environmental quality; and since 2000, environmental quality has become better and better.

Abstract: Water-based infrared ray shielding coating, that is, nanometer metal oxide is added to the water-based paint, which has anti-IR features without affecting the transparency of the paint. In this paper, the nanometer oxides are prepared by sol-gel method, added into polypropylene sour. In order to improve the infrared ray shielding of the thin film, two kinds of nanometer oxides are added into the polypropylene sour with different volume ratios, the shielding performance of the paint is studied. Experimental results show: in the 8000 ~ 4000cm^-1 range, the transmittances of infrared ray is 30% to 75%; in 4000 ~ 400cm^-1 range, transmittances decrease significantly; 3% ZnO, 3% Fe₂O₃, 3% Y₂O₃, 2% Al₂O₃ are the best mass ratio of every single nanometer oxide; the infrared shielding rate of Fe₂O₃ and Y₂O₃ mixture with the volume ratio of 1 to 4 is better than Fe₂O₃ and Y₂O₃ single.

Abstract: Al-pillared rectorites (Al-REC) were synthesized from naturally occurring rectorite through exchange of interlamellar ions with hydroxyalumina polycations. Furthermore, Powder X-ray diffraction (XRD), Nitrogen adsorption-desorption isotherms, and Transmitting electronic microscopy (TEM) were applied in order to study the themal stability and hydrothermal stability of pillared materials. The Al-REC are thermally stable up to 800 °C. X-ray diffractograms of Al-REC calcined at 800 °C show a sharp and intense d001 peak, corresponding to a basal spacing of 2.75nm. In a 100% steam flow under atmospheric pressure at 800 °C for 20h, the characteristic d001 spacing of Al-REC decreases from 2.74 to 2.52nm, the sharp and intense d001 peak is still observed. And micropore area, mesopore volume and micropore volume retain 62, 33 and 67%, respectively, which affirms that this pillared clay has exceptional hydrothermal stability.

Abstract: It is a method of preparing hypophosphorous acid with electrodialysis. It comprises Ti-PbO2 anode, an insoluble cathode and an aqueous solution of hypophosphite anions in six-compartment electrolytic cell. The direct current, through the insoluble anode to cathode in electrical contact with the aqueous solution to generate H+, forms hypophosphorous acid solution. In this paper, the best term of different factors about the experiment was studied. The best condition was to keep the NaH2PO2 concentration between 300 and 500g/L, current value 3.0A, reaction time 12-18 h. The process is simple, low cost and highly efficient, which is a cleaner production without waste residue and waste water.