Advanced Materials Research Vol. 508

Abstract: Titanium substituted SBA-15 mesoporous materials have been prepared by direct synthesis under hydrothermal conditions. Ti-SBA-15 was prepared by TiCl₄ and Tetrabutyl titanate (TPOT) as titanium precursor. The synthesized materials were characterized by X-ray diffraction (XRD), UV-Vis spectrometer (UV-Vis), N₂ adsorption/desorption, SEM etc. The results exhibited that the synthesis of mesoporous materials are ordered, and Titanium is tetrahedral and highly dispersed through the inside of SBA-15. Spherical particles of mesoporous have been synthesized by TPOT. The mesoporous materials synthesized by TiCl₄ had non-uniform particle morphology. The titanium precursor TPOT incorporation in SBA-15 makes surface area increase due to make the pore walls slimmer. The titanium precursor TiCl₄ had great influence of the particle morphology and pore characters and no influence on crystal structure.

Abstract: 0.1%Tb³⁺ and 0.2%Sm³⁺ co-doped TiO₂ have been prepared by sol-gel method and characterized by the techniques such as XRD and SEM/EDAX. The photocatalytic degradation of Methylene blue in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The effects of process parameters like, pH and initial methylene blue concentration on the extent of photodegradation have been investigated. The results show when the solution is at pH 7, with initial methylene blue concentration of 4 mg/L, the photodegradation is best. Key words:

Abstract: Microbial leaching was used to mobilize copper from two kinds of waste electronic scraps used as raw materials for printed wire boards. Both of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans used to solubilize copper from the samples. The experimental results demonstrated that the percentages of copper basically increased with decrease of sieve fraction of the samples. The green non-conductive coating of the waste electronic scraps was proved to have little effect on the leaching efficiency of both of the pure culture of Acidithiobacillus ferrooxidans and Acidithiobacil thiooxidans or their mixed culture. Acidithiobacillus ferrooxidans has larger solubilizing capability for copper than Acidithiobacillus thiooxidans.

Abstract: A new molten steel end temperature prediction model is built employing LS-SVM. To seek the optimal parameters of regularization parameter γ and kernel parameter σ in LS-SVM, an PSO algorithm is also proposed. To test the proposed predictor, the prediction model is applied on practical data from Fujian Sangang steelmaking collected in 100t BOF, and the validation is carried on the performance of the prediction. The model overcomes the blindness and the burden in time consuming of cross validation method, and at the same time, inherits the strong learning ability from small sample and the characteristics of simple calculation of LS-SVM. In the LSSVM optimized by PSO test cases, the Maximum Absolute Error (MAE) and the Root Mean Squares Error (RMSE) are the lowest, and the Pearson Relative Coefficient (PRC) is the highest. The results suggest that the LS-SVM optimized by PSO model can be extended to end-point judgment applications in achieving greater forecasting accuracy and quality.

Abstract: Controlled grafting of S-1-(1-naphthyl) Ethylamine-imprinting polymer layer on the silica-gel was carried out by the surface-initiated atom transfer radical polymerization (ATRP). Polymerization time was used as the independent variable to manipulate the amount of grafted imprinting polymer on the silica-gel. For comparison, molecularly imprinted polymers (MIPs) without silica-gel also prepared at the same condition. SEM, FT-IR and UV spectrum were used to study the structural morphology and selectivity of polymers and probe the incorporation of imprinted polymer layer on the surface of substrates. Results indicate that the integration of ATRP and molecularly imprinted polymerization realize preparation of molecular selective polymers and it is possible to tune selectivity and morphology in rational way by changing polymerization times. Meanwhile, we achieve a reference strategy for the development of molecularly imprinting polymer for drugs and to handle forms in certain applications such as chromatographic stationary phases for chiral separations.

Abstract: The lunar surface is covered with the deposit of regolith which is loose and dry powder. In the earth condition, the mechanical properties of lunar soil simulant from eruption powder will greatly influence the precision and reliability of the rover test results. This article measures the parameters by means of the vertical load which is representing the pressure generated by vehicle wheel, and the formula of vertical pressure-sinkage relationship: p=[k_с/b+k_φ]*zⁿ. It was discussed that the value of n, k_с, k_φ changed under three different velocities and four different radiuses of circular plates. Because these parameters are sensitive to bulk density of lunar soil simulant, the paper could only discuss the range of k_сk_φ and n, and the results of the measurement are n= 0.698~ 1.123, k_с= 0.524~ 5.928, k_φ= 0.124~ 1.926. The lunar soil will make the poor trafficability for lunar rover. This article could provide basis and criterion for evaluation rover behavior at the surface of moon and design the wheel parameters of lunar rover.

Abstract: LY12 aluminum alloy samples were treated by microarc oxidation in sodium metasilicate electrolytes. The effects of treatment time on cell violate and ceramic coating thickness were investigated. The results indicate that the micro-arc oxidization process was divided into two stages, at the first stage, the cell voltage increased linearly at a very high rate of 70 V/min, at the second stage, in the range of 430-470 V, the cell voltage reached a relative stable value. The thickness of the coating increased linearly at the whole stage with increasing treating time. XRD analyses indicate that the ceramic coatings fabricated on the surface of aluminum alloys by micro-arc oxidization are composed of Al phase Al2O3 phase. SEM show that the maximum porosity of the ceramic coatings with distributing uniformly pore diameter are decreased with the increasing treatment time.

Abstract: The morphology of typical carbon materials including granular graphite, carbon nanotubes and graphenes was observe by scanning probe microscope (SPM). When water is used as the dispersants for preparing observing samples of the above carbon materials, the typical morphology characteristics of spherical graphite, curved carbon nanotubes and graphene sheets are distinctly exhibited by SPM. However, for graphene materials, when alcohol or dimethylformamide (DMF) is used as dispersants, the quality of SPM images becomes poor. The interaction between the dispersants and materials should be responsible for these observation results.

Abstract: In order to select best filtration velocity of bag filters and to improve gas flow distribution, to increase collection efficiency and to reduce operation resistance, gas flow distribution was tested by using hot-wire anemometer, CFD simulation was made and basic accordant result was obtained by comparing simulation result with experimental result. Test results and analysis showed that: Uneven distribution of flow field was caused by jet flow, critical filtration velocity exited in flow field distribution. Improving measure of flow field and optimize method of bag filter structure was putted out.

Abstract: Pure BiVO₄, single doped and co-doped BiVO₄ have been prepared by chemical precipitation method and characterized by the techniques such as XRD and SEM/EDAX. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate pure BiVO₄, single doped BiVO₄ and co-doped BiVO₄ photocatalytic activity. The results show that doping of single doped and co-doped significantly enhance the photocatalytic activity of BiVO₄. When the 0.1%Gd³⁺ and 0.2%Sm co-doped, the BiVO₄ degradation rate reaches 91%.