Advanced Materials Research Vols. 156-157

Abstract: The influence of the mixed rare earth metal, Lathanum and cerium, as an alloying additive on the electrochemical behaviour was studied by means of self-depassivation, linear sweep voltammetry and a.c. impedance spectroscopy in 1.28g/m3 H2SO4 at 250C. Studies on Pb-Ca-Sn-Al-Ag-La-Ce alloys indicated the mixed La and Ce can refined crystal grains, inhibit the hydrogen evolution and oxygen evolution, and improve the corrosion-resistance performance. So the mixed La and Ce can prolong life of electric vehicle batteries.

Abstract: During the research of the modification theory of toroidal worm-gearing, new theory of modification of toroidal worm-gearing is discussed. This paper mainly gives the proving process of the curvature modification formula[1] in theory. Accordingly, the principle of curvature modification is established.

Abstract: In order to improve the water-solubility of chitosan, N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (quaternary chitosan) was synthesized by the heterogeneous reaction between glycidyl-trimethyl-ammonium chloride and chitosan. The quaternary chitosan was then applied to Antheraea pernyi (A. pernyi) silk filaments/fabrics in the presence of 1,2,3,4-butane tetracarboxylic acid (BTCA). The structure and properties of A. pernyi silk before and after treatment were studied. It was found that the quaternary chitosan treatment contributed to enhance the mechanical properties including breaking strength, breaking elongation, initial modulus, rupture work and wrinkle-resistant performance of the A. perny silk filaments. When dyed with acid dyes, the dyeing uptake and shade depth of the quaternary chitosan treated A. perny silk fabrics were greatly improved.

Abstract: Although enzyme-assisted aqueous extraction processing (EAEP) is an environmentally friendly alternative technology to hexane extraction of soybean oil，it’s application is limited by enzyme price. This processing employs microbial fermentation to extract oil and protein from a variety of pretreatment full fat soy flours, and optimizes the fermentation conditions using the Response Surface Methodology (RSM). The results showed that extrusion combination with wet- thermal treatment were beneficial to improving oil and protein extraction, and total oil extraction yield achieve the highest value 95.1% at 7.4% extruded full fat soy flour, 5.4% inoculation volume, the initial pH8.4. At this condition, protein extraction yield reached to 86.1%. These advances make the microbial fermentation extraction processing attractive channel as the front-end of a soybean biorefinery.

Abstract: This paper establishes the simulation error data models of roundness error, spindle rotation error and noise signal from the characteristics of error signal based on three-point method. From the Matlab simulation, the influence of installation angle error of the sensor, roundness error magnitude and the noise on the segregation accuracy was studied in detail. This makes up the deficiencies of previous studies, and also provides a good foundation for further improving the accuracy of three-point method.

Abstract: A new inorganic polymer coagulant，ploy-high-ferric-silicic coagulant with various Si/FeO42- ratios and salt-basicity, was prepared using the fly ash extract and potassium ferrate. The influence of both Si/FeO42- ratios and salt-basicity on the complexation process was explored with many analytical methods, such as transmission electron microscope (TEM), lased particle size analysis (LPSA) and infrared spectrum (IR). The results show that the ploy-high-ferric-silicic is a complexation compound, instead of a simple mixture of raw materials. The complexation process between Si and Fe may be different from various Si/FeO42- ratios and salt-basicity. The bonding can help revealing the high-ferric groups function in synthesis process. From analyzing the different ferrosilicon bonding modes, it can provide some theoretical basis to compound high-ferric coagulant.

Abstract: Mesoporous carbon (MC) materials with wormhole-like mesopores were prepared and incorporated into the polymer gel electrolyte comprising of polyvinylidene fluoride and 1-methyl-3-hexylimidazolium iodide. These gel composites were employed as the electrolyte for quasi-solid-state dye-sensitized solar cells. The photovoltaic performance of the quasi-solid-state dye-sensitized solar cells improved through incorporating MC into electrolyte. The dye-sensitized solar cell with composite gel electrolyte containing 3 wt% MC achieved the best photovoltaic performance, and the corresponding open-circuit voltage, short-circuit current density, fill factor and overall conversion efficiency were 0.59V, 13.22 mAcm-2, 0.66 and 5.15%, respectively. The stability of dye-sensitized solar cells with composite gel electrolyte was found to be far superior to the cell with organic liquid electrolyte.

Abstract: A problem solving strategy based on practical engineering projects in physics has been developed. The survey shows that 85% of the students think this strategy can help them improve self-directed learning skills, their communication skills and problem solving skills in their learning process.

Abstract: In this work, the variational trend of the stresses for the diesel engine piston under the operation conditions is analyzed by using finite element method (FEM) and the fatigue strength of the diesel engine piston is evaluated. The muhiaxial stress was converted into the uniaxial stress with the maximum principal stress method, and the material curve is amended by Goodman’s amendment. Finally the fatigue life and the fatigue safety factor of the diesel engine piston is obtained, which provides a better reference for structural improvements and optimization for the design of the piston.

Abstract: Composites of phenol formaldehyde (PF) resin/graphite reinforced by milled carbon fibers (MCFs) for bipolar plates are obtained by hot compression molding. The raw materials of the MCF particles, PF resin powder and graphite powder are simply dry powder ball milled and mixed. The effects of PF resin content and the content, granularity and surface treatment methods, such as air oxidation and Fenton/ultraviolet (UV) liquid-phase oxidation of MCFs on the electrical conductivity and flexural strength of the composites are measured by methods of four-point probe technique and three point flexural test, and the fracture patterns of the composites are analyzed by scanning electron microscope (SEM). The results indicate that the electrical conductivity decreases and flexural strength increases with the increase of PF resin content. Especially, the values of electrical conductivity and flexural strength can reach 165.28 S.cm-1 and 55.11MPa respectively when the PF resin content was 17% in weight. The properties of composites reinforced by air oxidation treated MCFs are better than those by liquid-phase oxidation treated one. The electrical conductivity and flexural strength of the composites are 208.12S.cm-1 and 57.44 MPa when they reinforced by 5% MCFs which treated by air oxidation at 450 . Compared with the nonreinfoced composites, the properties of reinforced composites increase 25.92% in electrical conductivity and 4.23% in flexural strength.