Advanced Materials Research Vols. 503-504

Abstract: A feasible method to fabricate glucose biosensor was developed by covalent attachment of glucose oxidase (GOx) to a silica nanoparticle monolayer modified gold electrode. Electrochemical impedance spectroscopy (EIS) of ferrocyanide followed the assembly process and verified the successful immobilization of GOx on silica nanoparticle modified on gold electrodes. Cyclic voltammetry (CV), performed in the presence of excess glucose and artificial redox mediator (ferrocenemethanol), allowed to quantify the surface concentration of electrically wired enzyme. The signal of proposed electrode was more than 2.5 times of that on electrode lacking silica nanoparticles. As a result, silica nanoparticles are a good biocompatible solid support for enzyme immobilization.

Abstract: Due to significant difference of thermal expansion coefficients between ceramic and metal, the residual stresses are deemed to be induced into the interior of matrix composites within the ceramic-metal seal systems. Many investigations of the residual stresses distributions on dissimilar solid materials joints so far have been carried out theoretically and experimentally, whereas ones of the residual stresses distributions within the thin-walled ceramic-metal seal systems are rarely performed. In order to obtain information for improving their seal structures in the future, the residual stresses distributions resulted from the thermal expansion behavior in the typical configuration of the thin-walled ceramic-metal seal are investigated by theoretical formulae, experimental observation and finite element method (FEM) simulation in this paper. The changing trends of the computational results of the residual stresses distributions agree with the experimental results of the measurement with X-ray diffractometer. The overall residual stresses are found to increase drastically near the welding interfaces. The highest tensile stress occurs at the outer surfaces of the ceramic near the welding interfaces.

Abstract: This paper studies the old offset machine mathematical model, corrects the shortcomings of its mathematical model and presents a more effective, more reasonable mathematical models. Then the conceptual designs, system design, structure design of the model are carried out. After nearly 2 years operating, the deviation adjusting mechanism has been proved to possess a good practicability and adjusting deviation.

Abstract: In our studied phosphating system, the morphology, chemical composition, phase and corrosion resistance of the phosphate film were characterized by EDS, AES, XRD and cathodic polarization curves. Test results indicated that the phosphate coating was made of the two kinds of Zn3(PO4)2•4H2O and Fe2Zn(PO4)2•4H2O crystals composed. On this basis, we came up the film-forming mechanism of low temperature phosphating technology.

Abstract: The tensile and the fatigue tests of three different rolling states of SUS301L stainless steel welded joints were investigated, and their S-N curves were obtained and analyzed. The typical fracture morphology of fatigue specimens were observed by scanning electron microscopy (SEM). The results indicate that the tensile strength and the yield strength of three kinds of SUS301L stainless steel welded joints increase with increasing of rolling degrees, while only the elongation rate decreases with the increasing of rolling degrees; the median fatigue limit of SUS301L-DLT、SUS301L-ST、SUS301L-MT for fatigue life 2×106 cycles are 247.5MPa, 331MPa, 266.7MPa.

Abstract: The objective of this research was to investigate the effect of pH(7.0, 8.0, 9.0, 10.0) on the properties of soy protein isolate (SPI)/guar gum (GG)composite films casted with 0.2 %(w/v)guar gum polysaccharide, 5.0 %(w/v)SPI, 1.5 %(w/v)glycerol plasticizer, and 4:1(v/v) mixture of distilled water and anhydrous alcohol. Composite membranes from different pH conditions were evaluated from following aspects: tensile strength (TS), elongation at break (EB), water vapor permeability (WVP), water solubility (WS) and surface hydrophobicity(SH)

Abstract: Density functional theory (DFT) calculations are performed to investigate the structures of phenyl silsesquioxanes Si2nO3nPh2n (n=1-5). Our study focuses on the structures, stabilities, and electronic properties of the phenyl silsesquioxanes. The large HOMO–LUMO gaps, which range from 5.14 to 6.30 eV, imply optimal electronic structures for these molecules. The energy differences between the possible conformers of same size phenyl silsesquioxanes are small.

Abstract: An energy-based model is presented to predict the deflection and resonance frequency shift of a microcantilever induced by chemisorption. The chemisorption of oxygen on Si(100) surface is taken as a representative example. The connection between the continuum-level cantilever responses (e.g. static deflection, resonance frequency) and the molecular-level interactions (covalent bond interactions) are established. The mechanical behavior of the cantilever on the density of adsorbed atoms/molecules and the property of the substrate is investigated. This study is helpful for designing microcantilever-based sensors which have many technologically important applications

Abstract: The nickel sulfides of NiS and NiS2 have been synthesized successfully at 180 °C and 160 °C by hydrothermal method from NiCl2•6H2O, S powder and NaOH. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the major phase of the powder product obtained at 180 °C is NiS2. The Ni-S powder obtained at 180 °C shows granular and hexagonal shapes with sizes of about 200~300 nm. The product powder obtained at 160 °C has the major phase NiS and minor phase NiS2. The morphology of this product was regular hexagonal flakes with side-length 200nm.

Abstract: The effects of rare earth metals on the inclusions and the mechanical properties of 2205 duplex stainless steel were studied by metallographic examination, scanning electron microscope (SEM) and energy spectrum analysis. The results show that the morphologies and sizes of non-metallic inclusions in 2205 duplex stainless steel are changed, and rare earth metals played a very good role of modifying inclusions. The fracture mode of 2205 duplex stainless steel is typical cleavage fracture, but quasi-cleavage and dimple fracture after adding RE into the steel, and the spherical inclusions of rare earth oxysulfide in the dimple are the main factors for this transformation. The transverse impact toughness of 2205 duplex stainless steel is improved obviously by RE. In comparison with 2205 duplex stainless steel without RE, the transverse impact toughness of 2205 duplex stainless steel with RE is increased 20.49% at -40°C, and the room temperature strength are improved, the elongation and reduction of area have been improved 11.67%, 24.55% respectively.