Abstract: A novel immunosensor based on porous silicon (PSi) for antigen detection was reported in this paper. The antigen (SpaA) and the specificity of the antibodies are employed as the target and the probe in our laboratory, respectively. The immunosensor structure was prepared using bioconjungation. After the antigen-antibody reaction, the red shift of the reflection spectrum of the immunosensor increases in proportion to the concentration of SpaA. The sensitivity of this immunosensor is 41nm/ µg•ml-1 and the detection limit is 2.44×102pg•ml-1, they are better compared with our previous work by using this method. Controlled experiments were also presented with non-immune antibody and the results show that this immunosensor possesses high specificity.
Abstract: Three kinds of particles which produced by the processing of bamboo flooring were taken as the raw materials and analyzed of chemical constituents. Cellulose crystallinity and the reactive oxygen species (ROS) free radicals produced from laccase-treated bamboo were examined by X-ray Diffraction (XRD) and Electron Spin Resonance (ESR), respectively. Physical and mechanical properties of laccase treated bamboo particle boards which made from surplus materials of bamboo flooring process were investigated. In order to provide some theoretical basis for producing particle board with the surplus materials of bamboo flooring process by using laccase, the relations between physical properties and chemical constituents, cellulose crystallinity or the ROS free radicals of bamboo particle boards were researched.
Abstract: Weight reduction at wheels is important due to its unsprung mass and the associated reduction of fuel consumption and the better ride-and-handling comfort. Especially in the front of the car, a weight reduction is necessary to ease the critical mass distribution at the front axle and therefore increase driving safety. The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers. In this paper, computer simulations have been carried out to analyze the flow of molten metal. Using Anycasting software to numerical simulating the process of car wheel molding filling and solidification, materials selecting and casting process characteristics and defects of the parts are studied, the causes of casting defects are analyzed.
Abstract: The innovation of this paper is that it forwards a new algorithm of target extraction form military infrared images with texture background according to the Mean-shift smooth and segmentation method combined with eight directions difference clustering. According to the texture characteristics of background image, smoothing and clustering are both carried out to extract the characteristics of target. The method is relatively simple making it easy for practical applications. The experimental results show that the algorithm is able to extract the target information form complex military infrared texture background with better self-adapting and robustness.
Abstract: This paper reports progress in the numerical simulations of movement and the coalescence of two neighbor bubbles (leading and trailing bubble) in a reciprocally stirred liquid flow field. The full Navier-Stokes equations are solved by the volume-of fluid (VOF) method for tracking the interface between the bubble and the liquid flow. A dynamic mesh method was used to predict the gas-liquid flow in a two-dimensional foaming tank. Results indicate that the motion and merge behavior of the bubbles is dominantly influenced by the initial locations and the sizes of the bubbles as well as by the surface tension, while the reciprocating effect is insignificant.
Abstract: This paper reports progress in the numerical simulations of a droplet impingement upon the wall film of the same liquid. The full Navier-Stokes equations are solved in axisymmetric formulation. The surface tension force is modeled by a continuum surface force (CSF) model. An adapting local refinement technique is used to provide the fine grid coupled by the volume-of fluid (VOF) method for tracking the interface between the gas and the droplet and liquid film. Results indicate that the motion behavior of droplet impingement upon the liquid film is dominantly influenced by the initial kinetic energy and the thickness of the film as well as the surface tension and the liquid viscosity.
Abstract: A novel method of the combination of high energy milling and hot pressing was adapted to fabricate dense titanium nitride-alumina (TiN/Al2O3) in situ composites using Ti, Al and TiO2 as raw materials. Full dense and pure TiN/Al2O3 composites were fabricated at 1300 °C for 1 h under 10 MPa. The composition, microstructure and mechanical properties of the as-fabricated products were investigated. The results show that the synthesized TiN/Al2O3 composites possess high purity. The TiN/Al2O3 composites have a good combination of mechanical properties of hardness of 18.0 GPa, the flexural strength of 500 MPa, and the fracture toughness (KIC) of 5.2 MPa•m1/2. The strengthening and toughening mechanisms are also discussed.
Abstract: The mechanically induced self-propagating reaction (MSR) and hot-pressing consolidation were adapted to synthesize Ti2AlC and Ti3AlC2 using Ti, C and Al powder mixtures. The effects of Al content on the microstructure and mechanical properties of fully dense Ti2AlC and Ti3AlC2 were investigated. The results reveal that the Ti3AlC2, TiC and TiAlx transitional phases were formed by mechanically alloying according to the mechanically induced self-propagating reactions (MSR). Through hot pressing the as-milled powders with initial composition of 2Ti/1.5Al/C and 2Ti/Al/C, respectively, at 1100°C for 1 h, the desired high purity Ti2AlC and Ti3AlC2 were produced. SEM images confirmed that the as-fabricated Ti2AlC and Ti3AlC2 grains are plate-like with nanoscale layered structure and dispersed uniformly.
Abstract: We present a novel method to fabricate uniform GaN nanocone arrays (GNA) using Nickel-nanoisland masks. The nanoscale conelike arrays with high density can be formed over the entire 2-inch wafer by inductively couple plasma etching. The results of X-ray diffraction exhibit significant decrease on the (102) reflection in GaN sample with the GNA. Field-emission measurements show that the GNA with sharp tips have a turn-on field of ~ 5.5 V/μm. It is believed that the high aspect ratio resulting from the conelike morphology is responsible for the enhancement of the field-emission properties of GNA.
Abstract: Biaxial tensile tests of 5754O aluminum alloy sheet and B170P1 steel sheet were performed under linear loading paths with cruciform specimens and a biaxial loading testing machine. The stress-strain curves under different loading paths were obtained. It is found that the loading path has a significant influence on the stress-strain curves, i.e., the stress-strain curves vary with the loading path. The stress-strain curves in the rolling direction become higher with the decrease of the loading ratio (the ratio of the load along the rolling direction to that along the transverse direction) from 4:0 to 4:4. Meanwhile the stress-strain curves in the transverse direction become lower with the decrease of the loading ratio from 4:4 to 0:4. Based on Yld2000-2d yield criterion, the experimental phenomena of the two kinds of sheet metals under biaxial tension were explained theoretically.