Advanced Materials Research Vols. 341-342

Abstract: A novel structure is proposed to design accelerometer, that is, two parallel cantilever beams are selected instead of single-beam, which would effectively improve accelerometer’s sensitivity. The novel structure can be integrated fabricated, which is suit for lot manufacturing. The characteristic parameters of the microstructure are analyzed by ANSYS. It can be concluded that the sensitivity is, anti-overload capacity is 1e5g, measuring range is±20g.The microstructure is manufactured by means of the silicon-on-insulator craft and the thickness of the beam is 20 um, the length is 3500 um. The test results show that the resonance frequency is 1840Hz, which is consistent with the results of the calculation and simulation.

Abstract: On-line tool wear condition monitoring is a significant area of research in automated machining process. This study concerns the development of an on-line tool wear condition monitoring system based on a fuzzy logic scheme. The feed motor current was measured and used as the input of a fuzzy process. Previously, most studies in this field have assumed the workpiece as rigid. However, in practice, cutting force causes the elastic deflection on workpiece and changes actual cutting depth. Therefore, due to coupling between actual depth of cut and feed motor current, the measured current values vary on cutting length according to workpiece elastic deflection pattern. This oscillation in current signal which is used as the input of monitoring system, can affect output results. Thus, in this study in order to achieve more accurate results, the workpiece clamping condition has been considered and through monitoring software a correction factor has been applied on outputs. Experimental results indicate that the proposed method can be reliable for practical applications of tool monitoring systems.

Abstract: Forging is a process of forming metals which leads to the deforming of work piece through its pressing. Shape and the number of pre-forms are the most significant issues in designing the process of closed die forging. The criteria for producing the pre-forms are creating a faultless die, fully the die completely, and homogenous deformation. In this study simulation in the designing the forging process of connecting rod via Pro/Engineer software and optimization of pre-form die and its analysis through the use of SuperForge software were investigated. Concerning the results, the simulation forging of connecting rod, power and energy of each phase and the effects of other significant factors such as temperature can be explored.

Abstract: During the high-speed machining, cutter path of numerical control needs to satisfy the following requirements. There has no colliding among work pieces, fixtures and so on. The cutter path variation cannot too dramatically and the vibration should in the controlled area during the process. Feed speed can modify with path curvature variation and cutting depth need to be equality. This article will analyze and research in the mode of cutter advanced and retreats, cutter movement mode, cutter feed mode and cutter path of corner treatment during the high-speed process programming that could effective optimize cutter path, process efficiency and quality.

Abstract: In this paper an Asymmetric Fuzzy Method for MPPT Control of PV System was described, which is focus on the nonlinear characteristics of solar arrays and it is necessary to create control rules that meet the output characteristics of the solar arrays. Asymmetric Fuzzy control method can solve this question: the input function and membership function reflect characteristics of photovoltaic array adequately, which is different from traditional symmetric fuzzy control. So we can adjust to the disturbance step according to the characteristics of photovoltaic array.

Abstract: This study is based on the image processing system by the authors, and performs microscope observations of the bubbles flow in dense-phase transport region of circulating fluidized beds. The research has tested and experimented on a cold scale-model circulating fluidized bed with a riser that has a 0.30mm × 0. 28mm cross-section and is 2.90 m tall with a video camera utilized to visualize the bubble structure through a transparent Plexiglas wall. The experiment was carried out at different particle sizes, different bed materials ,different heights and different height regions .The result analyzes the impact factor of the bubble size, shape and so on in the wall.

Abstract: Post-Transcriptional Gene Silencing and RNA interference (RNAi) are terms describing the specific suppression of genes by complementary dsRNA. High-efficiency transfection is an essential first step for achieving effective gene knockdown. Non-viral transfection include chemical-transfection and electrotransfection. For a particular cell line, select the appropriate transfection method is very important. In this study, we compared a variety of commercially available reagents and electrotransfection, approaches to define methods for efficient delivery of siRNA to NB4 cells. Fluorescently-labelled siRNA were tested. We report that different methods have different effects. The results provide guidelines for optimal siRNA-mediated knockdown in the NB4 cells.

Abstract: Activated ozone as the carrier，crylic acid as the monomer and glutaraldehyde as the cross-linking agent were used to research the immobilization of transglutaminase on polypropylene microporous membranes. The effect of ozone activation time，grafting time，grafting temperature，monomer concentration and ammonium ferrous sulfate concentration on grafting degree were studied, the Immobilization conditions were also studied. We found the optimal reaction conditions as following: consistency of hexamethylendiamine was 15%，at 50°C for 120min and consistency，at 30°C for 45minites，consistency of enzyme was 15mg/mL at 4°C. So the immobilized amount of protein could come to 30.23mg/g membrane and the activity of immobilized MTG come to 16.9U/g membrane.

Abstract: In the thesis, the dynamic bifurcation characteristics of the Hindmarsh-Rose neuron are analyzed and discussed by the neurodynamic theory and methods. Under the stimulation of the current, the neuron’s discharge pattern changes from the resting state to the tonic firing, which needs the current’s amplitude reaching a certain value. Moreover the stimulation strength threshold has something to do with the parameter r of the neuron. When the stimulation current increases gradually, the general trend of the membrane potential’s ISI is the gradual decrease(The discharge frequency of the neuron increases gradually). The discharge patterns of the neuron are changed, and the neuron undergoes the process of dynamic bifurcation. This bifurcation process of the neuron has something to do with the parameter r. and different parameter r causes different bifurcation. Under a certain current’s stimulation, the HR neuron has plenty of discharge patterns with the parameter r’s changing. From the view of neurodynamics, the discharge patterns of the HR neuron are changed, in substance, the HR neuron undergoes dynamic bifurcation process. Therefore, The HR neuron’s discharge patterns can be adjusted and controlled by the stimulation current I and the parameter r. This investigation is helpful to know and investigate deeply the dynamic characteristics and the bifurcation mechanism of the HR neuron; and it provides a certain theory assist to investigate many neurons’ synchronization and the neural network’s synchronization.

Abstract: The hippocampal CA1 pyramid neuron has plenty of discharge actions. In the thesis, the dynamic characteristics of the hippocampal neuron model are analyzed and discussed by the neurodynamic theory and methods. Under the current stimulation, the hippocampal CA1 pyramid neuron has plenty of discharge patterns, and can generate many discharge patterns such as period, the chaos, and so on. Under the stimulation current amplitude unchanging, the dynamic characteristics of the hippocampal neuron have something to do with not only the current’s stimulation amplitude, but also the stimulation time’s length, which isn’t the same with common neurons such as the Hindmarsh-Rose neuron. When the stimulation amplitude increases gradually or the stimulation time prolongs, The neuron model’s ISI gradually drops off, whose changing trend approximates to an exponential function, that is to say, the discharge frequency gets quicker and quicker. In addition, the hippocampal CA1 pyramid neuron model has class II neural excitability. This investigation is helpful to know and investigate deeply the dynamic characteristics and the bifurcation mechanism of the hippocampal neuron; and it provides a certain theory assist to investigate the neural diseases such as the Alzheimer disease by neurodynamics.