Abstract: This paper uses transmission electron microscope technology, studies microcosmic structure’ s feature of BN fiber, clarifies existing crystal structure’s state of BN fiber during its producing and transform course. It is studied that BN fiber has a sound mechanical properties, which most of crystalline phase is turbine layer phase and whose nitrogen is high and size is small .During the course of BN fiber’s producing, adding suitable tension from axial can promote directional arrange of BN fiber’s surface crystalline grain and put forward the improving direction of manufacturing technology in order to improve materials’ mechanical properties. BN fiber(indicated by BNf) is a kind of new inorganic material. Because of its fine stable, corrosion-resisting, anti-oxidant properties and high ability of absorbing neutron and so on, it is attached more and more importance and it get constant development and usefulness. BNf and ceramics, metal, various compound materials made of resin material can be used in metallurgy, electron, aviation etc science and technology fields. But the intensity of BNf and its elasticity modulus are lower than basic fundamental material. When BNf’s compound material get fine properties above mentioned, the mechanics properties of the material will drop. So its application degree will be limited to a certain extent. In order to improve and raise BNf’s mechanics properties, this essay makes use of electron micro analytical technology to study its microcosmic structure and mechanics properties, providing scientific basis for designing reasonable manufacturing technology.
Abstract: The microstructure characteristics of Si3N4/nanometer SiC multiphase ceramics material was studied by electronic microscopy, and the different of the nanometer multiphase and the single-phase Si3N4 ceramics microstructure was analyzed. The relations of the multiphase ceramics material mechanical properties and the microstructure were discussed. The nanometer grain in material restrain Si3N4 crystallinity, improve the mechanical properties of material. Nanometer multiphase ceramics is a new kind of ceramics material which developed in several years, in which Nanometer crystalline grain is smaller than 500nm, because of its small crystalline grain and interface out of order, it has much better feature than that of traditional ceramics materials, it is one of directions on which ceramics material develop in future. The study shows, the temperature indoor strength and toughness is higher 2-3 times than single set material in nanometer multiphase ceramics, at temperature indoors, toughness, strength and anti-creep etc improve a lot. Use high resolving power analyzing technology and electron diffraction analyzing technology of transmission electron microscope can distinguish crystal size, appearance distribution form, dislocation and crystal boundary phase of different material in one sample, in the order to study deeply the relation between microcosmic structure feature of the material and mechanical properties and valuable information to improve material.
Abstract: Researchers, environmentalists, and policy makers are keen to reduce the dependency on use of fossil fuels towards climate change. Various alternatives are being implemented for alternate sources of energy for transportation sector; Biofuels can reduce the dependency on the import of the fossil fuels. Different kind of biofuels are available compositions are alcohols, ethers, esters etc. Commonly available biofuels are ethanol, methanol and biodiesel. They can be produced from various thermo-chemical and bio-chemical processes. Methanol has been gaining momentum as a potential alternative for traditional fossil fuels in transportation sector. There is an increased trend in the development of methanol as a fuel around the world. This paper deals with the study of the use of methanol as an automotive fuel. Methanol has certain positive properties on the vehicle’s performance. However, methanol cannot be used directly as a fuel in the vehicles due to volatility and compatibility issues. But it could be used as a blend with the gasoline for its characteristics such as high octane number and lower emissions. Blending of methanol with gasoline will have affect on the properties of blend, this paper discusses about the change in properties and its effects on engine.
Abstract: The control of the rail pressure is quite important for a common rail (CR) fuel system since the precise rail pressure control is the basis of optimization for many controlling parameters for CR fuel system, and has a great impact on engine power and emissions. This paper presents the experimental investigation of rail pressure characteristics of a CR fuel system. The rail pressure was tested in varied operation conditions with different boundaries and control parameters. The transient rail pressure characteristics were acquired. Furthermore, the pressure fluctuation was analyzed by means of frequency-domain method. This research shows that the pressure fluctuation in the fuel rail is induced by fuel pump and injectors but not the flow measurement unit.
Abstract: The rolling bearing is the common component in machinery, especially the high-speed rolling bearing. The running state will influence the performance of the whole machine directly. In this paper, it will analyze the design of filter and the fault characteristics frequency. And, through the examples, the paper designs the testing system and verifies the method effectively and reliably.
Abstract: An adjustable defected microstrip structure is discussed in detail in this paper. To obtain a better bandstop property, a simple U-shaped slot is etched in the center of microstrip line, the lower insertion loss in the passband and higher rejection level has been exhibited. The resonant frequency is extracted using transmission line network analysis. At the same time, an accurate method of adjusting the resonant frequency is proposed to match the designed resonant frequency exactly. A fabricated sample has been tested to verify the design. Measurement results are in very good agreement with simulations.
Abstract: This paper addressed the completed researching and developing procedure for the whole system with below parts： The pipe part of the whole system which according to the principle of the pressure reducing valve and the related standard; The electrical control system, adjusting control system, data collection system; We simulated customer’s operating on the valve based on PLC controlling the action of the Solenoid Valve which achieved the goal for life test .Meanwhile the paper introduced PPI protocol with which PLC computer communication each other. The experimental data of current capacity test, pressure characteristic test, flow coefficient (Cv) test and life test show the performance of the whole system is good.
Abstract: This paper will introduce and optimize a new model of demodulation algorithm named Energy Operator Demodulation Approach to improve the limitation of the demodulation analysis widely used in many fields at present. Compared with Hilbert transform method, and optimized algorithm through Simulation test, which shows optimized Energy Operator algorithm is more simple ,faster and accurate than other algorithms. Finally, it is verified that research on fault diagnoses of rolling bearing based on the energy operator demodulation approach is very effective.
Abstract: The retainer bearing will be misaligned for mechanical errors, which leads to the uneven air gap of AMB and affects the performance of AMB. To study this problem, the electric-magnetic force model was built first with the misalignment of retainer bearing. With this model, the influences of the misalignment on the system stiffness, damping and damping ratio of AMB were studied through theory analysis and simulation based on the PID controller with low-pass filters. The study indicates that the system stiffness and damping ratio of AMB employing PID controller will increase with the increase of retainer bearing misalignment. The results provide certain references for the system structure optimum design, system debugging and fault diagnosis and performance improvement of AMB-rotor system.
Abstract: Based on characteristics and operating principle of reciprocating machinery, we presented fault diagnosis and data testing method of reciprocating machinery, which features the testing based on crank phase signal, cylinder pressure, temperature, vibration and ultrasonic signal, developed a embedded data acquisition system, and described system composition and module functions. We also realized a CAN bus-based data transmission and communication mode, introduced the slave computer software working flow of the testing system, and developed the data processing and fault analysis software with LABVIEW. The practical tests show that crank phase signal-based data testing can meet requirements on fault diagnosis and data acquisition of reciprocating machinery.