Advanced Materials Research Vols. 616-618

Abstract: In this paper, we report the structural and optical properties of bamboo-like silicon-doped boron nitride nanotubes. The morphologies and structures of the nanotubes were characterized using electron microscopy and FTIR spectroscopy. Three strong broad peaks centered at 1.76ev, 2.20ev, 2.40ev were observed from the room-temperature PL spectrum of the nanotubes. The spectrum suggested the existence of multifold energy levels within the band gap.

Abstract: LiFe_0.97Nb_0.03PO₄/C was synthesized by the method of high temperature ball milling (HTBM), using raw materials including Fe₂O₃, LiH₂PO₄, Nb₂O₅ and glucose, which was used as reductant and carbon source. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical performance test. The sample synthesized at 700 °C for 8h showed excellent electrochemical properties, with the discharge capacity as high as 140 mA•h/g at 0.1C rate respectively. The sample also showed an excellent capacity retention as there was no significant capacity fade after 10 cycles.

Abstract: The crystallization of anatase from amorphous TiO₂ nanotube arrays (TNTs) has been carried out by annealing in air and hydrothermal treatment in water. The morphology and crystalline phase of obtained TNTs membranes were detailedly characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The surface electronic structure and photoelectrochemical properties (PEC) of TNTs obtained by different crystallization methods were investigated. The results show that the TNTs electrode crystallized by hydrothermal treatment method demonstrate a broader surface photovoltage response range and higher photoelectrochemical properties than that of TNTs electrode directly annealed in air due to effective Ti³⁺ sites.

Abstract: In this paper, analysis an example of medium pressure gas pipe network,application of the hybrid algorithm, the results proved consistent with the actual situation, shows that the algorithm can still use.

Abstract: A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control has better dynamic, static and robust characters by using the auto-disturbance rejection controller.

Abstract: Turbine blade tip clearance continues to be a concern in the design and control of gas turbines. Ever increasing demands for improved efficiency and higher operating temperatures require more stringent tolerances on turbine tip clearance. An implicit active generalized predictive control with AR error modification and fuzzy adjustment on control horizon of aero-engine turbine tip clearance is presented and evaluated. The results show the resultant active tip clearance control system has good steady and dynamic performance and benefits of increased efficiency, reduced specific fuel consumption, and additional service life.

Abstract: The theory of aircraft ground deicing processes is studied in this paper. Aiming at the civil aviation airport with a number of parking bays, a model considering multiple constraints is presented. According to the first come first service scheduling, simulation is carried out to get the relationship between the quantity of flights and the delay time, based on the flight plan data of Beijing Capital International Airport. Then, taking into account the cooperation of the airports with airlines, besides the competition between airline companies, priority comparison method is proposed to optimize the airline flight deicing scheme. The result of research shows that the optimization method can effectively reduce the delay time.

Abstract: The chemical oxygen demand (COD) is an important indicator of the characterization of organic substances in water content, reflecting the situation of water pollution. This system takes the IC, A/D and AT89C52 as key module, according to Lambert-Bill’s law and colorimetric principle, uses silicon photovoltaic cells and operational amplifier to realize photoelectric conversion. Incident light and transmitted light intensity of liquid are measured. The microcontroller can be automatically calculated the solution of the chemical oxygen demand (COD) value. The system also has real-time clock, over-range alarm and other functions.

Abstract: As an important aspect of the environmental protection, there has been a problem of the high cost and low accuracy for the accurate measurement of the discharge sewage. Introduced a kind of improved slab intelligent sensor for flow measurement which is the independent research and development, its principle of the system, hardware design and software structure. Through compared the data of the flow testing experiment of the Parshall flume in the laboratory, the average error of the improved sensor is 1.76%, greatly reduced the error of the old one, the sensor makes the precise and low cost requirements come true, and has a broad application prospect in the market.

Abstract: With the rapid development of China's national economy, high capacity, high parameter unit has become the main force of China's power industry. Because of the scarcity of water, Country demand repeatedly saving, energy conservation, efficiency for circulating cooling water applications.