Applied Mechanics and Materials Vols. 347-350

Abstract: In his paper, main technology about spurious emissions measurement on WCDMA base station transmitters by using spectrum analyzer is provided. The limited requirements of spurious emissions, and the requirements of spurious emissions measurement with a spectrum analyzer, and the calculations of spectrum analyzer dynamic range and spurious limited are discussed in detail. In the end a example of spurious testing system is provided.

Abstract: This paper set up the slip control mode of drive wheel base on the fuzzy theory .By the made of input and output variable of fuzzy controller and ruler ,the mode of slip control is set up ,to communicate between the MATLAB and the AMESim system, by the simulation and calculation of the control of valve output , the result of calculation tested the controller s rationality and practicability.

Abstract: This paper introduces a homemade high-resolution miniature fiber optic spectrometer for LIBS detection. The circuit part of the system is mainly controlled by a cortex-M3 chip, transmits data to the personal computer (PC) through the Universal Serial BUS (USB2.0), and a set of spectrometer test software is finished. The optical system is based on Czerny-Turner imaging system, using 1800grv/mm plane diffraction grating, 16μm slit and 2048 pixels linear array CCD as detector, high-resolution spectral output in the range of 335-455nm is required. By precisely calibration and testing, the precision of the system is 0.05nm, and the resolution of the wavelength at the blaze wavelength can up to 0.1nm which can fulfill the general LIBS detection.

Abstract: A current-model Triple Langmuir probe was developed and used to measure electron temperature and density of the Pulsed Plasma Thruster plume. To decreasing the errors in measurement, Probe, collection circuit and glow cleaning devices were elaborately designed. A FIR digital Filter based on Matlab was designed and the software for date processing was developed by Labview. Measurements were taken at various position in the plume of a Pulsed Plasma Thruster operating at discharge energy of 6-24J. The results show the thruster plume has electron temperatures in the range between 0.6and 5.4eV, electron densities between 0.9×10¹⁹ and 4.1x10²¹m^-3 for all discharge energy levels considered. Electron temperature and density decrease with increasing angle away from the centerline and with decreasing discharge energy.

Abstract: Fluorocarbon films with different structural and optical properties were deposited by Pulsed Plasma Thruster. The film composition and chemical structure was investigated with XPS. Transmittance and reflectance of the films were tested using UV-vis spectrometer. The results showed that, each sample basically has a strong absorption property for wavelength below 600nm and relatively weak absorption property for wavelength over 600nm. Chemical composition and structure influenced the optical properties of the films and different transmittance and reflectance was observed at different angle.

Abstract: Piezoelectric actuators (PEAs) have been widely used in micro fabrication. But the hysteresis inherited in PEAs leads to a severe inaccuracy and deteriorated tracking performance. In this paper, a hysteresis observer is designed for PEAs to estimate the hysteresis, mechanical parameter varieties, positioning error and external disturbance. A Bouc-Wen model is associated with a linear second-order mass-damping-spring trio to model the dynamics. An asymptotic sliding surface is selected. Lyapunov stability theory is applied to guarantee the asymptotical stability for the trajectory tracking error. Experiments are conducted to validate the effectiveness of the proposed method. Results show that a satisfied tracking response to a sinusoidal trajectory is achieved, and the positioning errors under a triangle scanning contour are dramatically reduced compared with the traditional SMC.

Abstract: To study the current state of the Earths health, we divide the Earth into dozens of regions and construct a complex network. Based on the network, we analyze the Earths present health and predict its developing trend. Moreover, the reasonable health level of the Earth can be reached via pinning control. Taking the population for example, we analyze the trend of population in the dynamic network both with control and without control. The results indicate that human behaviors and government policies have great impact on population growth.

Abstract: Comparing to the single aperture imaging system, Artificial Compound-Eye (ACE) imaging system has some nice features, such as small size and stereo vision. Based on the pictures captured by ACE, the displacement of an object can be easily deduced. This paper introduces our multiple-focus ACE imaging system. The system mainly consists of (a) a micro-lens array fabricated by Micro-Electro-Mechanical-System (MEMS) technology, (b) a CMOS chip, (c) a 3D mechanical moving stage, and (d) a software module. It can measure the displacements of an object in 212D space without calibration. The experiment validation is included.

Abstract: This paper introduces a method of studied and manufactured reference material for calibrating magnification of computed tomography system. The measurement procedure and certified value method of the reference material were also described. Moreover, uncertainty of measurement was evaluated in this paper, by which a state level of confidence was accompanied. Finally one example of application of the reference material was described. We thought that reference material of CT system will update its function and develop its applied field.

Abstract: An exhaust temperature test system is developed for resolving the problem that the exhaust temperature of a certain type aeroengine can not be real time monitored. The exhaust temperature test and temperature compensation circuit are designed and data collecting, processing and displaying program are written in this system which utilizes PC104 built-in industry computer as its core controller. The exhaust temperature of aeroengine can be real time monitored during test-drive by ground guarantee staff, which can help them to judge the condition of the aeroengine.