Advanced Materials Research Vols. 383-390

Abstract: ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.

Abstract: Highly c-axis oriented ZnO thin films were deposited on n-Si (111) substrate at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), Atomic force microscopy (AFM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. X-ray photoelectron spectroscopy (XPS) was used to analyze relationships between chemical shifts of XPS energy spectra and stoichiometric ratios of ZnO thin films, and quantitative relationships between content of Zn, O and oxygen partial pressures. An optimal crystallized and stoichiometric ZnO thin film was observed at the oxygen partial pressure of 6.5Pa.

Abstract: The surface brightness values in different directions are different, the measurement of the existing optical gloss meter only once can not simultaneously achieve measurement from different directions, for this phenomenon using orthogonal pairs of optical measurement method, two groups of measurements should be averaged. Measuring probe is made of a 2kHz pulse modulation circuit, silicon photovoltaic cells, I / V conversion, high-pass filter, such as precision rectifier circuit. Measurement probe output signal by the dual analog switch and the ADC into the computer. System software using VB, can realize to show the average computation, numerical analysis and results of statistical functions. Semiconductor laser light source eliminates the need of optical collimating lens. Measurement of laser modulation frequency is 2kHz, much higher than the environmental stray light, using techniques based on frequency domain interference with satisfactory light scattering resisting effect,the test shows that the error caused by stray light is less than 1.5% ,when the instrument works open-ended in the light path.

Abstract: Paper has been removed due to double publication.

Abstract: Aiming at laser weapon damage to anti-ship missile, laser damage to IR guidance anti-ship missile detectors was researched. First, model on laser weapon damage to IR guidance anti-ship missile detectors was set up. Then 1.06μm and 10.6μm laser atmospheric transmittance on the sea was calculated. Finally, 10.6μm laser was given as an example, the necessary laser energy which can damage effectively the IR guidance anti-ship missile detectors was calculated. Some valuable data and conclusions were gained. It is concluded that laser weapon damage to IR guidance anti-ship missile is feasible at present.

Abstract: Currently, the continuous rotary north-finder is widely discussed for its outstanding performance. However, few researches on the influence of turntable error to the continuous rotary north-finding algorithm can be found. Turntable errors, such as the stability of rotate speed, the periodic angle measurement error and the discrete angle measurement error, are studied for the north-finder based on rate biased RLG (ring laser gyro). Two north-finding algorithms are designed, which can restrain the influence of angle measurement errors and the stability of rotate speed separately. Finally, simulation and experiments are performed to verify the algorithms.

Abstract: In order to improve the accuracy of signal processing in Laser Doppler Velocimetry, a method based on the association of spectral refinement and correction is presented. Zoom-FFT and ratio correction are adopted to realize this method. Basic principles of zoom-FFT and ratio correction are expounded. FFT and the method are adopted to process sinusoidal signals and simulated laser Doppler signals with different frequencies separately in circumstance of MATLAB 7.0. Comparisons between the results of FFT and the method are carried out. The comparisons show that this method has the capability to improve the accuracy of laser Doppler signal processing significantly and the operation time is acceptable for LDV system.

Abstract: Process planning strategies for surface hardening by laser robot was introduced. It has many characteristics, such as integration, flexibility and environmental protection. According to technology requirement, the path planning and robotic hardening program were accomplished automatically. The FANUC ROBOGUIDE was used to realize simulation. Experiments were carried out to evaluate the application of process planning strategies for laser surface hardening.

Abstract: A pulse laser-diode-array (LDA)-pumped, intracavity frequency-doubled Nd: YVO4 laser has been demonstrated. An birefringent filter consisting of a KTP crystal and two Brewster plates(BP) has been used in the system to realize single-frequency output. Up to 72.4 mW average output power is obtained for 800 mW pumping power with an optical-to-optical conversion efficiency of 9.1%. The maximum peak power of the single-frequency green laser is 22.3 W with the pulse width 162μs.

Abstract: Impact of product on the replication performance of mold cavity was tested and studied in the high-temperature rapid molding process based on high-fitness mold for in-vehicle Bluetooth module compartment cover. The results indicated that the main difference between high-temperature rapid molding and common molding is that when the mold temperature rises to around the plastic heat distortion temperature, the product’s reproduction rate of the mold cavity surface is improved significantly. In the area lower or higher than the plastic heat distortion temperature, the changes on mold temperature hardly influence the reproduction rate of product and the impacts of other parameters are similar to those of common molding; the impacts of major molding parameters on the product mass from large to small are “packing pressure- dwell time- injection time- mold temperature- injection pressure- melt temperature”.