激光探测器表面响应度相对分布的计算机自动检测系统

本文介绍了自动检测系统的工作原理,系统中的两维扫描平台,电流一电压转换器,获得国家专利的专用检测仪器等设备;针对两种不同的检测目的,分别介绍了检测方法和电子计算机程序流程。

Modeling and analysis of surface roughness on machining of Nimonic C-263 alloy by PVD coated carbide insert

The effects of the cutting parameters （cutting speed, feed rate and depth of cut） on the surface roughness in machining the Nimonic C-263 alloy were investigated. The experiments were conducted using Taguchi＇s experimental design. The effect of cutting parameters on surface roughness was evaluated and the optimum cutting conditions for minimizing the surface roughness were determined. A second order model was established between the cutting parameters and surface roughness, using the response surface methodology. The experimental results revealed that among the parameters considered, the feed rate is the most significant which influences the surface roughness, followed by the cutting speed. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the surface roughness in machining the Nimonic C-263 alloy. The predicted values are validated using the additive law.

Evaluation of surface roughness and optimization of cutting parameters in turning of AA2024 alloy under different cooling-lubrication conditions using RSM method

In the present study,the effect of reduction of cutting fluid consumption on the surface quality and tool wear was studied.Mathematical models were developed to predict the surface roughness using response surface methodology(RSM).Analysis of variance(ANOVA)was used to investigate the significance of the developed regression models.The results showed that the coefficient of determination values(R^2)for the developed models was 97.46%for dry,89.32%for flood mode(FM),and 99.44%for MQL,showing the high accuracy of fitted models.Also,under the minimum quantity lubrication(MQL)condition,the surface roughness improved by 23%−44%and 19%−41%compared with dry and FM,respectively,and the SEM images of machined surface proved the statement.The prepared SEM images of tool rake face also showed a considerable decrease in adhesion wear.Built-up edge and built-up layer were the two main products of the adhesion wear,and energy-dispersive X-ray spectroscopy(EDX)analysis of specific points on the tool faces helped to discover the chemical compositions of adhered materials.By changing dry and FM to MQL mode,dominant mechanism of tool wear in machining aluminum alloy was significantly decreased.Breakage wear that led to early failure of cutting edge was also controlled by MQL technique.

Characteristics of Schottky Barrier Junction Based on Hexagonal Microtube ZnO

Hexagonal microtube ZnO was firstly grown on single crystal p-Si (111) substrates by hydrothermal method, and fabricated Ag/n-ZnO and Au/n-ZnO Schottky junction. Schottky effective barrier heights were calculated by I-V measurement. It is confirmed that the presence of a large amount of surface states related possibly to lattice imperfections existed near the surface leads to the pinning of the surface Fermi level at 0.35eV below the conduction-band edge. Then the fabricated Schottky barrier junctions are evaluated for their use as UV photodetectors.

Effect of Shear Wave Velocity on the Ground Motion Parameters of Site Surface

Based on the data from typical sites in the Jianghuai region,many kinds of soil layer seismic response are modeled by increasing and decreasing the measured values of shear velocity to a certain scale. The seismic response of soil layer sites are calculated using the one-dimensional equivalent linear method in the frequency domain by choosing the Taft,Kobe and El-centro records as the ground motion input. The results show that the impact of shear velocity variability on the surface ground motion is in relation to the soil layer structure and ground motion input parameters such as amplitude and spectral characteristic. With the increase of shear velocity,the PGA( peak ground acceleration)on the surface of site will increase,however,the characteristic period of the acceleration response spectra is decreasing.

A Study on Modelling Surface Finish in Electrical Discharge Machining Tablet Shape Punches Using Response Surface Methodology

This paper introduces a study on modelling surface finish in EDM （Electrical Discharge Machining） of tablet shape punches when using copper as electrode material. In this study, 27 experiments were performed based on BBD （Box-Behnken Design） and the work-piece material was 9CrSi steel. The input process parameters were the current, the pulse on time, the pulse off time and the voltage. The effects of the input parameters on the surface finish were evaluated by analysing variance. Besides, from the results of the experiments, a regression equation for determining the surface roughness is introduced. Also, the optimum input parameter values were found in order to get the minimum surface roughness.

Process Optimization and Characterization of Sorghum Based Extruded Product

Expanded snacks made up of corn, wheat and rice is very popular because of their texture. Sorghum is one of the important cereals, which is not so far studied well for extrusion processing. Due to presence of high amount of starch （56%-73%）： sorghum could be the good candidate for manufacturing of expanded snacks. The extruded products obtained using extrusion conditions such as feed moisture content （12%-16%）, die temperature （150-190℃）, screw speed （150-210 rpm） and feed rate （50-70 g min1） are further characterized by analyzing bulk density, expansion ratio, water absorption index （WAI）, water solubility index （WSI）, textural properties, color and sensory evaluation. Increase in feed moisture content resulted in extrudates with gradual increase in density, WAI and hardness and decrease in expansion, WSI, crispness and whiteness. Higher barrel temperature reduced the extrudate expansion, bulk density and hardness and increased the WSI and crispness of the extrudates. The most acceptable product is obtained using response surface methodology （RSM）.