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光散射的镜面反射分量与随机表面高度分布的表征 被引量:1
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作者 程传福 亓东平 +3 位作者 滕树云 刘曼 贾天卿 徐至展 《中国科学(G辑)》 CSCD 2003年第3期249-256,共8页
从理论上分析了随机表面散射光强的镜面分量与表面高度概率分布的关系。表面高度分布的提取需要用到镜面反射分量的振幅和相位。由镜面反射分量的强度随波矢量的垂直分量变化的实验数据恢复光波的相位,实现了表面高度概率分布的光散射... 从理论上分析了随机表面散射光强的镜面分量与表面高度概率分布的关系。表面高度分布的提取需要用到镜面反射分量的振幅和相位。由镜面反射分量的强度随波矢量的垂直分量变化的实验数据恢复光波的相位,实现了表面高度概率分布的光散射表征。相位的恢复采用了Gerchberg-Saxton迭代算法。实验上分别对具有Gauss高度分布和准二值高度分布的两个样品进行了高度概率的测量,测量结果与原子力显微镜的测量相吻合。这对于随机表面的非接触标定与研究有重要意义。 展开更多
关键词 光散射 镜面反射分量 原子力显微镜 表面高度分布 相位恢复 随机表面模型 光学测量 表面高度概率函数
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Locating method of fire source for spontaneous combustion of sulfide ores 被引量:8
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作者 刘辉 吴超 石英 《Journal of Central South University》 SCIE EI CAS 2011年第4期1034-1040,共7页
in order to achieve a more efficient way to accurately detect the position of the fire source of spontaneous combustion underground mine, a simple fire source locating method, based on infrared scanning system which c... in order to achieve a more efficient way to accurately detect the position of the fire source of spontaneous combustion underground mine, a simple fire source locating method, based on infrared scanning system which can determine the point where the highest temperature on the surface of igniting ores occurs, was proposed. First, the differential equations that describe heat flow in ore body were presented and the relationship between the surface temperature distribution and the depth and intensity of inner fire source was established with a relatively simple heat transfer model. With the solution of equation, the expression of the relationship between the surface temperature distribution and the inner fire source was deduced and the mathematical-physical model of heat transfer process was set up. Then, with the model, visualization of fire source on the basis of MATLAB simulation platform was realized. The results show that: 1) within 10 m, when the detecting depth is less than 2 m, the temperature perturbation on ores surface can change rapidly, and then slowly; after 4 m, in contrast, it changes very little, and is even close to zero at 10 m; 2) When it is close to self-ignition duration and the detective depths are 2, 5 and 10 m, respectively, the maximum temperature differences are correspondingly 0.5, 0.04 and 0.005 ℃ in the scope of 1 m×1 m; under the same condition, the maximum temperature differences are 1.391, 0.136 and 0.018 ℃, respectively, in the scope of 2 m×2 m. Therefore, this system can be used to measure the temperature differences on the surface of ore body and determine the highest temperature point directly. Also, it is possible to determine the depth of fire source and its intensity by locating method of fire source indirectly. 展开更多
关键词 sulfide ores spontaneous combustion location of fire source DETECTION
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Research on temperature rise of hoisting machine disk brake
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作者 MA Jun JANG Hai-bo 《Journal of Coal Science & Engineering(China)》 2012年第4期423-427,共5页
A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake sys- tem was constructed, limit conditions were defined, and the law of temperature rise of brake shoes duri... A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake sys- tem was constructed, limit conditions were defined, and the law of temperature rise of brake shoes during emergent brake course was analyzed and calculated by using finite element software. By analyzing the calculation results, the law of tempera- ture change of surface of brake disk and shoes during the braking process was found. The law of brake shoes surface tempera- ture distribution and the law of temperature change along with thickness of brake shoes at brake time 0.5 s, 1.0 s and 1.5 s was analyzed. A hoisting machine emergent braking test was carried out. Finally, the author concluded that velocity rebound in the process of hoisting machine emergent brake is due to decreased friction coefficient caused by the temperature rise of the brake shoes surface. 展开更多
关键词 hoisting machine disk brake brake shoe temperature distribution finite element method
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IDFT Numerical Simulation Method for Gaussian Rough Surface with Relatively Large Correlation Length
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作者 王廷剑 王黎钦 赵小力 《Transactions of Tianjin University》 EI CAS 2015年第3期216-222,共7页
A numerical simulation method based on inverse discrete Fourier transform(IDFT)is presented for generating Gaussian rough surface with a desired autocorrelation function(ACF). The probability density function of the h... A numerical simulation method based on inverse discrete Fourier transform(IDFT)is presented for generating Gaussian rough surface with a desired autocorrelation function(ACF). The probability density function of the height distribution of the generated Gaussian surface and the root-mean-square height of the rough surface are also considered. It is found that the height distribution of the generated surface follows the Gaussian distribution, the deviation of the root-mean-square height of the modeled rough surface from the desired value is smaller than that of Patir's method, and the autocorrelation function of the modeled surface is also in good agreement with the desired autocorrelation function. Compared with Patir's method, the modeled surface generated by the IDFT method is in better agreement with the desired autocorrelation function, especially when the correlation length is relatively large. 展开更多
关键词 numerical simulation Gaussian rough surface autocorrelation function root-mean-square height IDFT
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