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基于光片模型高光线法的曲面品质评价 被引量:1
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作者 神会存 梁纪凤 宗万栓 《航空学报》 EI CAS CSCD 北大核心 2011年第1期172-180,共9页
提出了曲面品质评价分析的光片模型高光线法。该方法的基本原理是:首先从光柱中切出一片包含轴心线的光片来代替光柱,使所有光线都位于一个光源平面内;然后根据本文提出的相应于光片模型的距离函数计算公式,通过使距离曲面与不同的平面... 提出了曲面品质评价分析的光片模型高光线法。该方法的基本原理是:首先从光柱中切出一片包含轴心线的光片来代替光柱,使所有光线都位于一个光源平面内;然后根据本文提出的相应于光片模型的距离函数计算公式,通过使距离曲面与不同的平面求交,得到一系列曲面上的高光点;最后,采用三次Hermite插值方法,拟合出通过这些点的连续高光线簇。实例表明:光片模型高光线法克服了光柱模型高光线法中高光线与基准光线相关,以及评价结果不能很好地反映曲面上曲率变化较剧烈区域光顺性的不足。另外,该方法运行效率较高,是一种较为理想的曲面品质评价方法。 展开更多
关键词 曲面品质评价 线 光片模型 模型 距离函数
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基于片光模型的三维标定方法研究 被引量:1
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作者 马腾 赵德安 +2 位作者 李长峰 盛亮 陈辉 《软件导刊》 2021年第7期81-85,共5页
三维标定参数精度对3D视觉测量的作用至关重要。为解决传统激光三角法标定原理复杂、过程繁琐以及在倾斜平面标定精度不稳定问题,提出一种基于片光模型的三维标定方法。采用曲面灰度值拟合算法,结合标准量块几何尺寸与视差图像中的深度... 三维标定参数精度对3D视觉测量的作用至关重要。为解决传统激光三角法标定原理复杂、过程繁琐以及在倾斜平面标定精度不稳定问题,提出一种基于片光模型的三维标定方法。采用曲面灰度值拟合算法,结合标准量块几何尺寸与视差图像中的深度信息映射关系生成标定系数,解决激光三角检测系统在不完全水平基准面标定精度不稳定问题。利用经验值加标定矫正方式保证标定精度。实验结果表明,该标定方法能准确测量物体高度,Z轴平均绝对测量误差为0.0018mm,倾斜平面标定精度较高,能满足高精度测量需求。 展开更多
关键词 三维标定 模型 曲面灰度值 标定矫正
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Preliminary Study on Spectra Diagnosis Model for Nitrogen Nutrition in Rice Leaf 被引量:4
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作者 李晓利 刘明博 +1 位作者 楼佳 唐延林 《Agricultural Science & Technology》 CAS 2011年第2期168-170,共3页
[Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice var... [Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice varieties(Xiangyou 109 and Shanyou 98),different growth periods and different nitrogen levels,we analyzed the correlation between leaf spectra and their nitrogen contents,and built prediction model of spectral index for nitrogen content in rice leaf.[Result] The detection precision of this model was above 80% that can be used on diagnosing of rice nitrogen nutrition.[Conclusion] The study provided evidence for monitoring nitrogen nutrition status of rice. 展开更多
关键词 RICE LEAF Nitrogen content Spectral index MODEL
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Fabrication of Multilayer Optical interference Filter as Colored Glazed Buildings Fa(;ades for Thermal Solar Collectors Using MgF2/SiO2
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作者 Abdul- Hussain Kh. Elttayef Zainab I. Al-Assadi 《Journal of Physical Science and Application》 2016年第1期49-55,共7页
A simple idea to obtain a desired color that hiding the black color, and the visibility of tubes and corrugations of the metal sheet (absorber) of the thermal solar collectors which is consider the main obstacle to ... A simple idea to obtain a desired color that hiding the black color, and the visibility of tubes and corrugations of the metal sheet (absorber) of the thermal solar collectors which is consider the main obstacle to facade integration buildings of solar thermal collectors will be presented in this study by designing a multilayer optical interference filter during RF magnetron sputtering process. This filter work as antireflection coating in the near IR region and also includes a high colored reflectance at a specific wavelength in the visible region, this is to gain an esthetic aspect for the thermal solar collector which can be used as building facades by employing appropriate dielectric materials with high refractive index (H) like SiO2 and low refractive index (L) such as MgF2 which they deposited on glass substrate for quarterwave thickness and for the optical model air//HL//glass. 展开更多
关键词 colored glazed solar collectors interference filters.
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Slicing-response model for ablation mass removal of polyformaldehyde irradiated by pulsed CO_2 laser in vacuum 被引量:3
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作者 LI Gan CHENG MouSen LI XiaoKang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第1期158-162,共5页
The interaction between CO2 laser and polyformaldehyde(POM)is quite important in the research of laser irradiation effects and mechanisms.At this time,the accuracy of the existing mass-ablation models for POM irradiat... The interaction between CO2 laser and polyformaldehyde(POM)is quite important in the research of laser irradiation effects and mechanisms.At this time,the accuracy of the existing mass-ablation models for POM irradiated by CO2 laser is poor compared with the experimental data.Based on the energy distribution deposited in the POM target,the active area excited by laser is divided into four slices,the ablation slice(the temperature-rising slice,the perturbation slice,and the undisturbed slice),and a slicing response model for the mass ablation of POM induced by pulsed CO2 laser irradiation in vacuum is developed.A formula is deduced to predict the ablated mass areal density from the model and is verified with data from several studies and our own experiments.The results show that our model fits the experimental data quite well before the shielding effect of ablation products becomes notable.The applicability of the model to other materials and the mass ablation in atmosphere are also briefly explored. 展开更多
关键词 laser ablation pulsed CO2 laser polyformaldehyde(POM) ablation model
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