期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
薄透镜的反射成象
1
作者 任学藻 郑文虎 《西昌师专学报》 1995年第4期36-38,共3页
一般光学教材及实验教材都只对透镜的折射成象进行了详细的分析讨论,但对透镜的反射成象却没有给予讨论。这主要是因为入射光的能量经过透镜时有90%以上的能量是透射,而只有大约4%左右的能量被界面所反射。但如果认为这样弱的反射光形... 一般光学教材及实验教材都只对透镜的折射成象进行了详细的分析讨论,但对透镜的反射成象却没有给予讨论。这主要是因为入射光的能量经过透镜时有90%以上的能量是透射,而只有大约4%左右的能量被界面所反射。但如果认为这样弱的反射光形不成清晰可见的象就错了,因为人眼对光能量的变化是不太敏感的,在很弱或很强的光照下,我们都能看清楚物体就是有力的证明。另一个明显的例证就是在讨论等倾等厚干涉时。 展开更多
关键词 反射成象 薄透镜 折射成象 透镜焦距 分析讨论 等厚干涉 反射 光学教材 实验教材 光能量
下载PDF
二维反射地震成象──界面与速度的联合反演 被引量:8
2
作者 赖晓玲 张先康 杨健 《华北地震科学》 北大核心 1994年第4期9-17,共9页
介绍了利用反射走时联合反演地震界面起伏形态和速度横向分布的方法。正问题采用了一种简单而有效的二维介质中两点射线追踪方法。反问题在广义最小二乘意义下求解。描述界面和速度的两类参数不必要先进行分离。数值模拟的结果表明方法... 介绍了利用反射走时联合反演地震界面起伏形态和速度横向分布的方法。正问题采用了一种简单而有效的二维介质中两点射线追踪方法。反问题在广义最小二乘意义下求解。描述界面和速度的两类参数不必要先进行分离。数值模拟的结果表明方法是有效的。处理了通过唐山震区的柏各庄-丰南-丰宁深地震测深剖面,得到了有意义的结果。 展开更多
关键词 反射成象 联合反演 速度分布 地震勘探
下载PDF
测定球面透镜结构参数的实验方法
3
作者 秦庚生 《宁夏大学学报(自然科学版)》 CAS 1993年第4期42-45,共4页
本文将透镜的结构参量与光学参量联系起来进行测定实验,并提供了在光具座上可以实现的方法和手段。
关键词 透镜 球面反射成象 球面透镜
下载PDF
Advances in the Theory of Conjugation for Reflecting Prisms in China 被引量:1
4
作者 连铜淑 《Journal of Beijing Institute of Technology》 EI CAS 1992年第1期1-12,共12页
The achievements made in China in the field of the theory of conjugation for reflecting prisms are outlined which mainly includes 6 theorems, 2 corollaries, over 30 formulae, 4 matric operators, 20 characteristic para... The achievements made in China in the field of the theory of conjugation for reflecting prisms are outlined which mainly includes 6 theorems, 2 corollaries, over 30 formulae, 4 matric operators, 20 characteristic parameters, a new principle for dassification, and a new system of graphical tabulation for reflecting prisms. As an approach to developing the theory, an imaginary physical model called 'rigid body's kinematics model' has been creatively initiated to simulate the real physical phenomena of both image formation and image motion for reflecting prisms. Such a method of treatment has been successfully making the evolving theory more complete, more systematic, more generalized, and unique as well. 展开更多
关键词 PRISM MIRROR image formation adjustment scanning/imag stabilization
下载PDF
Tomatoes Maturation Analysis with Reflectance Spectral Images
5
作者 Julia Lopes Governici Rodrigo Magalhaes Faria +1 位作者 Rodolpho Cesar dos Reis Tinini Barbara Janet Teruel Mederos 《Journal of Agricultural Science and Technology(B)》 2017年第6期426-431,共6页
The demands for high quality products are increasing in the market, so several tests are performed. These analyses are destructive, time consuming and sometimes expensive. The spectral imaging technique is an alternat... The demands for high quality products are increasing in the market, so several tests are performed. These analyses are destructive, time consuming and sometimes expensive. The spectral imaging technique is an alternative that can reduce costs and time and increase the efficiency and cost-effectiveness of these analyses. In this context, the aim of this study was to verify the spectral behavior of the tomato in function of the maturation and its potential use for non-destructive evaluation of food quality. Eighty tomatoes of the Italian group were selected in four stages of maturation (green, pink, light red and red). Images were collected in wavelengths 480 nm to 710 nm (every 10 nm). After the images were collected, the fruits were submitted to the physical-chemical analyses. The following parameters were analyzed: color, color index (CI), pH, soluble solids (SS), total titratable acidity (TTA) and ratio (SS/TTA). After characterization the mean spectrum was obtained by the extraction of the spectral characteristics. It was observed that the spectral behavior was the same for all stages of maturation. It was possible to differentiate the green tomatoes in the wavelengths from 520 nm to 560 nm and from 610 nm to 660 nm. These intervals represent the area of reflection of chlorophyll and lycopene, respectively. Near the wavelength 560 nm, the highest absorbance was recorded by ripe tomatoes due to the concentration of lycopene. It is concluded that the best wavelengths for analysis are those in which green has the highest reflectance and it is possible to apply this technique for non-destructive analysis of the maturation of tomatoes. 展开更多
关键词 Non-destructive analysis mean spectrum physical-chemical analysis Solanum lycopersicum
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部