共查询到19条相似文献,搜索用时 93 毫秒
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本文研究以ZrO2为母相,掺杂MgO的混合烧结陶瓷材料对于X-Ku波段超高频电磁波的反射衰减特性。采用微波矢量网络分析仪扫频测试结果表明:纯MgO和纯CrO2陶瓷材料对X-Ku波段的电磁波的反射衰不如ZrO2+MgO混合烧结陶瓷。对MgO加入CrO2后改变混合烧结陶瓷的介电特性进行了分析,认为MgO使ZrO2中的带电缺陷增加以及使ZrO2母相的晶体点产生较大的畸变是提高MgO+ZrO2混合烧结... 相似文献
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图像测量中自动调焦函数的实验研究与分析 总被引:13,自引:6,他引:13
给出了几种常用图像测量中自动调焦算法的对比分析,并分别在不同照明方式和不同背景条件下对主要的调焦函数特性参数进行测试,得到了调焦函数的实用性能的客观评价.实验结果表明:在透射照明条件下,灰度梯度类调焦函数特性均较好.其中Variance函数以及灰度变化率和函数具有较大的调焦范围,且近似为线性变化,但是灵敏度较低,因此适于大范围粗调焦;Laplacian函数和Tenengrad函数灵敏度高,稳定性好,但调焦范围小,因此适合于小范围精确调焦.在反射照明条件下,只有Tenengrad函数和Brenner函数仍然保持单峰性,但灵敏度明显下降.当存在较复杂背景时,调焦函数普遍失效.因此在实际测试中,应当优先选择透射光照明,尽可能少用反射照明,而且应尽可能避免背景的干扰. 相似文献
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由于KNSBN:Ce光折变晶体对He-Ne激光有较强的非线性效应,在双光束耦会放大中有较大的耦合放大系数,在全息记录中又可达到较高的衍射效率,且易生长,加工,又由于He-Ne激光的实用性和稳定性,因此KNSBN:Ce光折变晶体在全息存储等方面将会得到更普遍的应用。无论是透射或反射的体积全息图,当全息图再现时,只有满足布喇格条件,全息图才可以产生一个再现象,在通常的全息记录条件下,若不采用特别的措施一般难以同时制作透射和反射全息图,因此也无法同时得到这两种全息图的两个再现象。在使用KNSBN;Ce光折变晶体的全息实验中,我们发现:由于晶体内表面的反射,人射的物光除大部分透射外,还有小部分反射。这束反射光虽然相对其人射物光或参考光而言很弱,但是在一定的条件下,这束微弱的反射物光仍然可以在和参考光的双光束耦合中得到放大并形成具有较高衍射率的全息图。在文献”‘中我们已分析讨论了利用晶体的人射光以及由晶体内表面的反射光作为泵浦光简单地产生相位共扼光的方法。这里我们进一步提出,用KBSBN:Ce光折变晶体作为全息记录介质可以在记录物体反射全息图的同时,又记录物体反射光而产生的透射全息图. 相似文献
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《仪表技术与传感器》1978,(1)
光电式产品外观质量检验机是利用光照射在产品表面上,利用其对好面与缺陷反射(或透射)的差异(反射率的大小,反射方向的变化)直接或通过一定的光学系统,用光敏元件将其变化转换成电信号后,对产品进行分类的机器。这类分选设备中的主要部件—光电传感器,具有识别表面特征的能力,可以代替一些靠人的感觉进行的检查工作。光电传感器无论是使用在反射或透射情况,其原理均可用反射接收的情况来说明。重庆大学已研制成功用于产品外观检验机 相似文献
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Laser light, with a photocell giving a logarithmic response, is used to measure the specular and diffuse reflection from ground and ground and lapped metal surfaces. Theory suggests that the probability distribution of roughness heights determines the specular reflection, while the distribution of surface slopes determines the diffuse reflection. For specular reflection the theory gives useful results even in the range of grazing incidence (70° or 80°) which must be used for the roughness range 0.2 to 1.5 μm.The optical and profilometer results suggest skewed non-Gaussian probability distributions, and a theoretical model which may account for such distributions is suggested. The diffuse light results show that, except for the roughest specimens, the slope distribution is also non-Gaussian. The standard deviation of the slopes increases with roughness, and the relation between them is obtained. 相似文献
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The method of determining elastic constants of crystals by measuring thermal diffuse X-ray scattering around some Bragg reflections, is extended to measuring thermal diffuse electron scattering for the first time, in a transmission electron microscope, equipped with a field-emission gun, an [Formula: see text] -type energy filter and a multi-scan charge-coupled device. Quantitative diffuse electron scattering in the vicinity of the [Formula: see text] Bragg reflection was measured on a Si crystal in order to obtain information about elastic constants. Values of the elastic constants ratios C(12)/C(11)=0.4246, C(44)/C(11)=0.4707 obtained by simplex fitting method are consistent with the values C(12)/C(11)=0.3856, C(44)/C(11)=0.4804 determined by other traditional methods. This method may be expected to open a new route to measuring elastic constants of polycrystalline, nanometer-scaled and composite materials. 相似文献
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色标检测光电传感器的研究‘ 总被引:5,自引:0,他引:5
根据光的镜反射及漫反射规律和色标检测的特点,论述光早式色标检测传感器的设计原理,介绍色标检测传感器的系统构成,提出色标检测传感器设计中若干关键技术问题的解决方法。 相似文献
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近红外光谱和气相色谱-质谱联用技术对橄榄油掺杂及品质分析研究 总被引:1,自引:0,他引:1
分别采用近红外光谱技术及气相色谱-质谱联用技术对橄榄油样品进行分析。采用透射方式采集橄榄油样品的近红外光谱比漫反射方式可以获得更好的重现性;通过直观分析、二阶求导以及主成分分析可快速判别橄榄油与掺杂橄榄油。0.10 g橄榄油样品经过10 mL的KOH-甲醇溶液甲酯化处理后,加入10 mL正己烷和10 mL水进行液液萃取,并对正己烷提取液进行气相色谱-质谱分析,对39种橄榄油脂肪酸甲酯含量的分析结果与近红外光谱的主成分分析图对比得出,油酸和亚油酸是影响橄榄油近红外光谱扫描结果的主要成分。 相似文献
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J.M. BUENO C.J. COOKSON† M.L. KISILAK†‡ & M.C.W. CAMPBELL†‡§ 《Journal of microscopy》2009,235(1):84-93
A simplified procedure based on Mueller-matrix polarimetry has recently been reported as a method of retinal image improvement in a confocal ophthalmoscope [J. M. Bueno et al ., J. Opt. Soc. Am. A 24, 1337 (2007)]. Here, we have applied the technique to imaging static samples providing well-defined reflection properties. The method uses a generator of polarization states in the illumination pathway of a confocal scanning laser system. From the calculated four elements of the Mueller matrix of any sample and instrument combination, the best images defined by different metrics were constructed. For samples with specular, diffuse and mixed reflections, the best-constructed images showed an enhancement in both objective and subjective image quality compared to the original images and those obtained from frame averaging. This technique could improve microscopic imaging in many diverse fields, particularly in biomedical imaging. 相似文献
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E. F. Ivankin E. V. Peteshchenkov V. A. Ponkin 《Optoelectronics, Instrumentation and Data Processing》2008,44(3):256-263
The developed method for computer designing physically accurate pictures of irregular objects having optically coupled surfaces with diffuse, mirror, and diffusely-mirror reflections is based on solving generalized equations of theoretical photometry. The method is approved by results of mathematical simulation. Applicability of the method for designing pictures of a wider class of objects with diffusely-guided surface reflection is shown. 相似文献
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傅立叶光谱仪用红外漫反射装置 总被引:1,自引:0,他引:1
简要介绍了傅立叶交换光谱仪上用的红外漫反射装置的基本原理和设计思想,并对设计该装置的一些主要问题进行了讨论.该装置辐射能量损失27%,光斑缩小6倍.最后给出了在FTS-7傅立叶变换光谱仪上用该红外漫反射装置测量的几种样品的光谱图,并对该装置的特点作了介绍. 相似文献