首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 521 毫秒
1.
本文提出了单模波导参数(薄膜的折射率和厚度)的双偏振测量方法,给出了单模波导参数及其测量误差的计算公式,并测量了单模玻璃波导参数。测量结果表明,这个方法比单模波导参数的多波长测量简单,其测量精度接近波导参数的多模测量方怯。  相似文献   

2.
《工程热物理学报》2021,42(5):1200-1204
风力机叶片覆冰现象严重影响其安全、经济运行,开展覆冰厚度在线测量技术研究具有重要的实际意义。本文提出了共面波导-微带耦合谐振器测量覆冰厚度的方法。通过耦合谐振器等效电路分析,得到了介质厚度测量的理论关系式;建立了耦合谐振器电磁场仿真模型,在谐振器表面覆盖不同介电常数、不同厚度的介质,计算得到了谐振器的谐振频率,进而得到了测量介质厚度的通用关系式,给出了谐振器谐振频率、介电常数和介质厚度之间的函数关系;制作了共面波导-微带耦合谐振器,开展了谐振器表面覆冰实验,测量厚度和实际厚度的相对误差在15%以内,验证了共面波导-微带耦合谐振器测量风力机叶片表面覆冰厚度的可行性。该方法对研究飞机机翼覆冰及其他介质厚度测量具有一定借鉴意义。  相似文献   

3.
周进朝  黄佐华  曾宪佑  张勇 《光学学报》2012,32(12):1212001
依据全反射理论和棱镜耦合原理,实现了对棱镜折射率及波导薄膜材料折射率和厚度的同步测量。使用高准直半导体激光器激光入射到棱镜内部与波导膜的分界面上,逐步旋转棱镜或改变棱镜的入射角,得到棱镜耦合M线,曲线前面几组的波谷为波导模激发,在M线左侧收尾处有一个不完整波峰,其反射光强随入射角迅速衰减,为全反射时的临界点,由此可实现棱镜及波导薄膜参数的同步测量;用此法测量了棱镜耦合一体化平面波导棱镜的折射率和聚甲基丙烯酸甲酯(PMMA)聚合物波导薄膜的折射率和厚度。测量棱镜折射率精度为±1.9×10-4,波导薄膜折射率和厚度的精度分别为±6.2×10-4 μm和±1.6×10-2 μm。  相似文献   

4.
 介绍了一个可用于天线罩电厚度与介质材料介电常数测量的六端口反射计系统,它由对称波导五端口结与定向耦合器组成,其关键部件波导五端口结用HFSS软件仿真与设计。介绍了天线罩相对电厚度复反射系数的测量方法。用该系统对滑动短路器复反射系数进行了测量,测量结果表明,系统工作稳定,测试精度高。利用短路波导法测量了材料介电常数和损耗角正切,测量结果显示:介电常数测量的精度和稳定度较高,损耗正切的测量误差较大。  相似文献   

5.
利用双面金属铝包覆波导的测量方法,测量了硅片的厚度和折射率。这种方法利用双面金属铝包覆波导的超高阶模的偏振不灵敏和对金属层要求较低的特点,降低了对仪器的要求和测量的成本。同时,由于应用高灵敏的超高阶导模为探针,测量精度较高,结果显示测量精度在1%以内。  相似文献   

6.
《光学学报》2011,(2):244-249
波导式光学吸收腔在气体和液体浓度测量等领域有广泛的应用前景.吸收腔的有效光程与系统的灵敏度有直接的关系.提出了波导式吸收腔有效光程率的数学模型.从理论上分析了波导的内壁镀膜折射率和厚度、波导内径和弯曲以及输入光场能量分布等因素对波导式吸收腔有效光程率的影响.对提高系统灵敏度和测试系统的误差补偿提供了重要参考.计算结果与...  相似文献   

7.
采用镀K9玻璃薄膜方法来解决离子交换掺铒磷酸盐玻璃波导表面的侵蚀问题,对K9玻璃薄膜的厚度进行了优化研究。测量分析了样品的荧光光谱和荧光寿命,采用光学显微镜和棱镜耦合技术对不同K9玻璃薄膜厚度下制备波导的表面形貌和导光特性进行了表征和测试。结果表明,与掺铒磷酸盐玻璃原材料相比,镀K9玻璃薄膜后荧光光谱保持不变,荧光寿命稍有下降(约0.2 ms);K9玻璃薄膜的厚度在60~80 nm的范围内保护效果最佳。为下一步制备掺铒有源玻璃光波导器件奠定了良好的实验基础。  相似文献   

8.
利用泄漏波导测量低折射率薄膜的折射率和厚度   总被引:1,自引:0,他引:1  
根据泄漏波导原理对K_9玻璃基板上的冰晶石薄膜进行折射率测量,达到的精度为1×10~(-4),与真实波导的情况相似。文中讨论了利用添加高折射率薄层减小待测薄膜的最小厚度的可能性。文中还利用光电方法观察反射光中暗条纹的方法判别波导的激发,并测出了冰晶石薄膜在4500到6500范围内的折射率。  相似文献   

9.
本文提出了一种新的测量多层光学薄膜参数的方法。利用玻璃载物片夹一层水再夹一层酒精构成了含有两层准光波导薄膜的多层薄膜结构。观察并测量了这两层准光波导的m线,得到了薄膜的光学参数。薄膜折射率的测量误差为±1×10~(-3),薄膜厚度的测量误差为±0.1μm。  相似文献   

10.
通过棱镜耦合方法测量了聚合物薄膜构成的三层平板介质波导不同阶导模下的有效折射率,通过计算机编程解光波导的色散方程,得出了介质薄膜的折射率和厚度.  相似文献   

11.
大庆油田和南阳油田采出水的分析   总被引:3,自引:0,他引:3  
王莹  康万利  高超  杜涛  辛士刚 《光谱实验室》2011,28(3):997-1001
采用高压消解罐法消解处理样品,对大庆油田和南阳油田几个驱块的采出水样品进行了全离子分析.用ICP-AES测定了其中Na、K、Ca、Mg、Al、Ba、Sr、Mn、Si元素的含量.方法回收率在95.00%-106.00%,相对标准偏差小于2.15%.采用离子色谱测定了各驱采出水中Cl<'->、SO<,4><'2->含量,方...  相似文献   

12.
To investigate cross-cultural differences in the community response to road traffic noise, social surveys were conducted in Gothenburg, Sweden, and Kumamoto and Sapporo, Japan, using the same questionnaire and noise measurement method. Typical residential areas with detached houses and apartments were selected as the target areas in each city. The questionnaire comprised 40 questions relating to environmental, housing and personal factors. The key questions concerned annoyance caused by road traffic noise. The total numbers of respondents were 1142 in Gothenburg, 837 in Kumamoto and 780 in Sapporo. The response rates were 68·8, 69·3 and 57·5% respectively. After the questionnaires were completed, noise measurements were made in each area. Community responses were compared on the basis of the dose-response relationships. There were no systematic differences between community responses in Sapporo and Kumamoto, which have the same culture. People living in detached houses in Gothenburg were more annoyed by the same road traffic noise than the people living in Japanese cities. There were no systematic differences among the three cities with regard to activity disturbances indoors, but significant disturbance of activities and resting in gardens or on balconies was noted in Gothenburg. The difference in activity disturbance was due to the differences between lifestyles in the two countries. People living in detached houses were more annoyed by the house vibration caused by road traffic than those living in apartments and people were annoyed by the exhaust from road traffic to the same extent as noise.  相似文献   

13.
Gap detection thresholds for speech and analogous nonspeech stimuli were determined in younger and older adults with clinically normal hearing in the speech range. Gap detection thresholds were larger for older than for younger listeners in all conditions, with the size of the age difference increasing with stimulus complexity. For both ages, gap detection thresholds were far smaller when the markers before and after the gap were the same (spectrally symmetrical) compared to when they were different (spectrally asymmetrical) for both speech and nonspeech stimuli. Moreover, gap detection thresholds were smaller for nonspeech than for speech stimuli when the markers were spectrally symmetrical but the opposite was observed when the markers were spectrally asymmetrical. This pattern of results may reflect the benefit of activating well-learned gap-dependent phonemic contrasts. The stimulus-dependent age effects were interpreted as reflecting the differential effects of age-dependent losses in temporal processing ability on within- and between-channel gap detection.  相似文献   

14.
安徽升金湖是典型的长江中下游自然通江湖泊湿地,是越冬候鸟尤其是珍稀鹤类的理想越冬地,水利设施的修建改变了升金湖的自然连通状况,使湖泊水位变化受人为控制,继而引起景观格局变化,从而影响越冬候鸟生境。为探究水位波动对越冬候鸟生境影响规律,基于Landsat-8(OLI)多光谱遥感影像对升金湖土地利用类型进行分类,结合水位数据和候鸟种群特征数据,选取景观斑块谱特征指数并对其分级,分析不同水文期升金湖湿地水位变化规律,探索湿地景观斑块谱特征时空变化特征,探究不同水文时期自然湿地景观格局和越冬候鸟生境变化规律。结果表明:空间上该区域丰水期大斑块面积占优,枯水期中等斑块面积达到峰值,在退水期和枯水期景观格局分布良好,景观整体表现出大斑块面积占优、数量较少且形状复杂,小斑块分布分散、数量巨大且形状规则,中小型斑块面积均匀,形状各异。时间上景观格局随水位变化,斑块总数随水位升高先增后降,小斑块数量变化最大且稳定性差易受水位波动影响;水位对大斑块形状指数影响较大,水位升高大斑块形状趋于复杂化,涨水期和丰水期大斑块形状指数最大,趋于狭长式分布,景观边缘效应趋于明显,内部结构异质性降低;四个水文期香浓多样性指数分别为1.754 2(涨水期)、1.571 7(丰水期)、1.762 3(退水期)、1.790 1(枯水期),香浓多样性指数减小,景观类型多样性趋于单一。越冬候鸟生境面积与水位高低呈负相关,草滩地、泥滩地和芦苇滩地三种类型面积此消彼长并长期处于平衡状态,草滩地面积在生境面积中占比最高起主导作用(68.01%),总体生境面积在候鸟越冬末期(枯水期)达到峰值,利于越冬候鸟觅食等行为活动。基于此,建议在越冬候鸟前期(8月-翌年1月)通过控水闸人为调控升金湖水位,使各生境类型面积增加,为越冬候鸟提供优质生境。  相似文献   

15.
韦薇  杨怡  黄凡  王中良 《光谱实验室》2010,27(3):977-982
探讨微量元素与糖尿病间的关联性及临床意义。采用ICP-AES等离子体发射光谱仪测定了楚雄地区糖尿病患者人发中11种元素,采用2,3-二氨基萘荧光法测定发样中的硒元素。选取糖尿病患者120例,对照组35例。糖尿病组发样中常量元素Ca、Mg低于对照组,P高于对照组;除Cd、Cr、Fe外,微量元素Zn、Se、Ni、Mn、Cu等5种元素低于对照组,并有显著差异(P0.01)。糖尿病组间性别比较数据显示男性除发Ni、Mn、P外,其余元素含量均低于女性,其中发锌远低于女性。3个不同年龄段糖尿病人群的微量元素含量变化显示Fe、P2种元素随年龄增加含量增高;Mg、Cd2种元素随年龄增加含量减少;其余各元素变化情况为Fe、P元素在老年组中较高,Cu、Cd、Mg较低;Mn、Cr、Cu元素含量在中年组中较高,而Zn、Se略低;Zn、Se在青年组较高,而Mn、Cr低。城市人群发中Zn、Cd、Cu、Mg、Ca含量比农村人群高;Se元素含量二者间差别也不大,其余元素含量均低于农村人群。楚雄地区糖尿病患者发中Zn、Se、Mg、Mn4种元素水平低,楚雄地区糖尿病患者致病原因可能与地区属低Se水平和患者体内硒水平低有关。  相似文献   

16.
The purpose of this study was to evaluate the ability of touch to discriminate fine-surface textures and to suggest possible mechanisms of the discriminations. Two experiments were performed. In experiment 1, aluminum-oxide abrasive papers were adopted as stimuli, and psychometric functions and difference thresholds were determined in fine-surface-texture discrimination tasks. The grit values of abrasive papers were 400, 600, 1200, 2000, 3000, 4000, and 8000; corresponding average particle sizes were 40, 30, 12, 9, 5, 3, and 1 micron, respectively. Ten subjects participated in experiment 1. The difference thresholds obtained in experiment 1 were between 2.4 and 3.3 microns. In experiment 2, the tasks were discriminations of ridge height. The cross sections of the etched ridges were rectangular and the ridge heights were 6.3, 7.0, 8.6, 10.8, 12.3, 18.5, and 25.0 microns. Six subjects participated in experiment 2. The difference thresholds in experiment 2 were between 0.95 and 2.0 microns. It was reasoned, based on the Weber fraction values calculated from the difference thresholds and on the limit of neural information-processing ability of humans, that the subjects discriminate fine roughness only from the amplitude information presented in surface unevenness.  相似文献   

17.
为揭示单味煎剂与方剂间的关系,分别测试分析了生地当归药队、单味药生地和单味药当归煎剂的表面增强拉曼散射(surface-enhanced Raman scattering, SERS)光谱,并对其进行谱峰归属。本文主要针对存在于三种煎剂中的17个拉曼信号(538,622,732,761,835,876,959,1 145,1 245,1 276,1 326,1 402, 1 456,1 470,1 518,1 546和1 605 cm-1)进行讨论。生地当归药队煎剂SERS光谱在538,732,761,835,876,959,1 145,1 245,1 276,1 326,1 402,1 456,1 470,1 518和1 605 cm-1处,出现15个明显的拉曼信号;生地煎剂SERS光谱在538,761,835,876,959,1 145,1 245,1 276,1 326,1 402,1 470,1 518和1 546 cm-1处,出现13个明显的拉曼信号;当归煎剂SERS光谱在538,622,732,761,835,876,959,1 245,1 326和1 402 cm-1处,出现10个明显的拉曼信号。生地当归药队煎剂SERS光谱保留了和未观察到生地和当归单味煎剂的某些拉曼峰,且产生了生地和当归单味煎剂中所没有的拉曼信号(1 456和1 605 cm-1),即产生新药物成分。生地当归药队煎剂所包含的药物成分并非是生地和当归单味药物煎剂所含药物成分的简单相加。结果表明,SERS光谱可能为方剂研究提供一种高灵敏度、快速准确和操作简单的检测方法。  相似文献   

18.
The dynamics of plastoglobules in chloroplasts in aging watermelon leaves were examined by means of transmission electron microscopy, with the aim to understand the intracellular sites for the degradation of plastoglobules in response to leaf senescence. Plastoglobules in chloroplasts in aging leaves with 40% loss of chlorophyll increased drastically in number and size in comparison with young and mature leaves. As senescence advanced, plastoglobules underwent degradation within chloroplasts, or were secreted outside chloroplasts. There were two distinct types of secretion. One type was that chloroplasts protruded to form plastoglobule-containing vesicles and, as the vesicles were detached from chloroplasts, plastoglobules were carried outside chloroplasts. The other type was that plastoglobules squeezed out through the chloroplast envelope into cytoplasm. Lipid droplets were present in the vacuole and underwent degradation therein. Lipid droplets in the vacuole shared similar ultramicroscopic appearance with plastoglobules in chloroplasts, indicating that plastoglobules were engulfed and degraded by the vacuole after they were secreted outside chloroplasts. These results suggested that senescence induces both in-situ and vacuolar degradation of plastoglobules in aging watermelon leaves.  相似文献   

19.
“烧蚀模式”激光推进的实验研究   总被引:12,自引:7,他引:5       下载免费PDF全文
 采用单脉冲激光进行了大气环境下激光烧蚀小钢珠实验,得到其推进效应参数,发现并分析了钢珠在不同放置位置(焦前与焦后)时不同的物理现象;为了得到一系列定量实验数据,采用自行研制的激光冲量靶仪进行了单脉冲激光烧蚀推进效应实验测试,得到了不同环境条件、不同靶材料的激光推进效应参数,并与国外的实验数据以及数值计算结果进行了比较。实验表明,靶材料和激光功率密度是影响冲量耦合系数的主要因素,冲量耦合系数随环境气压的降低而升高。  相似文献   

20.
无衍射贝塞尔光束相干的理论与实验   总被引:3,自引:3,他引:0       下载免费PDF全文
 分别使用两种不同底角的轴棱锥产生无衍射贝塞尔光束。理论分析了单束贝塞尔光及两束贝塞尔光相干叠加后光场的光强分布,分析了产生的局域空心光束在一个完整周期内的特性。数值模拟了光沿纵向传播时光场的横向光强分布,并给出了相关的实验。对单束贝塞尔光及两束贝塞尔光干涉后的中心光斑的大小进行了测量,测量结果与理论计算结果吻合。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号