Continuous monitoring of wooden works of art using fiber Bragg grating sensors     

R. Falciai  C. Trono  G. Lanterna  C. Castelli 《Journal of Cultural Heritage》2003,4(4):285-290

In recent years the control and monitoring of works of art has gained more and more importance. In particular, works partially or totally realized with wood, such as polychrome sculptures, painted panels or Crucifixes, are highly sensitive and delicate and thus need a particular attention. The wooden support is, in fact, an essential element for the stability of pictorial layers: the color lies on a preparation, which in turn, is anchored to the wood. Wrong conservation methods, i.e. in an environmental climate that is not controlled, or intrinsic mechanical stresses, can warp such structures, and the effects can be irreversible and destructive to the painted layer. The use of fiber Bragg grating (FBG) sensors for the quasi-distributed, in situ measurement and continuous monitoring of deformations in painted wood panel is proposed. In order to demonstrate the applicability of FBG sensors to painted wood panels, a wooden support, made using the same 15th–16th century techniques, was prepared in the Opificio laboratories. A number of Bragg grating sensors were affixed in several critical points, on the back and front sides and on the strengthening cross-beams, in order to detect deformations in the panel dependent on the variations in the environmental relative humidity (RH). Measurements during the removal of the cross-beams are also reported. The results of measurements have shown the applicability of FBG sensors for the continuous in situ monitoring of valuable wooden objects and works of art.  相似文献   

Use of imaging spectroscopy,fiber optic reflectance spectroscopy,and X-ray fluorescence to map and identify pigments in illuminated manuscripts     

John K. Delaney  Paola Ricciardi  Lisha Deming Glinsman  Michelle Facini  Mathieu Thoury  Michael Palmer 《文物保护研究》2014,59(2):91-101

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几何光学课程教学改革与实践     

岳保旺  高雁 《中国现代教育装备》2014,(7):43-44

针对学生实际和课程的发展,在几何光学教学中,根据教学内容的取舍、数学处理的详略、科学素质的培养和多媒体的使用等进行了研究和实践探索,取得了较好的教学效果。  相似文献   

两种光学薄膜反射系数计算方法的对比     

张颖颖  宋炜  徐小兵 《南京晓庄学院学报》2014,(6):21-24

该文介绍了两种光学薄膜反射系数的计算方法——等效界面法和导纳矩阵法,并比较了两种方法在多层光学薄膜结构下的反射率和相位差计算结果.发现当计算数值有效位数为15时,两种方法的反射率和相位差结果差异分别为10-15量级和10-14rad量级,远小于反射率和相位差的测量分辨率,可以认为两者的结果相同.这说明两个基于相同理论基础的方法,计算结果也是相同的,并通过实验证实了计算结果的可靠性.  相似文献   

利用三脚型人工原子的共振激发实现几何相位门     

胡晓亮  陈翠云 《湖南科技学院学报》2009,30(4)

考虑了由SQUID量子电路构成的三脚型四能级人工原子,利用共振激光脉冲获得几何相位门. 阐明了量子态几何相位的形成,其变化可由三束激光脉冲波形、相对强度及其相位来控制. 同时,基于几何相位,给出了实现单量子比特门、Hadamard门和两量子比特受控非门的方案.  相似文献   

A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide     

Dong-lin Tang  Xiao-dong Zhang  Guang-hui Zhao  Zhi-yong Dai  Xin Lai  Feng Guo 《浙江大学学报(A卷英文版)》2009,10(4):595-600

An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.  相似文献   

Towards a representation of diffusion and interaction of scientific ideas: The case of fiber optics communication     

Yuxian Liu  Ronald Rousseau 《Information processing & management》2012

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基于布里渊散射的长距离分布式监测网络技术   总被引：2，自引：0，他引：2  

刘德华  宋牟平  金伟良  张恩勇  邵剑文 《科技通报》2004,20(5):415-419

研制开发了基于布里渊散射的分布式健康监测网络,实时监测大范围、长距离土木工程结构.通过获取构筑物结构变化的信息,自动预警严重事故,综合评估结构的可靠性.借助分布式系统串联技术解决了超长距离传感问题,利用波分复用技术实现了单根光纤传感与数据通信复用,采用以应变模态概念为基础的结构诊断技术智能分析判断结构状态.单个系统传感距离可达到40km,多级串联后可达到几百公里,空间分辨率 15m,应变分辨率 500με.  相似文献   

一维光子晶体传输矩阵法的分析改进   总被引：2，自引：0，他引：2  

王卓远  邵汀汀  王一刚  闫文哲 《科技通报》2007,23(6):774-777

为了更准确地分析一维光子晶体的光子禁带特性和研究改善光子晶体性能的方法,通过在传输矩阵法的推导过程中加入了多重反射的概念和修正了传输矩阵的相位项,改进了用传输矩阵分析一维光子晶体禁带特性的方法,提高了计算精确度,结合理论仿真数据与实验测量值的对比证明了该改进算法的有效性,尤其是在非垂直入射的情况下,改进算法与实验数据符合良好。另外还探讨了组成光子晶体膜层的高低折射率介质的折射率比值,光学厚度,周期数等参数对光子禁带特性的影响,并提出了通过选用合适的光学厚度和周期数,采用新型材料,引入多缺陷态结构等改进一维光子晶体禁带特性的初步设想。  相似文献   

突出军校专业特色 建设现代光学实验中心     

沈洪斌  李刚  胡文刚  张雏 《实验室研究与探索》2011,30(2):91-94

结合教学工作评价和军队"2110工程"建设,抓住新的发展机遇,大力建设高水平现代光学实验中心。论述了实验中心建设中的指导思想和具体做法,达到了"立足光学前沿理论技术,跟踪新装备发展,满足多层次教学"的建设目标,为培养创新型光电专业军事人才打下良好基础。  相似文献