OMA-CH1型光学多道分析仪的光学特性

OMA—CH1是作者研制的光学多道分析仪,本文分析研究了该仪器的光学特性:分辨率,色散率,仪器函数,偏振效应等。并应用该仪器作了许多光谱实验,效果良好。     

光学教学中培养学生科研能力模式的探析

文章主要讨论在光学教学中培养学生的科研兴趣及树立科研的信心,以及在光学教学中如何培养学生科研能力的一些措施及途径,目的是寻找一种合适的教学模式,使高校的光学教学与科研有机地紧密结合,促成更多学生参与科研、创新活动,提高光学理论教学和实验教学效果,有效推进光学教学改革,培养出更多、更好的适应社会发展的创新性、应用型的人才。     

光纤到户技术应用及楼内综合布线策略

在国家三网融合的进程中,通过对光纤到户工程的实施、对各运营商操作,及对现实楼内光纤综合布线施工方案进行分析,据此提出科学合理的光纤到户在城市建设综合光纤布线策略.     

光盘网络信息检索系统开发与应用

光盘网络信息检索是90 年代随着计算机网络通讯技术的发展而兴起的一种信息检索技术。文章对图书馆光盘网络信息检索系统的系统结构设计、系统功能设计以及系统应用效果等方面进行了详细的介绍。     

An NDT electro-optic system for mosaics investigations

Electronic speckle pattern interferometry (ESPI) is a well-known tool in cultural heritage diagnostics. It is also suitable to reveal cracks and debondings of tiles in ancient mosaics of Roman and Medieval age. This paper describes a portable electro-optic system as a diagnostic tool to evaluate the state of conservation of ancient mosaics. The proposed system is based on the integration of ESPI and local speckle correlation techniques. Some experiments have been carried out on real, ancient, mosaics in laboratory and in situ. The different features of each technique are outlined and a comparison with holographic interferometry is also given.     

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

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.     

新一代光传送网———OTN技术及应用

OTN是以波分复用技术为基础、在光层组织网络的传送网,是下一代的骨干传送网。文章阐述了光传送网的概念、特点、复用和映射原理、OTN设备,并对OTN光传送网的应用进行了简要的介绍。     

《自组显微镜》设计性实验的探索与实践

通过分析《自组显微镜》设计性实验的现状,针对其问题进行探索与实践,使该实验成为严格意义上的设计性实验。实践表明,改革后的实验为学生提供了一个很好的设计性实践平台,进一步激发了学生的学习兴趣和创新意识,提升了学生的科研能力。     

Mineralogical and microstructural characteristics of historic Roman cement renders from Budapest,Hungary

Roman cements, one of the most extensively produced types of hydraulic binders of the second half of the 19th century, played an important role in the architecture of many European countries. This paper deals with the chemical-mineralogical and microstructural characterisation of historic Roman cement renders from Budapest, Hungary. Different microscopic techniques were used on polished thin sections and fracture surfaces in order to understand the method of producing these renders and the effect of urban pollution on them. The renders exhibited characteristics typical to a Roman cement mortar, such as high binder to aggregate ratios (b/a), mostly fine-grained aggregates and high capillary porosity, but without the shrinkage cracks that are also normally present. This research suggests that coarse residual cement grains may have acted in a manner similar to aggregates by absorbing stress and thereby reducing the formation of shrinkage cracks. Based on the mineral characteristics of residual cement grains, the samples could be divided into two groups, which correspond to either a higher or lower temperature of calcination of the original source material of the cement. Chemical characteristics of the binders suggest the presence of intermixed CaCO₃ originating from the carbonation of hydration products and partly from residual calcium carbonate of the raw material. Despite dense and often impermeable coats applied in later renovations and exposure to a polluted urban environment, which resulted in formation of gypsum on the surface of the renders, the samples show good to excellent state of preservation after more than a century. The strong “house of cards”-like arrangement of the complex C-(A)-S-H-type phases is responsible for both the high capillary porosity and the good resistance of Roman cement renders to atmospheric pollution and potentially damaging salts such as Na- and K-chlorides which are found near the base of the building due to sidewalk de-icing. These results help to better understand the behaviour of historic Roman cement renders, which in turn assists in making good decisions in choosing a repair material to future restorations of 19th century façades built with this material.