N-异丙基丙烯酰胺对软接触镜材料性能的影响

以0.2%的2-羟基-甲基苯基丙烷-1-酮(1173)为引发剂,0.5%的二乙二醇甲基丙烯酸酯(EGDM A)为交联剂,常温下用紫外灯合成了N-异丙基丙烯酰胺(N IPAm)/甲基丙烯酸2-羟基乙酯(HEM A)/N-乙烯吡咯烷酮(NVP)三元共聚物;与相同条件下合成的HEM A/NVP共聚物进行了试验对比。凝胶在水中的溶胀实验证明,含N IPAm的三元共聚物溶胀率对温度的敏感性强于HEM A-NVP共聚物;傅立叶红外光谱与热重测试显示了两种材料的结构差异。     

Optical quality of intraocular lenses after several years in the human eye

The optical quality of explanted intraocular lenses (IOLs) was analysed to verify if their quality is maintained after having been in the human eye for several years. Twenty-five explanted IOLs were studied, 10 because of intraocular luxation and 15 from corneal donors. The dioptric power and modulation transfer function (MTF) were determined to discover the image quality of the IOLs. The spectral transmission was also established to ascertain whether the filter against ultraviolet (UV) radiation was still effective. The results show that the MTF of implanted IOLs is maintained and therefore so is the image quality they provide. Only decay in the MTF of some of the explanted IOLs was observed because of intraocular luxation. The transmission of the UV filters incorporated in the different IOLs hardly varied; thus they maintained their effectiveness.     

紫外光纤的激光传输特性测试

为适应紫外激光传输需要，试制了高透过紫外石英光纤，设计了实验装置，并测量了该种光纤的紫外传输损耗、弯曲损耗、激光损伤阈值和非线性光学效应，并与普通商用石英光纤作比较。分析并获得了紫外光纤的激光传输特性。     

超精密光学镜片三维表面形貌参数评定方法研究

分析了当前超精密光学镜片表面评定方法及其存在的不足,提出引用ISO 25178-2中规范的部分表面3D参数来表征精密光学镜片三维表面,找出光学镜片表面形貌与对应的光学性能存在的关系,并实现ISO对超精密光学镜片三维表面的评定。仿真实验表明:当光学镜片表面的高度服从高斯分布时,其评价光学系统性能的传递函数随着均方值的减小而增大。用实例说明ISO的部分三维参数对光学镜片三维表面可以很好地区分,利用新的综合评价方法评定光学镜片表面形貌具有一定的可行性。     

Methods and Facilities for Determining the Metrological Characteristics of Contact Heat Flow Transducers

Questions of metrological provisions for contact heat flow transducers by means of which it is possible to monitor heat losses at the surface of thermal energy objects are considered.     

超表面在红外波段的光传输特性:偏振控制、旋光性和不对称传输

超表面(Metasurfaces,MMs)是拥有亚波长尺寸谐振单元结构的人工平面材料,其电磁特性主要由结构决定。超表面具有极强的波前控制能力。本文着重介绍了近年来纳米结构超表面在红外波段的光传输特性,包括光波偏振控制、旋光性、不对称传输等方面的理论和实验研究进展,简要介绍了制备纳米结构超表面的工艺技术。     

Standardization in Transmission Spectrophotometry in the Visible and Ultraviolet Spectral Regions

In an instrument as complex as a spectrophotometer there are many potential sources of error. Because of this it is useful to have available standard materials whose spectral transmittances are known accurately. Periodic measurement of such standards provides a useful indication of whether a spectrophotometer is producing accurate results.If the spectral transmittance functions of these standards are chosen suitably, the measurements can provide diagnostic information to indicate what type of error is occurring. Among the factors that most often lead to errors in spectrophotometry are the slit-width, the wavelength scale, the photometric scale, and stray radiation. Suitable material standards can provide indications of the occurrence of these errors. However it is sometimes difficult to identify a particular error since often several errors will occur at the same time.Several sets of standards for testing spectrophotometers are available or can be constructed easily. Most of these are glass filters, but interference filters, perforated screens, and rotating sectors are also used. Liquid filters have some advantages, especially in the ultraviolet where glass filters absorb too strongly to be useful. However difficulties in preparing and handling liquid filters can introduce uncertainties.It is important that standard materials are insensitive to environmental conditions (such as temperature) and that they are stable over a long period of time. Unfortunately, many of the materials with the most suitable spectral characteristics are least suitable in these respects, and it would be very useful if new and better materials could be developed.     

基于光学基准法的导弹弹体几何参数检测

导弹控制系统、瞄准系统及装弹要求对导弹弹体纵轴线垂直度、空间尺寸及位置测量提出了一定精度要求。本文提出用光学基准法代替传统检测方法,对导弹弹体坐标及几何参数进行检测,精度高、快速准确,得到了实际应用。     

电力输变电系统金具与输电导体的接触电偶腐蚀及保护方法

对热镀5%铝锌合金和纯锌的电力金具与铝导体接触电偶腐蚀行为进行了研究.测定了两种镀层电力金具与输电铝导体接触电偶腐蚀电流密度与时间的关系,分析了腐蚀产物的形貌,测定了不同镀层的中温抗烧蚀性能.结果表明,热镀5%铝锌合金镀层与铝导体的接触电偶腐蚀电流密度比热镀纯锌镀层平均降低了22%,镀层的腐蚀产物主要为非晶物质,镀层在400℃下加热96 h,热烧损失重降低92%.对电力金具钢基体热镀5%铝锌合金,其表面接触电偶腐蚀及热烧损失重比传统热镀纯锌效果更佳.     

世界主要国家良好农业规范标准体系比较与借鉴研究

尽管不同国家和地区的良好农业生产规范标准(GAP)具有相似性,但也在很多方面表现出差异性。发达国家之间、发达国家和发展中国家之间,在认证标准制定、政府作用、认证产品体系、认证重点目标、生产主体、基础设施、认证文化等方面都有明显的不同。中国的良好农业规范认证,应在借鉴其他国家认证经验的基础上,充分发挥政府作用,立足于小农国情,提升生产主体的组织化程度,以促进外贸出口为重点。     

弹流油膜光学测试系统的特性分析

光干涉法是弹流润滑膜厚度测量的最有效的方法之一。传统的理论认为光弹流干涉主要是双光束干涉，即光干涉强度是油膜厚度的余弦函数，通常应用该余弦关系分析弹流干涉图象。然而，几个光弹流实验均表明干涉强度随油膜厚度的变化同科弦规律有明显的偏离。应用薄膜光学理论对光弹流测试系统进行了分析，干涉强度的计算结果和实验数据吻合一致，弹流光学系统的多光束干涉本质和金属膜的光吸收特性是干涉强度偏离余弦分布的原因。     

LOW-E薄膜光学性能的计算机辅助模拟

本文对低辐射镀膜层的理论光学特性的计算机辅助模拟 (CAS)进行了探讨。研究表明 ,在可见光和红外区范围内进行的低辐射镀膜层光学测量显示了计算机辅助模拟理论计算与实验结果存在较好的对应关系     

反射式横向位移光纤传感器特性

在实验测量的基础上形成了一种在高斯光束几何反射模型下的一维数值计算方法,可以在计算机上对反射式横向位移光纤传感器的特性进行计算分析,为该传感器的优化设计提供了一个必要工具.对用62.5/125多模光纤组成的并列反射式横向位移光纤传感器的计算分析结果表明:接收光纤端面处的反射光斑半径在180 μm附近时有最大的接收光强和最佳信噪比;反射光斑半径在180 μm～600 μm时接收光强对反射条边缘的横向位移或横向振动的动态范围、线性关系和信噪比都较佳;接收光强对反射条横向位移的分布宽度主要取决于反射条的宽度和接收光纤的芯径.     

小型非球面光学元件测量技术研究

非球面光学元件应用越来越广泛,其测量技术非常关键.本文研究了小型非球面光学元件的各种面形测量方法,针对其测量原理进行了分类和对比,对其优缺点和适用范围进行了讨论,同时分析了各种测量方法实现的关键技术和面临的挑战.     

多尺度方法在微/纳接触行为模拟中的应用进展

多尺度方法在求解的不同区域采用不同尺度的力学模型,在精确描述材料力学行为的同时,提高了计算效率,是近年来得到较大发展和广泛应用的一种材料计算方法。介绍了跨原子和连续介质多尺度算法的过渡区设计、基本算法,以及影响算法精度的主要因素。评述了多尺度方法在微/纳粗糙表面接触行为研究中的应用,在三维多尺度算法中更好地控制温度将提高模拟精度。     

眼球系统中关键屈光元件的光学模型研究

角膜和晶状体是人眼光学系统中两个关键的屈光元件,为了理解眼内各介质和整个眼球的屈光状态以及视网膜上的成像,有利于眼科临床方面的应用,需要分别对二者进行光学特性模型的分析与研究。根据角膜和晶状体的光学特性,应用光学设计软件Zemax和有关的数学工具,从光学成像角度,分别对角膜和晶状体模型进行研究:基于结合人眼光学模型的角膜双二次曲面模型的建立方法,统计分析了我国人眼实测角膜参数的数据;通过对晶状体折射率分布特点的分析,分别在轴向和径向上进行了综合分析。最后给出了符合我国人眼特点的角膜面型的统计数值,完善了我国人眼角膜光学模型的建立;获得了形式简单且能够表示晶状体折射率分布一般特征的梯度渐变模型表达式。基于收集的我国人眼实测数据的角膜面型模型和晶状体梯度渐变形式的折射率模型,为解决人眼光学系统研究中的关键问题提供了新的方案和思路。     

光纤功率计非线性度校准方法及不确定度评定

介绍了两种光纤功率计非线性度的校准方法，并对两种方法的测量不确定度来源进行了分析、比较。     

超薄电子信息玻璃光学均匀性的检测方法

光学均匀性是衡量电子信息玻璃质量的重要参考指标。在电子信息显示产品中,对电子信息玻璃光学均匀性要求非常高,尤其是超薄电子信息显示玻璃,会直接影响其显示效果。本文详细介绍了几种用于测量玻璃光学均匀性的方法及其原理。对比发现,平面干涉与其他方法相比精度较高,较适用于超薄电子信息玻璃光学均匀性的检测。且常用的检测方法无法实现对毛坯玻璃的高精度检测,只有平面干涉法才能满足这一要求,使检测精度高达0.5×10-6,具有较好的应用价值。     

External-Field Shifts of the 199Hg+ Optical Frequency Standard

Frequency shifts of the ¹⁹⁹Hg⁺ 5d¹⁰6s ²S_1/2 (F = 0, M_F = 0) to 5d⁹6s^{2 2}D_5/2 (F = 2, M_F = 0) electric-quadrupole transition at 282 nm due to external fields are calculated, based on a combination of measured atomic parameters and ab initio calculations. This transition is under investigation as an optical frequency standard. The perturbations calculated are the quadratic Zeeman shift, the scalar and tensor quadratic Stark shifts, and the interaction between an external electric field gradient and the atomic quadrupole moment. The quadrupole shift is likely to be the most difficult to evaluate in a frequency standard and may have a magnitude of about 1 Hz for a single ion in a Paul trap.     

Experimental Investigation of Load Sharing in Multiple Gear Tooth Contact Using the Stress‐Optical Method of Caustics

Abstract: In this paper, a comprehensive methodology for calculating load sharing in multiple tooth contact is presented based on the experimental stress‐optical method of caustics. The technique is applied to a set of poly‐methyl‐methacrylate gears at various meshing positions covering a complete meshing cycle, including single and multiple gear tooth contact. The load sharing factor (LSF) is calculated using well‐established mathematical formulae from the photographs of the transmitted caustics and the obtained results are compared with the pertinent International Organisation for Standardisation and American Gear Manufacturers Association standards with which good agreement is verified. The proposed method is a reliable alternative for measuring load distribution in gear teeth compared with photoelasticity and other experimental techniques.