以BMA-MA共聚物为成膜树脂的光致聚合物材料的全息性能

采用溶液聚合法合成了水溶性的甲基丙烯酸丁酯-甲基丙烯酸(BMA-MA)共聚物,以这种共聚物为成膜树脂制备了光致聚合物全息材料,研究了光致聚合物全息材料的光敏性、衍射效率、空间频率响应、折射率调制度、曝光能量常数等全息性能。结果表明,在记录信号空间频率为1580 cy/mm时,以BMA-MA共聚物为成膜树脂的光致聚合物全息材料的灵敏度可达15 mJ/cm2,最大衍射效率为92.8%,曝光能量常量为10.9 mJ/cm2,衍射效率随所记录信号空间频率的增加而降低,材料的最大折射率调制度为2.85×10-3,是一种具有一定应用前景的光致聚合物全息材料。     

对绿光敏感的全息存储光致聚合物性能的研究

报道了一种对绿光敏感的以丙烯酰胺为单体的光致聚合物，该光聚物由单体、光引发剂、共引发剂和成膜物组成。可以得到材料的最大衍射效率为55％。将光聚物用不同温度进行烘烤加热，可以看到材料的折射率调制度会增加。使用角度复用技术在光聚物中存储10幅全息图，说明所研究材料有希望于大容量体全息存储。     

全息涂料用丙烯酸树脂的合成工艺研究

研究探讨了一种适用于全息图文模压复制涂料的丙烯酸树脂的合成工艺.通过讨论单体配比、合成温度、聚合时间以及引发剂的类型和用量对树脂性能的影响;对丙烯酸树脂合成工艺条件进行了优化:当单体MMA∶MBA∶BA∶MAA组成比为60∶30∶5∶5,反应温度为120～126℃,聚合反应时间为5h,引发剂偶氮二异丁腈的用量为单体质量的1.5%时,所得的树脂固含量为49.9%,粘度为5690mPa·s,涂膜铅笔硬度为1H,光泽度高达90.5Gs,适合制备纸张全息图文模压复制涂料.     

纸基全息印品图文质量的影响因素分析

介绍了纸基全息印品的生产工艺流程,分析了全息涂料的单体组成对涂膜性能的影响,讨论了激光全息图文质量的光学特性指标--衍射效率和信噪比,着重阐述了模压温度、纸张表面光泽度和背景颜色对衍射效率的影响.     

一种新型绿敏光致聚合物及全息特性研究

报道了一种新型的对绿光敏感的光致聚合物材料,对环境湿度不敏感,材料的干燥时间短。该材料以丙烯酰胺为单体,N-苯基甘氨酸作为引发剂,藻红B作为光敏剂,并加入成膜剂聚乙烯醇及增塑剂二甲亚砜。对材料中光引发剂、光敏剂及增塑剂浓度进行了优化,发现其有一个最佳值。本材料记录的全息图衍射效率可达50％以上,感光强度为60mJ／cm^2。在光聚物介质上能够记录信噪比比较高的图像,说明该材料可用于全息存储。     

数码激光全息技术

一、数码激光立体(全息)照排系统数码激光全息(DigitalHolography)技术是通过计算机程序控制、全智能化设计和制作动态激光全息图像与文字的高新技术,用数码激光全息图像技术形成的“数码激光立体(全息)照排系统”是光、机、电和计算机技术的高度集成。在计算机技术、激光全息技术、数字图像处理技术、精密光学控制技术、衍射光学制造技术和工艺发展的基础上,激光无油墨印刷技术有了突破性的发展,产生了激光防伪包装印刷这一新技术,在包装、印刷和防伪行业有了巨大的发展空间。数码激光图像技术的核心是数码激光图像的生成、处理、控制和制…     

铬胶全息干板及其在全息领域中的应用

重铬酸盐明胶(简称铬胶)作为全息记录介质,具有高衍射效率、高分辨率(6000线/毫米)、高信噪比和低噪音等特性。最近十几年来广泛引起人们的注意。铬胶全息干板不仅可以用于氦镉激光(441nm)、氩激光(488nm,514nm),而且经过光谱增感后,还可以用于氦氖激光(633nm)。用铬胶全息干板可以制做光栅、光学透镜、滤波器等多种全息光学元件,而且体小质轻、形状可变,在空间技术、军事领域特别受到重视。本文介绍了铬胶作为全息记录介质在国外的发展情况;铬胶全息干板的全息特性、制做、处理程序以及影响因素,此外还介绍了铬胶全息干板在全息领域中的各种应用。     

一种基于聚乙烯醇/丙烯酸-2-羟基乙酯的新型全息存储材料

本文研究了一种基于聚乙烯醇/丙烯酸-2-羟基乙酯的新型全息存储材料;研究了不同浓度的丙烯酸-2-羟基乙酯对光聚物材料衍射效率的影响;在厚度为95μm的光聚物薄膜中当曝光能量为231mJ/cm2时获得了近75%的高衍射效率。应用Matlab软件以光化学漂白理论、角度响应曲线理论为拟合模型,进行了基于Levenberg-Marquardt算法的非线性曲线拟合;通过非线性曲线拟合研究了不同浓度的丙烯酸-2-羟基乙酯对摩尔吸收系数、量子产率、折射率调制度、光聚物薄膜厚度等多个全息参数的影响;实验表明,丙烯酸-2-羟基乙酯的加入可有效增加光聚物薄膜的厚度并且改善光聚物薄膜的结构和性能,达到提升聚乙烯醇/丙烯酰胺光聚物初始材料的全息特性,改进光聚物材料全息光学数据存储容量的目地。     

含氟有机减反射膜的研究

采用低温等离子体辉光放电技术,用含氟有机单体在硅太阳电池表面聚合成膜。测定膜的光电性能和反射率证实:有膜电池的短路电流、光电转换效率及光谱响应都有明显增加,反射率绝对值降低2％左右,膜为非晶结构。此外,还研究了成膜工艺因素和膜电池性能的关系。     

巯基-双键点击反应制备光固化红光转光膜及其性能

本研究将不同含量的稀土转光剂与含巯基和双键单体共混制备了光固化树脂,然后经巯基-双键或双键-双键点击反应制备了两种农用转光膜,通过荧光光谱、UV光谱、SEM、拉伸性能测试等对转光膜的结构与性能进行表征。研究结果表明,添加0.5%(质量分数)稀土转光剂的转光膜能将波长为353 nm的紫外光转换为波长为613 nm和617 nm的红光,且该转光膜具有良好的透光性能和力学性能,拉伸强度达到12.72 MPa,在农业大棚、玻璃温室等方面具有良好的应用前景。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...