磁光调制法测量玻璃内应力

提出了一种基于磁光调制法测量玻璃内应力方向和大小的方法,并建立了基于磁光调制的内应力测量系统。首先,采用光线追迹的方法,根据偏振光的琼斯矩阵描述方式推导了系统的测量模型;采用磁光调制器,对信号光束进行正弦交变的磁光调制,将直接测量光强信号改为测量频率信号,提高了测量准确度;采用磁旋光器,消除了人为操作引起的误差,并通过控制旋光器外加线圈驱动电流的大小,改变调制信号光偏振方向的旋转角度;最后,对待测样品进行了多次旋转测量。测量结果显示,本方法对玻璃内应力方向的测量准确度为5″,对应力双折射的测量准确度为0.3nm/cm。得到的结果验证了该方法的有效性和稳定性,显示系统具有稳定性高、准确度高、容易实现工程化等特点。     

前沿

大口径高光学均匀性磁旋光玻璃研制成功由中鼠科学院西安光机所承担的“大口径高光学均匀性磁旋光玻璃研制”项目日前通过专家鉴定。磁旋光玻璃是一种具有磁光效应的特种光学玻璃,又称法拉第旋光玻璃,主要用于可见光及近红外波段大功率激光输出控制,被广泛用作磁光隔离器、开关、调制和磁光传感器,是高性能大口径法拉第旋转元件不可替代的材料。5月24日,由中国科学院西安分院在西安主持召开了“大口径高光学均匀性磁旋光玻璃研制”项目鉴定会,来自我国7所著名大学和相关研究所的8位专家组成了项目鉴定委员会。会议期间,专家组听取了项目研制…     

光通信用磁光材料的研究进展

综述并分析了磁光玻璃、晶体和薄膜3类磁光材料的影响因素、制备工艺、性能和研究现状,并分别将3类磁光材料的研究成果列表对比。重点介绍了磁光晶体YIG的生长工艺因RoHS的实施而向无铅化发展的情况和掺杂稀土铁石榴石在光通信波段中的性能优势和工艺瓶颈。最后对光通信用磁光材料的未来发展趋势进行了展望。     

显微镜高温台

高温显微术比膨胀测量法、金相测定和磁测定优越。因为它是直接的,而其他方法是间接的。本文介绍了高温炉“Vacutherm 2”的结构及性能,这种高温炉用作金属与某些非金属样品在高温条件下相变的观察和摄影。     

光学玻璃的直接通电熔化

光学玻璃被用来作照相机、显微镜望远镜等的透镜或棱镜,是一种没有光的吸收、散射的无色透明体,它要求不含有条纹、气泡等的均匀质量、没有畸变的各向同性等高质量的玻璃。为了要求更多用途的光学性质的玻璃,现在已生产了200余种,并正在采取多种少量的生产形态。以前主要是用燃烧加热的粘土钳锅熔化法,间接电气加热白金钳锅熔化法。     

高压内混扁平火焰油喷嘴及应用

原来玻璃工厂熔化玻璃的池窑,采用的是高压外混武油喷嘴。这种喷嘴是在喷嘴出口处进行雾化的,由于在雾化阶段不能很好燃烧,因而火根发黑、温度低,火焰喷射面积小、发软,为了正常熔化玻璃,就需要多喷油来提高温度,这就增加了耗油量。为了克服上述缺点,我们设计了一种高压内混扁     

基于稀土掺杂功能玻璃专用高温一体炉的设计

稀土掺杂功能玻璃是一种新型光学玻璃材料,已成为国内外广大学者研究的热点方向之一。本文设计一种稀土掺杂功能玻璃专用的高温一体化炉设备,其集熔化炉和退火炉为一体。该高温炉具备搅拌、随炉浇注,通气氛和可远程控制等特点,在一定程度改变了玻璃的传统制备工艺。本文主要介绍了高温一体炉的设计思想、结构及其主要功能和特点。     

含吖啶红玻璃的光谱特性及荧光寿命

测定了含吖啶红的玻璃复合材料的光谱及荧光寿命,分析了发光特性与玻璃结构间的关系。研究表明,有机碳氢化合物能够稳定地存在于玻璃之中是由于采用了玻璃的低温熔化工艺和玻璃结构中P-F键的存在。     

交变/旋转磁场下焊接缺陷磁光成像检测与分类

针对任意角度焊接缺陷难以检测的问题,研究在不同磁场激励下焊接缺陷磁光成像无损检测系统。重点介绍了由U形磁轭产生的交变磁场和平面交叉磁轭产生的旋转磁场激励焊件的机理,比较了交变/旋转磁场激励下不同焊接缺陷的磁光成像效果。基于法拉第旋转效应分析磁光成像特性与磁场强度之间的关系,磁光图像的灰度值可以匹配相应的漏磁场强度。采用主成分分析法提取融合图像列像素灰度特征和通过灰度共生矩阵提取磁光图像纹理特征,建立BP神经网络模型和支持向量机模型识别这些缺陷特征。试验结果表明,在旋转磁场激励下,BP神经网络模型和支持向量机模型的分类精度分别为94.1%和98.6%,相比交变磁场,分类精度分别提高了10.7%和8.5%。旋转磁场激励下的磁光成像克服了定向检测的局限性,能够实现对任意角度焊接缺陷的检测及分类。     

稀土镝铽在重点行业中的应用

素有工业"黄金"之称的稀土,是继石油之后被发现的重要矿产资源之一。凭借优良的光、电、磁等特性,形成了品类繁多、性能各异的新型材料,大幅度改善了产品性能,在军工、化工、机械、玻璃陶瓷等领域应用广泛。特别是作为军事战略资源,稀土被用来提高军用武器装备的性能和质量,可大大提高国防力量。     

真空平板玻璃的性能及制造技术研究

真空平板玻璃是一种透明、节能型玻璃深加工产品,真空平板玻璃有优良保温隔热性能、防雾防露、隔音性能、抗风压性能、超长的耐久性。真空玻璃运用保温瓶的原理,放置两片平行的玻璃板四周封边而形成空间,并对该空间抽真空,从而使其形成真空层。真空平板玻璃的封接一般采用高温炉熔封接法,真空平板玻璃的支撑可以采用在支撑物的至少一个端面上涂低熔点金属或焊接玻璃,通过加热处理使支撑物固定在玻璃板上,以确保其位置。     

一次生长多根硅芯设备的结构设计

多晶硅是单晶硅生产中必不可少的主要原料,硅芯是多晶硅生产过程中生长多晶的载体。而硅芯炉,主要用于生产多晶硅载体-硅芯。硅芯炉是在惰性气氛下,以高频感应加热,采用区熔法生长硅芯的设备,可一次同时生长多根硅芯,一炉次生产多组硅芯的设备。该设备由机械部分、电气控制部分以及高频电源三大部分组成。论文只对机械结构部份论述,其结构由底座、槽路支架、下传动、炉室、过渡付室、提拉头、真空系统、充气系统、水路等部分构成。     

A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials

An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr(55)Cu(30)Al(10)Ni(5) directly into rods up to ? 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.     

基于模糊预测控制的燃料电池温度控制系统的研究

PEMFC的温度控制系统表现为多输入多输出、耦合、时滞、时变性、非线性、不确定性、信息量少等特点,采用传统的控制方法通常不能得到比较好的控制效果。因此,文章从控制和建模的角度出发,选择了一种基于模糊模型的预测控制算法对PEMFC的温度进行控制,并且通过仿真试验得出了比较满意的控制效果。     

Rheological response of fatty alcohols in sliding elastohydrodynamic contacts

In this study, the authors investigated the appearance of anomalous film shapes in highly sliding circular contacts when fatty alcohols such as 1-decanol, 1-dodecanol, and 1-tetradecanol were used as lubricants. The film thickness distribution between a steel ball and a glass disc was measured via white-light optical interferometry. The experimental results revealed film thickening under high sliding conditions for all three fatty alcohols. It was observed that for 1-decanol, which has the lowest melting point, the thickened part of the film was the smallest; 1-tetradecanol, which has the highest melting point, produced the largest variation of the film shape.     

Analysis of vacuum melting, ultrasonic, and radiographic techniques for gas porosity evaluation in die castings

Parts manufactured using die-casting processes may have significant limitations, mainly due to the tendency for air to be trapped during die-cavity filling. The detection and accurate measurement of porosity due to trapped air are essential issues for improving the quality of manufactured parts. This paper focuses on a comparison of radiographic, ultrasonic inspection, and vacuum melting techniques for analyzing the porosity level due to trapped air in parts manufactured using die-casting processes. To this end, aluminum alloy parts manufactured in a horizontal cold chamber die-casting machine using different injection velocities and mold configurations are analyzed. For the radiographic and ultrasonic techniques, a methodology is established to determine the level of porosity in the part, while, for the vacuum melting technique, a test procedure is established and an expression is obtained to relate the quantity of gas trapped in the part with the pressure increments measured as the part is melted in a vacuum furnace. The advantages and limitations of these techniques to evaluate porosity levels in die-cast parts are discussed in detail. Finally, the possibilities of using these techniques to select operating conditions that reduce the amount of trapped air during the filling stage are analyzed.     

空气助燃窑炉换向期间压力补偿方案设计

窑炉压力是玻璃熔制过程中的主要控制参数之一,压力的波动直接影响到温度和液位的稳定.采用烟道开口补气的设计方案对窑炉换向期间的压力下降进行补偿,从而减小压力波动,稳定窑炉温度.     

Sliding mode controllers for a tempered glass furnace

This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system׳s parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results.     

玻璃钢化+退火集成工艺控制理论与试验研究

创造性地突破了传统的钢化玻璃生产工艺,将玻璃生产的退火工艺和钢化工艺集成到一起,在理论上和机构上均实现了对玻璃升温-降温-升温复杂过程材料内部应变的分析,对玻璃钢化+退火集成工艺过程及应力的变化规律,炉体结构设计制造方法及相关机制、制造工艺、温度控制规律等进行了研究,建立了玻璃钢化+退火温度场模型。运用基于双变异因子的自适应神经模糊控制的方法,对窑炉温度的时变和大滞后现象进行了分析,并开发出一套完整的玻璃钢化+退火一体炉计算机控制系统,为玻璃生产提供了高质量和低成本成型制造理论基础及工程化设计与控制方法。