直流驱动真空荧光显示器的阴极设计

当真空荧光显示器的阴极直流驱动时,其电位随位置的不同而变化,结果导致发光亮度的不均匀;阳极电压比较低时,显示屏二端的发光亮度相差近42%。本文通过改变栅极到阴极距离对发光亮度变化的分析;指出在阴极和栅极之间距离随位置作线性变化时发光亮度的均匀性可以很好地得到改善;并给出了极间距离的修正关系;修正后显示屏二端的发光亮度基本一致,全屏的发光亮度不均匀度小于±7%。本文讨论的结果可为设计低压直流驱动的真空荧光显示屏提供理论依据。     

“失效专利精选”(四)

真空绝热啤酒保鲜桶本实用新型涉及一种真空绝热啤酒保鲜桶,它是由外壳、内胆、大盖和放酒阀连接构成,在外壳上部扣接一个顶壳,顶壳与外壳的接口处安置着橡胶密封圈,顶壳上还安置有抽气嘴和真空表,抽气嘴和真空表与外壳内胆间的真空层相连通。本实用新型结构简单,密封性好,绝热保温性能高,生产简便,成本     

碳纳米管场发射显示屏发光规律研究

通过低压化学气相沉积法在硅片上制作碳纳米管薄膜阴极,用真空荧光显示器的封装工艺,制备了碳纳米管场发射显示器试验性样管。比较测试可知,直接测量显示屏的器件电压和测试电源驱动电压所得结果是不同的,用后者代替前者不够合理。通过光亮度与电压、电流、功率的关系曲线比较分析可知,用光亮度与电流成线性关系的结论表征碳纳米管场发射显示屏的性能比用电压更合理,更利于器件的分析和设计。     

真空微电子荧光平板显示器件的实验研究

描述了真空微电子荧光平板显示器件的工作原理，提出了采用反应离子刻蚀法制作大规模场致发射阵列的工艺，在动态真空系统中测定了荧光平板显示器件的场发射特性，并获得了结果。     

真空溅射镀膜机衬底加热装置的设计

真空溅射镀膜设备中加热装置在镀膜时常出现打火现象，本文采用金属屏蔽和外壳接地的方法很好地解决了这一问题。     

真空微电子荧光平板显示器件的实验研究

描述了真空微电子荧光平板显示器件的工作原理，提出了采用反应离子刻蚀法制作大规模场致发射阵列的工艺，在动态真空系统中测定了荧光平板显示器件的场发射特性，并获得了结果。     

青海发布实施7种土特产品地方标准

日前，我国《超白浮法玻璃》建材行业标准通过审查。《超白浮法玻璃》行业标准的制定和实施，不但为准确评价超白浮法玻璃产品质量提供了科学的依据，还将有效地指导企业组织生产，对于规范超白浮法玻璃产品市场，引导市场的消费与需求，     

数显水表的研发与传统水表准确度的比较

一、原理与设计 1．工作原理 电子数显水表由外壳、翼轮测量机构、流量传感器、电子计算仪、数字显示屏、连接体、连接件组成。被测液体流经电子数显水表后,冲击测量机构的翼轮旋转,翼轮上带有与翼轮同步旋转的信号发生体,通过传感器发出脉冲信号．同时将信号送到电子计算仪进行数据处理,最后经过显示屏显示出累计流量值,如图1所示。     

交流等离子体显示屏放电的瞬态辐射特性研究

为深入理解彩色交流等离子体显示屏的气体放电机制及提高器件性能，对三元混合气体He-Ne（26％）．Xe（3．7％）放电的辐射光谱组成和光谱线的瞬态过程进行了实验研究。通过采用高速增强型CCD（ICCD）和光电倍增管（PMT）测量混合气体不同压强时，在一个维持电压脉冲期间，放电所产生的真空紫外和红外各主要谱线的强度随时间的变化，研究了充气压强对谱线强度、辐射延迟、辐射持续时间的影响，并分析了放电产生的真空紫外辐射总强度和可见光光谱线强度随充气压强的变化关系。实验结果表明，随着充气压强的提高，真空紫外和红外光谱辐射延迟缩短，辐射持续时间减小，并且真空紫外辐射总强度增大，可见光强度减小。     

DL-7(ZJ-12)型电离规管的研制

本文介绍北大无线电系与无线电工厂研制的ＤＬ－７（ＺＪ－１２）型宽量程超高真空电离计管，采用Ｂ－Ａ式结构，玻璃外壳，测量范围为 １０－２－ ５ × １０－１０托。     

有限元法在42英寸多枪彩色显像管玻壳设计中的应用

由于多电子枪显象管玻壳是一个变厚度组合壳体 ,很难用板壳经典理论进行求解 ,所以在设计九电子枪彩管玻壳时用有限元方法预先知道该玻壳的应力分布。通过修改设计参数 ,使九电子枪彩管玻壳能满足强度要求。在设计玻屏时采用非均匀有理B样条的曲面分析方法 ,锥体采用四条组合的非均匀有理B样条曲线旋转一周得到。本设计实现了玻屏表面外形和曲率变化及玻壳结构设计的全参数化 ,提高了玻壳的设计效率。本文还给出了计算玻壳外型的公式和一些技术参数。计算机仿真结果表明 :4 2英寸九电子枪彩色无支撑CRT的玻壳既能满足强度要求 ,又具有好的视觉效果     

PBA／PMMA型核壳弹性粒子增韧环氧树脂研究

合成了一系列的ＰＢＡ／ＰＭＭＡ核壳型复合弹性粒子,并用于增韧双酚Ａ环氧树脂ＤＥＧＭＡ／ＤＤＭ体系。研究表明,适宜的ＰＢＡ／ＰＭＭＡ核壳比是核壳型复合弹性粒子增韧环氧树脂的先决条件,添加合适核壳比的复合粒子能提高改性体系的冲击强度、剪切强度、降低固体化系的内应力。随着核壳粒子橡胶相尺寸的减小,改性体系的冲击强度逐渐增加,内应力降低,但对体系的剪切强度影响并不显著。在外作用下观察到核壳粒子空穴化引起剪切屈服增韧。核壳粒子的形态由透射电镜观测（ＴＥＭ）。,改性试样的断裂表面扫描电镜观测（ＳＥＭ）。改性体系中分散相的尺寸由预测结构的核的核壳复合粒子控制。     

芯棒旋转式口模挤出玻纤增强聚丙烯管的研究

利用旋转芯棒口模成功地挤出了玻纤增强聚丙烯管。扫描电镜研究发现该玻纤管中玻纤沿管周向大量取向。并且取向程度由内壁到外壁逐渐降低。强度测试表明该玻纤管的周向强度由普通挤出的８４ＭＰａ提高到现在的１３５ＭＰａ。由于玻纤的周向取向，挤出管材的出模膨胀及周向热膨胀率皆有所降低。     

The structural strength of glass: hidden damage

We discuss “hidden damage” of glass by the rolling process, which results in heterogeneous distribution of microcracks on the edge surface of glass element, which are the fracture source deteriorating glass element strength. It is shown that removal of this damage on the edges of glass elements increases the engineering strength of float glass significantly. Using the “hidden damage” approach, we provide strength determination for the weakest specimens that is statistically relevant and is based on a reliable engineering parameter.     

A Study on Shearing Failure Strength of Discontinuous Material Consisited of Cohesive and Cohesionless Particles

The investigation on the shearing failure strength of discontinuous material such as soil and freshly mixed cementitious material etc. by microscopic approach is presented in this paper. After the behavior of particles in each stress state is examined, the formula for calculating shearing failure strength is induced by considering the balance of forces acting on all particles, to show the influence of mean principal stress and loading speed etc.. Moreover, a series of shearing tests are carried out with fresh mortar to verify the theoretical results after investigating the measuring method for shearing failure strength.     

盐雾环境对玻璃纤维增强树脂基复合材料力学性能的影响

采用中性盐雾条件模拟海洋大气环境进行加速老化试验, 评价玻璃纤维增强环氧改性酚醛树脂基复合材料( GFRP) 在海洋气候中的耐久性。通过该复合材料经盐雾老化后的质量变化和纵向拉伸强度、横向拉伸强度、压缩强度、层间剪切强度的变化, 结合湿热老化机理, 研究其老化规律。结果表明, 随着老化时间的增加, 复合材料的吸湿量增加, 力学强度下降, 压缩和层间剪切曲线表现出塑性特征。吸湿最初阶段对力学性能影响最大, 纵向拉伸强度、横向拉伸强度、压缩强度、层间剪切强度分别下降到56. 1 %、54. 7 %、54. 0 %、61. 0 %。其中拉伸强度变化趋势最稳定, 更适用于评价该复合材料的老化程度。      

Corrosion phenomena in glass fibers and glass fiber reinforced thermosetting resins

Specific interactions between chemical environments and glass fibers cause stress corrosion cracking in the glass fiber surface. The interaction between fibers and diluted acids can be characterized readily in terms of a visible core/shell morphology that develops during the extraction process. The investigations revealed several correlations between the extraction process, crack formation phenomena and fiber strength.

The corrosive environments clearly have an adverse effect on the fatigue properties of glass fiber reinforced resins. Superimposed on mechanically induced damage is a chemical damage component, which becomes increasingly important at longer testing times and hence at lower stress levels. Since corrosive environments act primarily to reduce the fiber strength, their influence is controlled by diffusion processes through the matrix and by penetration of the chemically aggressive substance into the material interior through cracks. While the latter mechanism is especially important for fatigue loading conditions, it can be assumed that the degree of damage will generally depend upon several factors such as glass content, test temperature, and the aggressiveness of the chemical environment.     

硼硅酸盐浮法玻璃的抛光温度

浮法工艺的优点之一是可以获得极佳的玻璃表面质量,硼硅酸盐浮法玻璃是近年来的研究热点。本文采用原子力显微镜(AFM)研究了温度和时间对硼硅酸盐玻璃浮法成形过程中抛光阶段的影响。研究结果表明:高温抛光过程中时间不是限制玻璃表面抛光质量的决定因素,温度是决定抛光质量的关键。硼硅酸盐浮法玻璃在大于1250℃以上的温度可以快速达到良好的抛光效果。     

Effect of Temperature on the Dynamic Mechanical Behaviors of Zr‐Based Metallic Glass Reinforced Porous Tungsten Matrix Composite

The dynamic mechanical behaviors of Zr‐based metallic glass reinforced porous tungsten matrix composite were investigated by a split Hopkinson pressure bar at different testing temperatures. The flow stress of the composite decreased, while the ductility increased with increasing testing temperature, which were attributed to that more microcracks were initiated in the tungsten phase as well as more microshear bands were induced in the metallic glass phase with increasing temperature. The failure mode of the composite is a mixture of shearing and axial splitting. The flow layer of the metallic glass phase in the shearing fracture surface at 473 K was longer and thinner than that at 223 K.     

Study of shear behavior of granular materials by 3D DEM simulation of the triaxial test in the membrane boundary condition

This paper studies the shear behavior of granular materials by using a three-dimensional (3D) discrete element method (DEM) simulation of the triaxial test. The experimental triaxial tests were conducted on glass beads samples for verification. DEM simulations of the triaxial test were carried out in the membrane boundary condition consisting of 37,989 membrane particles. A new method that divides the irregular sample shape into two parts of cones and parts of three-dimensional simplexes is used to follow the volume change of irregular deformation of samples. The free rotatable upper platen is considered during the shearing process, which influences the shear behavior of samples especially in the residual stage and formations of a single shear band or X-shape shear band. The confining pressures have been demonstrated to influence the rotation angle and angular velocity of the upper platen. Moreover, the timing of replacing a rigid wall boundary condition with the membrane boundary condition is investigated, which affects the porosity of samples before shearing and the mechanical strength. The DEM model in the membrane boundary condition reflects well the evolution of irregular sample deformation and shear band in the shearing process. From the perspective of micro structures, the normal force decreases and the tangential stress increases during the shearing stage. This study greatly improves the accuracy of DEM simulations of the triaxial test in the membrane boundary condition.