基于微分求积法的变密度印刷纸带振动特性分析

采用微分求积法分析纸带面密度沿宽度方向线性变化时运动矩形纸带横向振动问题。建立了印刷运动纸带的横向振动模型。研究了变密度运动矩形纸带的无量纲振动频率与无量纲轴向运动速度、密度系数、纸带张力比之间的关系。数值计算结果表明,用微分求积法求解变密度运动矩形纸带横向振动问题是切实可行的。该研究结果为改善印刷纸带在印刷过程中的动态特性提供了理论依据。     

ARALL层板剥离特性的研究（一）──胶粘剂对层板层间性能的影响

本文采用了Ｂｅｌｌ─剥离法研究了胶粘剂性质及其含量对ＡＲＡＬＬ层间剥离特性的影响。结果表明，层板的剥离过程为多重混合型破坏。由于芳纶／胶粘剂界面结合较差，其剥离强度值较低。使该界面脱粘而破坏，胶粘剂发生内聚破坏以及胶粘剂的韧性增大或含胶量提高均使剥离强度值提高。改善胶粘剂与芳纶的界面粘合状况、提高胶粘剂的韧性是提高层板层间性能的有效途径。     

ARALL层板剥离特性的研究（一）：胶粘剂对层板层间性能的影响

本文采用了Ｂｅｌｌ－剥离法研究了胶粘剂性质及其含量对ＡＲＡＬＬ层间剥离特性的影响。结果表明，层板的剥离过程为多重混合型破坏。由于芳纶／胶粘剂界面结合较前，其剥离强度值较低。使该界面脱粘而破坏，胶粘剂发生内聚破坏以及胶粘剂的韧性增大或含胶量提高均使剥离强度值提高。改善胶粘剂与芳纶的界面粘合状况，提高胶粘剂的韧性是提高层板层间性能的有效途径。     

数字刀口检测技术

为便捷地定量检测大口径光学元件面形,运用数字刀口检测技术,把传统刀口仪与CCD图像采集处理、计算机辅助计算相结合,构成数字刀口仪。采用图像处理来确定阈值对应的刀口位置,引入PSD来描述频域信息。对125mm和150mm口径的球面镜进行检测,实现了传统刀口仪不能完成的定量检测,获得了面形分布,检测精度P-V值达到0.12λ(λ=532nm)。通过与干涉仪测得P-V值0.057λ相比较,验证了数字刀口检测的可行性,而且得到的数据还可进一步进行像差分析,为镜面误差的加工修正提供依据。     

基于P型法的中间支承运动纸带横向振动特性研究

北人PRC250凹版印刷机,其承印物-纸带为200~300 g/m²的薄型纸板,多色印刷中的支承滚筒对印刷薄纸板形成中间支承和简支约束,可用板壳理论研究其动力学特性。该研究提出采用新型P型高阶微分求积升阶谱法求中间支承运动纸带动力学特性。根据Hamilton原理,推导运动纸带的能量泛函变分式,利用新构C1单元混合插值正交张量积形函数,对给出的能量泛函变分式进行求解,分析中间支承和速度对运动纸带横向振动特性的影响。结果表明:在对边简支对边自由约束条件下,运动纸带的复频率随中间支承的设置而增大,随速度的增大稳定区域逐渐变小;通过CAE软件Hypermesh有限元对比试验,证明该研究提出的方法求解中间支承运动纸带动力学特性,比有限元软件具有更良好的数值稳定性、平滑性和收敛性。     

基于插值数浮动的MTF精确测量方法

采用刀口法测量成像系统调制传递函数(MTF)时,刀口装置与探测器矩阵夹角的准确测量是难点和关键点之一.针对这一问题,首先模拟刀口图像倾角对应的理论基准插值,研究了加载噪声情况下插值数浮动与线扩散函数(LSF)波动性变化以及MTF曲线衰减特性的定量关系;接着对实际X射线数字化成像系统获得的特定倾角下的刀口边缘图像进行了基于插值浮动的MTF测量,并将由其获得的MTF值与线对卡结果进行比较,证明了该方法用于成像系统MTF测量的有效性.结果表明:角度测量误差造成实际插值数偏离理想基准插值,导致LSF曲线光滑性变差,MTF衰减程度高于实际衰减.通过插值浮动方法,能够有效地避免角度测量误差引起的MTF测量的误差,降低角度测量的高精密性要求.     

花色苷用作鱼肉鲜度指示标签

目的采取花色苷做鲜度指示剂,研究一种可用于生活中的天然指示剂标签。方法通过提取紫甘薯、凤仙花瓣、杜鹃花瓣的色素,制作成标签。研究温度、p H值和鱼肉变质对指示标签的影响。结果温度对标签颜色没有影响。紫甘薯标签和凤仙标签在p H值达到12.35时分别变为灰色和灰绿色。检测鱼肉鲜度时紫甘薯和凤仙指示标签产生明显的颜色变化,杜鹃标签变化不明显。以凤仙指示标签为例进行结构分析,主要由于花色苷主体上的官能团在碱性条件下发生亲核或亲电重排反应,形成类黄酮等物质,使之颜色变化。结论花色苷可以用作鱼肉鲜度指示标签,效果较好。     

新型低频隔振器的特性研究

通过并联具有负刚度特性的刀口支撑滑动梁和正刚度的线性弹簧,设计了全新型的超低频非线性隔振系统。分析了系统的静态力学特性,给出了系统的力-位移关系以及刚度曲线,系统的非线性特性明显。求取了系统具有近似动态零刚度时的参数配置并结合实际应用选定了系统工作平衡点。建立了系统的非线性动力学方程,在对方程进行简化后,采用谐波平衡法求解了Helmholtz-Duffing方程的响应,分析了系统的频响特性,得出了在激励幅值较小的激励下系统具有渐软特性,而激励幅值增大后系统会出现二次跳变,即先表现为软特性后表现为硬特性。对此种新型隔振器的设计提供了理论指导。     

艾利丹尼森推出可移除标签

正商品上难以去除的标签,成为日常生活中困扰消费者的烦恼,不良粘胶剂造成的标签残留甚至可能损害物品的表面。对此,艾利丹尼森(Avery Dennison)推出可移除标签系列产品可轻松为消费者减轻这一难题。该系列标签在被剥离时,易于揭除且被贴物表面无粘胶残留。这一优势极大地提升了消费者的使用体验,同时满足消费者的健康安全需求,从而帮助标签加工商和品牌商提高消费者对商品的好感度。艾利丹尼森标签与包装材料专项解决方案产品总     

信息孔纸带孔距测量仪

一、概述我厂生产的CK-160型快速纸带穿孔机所穿纸带孔距的精度,是该机质量的集中反应,因此检查纸带孔距的精度(特别是φ1.2毫米的中导孔距)是检查该机的质量关键。纸带孔距的要求如图1,纸带的厚度为0.1毫米,由于纸薄且软易变形,用一般的万能量具无法测量,     

The best inertia from a plate

What is the optimum cross-section for a compression member built by bending a plate of a given thickness and area? It is shown that a parabolic shape is 41% better than a tubular section. A number of examples are shown where this section is found in nature.     

The Constant-thickness Zone Plate as a Variational Solution

The diffractive properties of constant-thickness zone plates composed of arbitrary materials are presently well known. Less well known, however, is the fact that the constant-thickness zone plate is the best possible profile that can be created for maximizing the throughput diffraction efficiency of a zone plate system which has a certain symmetry constraint imposed on its geometry. The formal statement of this claim is set forth in this Letter as a variational exercise and the derived optimum constant-thickness solutions are shown to hold for materials of arbitrary complex indices of refraction ?.     

复合材料蜂窝夹层板结构的多工况优化设计研究

以复合材料蜂窝夹层板结构作为研究对象,建立了多工况优化模型,对众多的材料设计变量进行必要的取舍,通过优化分析确定复合材料蜂窝夹层板面板各分层的厚度以及蜂窝芯层的厚度等,使结构满足相应的频率约束、屈曲约束,以及强度约束、位移约束和尺寸限制等,同时达到结构的重量最轻。采用序列二次规划法对某卫星的承力筒结构进行了优化设计,优化结果表明:在满足其振动特性以及静力学特性的条件下,复合材料蜂窝承力筒的各面板层厚度以及蜂窝芯层的厚度均有所减小,减重效果显著,较好地实现了复合材料蜂窝夹层板结构的多工况优化设计。     

Viscous flow past a split plate

The situation of viscous flow past a split plate is treated within the framework of the Oseen equations. The problem is reduced to an integral equation defined on disjoint intervals. The solution of the integral equation is determined asymptotically for slow flow. The drag force is calculated and compared with certain single plate results.     

横流板式间接蒸发热回收装置的优化研究

运用遗传算法对横流板式间接蒸发热回收装置的经济性进行分析,建立优化设计数学模型,并对新、排风风量均为540m^3／h的横流板式间接蒸发热回收装置进行优化求解,探讨其经济性随各结构参数的变化规律。研究结果表明：遗传算法可以很好地实现横流板式间接蒸发热回收装置的优化;得到横流板式间接蒸发热回收装置的优化结构;随各结构参数的变化,目标函数呈抛物线的变化规律。该研究对于横流板式间接蒸发热回收装置的设计有一定的参考价值。     

Development of split gliding arc for surface treatment of conductive material

A gliding arc is one of the atmospheric-pressure plasmas and available for surface treatment. However, when this gliding arc is used to irradiate conductive materials, arc spots appear on the surface and seriously damage it. In the present study, in order to prevent such arc spot damage on a conductive substrate, a split gliding arc was designed with a multi-hole plate placed at the exit window. This split gliding arc was irradiated onto several metals, and its ability to treat the hydrophilic property was verified.     

Effect of high filling ratio on the weld strength of hot plate welded calcite filled polypropylene and its comparison with talc filling

In this paper, the effect of the hot plate welding parameters on the weld strength of 40 % calcite filled polypropylene were investigated by utilizing design of experiment and compared to talc filled polypropylene. The plate temperature and the heating time were considered as the process parameters. A mathematical predictive model of the weld strength was developed in terms of welding parameters. The results show that the mathematical model correlates well with the experimental results. The optimum welding parameters of calcite filled polypropylene are determined as 260 °C of plate temperature and heating time of 25 s. The welding strength of the joint welded at optimum parameters is found as 18.32 MPa. Hot plate welding efficiency of the 40 % calcite filled polypropylene is observed to be higher than 40 % talc filled polypropylene material.     

挂壁式空调器室内机风量、噪声及功率变化规律研究与应用

通过对科龙4款具有代表性的不同结构挂壁式空调器室内机的试验研究,得出挂壁式空调器室内机的风量、噪声、功率随转速变化的规律,拟合出其所遵循的函数方程,提出一种简单的室内机风量、噪声、功率的优化设计方法.     

On the failure indices of quadratic failure criteria for optimal stacking sequence design of laminated plate

The quadratic failure criterion, which is intended to predict fracture, may be used as an object function for optimal stacking sequence design of laminated plate. However, calculations using a symmetric laminated plate demonstrate that Tsai-Wu theory may give incorrect optimum predictions under uniaxial loading.     

Multiple-beam wedge-plate shear interferometer for collimation testing

We describe a modification of the wedge-plate shear interferometer for collimation testing. The surface of the wedge plate is coated to increase the reflectivity such that multiple-beam interference takes place resulting in sharp fringes. In addition to sharpening the fringes also tend to split when the test beam is noncollimated. This splitting has been used as a test criterion for collimation testing. Experimental results are presented.