印刷机滚筒的模态分析

印刷机滚筒的结构和动态性能对印刷机工作特性有很大影响,为提高印刷机的印刷质量,以纸箱印刷机滚筒为研究对象,在已有优化设计的基础上,利用ANSYS有限元分析软件,对优化前后的纸箱印刷机滚筒进行了模态分析,得到了印刷机滚筒的固有频率和振型,从动态特性上为静态优化结果提供了支持。     

集成电路板锡膏印刷机现场总线控制系统应用

论文分析了锡膏印刷机的控制系统机构,并通过对比常规DCS控制系统,研究了基于CAN总线的锡膏印刷机FCS控制系统。与传统的锡膏印刷机控制结构相比,CAN总线锡膏印刷机的控制系统机构减少了硬件配线,易于系统的模块化实现和故障诊断。CAN总线在保证锡膏印刷机系统可靠性的同时,提高了系统精度,降低了成本,具有重要的应用价值。     

我国凹版印刷机的现状及发展方向

介绍了在包装印刷领域应用非常广泛的国产凹版印刷机的生产和使用现状,与国外凹印机的差距,同时分析了国内凹印刷机生产厂家今后的努力方向和前景.     

参数化设计方法在印刷机设计中的应用研究

介绍了参数化设计的概念、方法及参数化设计系统的功能，从印刷机的设计现状入手，分析了参数化设计方法在印刷机设计中应用的必要性和可行性，对参数化设计方法在印刷机设计及其它行业的应用作了展望。     

当前包装印刷工业的发展趋势和面临的任务

根据当前印刷工业的发展趋势和面临的任务重点可以在以下几个方面进行突破。1.数字印刷及印刷数字化技术装备(1)数字印刷机,重点是喷墨数字印刷机目前,数字印刷机主要分静电成像数字印刷机和喷墨数字印刷机两大类。当前,我国数字印刷企业的主流设备是静电成像数字印刷机,但由于在幅面、承印物等方面的优势,喷墨数字印刷机发展潜力较大。目前我国尚不具备生产静电成像数字印刷机的能力,主要产品全部依靠进口,喷墨数字印刷机的研发则已经起步,具有较好的发展基础。     

印刷机设备状态监测与故障诊断研究进展

通过对国内外印刷机状态监测与故障诊断研究情况和发展趋势的分析,认为当前对印刷机监测的研究主要集中在振动信号的测试研究、专家经验知识的应用、模式识别算法引入等几个方面,并论述了当前基于印刷图像处理的印刷机故障诊断这一新方向的研究情况。由于印刷机不断朝着高速度、高精度、高自动化程度方向发展,传统故障诊断方法在印刷机系统中的应用已受到很大限制,研究认为,兼顾多元信息实现全面状态监测,融合经验知识与先进识别算法建立故障决策体系,从印刷画面信息中提取设备参数,将是今后印刷机故障诊断研究的重点。     

数字印刷的发展与市场

文章对数字印刷机的特点进行了分析，从概念上讨论了数字印刷与直接制版差别和使用范围，通过对数字印刷机特性的分析和印刷成本的分析，说明了数字印刷的发展趋势、市场定位，并对几种典型的黑白和彩色数字印刷机的主要用途进行了介绍。     

虚拟仪器与传感器融合在齿轮监测中的应用研究

目的研究印刷机齿轮在高速印刷时的振动状况。方法借助Labview软件为平台开发印刷机齿轮振动在线检测仿真系统,并结合虚拟仪器和传感器融合技术,研究印刷机的振动状况。结果通过仿真系统得出原始齿轮振动信号中的啮合频率受转频2倍频(23.6Hz)和3倍频(34.69Hz)调制。结论虚拟仪器与传感器信息融合技术可以监测到印刷机在高速印刷时的振动状况,并通过相关特征波形提取分析,实时检测到齿轮磨损、断齿故障。     

无轴传动在印刷机中的应用

阐述了无轴传动技术的定义、特点及在平版印刷机、柔性版印刷机、凹版印刷机中的应用,以及在大型多功能印刷设备中的应用,使得传动更为安全稳定,传动精度高.同时还使传动系统结构简单,便于维修、安装和调试.无轴传动技术在印刷机的应用,使得印刷机在高速运转时更加平稳,从而提高印刷品的质量.     

关注“十二五”期间印刷工业的发展趋势和面临的任务

一、重点发展产品 根据当前印刷工业的发展趋势和面临的任务,“十二五”期间,印刷机械行业要重点在以下几个方面进行突破: 1.数字印刷及印刷数字化技术装备 (1)数字印刷机,重点是喷墨数字印刷机 目前,数字印刷机主要分静电成像数字印刷机和喷墨数字印刷机两大类.当前,我国数字印刷企业的主流设备是静电成像数字印刷机,但由于在幅面、承印物等方面的优势,喷墨数字印刷机发展潜力较大.目前我国尚不具备生产静电成像数字印刷机的能力,主要产品全部依靠进口,喷墨数字印刷机的研发则已经起步,具有较好的发展基础,北大方正等企业已经能够生产喷墨数字印刷机.“十二五”期间,印刷装备制造行业要加大数字印刷机,尤其是喷墨数字印刷机的研发力度,研发具有自主知识产权的系列化喷墨数字印刷机,2015年主要设备达到当前的国际先进水平;关键部件研发取得突破,打破进口产品的龚断局面.     

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.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.……     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.