密度叠印率与色差之间关系的研究

目的 研究密度叠印率与其叠印色差的关系, 并尝试确定密度叠印率合格标准。方法 理论推导求解网点百分比叠印率与叠印色差的量化关系, 理论推导网点百分比叠印率与贝雷斯叠印率的量化关系,并通过Excel进行数据分析与计算。结果 当第2色实地密度为1.5时, M/Y, C/Y, C/M的贝雷斯叠印率合格标准分别大于或等于70%, 73%, 86%。结论 网点百分比叠印率与色差呈近似线性反比关系, 密度叠印率受多种因素影响, 叠印率合格标准仅在特定条件下有效。     

PostScript印刷测控条的开发与应用

根据制版和印刷质量控制理论,从使用测控条的目的和意义入手,采用PostScript语言编写出一种既能控制传统印刷过程,又能控制数字印刷质量的彩色数字印刷测控条.用测控条中的相应结构可监控印刷品的实地密度、网点增大、印刷反差、叠印情况、网点滑动或重影等印刷性能要求.     

CTP印刷质量控制参数测试与分析

阐述了实地密度、网点扩大、相对反差、叠印率4个参数在印刷质量控制中的意义,设计并印刷了CTP测试版样张,对随机抽样的22张样张的4个参数作了测试与计算,用数据信息表达了CTP印刷品质量状况,供CTP印刷相关人员学习和参考.     

铜版纸与哑粉纸印刷复制特性研究

采用实验方法,对铜版纸和哑粉纸的印刷复制特性进行了测试和比较。 结果显示,2 种纸张的最佳印刷反差和实地密度略有差异;在相同的印刷条件下,与铜版纸相比,哑粉纸印刷品相对反差大,网点扩大小,叠印率、颜色亮度、总油墨覆盖率高,色差小,但颜色饱和度低,局部范围色域较小。 为了获得最佳的印刷效果,应该采用不同的印刷参数,适当增加哑粉纸的用墨量。     

数码印刷产品质量分析与控制

针对DC2060 数码印刷机模拟SWOP 的色彩设置,获得数码印刷样品的实地密度、相对反差、网点增大及叠印等参数.对四色数码印刷曲线进行三阶多项式处理,并将参数与胶印产品的质量参数进行了对比分析.提出对环境条件、耗材、最大密度和输出曲线等控制以获得高质量的数码印刷品.     

基于密度的凹版专色叠印色光谱预测模型的研究及应用

目的 建立一种基于密度与光谱反射率关系的专色叠印色光谱预测模型。方法 首先建立前景色、后景色密度与其光谱反射率关系;基于此建立叠印色光谱反射率的计算方法;其次对模型进行优化,完成专色叠印色光谱预测模型的建立;再通过凹版印刷实打样30张专色叠印色样张,基于Malab利用色差以及拟合决定系数R²对预测模型进行验证;最后在相同工艺条件下实打样专色叠印色样张进行预测,通过色差完成对模型的精度检验。结果 验证表明,不同专色叠印色在同一网点面积率下与其对应的前景色、后景色密度之间存在较强相关关系,其拟合决定系数R²均大于0.9;模型精度检验中,73.7%的模型预测值与样张实测值色差为0~2.5个CIE1976色差单位,大部分色块色差为0~2个CIE1976色差单位,占总频率的60.54%,整体平均色差为1.92个CIE1976色差单位。结论 本文所建模型具有较高的预测精度,能基本满足对颜色预测的需求。     

数字印刷测试版的设计与应用研究

进入21世纪以来,数字印刷以其快速、高效、灵活、可变数据印刷的特点,具有广泛的应用领域。但由于数字印刷的作业特点,用于传统印刷的控制条无法作为其制版、印刷质量检验与控制的手段。为了实现印刷的数据化、规范化及标准化控制,我们必须设计出既能控制印刷过程又能控制印刷品质量的数字印刷测试版。从使用测控条目的和意义入手,本文采用PostScript语言编写出一种既能控制传统印刷过程,又能控制数字印刷质量的测控条,组合并输出为PS或EPS文件,把生成的PostScript数字印刷测控条与一般的质量控制元素如色彩再现等元素组合成数字印刷测试版,用于监控印刷过程,分析印刷品质量问题,实现对实地密度、网点扩大、印刷反差、阶调再现、叠印率、网点变形、重影、分辨率、印刷灰平衡等技术参数的控制。     

马口铁印刷中影响印刷反差(K值)的几大因素

印刷反差（K值）是评价印刷品质量的最重要指标,它是实地密度和网线密度之差和实地密度的比值,通常选取网点面积为75％的网点实地密度。它主要表现在印刷品的层次上,印刷反差越高,印刷品层次拉得越开,给人视觉上的冲击越大,反之,则使得印刷品层次并级,无精神,色偏,给人眼的感觉很不好。那我们怎样才能把它控制好呢？     

网点形状对胶印网点复制特性的影响

研究了胶印工艺中方形、圆形、圆方形网点在相同条件下的印版网点复制特性、印品网点复制特性和颜色复制特性,比较了3种网点在实地密度值、叠印率、印刷反差、网点增大、色域、饱和度等影响印刷质量的关键技术参数上的差异,提出了有利于印品阶调和色彩复制的网点形状选择依据,得出了对印刷过程具有一定的实际指导意义的结论。     

纸张数字印刷工艺及质量的研究

设计了数字印刷原稿,通过改变数字印刷的参数得到印刷样张,从实地密度、相对反差、叠印率、网点增大等方面,研究油墨浓度、激光强度两个因素对印刷质量的影响。油墨浓度和激光强度对印刷质量的影响曲线,为数码印刷工艺的进一步研究提供理论和实践依据。     

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.……     

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.……     

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...     

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.     

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.     

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.     

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 ...