彩色热浸镀锌的研究

系统研究了彩色热镀锌工艺和耐蚀性能，通过镀液成分和工艺试验，筛选出Ｚｎ－Ｍｎ－Ｃｕ和Ｚｎ－Ｔｉ－Ｎｉ两种成分镀液，在一定的浸镀 冷却方式下，可以获得表面光滑、色泽均匀的彩虹、金黄、紫、蓝等彩色镀层。盐雾腐蚀试验表明，彩色热镀锌层比常规热镀锌层的耐蚀性能约提高一倍。通过俄歇能谱检验及理论分析，认为Ｚｎ－Ｔｉ－ＮＩ热镀锌镀层表面产生颜色是由于氧化膜使光发生了干涉，表面颜色决定于氧化膜厚度；Ｚｎ－Ｍｎ－     

Zn-SiO2复合镀中氢的侵入及镀后逸出行为

对酸性硫酸盐体系Ｚｎ－ＳｉＯ２复合镀过程中氢侵入基体,在镀层中的包容及放置过程中基体内氢的逸出行为研究表明：Ｚｎ－ＳｉＯ２复合镀层比纯锌镀层包容的氢多,氢的渗透也更容易;随镀层中ＳｕＩ２含量的增加,镀样氢含量也增加,而基体中的氢含量在镀层中ＳｉＯ２达到一定量后便趋于稳定;由于氢在Ｚｎ－ＳｉＯ２镀层中容易迁移,经相同放置时间后,Ｚｎ－ＳｉＯ２复合镀样基体氢含量低于纯锌镀样。缺口试样恒应变速率拉伸实验     

氯化物电沉积Zn—Fe合金工艺

在氯化钾镀锌的基础上，通过添加铁盐，可得到Ｚｎ－Ｆｅ合金镀层。研究了镀液组成及工艺条件对镀含铁量的影响，控制它们在最佳值，可得到含铁量为０．４－０．７％的Ｚｎ－Ｆｅ合金镀层。确定了Ｚｎ－Ｆｅ合金镀层的黑色钝化处理工艺，并对镀液、镀层性能进行了测试。     

硝酸钠在Zn－SiO_2高速电镀中的作用

实验采用循环电镀装置及硫酸盐体系，在镀液ｐＨ值和温度、镀液流速和阴极电流密度保持一定的条件下，研究硝酸钠对Ｚｎ－ＳｉＯ２复合电镀的作用。在我们的实验范围内，当镀液中硝酸钠浓度超过０．５ｇ／Ｌ时，镀层ＳｉＯ２含量随它的增加而上升，相应复合镀层的颜色白灰色逐渐变为黑灰色。在高速电镀条件下，ＮａＮＯ３能提高ＳｉＯ２共析度。在５％ＮａＣｌ溶液浸泡实验中，Ｚｎ－ＳｉＯ２复合镀层和纯锌镀层的电位变化规律非常不同。在中性盐雾试验中，Ｚｎ－ＳｉＯ２复合镀层试样的出红锈时间比镀覆相同厚度纯粹镀层试样的要长得多，且前者红诱发展缓慢。借助ＳＥＭ和ＥＤＸ，我们发现Ｚｎ－ＳｉＯ２复合镀层上有富Ｓｉ层存在，这一点可以帮助解释硝酸钠能够提高镀层ＳｉＯ２含量的原因。     

在电沉积锌—铁合金镀液中柠檬酸的作用

用循环伏安法研究了柠檬酸对Ｚｎ－Ｆｅ合金电沉积的影响，结果表明，镀液中加入柠檬酸后使Ｚｎ－Ｆｅ合金电沉积的阴极极化增大。从含有柠檬酸的Ｚｎ－Ｆｅ合金镀液中获得的Ｚｎ－Ｆｅ合金镀层的阳极溶解峰与纯Ｚｎ镀层，从简单盐中获的Ｚｎ－Ｆｅ合金镀层相比，其峰电位正移，使Ｚｎ－Ｆｅ合的耐蚀性提高。     

NaH2PO2对Zn,Zn—Fe合金电沉积的影响

用循环伏安法研究了ＮａＨ２ＯＰ２对Ｚｎ，Ｚｎ－Ｆｅ合金沉积的影响，结果表明，镀液中加入ＮａＨ２ＰＯ２后Ｚｎ，Ｚｎ－Ｆｅ合金电沉积的阴极极化增大，获得的Ｚｎ－Ｐ，Ｚｎ－Ｆｅ－Ｐ合金镀层的阳极溶解峰与Ｚｎ层相比，其峰电位正移。     

NaH_2PO_2对Zn、Zn－Fe合金电沉积的影响

用循环伏安法研究了ＮａＨ２ＰＯ２对Ｚｎ、Ｚｎ－Ｆｅ合金电沉积的影响，结果表明：镀液中加入ＮａＨ２ＰＯ２后，Ｚｎ、Ｚｎ－Ｆｅ合金电沉积的阴极极化增大；获得的Ｚｎ－Ｐ、Ｚｎ－Ｆｅ－Ｐ合金镀层的阳极溶解峰与Ｚｎ层相比，其峰电位正移。     

氯化物电沉积Zn－Fe合金工艺

在氯化钉镀锌的基础上，通过添加铁盐，可得到Ｚｎ一Ｆｅ合金镀层。研究了镀液组成及工艺条件对镀层含铁量的影响，控制它们在最佳值，可得到合铁量为０．４％～０．７％的Ｚｎ－Ｆｅ合金镀层。确定了Ｚｎ－Ｆｅ合金镀层的黑色钝化处理ｘ艺，并对镀液、镀层性能进行了测试。     

Zn—Al2O3和Zn—SiO2复合镀层的研制

详细叙述了Ｚｎ－Ａｌ２Ｏ３和Ｚｎ－ＳｉＯ２复合镀层的制做方法，提出了复合镀液中所用微粒子和净化处理方法。对复合镀层的耐腐蚀性和结合力进行了测定，得出了耐腐蚀性和结合力均较好的Ｚｎ－Ａｌ２Ｏ３和Ｚｎ－ＳｉＯ２复合镀层中粒子的含量范围等有用的数据。     

Zn－Al_2O_3和Zn－SiO_2复合镀层的研制

详细叙述了Ｚｎ－Ａｌ２Ｏ３和Ｚｎ－ＳｉＯ２复合镀层的制做方法，提出了复合镀液中所用微粒子和净化处理方法。对复合镀层的耐腐蚀性和结合力进行了测定，得出了耐腐蚀性和结合力均较好的Ｚｎ－Ａｌ２Ｏ３和Ｚｎ－ＳｉＯ２复合镀层中粒子的含量范围等有用的数据。     

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.     

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...     

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.……     

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.     

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.     

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 ...