长效有机酸型轿车防冻液及其性能

随着全寿命无拆卸养护概念的提出,国外的装车防冻液对品质的要求日益严格,即能够长效、对环境友好、不含对人体和环境有害的物质,并在一些高档轿车上使用有机酸型防冻液作为装车纯正品.而在国内,由于经济因素的制约,有机酸型防冻液至今不能真正实现国产化.为此,采用有机和无机相结合的方式,开发出了具有长效、环保特点的高端防冻液产品,其使用价格仅相当于进口长效防冻液添加剂的1/4左右,产品规格高于SH/T 0521-1999的规范要求,满足了国内高档汽车的装车需求.     

东风雪铁龙轿车防冻液的研制

传统防冻液含有对人体和环境有害的物质,因而应用范围受到限制.采用有机羧酸与无机缓蚀剂作为防冻液的腐蚀抑制剂,研制出东风雪铁龙轿车发动机专用防冻液.玻璃器皿腐蚀试验和行车试验结果表明,由高效的无机缓蚀剂和有机羧酸盐组成的防冻液具有良好的防腐蚀性能,通过了法国PSA集团的产品检测.由于采用了环保配方,有着传统无机型防冻液无法比拟的优势,适用于对环保有要求的国产和进口轿车.     

如何识别次品防冻液

通常人们都认为防冻液是一种季节性的简单产品,就是冬天汽车水箱用来防冻的东西,其实这是一个误解。防冻液应该叫汽车防冻冷却液,它具有冬天防冻、夏天防沸的功能,并且能够防腐、防垢、保护发动机的冷却系统,改善散热效果,提高发动机效率。因此,防冻液不只是冬天用的,它应该替代水全年用于汽车发动机的冷却。防冻液的发展已经历了相当长的一段时间。最初防冻液的作用就是用来降低发动机水箱的冰点或是提高沸点而已,但随着汽车工业的发展,发动机功率的增大,转速加快,对发动机冷却介质——防冻液的性能要求也越来越高。按现在的要求来说,一种…     

汽车防冻冷却液的研究进展

从乙二醇型防冻冷却液的配方类型着手,对各配方的优缺点进行了探讨,并就国内防冻冷却液的现状做了详细的阐述.按照缓蚀剂组成将防冻冷却液分为无机盐为主的常规防冻冷却液类型(硅酸盐、硼砂、磷酸盐、钼酸盐)和以有机酸为主的防冻冷却液类型(复合了无机盐的有机酸配方、全有机酸配方).     

利用ASTM D 1384的试验方法和电位测试法调整发动机冷却液缓蚀剂配方的研究

摘要：目前,国内科研单位都是利用玻璃器皿腐蚀实验（SH／T0085）来测试发动机冷却液的性能,在国外已经引用电位测试法（ASTM D 1384）来研究。其主要是将有机酸型缓蚀剂、有机非酸型缓蚀剂和无机盐型缓蚀剂进行优化复配,筛选出了一种对汽车冷却系统多种金属有全面保护的高性能的冷却液配方,尤其对焊锡和铸铝的保护性能更为突出,适合现代汽车工业冷却系统向铝合金方向发展的需求。     

宁夏开发出高性能环保太阳能换能液产品

目前,国内存平板太阳能或真空热管太阳能热水器中使用的人多为汽车防冻液产品,主要成分为乙二醇。由于太阳能热水器使用环境与汽车发动机差异较大,汽车防冻液在热水器中长期使用会存在易结垢、腐蚀材质、换热效率低、毒性大、安全性能低等诸多缺陷。     

高强度汽车齿轮材料技术的现状及发展

本文结合作者的研究开发实践,概要地阐述了近年来日本在高强度汽车齿轮材料及材料表面强化研究方面的成果和应用现状,并对其研究成果进行了较深入的分析.特别是着重分析了日本及欧美汽车工业的新发展对高强度齿轮及材料强化所提出的急待解决的技术课题.     

利用ASTM D 1384的试验方法和电位测试法调整发动机冷却液缓蚀剂配方的研究

三、实验结果与讨论 1．配方筛选实验 通过资料调研，有机酸缓蚀剂物质之间、有机非酸类化合物和无机盐缓蚀剂之间存在着很好的协同作用。总结文献资料，在配方筛选前，确定了用硅酸盐作为铝的特效缓蚀剂，前期通过大量的筛选，从水质稳定剂、硅氧烷类专用稳定剂中筛选了一种专用硅酸盐稳定剂来抑制硅酸盐的凝胶或沉淀，首先解决了硅酸盐的稳定性问题。     

关于汽车散热器产品的故障研究

为了避免发动机过热,燃烧室周围的零部件(缸套、缸盖、气门等)必须进行适当的冷却。汽车发动机冷却装置以防冻液冷却为主,用气缸通道内的循环防冻液冷却,把通道内受热的防冻液引入散热器(水箱),通过风冷却后再返回到通道内。散热器作为发动机相关零部件冷却的一个重要部件。本文以故障件外观、水检、解剖分析等分析手段为基础,把散热器故障点划分为四个故障形式,来说明散热器在出现故障时的原因,同时提出相关预防建议。     

制丝加料前后非挥发性有机酸和高级脂肪酸变化分析

应用中甲酯衍生化和气相色谱法,分析烟叶样品的非挥发性有机酸和高级脂肪酸的含量,重复性较好.且分析时间较短。共鉴定制丝加料前后的6种非挥发性有机酸和4种高级脂肪酸的含量,结果表明:加料后,非挥发性有机酸和高级脂肪酸的含量均有不同程度的上升。     

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.……     

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.     

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 ...