达克罗涂液研究

通过正交试验优化了达克罗涂液的组分，并研究了涂液组成对涂层耐蚀性能的影响。优选组分为：涂液中酸总量占５％￣７％（质量百分数，下同），其中铬酸占６０％，硼酸占４０％，镍与铬当量比为０．２￣０．４，酸总量与氧化锌的质量比为４￣６，酸总量与金属粉的质量比为０．２￣０．３，其中锌粉占９０％，铝粉占１０％，表面活性剂占０．５￣０．７％，乙二醇占１５％￣１８％。     

化学沉积Ni—Mo—P合金

研究了溶液的组分及操作条件对Ｎｉ－Ｍｏ－Ｐ合金形成的影响，以得到合适的沉积工艺。试验结果表明，ＰＨ＝５．６，ｔ＝９０℃，溶液中的Ｎｉ＾２＋／ＭｏＯ４＾２－＝１３．９－１６．７；ｐＨ＝９．０，ｔ＝８５℃，Ｎｉ＾２＋／ＭｏＯ４＾２－＝２３．４－２８．５，有利于获得良好的Ｎｉ－Ｍｏ－Ｐ的合金层。     

溶胶—凝胶法制备锆酸锂陶瓷微球

采用溶胶－凝胶法制备出了粒径小于１ｍｍ的陶瓷微球。微球直径分布在０．４￣１．０ｍｍ，密度达８０￣９０％Ｔ．Ｄ．，比表面积为１８￣３２ｍ＾２／ｇ，压碎强度达１￣３ｋｇ／个球。该工艺克服了金属的氢氧化物难以沉淀的困难，并可推广到其他材料的制备。     

在三价铬Cl~--SO_4~(2-)体系中电沉积厚镀层的研究

研究了在新型尿素氯化物硫酸盐混合物三价铬溶液中电镀铬的工艺条件对镀层的影响,详细考察了电流密度、ｐＨ值、络合剂浓度、恒电流／恒电位方式对电流效率和镀层外观质量的影响。结果表明：ｐＨ值在１．９～２．３之间、电流密度在７～１１Ａ／ｄｍ２范围内、络合剂浓度为２ｍｏｌ／Ｌ时获得的镀层能达到较大厚度和较高的电流效率,镀层光亮致密。在此工艺条件下,可获得３０～４０μｍ的镀层。提出了三价铬电化学聚合的新假设。     

单柱离子色谱法分离测定复合镀铬液中的F^—和SO4^2—

采用单柱离子色谱系统，在样品中存在大量铬酸根的情况下，以３．０ｍｍｏｌ／Ｌ邻苯二甲酸氢钾作为淋洗液，简单快速地分离测定了镀铬液中的Ｆ＾－和ＳＯ４＾２－，并在此条件下作出了Ｋ２ＳｉＦ６的离解曲线。Ｆ＾－，ＳＯ４＾２－的线性范围分别为１．０￣１５０．０ｍｇ／Ｌ，１．４￣１５０．０ｍｇ／Ｌ，最低检出浓度分别为０．０２ｍｇ／Ｌ，０．０７ｍｇ／Ｌ（信噪比为２）。     

苹果酸生产中残留富马酸转成天门冬氨酸的研究

建立了固定化细胞分离Ｌ－苹果酸生产中残留富马酸并将其转化成Ｌ－天门冬氨酸的新方法。对生成Ｌ－天门冬氨酸的工艺条件进行优化，结果表明，当Ｌ－苹果酸反应液ｐＨ调至８～９，Ｌ－天门冬氨酸添加量为６～８ｇ／Ｌ，碳酸铵加量为１５～２０ｇ／Ｌ，Ｍｇ￣（２＋）、Ｍｎ￣（２＋）、Ｃａ￣（２＋）等二价阳离子加量为１ｍｍｏｌ／Ｌ时，固定化细胞可将Ｌ－苹果酸反应液中残留的２０％左右的富马酸几乎全部转化成Ｌ－天门冬氨酸，且Ｌ－苹果酸含量的损失小于５％。     

超临界流体干燥法制备超细钡铁氧体粉末：Ⅰ.制备参数对产品物相的影响

利用Ｘ－射线衍射仪（ＸＲＤ）对超细粉末ＢａＦｅ１２Ｏ１９的相变过程进行了考察。其中主要考察了溶液浓度、ｐＨ值、焙烧温度、时间以及气氛等对最终产品物相的影响．结果得出：溶液浓度为０．１０￣０．５０ｍｏｌ／Ｌ、ｐＨ值为１１．０￣、１．０、焙烧温度为７００￣７５０℃、焙烧时间为３．５￣４ｈ、在空气中焙烧时能得到单一相的ＢａＦｅ１２Ｏ１９晶体。     

钼酸盐对铝缓蚀性能的研究

通过静态实验在ｐＨ值２￣１１内研究了不同浓度的钼酸盐对名的缓蚀性能，得出了腐蚀率和缓蚀率的曲线，结果表明钼 盐的添加量为１．２５０￣１．７５０ｇ／Ｌ时，对铝有缓蚀作用。并将钼酸盐与柠檬酸共同试用于铝材的冷却水系统。     

溶胶共沉淀法制备ZrO2超细粉末的工艺研究

采用正交试验方法研究了溶胶共沉淀法制备ＺｒＯ２－Ｙ２Ｏ３陶瓷粉末的工艺过程，对粉体进行了粒度，ＸＲＤ，ＳＥＭ观察，结果表明，对粉体粒度影响最大的是母液浓度，而母液温度则无明显影响，母液ｐＨ值不同影响ＺｒＯ２的晶体，正交试验优化出了用ＮＨ４ＨＣＯ３作为沉淀剂制备了ＺｒＯ２粉末的最佳工艺参数，即：母液浓度１．０ｍｏｌ／Ｌ，ｐＨ＝５～６事实表明，用此法制粉成本低，周期短，效率高。     

单（双）波长分光光度法测定环境水微量铜

在ｐＨ５的醋酸盐溶液中，铜（Ⅱ）与２－羧基－２＇－羟基－５＇－磺基苯Ｚａｎ基苯（ＣＨＳＦＢ）反应，显色液由黄色变蓝色，对比波长△λ＝１４０ｎｍ，该显色反应有较高灵敏度和选择性。本文研究单波长和双波长光度法测定环境水中痕量铜，单波长法操作简便，相对标准偏差ＲＳＤ７．４％，加标回收率９３．３％￣１０４％；双波长法检出限仅０．０３４ｍｇ／Ｌ，工作曲线稳定性好，分析精密度较高，ＲＳＤ４．１％，加标回收率９     

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.……     

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...     

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.     

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 ...