高容量SiO2掺杂的（Ba,Pb）TiO3基高居里温度PTCR陶瓷

在制备高质量的（Ｂａ，Ｐｂ）ＴｉＯ＿３基高居里温度ＰＴＣＲ陶瓷时，一般采用铅气氛烧结方法。但是，这种烧结工艺制成的产品的相对成本是高的。作者的实验表明，高容量ＳｉＯ＿２掺杂烧结方法也可以用于制备高质量的（Ｂａ，Ｐｂ）ＴｉＯ＿３基高居里温度ＰＴＣＲ陶瓷。本文主要报道高容量ＳｉＯ＿２对（Ｂａ，Ｐｂ）ＴｉＯ＿３基高居里温度ＰＴＣＲ陶瓷烧结工艺和电特性的影响。     

Al_2O_3－MgAl_2O_4陶瓷的试验研究

在Ａｌ＿２Ｏ＿３中添加５－１５ｗｔ％ＭｇＡｌ＿２Ｏ＿４，采用热压注法制备Ａｌ＿２Ｏ＿３－ＭｇＡｌ＿２Ｏ４陶瓷。研究表明，Ａｌ＿２Ｏ＿３－ＭｇＡｌ＿２Ｏ＿４陶瓷具有良好的高温电阻率和抗熔渣－种子的腐蚀能力，经过进一步改进可望作为燃煤ＭＨＤ发电通道（半热壁型）阳极区电极间绝缘片材料。     

溶胶凝胶法制备YBa_2Cu_3O_（7－δ）超细粉体及其性质

用柠檬酸盐强的螯合作用，可以制得钇、钡、铜稳定的配位化合物，由溶胶－凝胶法使其转变成Ｙ＿２Ｏ＿３、ＢａＣＯ＿３、ＣｕＯ超微细粉的均匀混合物、９３０℃下制得单一相的ＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）粉体，粒径约１００ｎｍ。对ＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）合成反应的动力学进行了研究，对溶胶凝胶法制得的ＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）超细粒子进行的测定表明，其粒度、纯度、烧结性和超导性能形成上都比固相合成反应为优。     

Nb2TiO7陶瓷的热膨胀性能及电性能研究

研究了Ｎｂ＿２ＴｉＯ＿７陶瓷的烧结性能、热膨胀性能及电性能。结果表明，在Ｎｂ＿２ＴｉＯ＿７陶瓷中添加ＰｂＯ或ＳｒＯ，在１２００℃烧结时可得到相对密度９５％以上，抗折强度为１５０Ｍｈ的陶瓷材料。Ｎｂ＿２ＴｉＯ＿７晶格常数的热膨胀显示了较大的各向异性，平均线热膨胀系数为２．９×１０￣（－６）℃￣（－１）。烧结体中产生微裂纹后，导致热膨胀系数和介电常数下降。烧结体经过还原处理后，电阻率可达到１０￣（－２）Ω．ｃｍ。     

Fe－40Al合金与Al_2O_3陶瓷的界面润湿现象

本文采用座滴法研究了金属间化合物Ｆｅ－４０Ａｌ与Ａｌ＿２Ｏ＿３陶瓷的润湿性及界面的相互作用，重点考察了温度、保温时间以及合金元素对Ｆｅ－４０Ａ１合金／Ａｌ＿２Ｏ＿３润湿行为和界面反应的影响。     

SrTiO3复合功能陶瓷中烧结助剂的研究

采用一次烧成法制备出ＳｒＴｉＯ３电容－压敏复合功能陶瓷，着重研究了ＳｉＯ２－ＴｉＯ２－ＡｌＯ２系统结助剂对ＳｉＴｉＯ３陶瓷的结构和复合功能特性的影响。研究结果表明：组成合理的烧结助剂有助于促进ＳｒＴｉＯ３陶瓷的烧结，改善微观结构，并相应优化ＳｒＴｉＯ３陶瓷的复合功能。研究确定，优化的烧结助剂组成为０．５ｗｔ％Ｓｉ２Ｏ－０．２ｗｔ％ＴｉＯ２－０．０５ｗｔ％Ａｌ２Ｏ３。     

一种制备γ－Fe_2O_3薄膜的新方法

采用一种简单的新工艺分别在硅片和氧化铝陶瓷基片上制备了γ－Ｆｅ＿２Ｏ＿３薄膜。该工艺分３步完成：首先利用Ｆｅ（ＮＯ＿３）＿３酒精溶液通过浸渍涂布工艺制备α－Ｆｅ＿２Ｏ＿３薄膜，其次α－Ｆｅ＿２Ｏ＿３薄膜在氢气流中、３２０～３５０℃之间热处理３０ｍｉｎ被还原为Ｆｅ＿３Ｏ＿４薄膜，最后Ｆｅ＿３Ｏ＿４薄膜在空气中２５０℃左右热处理３０ｍｉｎ被氧化为γ－Ｆｅ＿２Ｏ＿３薄膜。ＸＲＤ和ＳＥＭ分析结果表明该γ－Ｆｅ＿２Ｏ＿３薄膜呈尖晶石物相和自由取向，晶粒为针形，具有疏松多孔的微结构。     

掺杂V_2O_3系PTC陶瓷中金属相的研究

报导在掺杂Ｖ＿２Ｏ＿３系ＰＴＣ陶瓷中引入Ｆｅ金属相，采用ＸＲＤ，ＳＥＭ分析技术确定Ｆｅ金属相在材料中的结构状态，并结合材料ＰＴＣ性能测试结果讨论了Ｆｅ金属相对材料烧结性能和ＰＴＣ性能的影响。     

2Y2O3—xCeO2对ZTM复相陶瓷相组成,显微结构,力学性能的影响

采用原位反应烧结工艺制备了ＺｒＯ２增韧莫来石（ＺＴＭ）复相陶瓷。研究和分析了在Ｙ２Ｏ３为２ｆｍｏｌ％的情况下，ＣｅＯ２添加量（用２Ｙ２Ｏ３－ｘＣｅＯ２）对ＺＴＭ复相陶瓷相组成，显微结构及力学性能的影响，结果表明，当ＣｅＯ２添加量（用２Ｙ２Ｏ３－ｘＣｅＯ２）对ＺＴＭ复相陶瓷相组成、显微结构及力学性能的影响。结果表明，当ＣｅＯ２添加量在１．５～４．５ｍｏｌ％时，ＺｒＯ２晶格畸变，晶胞长大，缺陷增加，Ｃ     

锆对银－铟合金在氧化物表面附着功的影响

在１０９３－１１７３Ｋ温域内用座滴法研究了ＡｇＩｎＺｒ系合金对烧结Ａｌ＿２Ｏ＿３和ＺｒＯ＿２基板的润湿性与附着功。实验结果表明，添加少量Ｚｒ有利于合金熔体对Ａｌ＿２Ｏ＿３的润湿，提高系统附着功，附着功达到稳定值时的Ｚｒ含量约为１ａｔ％。ＡｇＩｎＺｒ／ＺｒＯ＿２系附着功在３．５ａｔ％Ｚｒ附近达到峰值，其后，继续增加Ｚｒ浓度，系统附着功迅速下降并导致合金熔体不润湿ＺｒＯ＿２。     

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.     

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...     

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.     

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.     

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.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.