烧结温度对钨镁酸铅基陶瓷X7R特性及显微结构的影响

研究了烧结温度对钨镁酸铅基陶瓷Ｘ７Ｒ特性及其显微结构的影响，实验结果表明：烧结温度在９５０－９８０℃范围内，该体系电容随温度的变化率（即ＴＣＣ）满足Ｘ７Ｒ要求。显微分析可知：体系的微观结构中存在富钨和富锆的不均匀微区，温度升高，微区间均匀性增加，在１０００℃以上，各微区成份接近，但容温变化偏离Ｘ７Ｒ要求的范围。     

Mg—PSZ中二种析出相的初步研究

本文采用较简便的烧成工艺的制度制备Ｍｇ－ＰＳＺ材料，用ＴＥＭ对这种Ｍｇ－ＰＳＺ材料中的析出相进行了观察，对析出相的结构进行了初步的研究，发现了其中的二种未知析出相Ｘ１相和Ｘ２相。Ｘ１相具有简单四方结构，点阵常数约为ａ＝１．４４８ｎｍ，ｃ＝２．１００ｎｍ。Ｘ２相也具有简单四方结构，点阵常数约为ａ＝１．４４０ｎｍ，ｃ＝４０．０７２ｎｍ。     

X－300照相机性能和结构原理（下）

Ｘ－３００照相机性能和结构原理（下）徐鸿浩，鲍春山四、Ｘ－３００照相机的快门机构Ｘ－３００照相机的快门是电子控制的横走式焦平面幕帘快门，这种快门与ＤＦ－１系列照相机不同，它采用的是三轴式齿轮啮合上弦机构，其外形见图１－１３。Ｘ－３００相机的快门幕帘上...     

离子束溅射沉积作用下聚四氟乙烯膜的制备和结构分析

本文首先利用离子束溅射聚四氟乙烯靶材的方法制备了薄膜，进而研究了其结构。由ＸＰＳ的结果可知，所得薄膜主要由ＣＦ２结构组成；由ＦＴ－ＩＲ的结果可知，在１１６９ｃｍ＾－１和１０８３ｃｍ＾－１处出现了Ｃ－Ｆ的最强吸收峰，在７３４ｃｍ＾－１，６１９ｃｍ＾－１和５００ｃｍ＾－１处出现了聚四氟乙烯的特征吸收峰。ＸＰＳ和ＦＴ－ＩＲ的结果是一致的，所得薄膜呈现聚四氟乙烯的结构特征。     

Mg－PSZ中二种析出相的初步研究

本文采用了较简便的烧成工艺制度制备Ｍｇ－ＰＳＺ材料．用ＴＥＭ对这种Ｍｇ－ＰＳＺ材料中的析出相进行了观察，对析出相的结构进行了初步的研究，发现了其中的二种未知析出相Ｘ１相和Ｘ２相．Ｘ１相具有简单四方结构，点阵常数约为ａ＝１．４４８ｎｍｃ＝２．１００ｎｍ．Ｘ２相也具有简单四方结构，点阵常数约为ａ＝１．４４０ｎｍ，ｃ＝４．０７２ｎｍ．     

Hg1—xCdxTe液相外延薄膜的晶体质量分析

本文用Ｘ－射线双晶遥摆曲线，分析了Ｈｇ１－ｘＣｄｘＴｅ外延薄膜的晶体质量。结果表明，用垂直浸渍液相外延方法生长的Ｈｇ１－ｘＣｄｘＴｅ薄膜，结构均匀性好，晶体质量高，Ｈｇ１－ｘＣｄｘＴｅ外延薄膜表面层的晶体质量，优于其界面层；同时，Ｈｇ１－ｘＣｄｘＴｅ外延薄膜表面层的位错密度，可通过Ｘ－射线双晶遥摆曲线的半峰算得到。     

Ti1—xAlxN薄膜的制备及性能研究

介绍了利用反应溅射法制备Ｔｉ１－ｘＡｌｘＮ薄膜的工艺过程，测量并分析了Ｔｉ１－ｘＡｌｘＮ薄膜的光学性能及电阻率与薄膜成分的关系。结果表明Ｔｉ１－ｘＡｌｎＸ薄膜的折射率和消光系数均随薄膜中Ａｌ含量ｘ的增加而减小，电阻率则随ｘ的增加而增大。并从薄膜的基本结构变化对实验结果作出解释。     

前驱体制备途径对PFN-PMN二元铅基铁电陶瓷性能的影响

综合运用 ＸＲＤ、ＳＥＭ、ＴＥＭ、ＥＤＳ和介电测量等方法,考察了一步预煅烧法和二步预煅烧法等前驱体制备途径对Ｐｂ（Ｆｅ_１／２Ｎｂ_１／２）Ｏ_３（ＰＦＮ）－Ｐｂ（Ｍｇ_１／３Ｎｂ_２／３）Ｏ_３（ＰＭＮ）二元系铁电陶瓷显微结构和介电性能的影响．研究结果表明,对（１－Ｘ）ＰＦＮ－ＸＰＭＮ二元系而言,在所考查的组成范围内（Ｘ＝０～０.５）;其居里温度与ＰＭＮ的含量近似成线性关系,且随Ｘ的增加,居里温度向低温方向移动.峰值介电常数随Ｘ的增加而降低．（预）煅烧和烧结条件对显微结构和介电性能都有不可忽视的影响．对用一步预煅烧法和二步预煅烧法得到的样品的介电性能和其他性能进行了比较,并对其差异产生的可能机制进行了讨论．     

机械合金化方法制备的Nd（Fe,V,Ti）12Ny磁体的结构与磁性

采用Ｘ射线和磁性测量研究了退火机械合金化ＮｄＦｅ１０．５＋０．５ｘＶ（１－Ｘ）Ｔｉｘ合金相的形成和磁学性能。根据Ｘ射线和初始交流磁化的结果作出了ＴｈＭｎ１２结构１－１２相的形成与钛的含量，退火温度的关系图。     

生物活性梯度涂层的显微结构与附着强度

采用ＳＥＭ、ＥＤＳ和ＸＲＤ等测试手段研究不同组分羟基磷灰石基生物活性梯度涂层的显微结构和残余应力,探讨涂层材料的组成－显微结构－附着强相关规律。     

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.……     

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.     

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.     

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.