退火对立方相 MgxZn1-xO薄膜的结构和光学性质影响

在蓝宝石（0001）衬底上低温生长立方相MgxZn1-xO（x〉0．5）晶体薄膜，用X射线衍射（XRD）和透射光谱分析高温退火对薄膜的结构和光学性质的影响．结果表明;对Mg0．53Zn0．47O薄膜，在900℃的退火温度下，（0002）衍射峰以及透射光谱上双吸收边的出现均表明有六方结构从其立方结构中分离出来；但对于Mg含量高于55％的样品，即使经历了1000℃的高温退火，也不会有任何相分裂现象出现．而电学测试结果表明，高温下热稳定性良好的立方相Mg0．55Zn0．45O晶体薄膜还能用于金属-绝缘体-半导体的绝缘层，并且漏电流小．由此可以判断，x≥0．55的超饱和MgZn1-xO薄膜具有稳定的立方相晶体结构和优良的光学、电学性质，因而是制作高质量的光电子器件和量子阱激光器的理想材料．     

对向靶溅射高饱和磁化强度（Fe,Ti）—N薄膜

本实验用对向靶溅射仪分别在Ｓｉ（１００），ＮａＣｌ单昌衬底上成功地制备出具有高饱和磁化强度的（Ｆｅ，Ｔｉ）－Ｎ薄膜，研究了氮气分压和衬底温度对结构与磁性的影响。氮气分压为０．０４－０．０７Ｐａ，衬底温度淡１００－１５０℃时，有利于Ｆｅ１６Ｎ２相的形成，在此条件下制备的（Ｆｅ，Ｔｉ）－Ｎ薄膜的饱和磁化强度为２．３－２。．４６Ｔ，超过纯Ｆｅ的饱和磁化强度值。     

对向靶溅射高炮和磁化强度(Fe,Ti)-N薄膜

本实验用对向靶溅射仪分别在Si（100），NaCl单晶衬底上成功地制备出具有高炮和磁化强度的（Fe，Ti）－N薄膜，研究了氮气分压和衬底温度对薄膜结构与磁性的影响。氮气分压为0．04～0．07Pa，衬底温度为100～150℃时，有利于Fe_(16)N_2相的形成，在此条件下制备的（Fe，Ti）－N薄膜的饱和磁化强度为2．3～2．46T，超过纯Fe的饱和磁化强度值。     

纳米Dy0.15Fe1.85O3磁颗粒的低温磁特性研究

采用共沉淀–相转化法制备了纳米Dy0.15Fe1.85O3磁颗粒,研究了低温条件下温度变化对其磁学特性的影响.采用XRF、TEM、XRD和超导量子磁强计(SQUID)对样品的化学成份、形貌、晶型结构和磁学性能进行了表征.结果表明:样品中的金属离子主要是Dy3+、Fe3+,含量分别为12.17wt%、51.88wt%.形貌为类球形,平均粒径约15 nm,且结晶性完全,晶型为面心立方尖晶石结构.在56.5～200.2 K范围内,样品的饱和磁化强度(MS)、矫顽力(HC)均随温度的降低呈现出增大的变化规律,当温度T≥142.8 K时,呈超顺磁性状态;当T<142.8 K时,由超顺磁性状态转化为铁磁性状态.     

低温烧结Ph(Zn_(1/3)Nb_(2/3)O_3基复相陶瓷中的两相共存与介电性能

分别采用氟化物和硼硅玻璃为助烧剂制备了低温烧结PZN基复相陶瓷，并借助介电温度特性研究了复相陶瓷中的两相共存与助烧剂的关系．结果表明，添加剂引入的晶格缺陷对复相陶瓷中的两相共存有显著影响,LiF助烧剂因引起晶格氧空位促进两相固溶化，而MgF2和硼硅玻璃助烧的PZN复相陶瓷可保持两相共存．以硼硅玻璃为助烧剂获得了低温烧结、具有X7R温度稳定特性的PZN基复相陶瓷．     

一种提高低温流体比体积计算精度的方法

采用了一个既能提高立方型状态方程比体积计算精度，又不影响气液平衡条件的简单摩尔修正项来改进PR方程比体积的计算。本文对19种低温流体给出其修正项的值，计算饱和蒸气和液体比体积，并与未修正的PR方程的计算值比较，结果表明这种修正能显著提高低温流体（包括量子流体氢、氦和强极性的氨气）饱和液体比体积的计算精度，并对蒸气比体积的计算也略有改进。     

含二氧化碳和水蒸气的氮气增压输送液氮模拟试验

进行了低温液体火箭推进系统的液氧箱自生增压输送过程的模拟试验，专门设计加工了液氮箱增压输送模拟试验台，试验得出了液氮增压输送过程中温度、压力、流量的变化规律以及含饱和CO2、H2O的氮气通过过滤器时，对系统的流量和压降的影响。指出为保证低温流量计测量准确，必须重视在避免管路中出现两相流方面采取措施。试验结果表明，本试验装置能有效地进行含CO2、H2O(气)的氮气增压输送试验，保证了试验的圆满成功。     

超高真空化学气相淀积自组织生长锗量子点

采用超高真空化学气相淀积系统制备了小尺寸、高密度、纵向自对准的Ge量子点．通过TEM和AFM对埋层和上层量子点的形貌和尺寸分布进行了研究，对生长的温度和时间进行了优化．采用硼预淀积的方法得到了尺寸分布小于3％的均匀的圆顶形Ge量子点．采用低温光荧光测量了多层量子点的光学特性．在10K的PL谱可以观察到明显的蓝移现象，表明量子点中较强的量子限制效应．量子点非声子峰的半高宽约为46meV，表明采用UHV／CVD工艺生长的多层量子点具有较窄的尺寸分布．     

机械合金化制备各向同性SrFe12O19磁性的研究

用机械合金化方法制备了各向同性Ｍ型ＳｒＦｅ１２Ｏ１９磁性粉末，系统地研究了球磨条件对磁性的影响。结果表明，在相结构转变上，低温退火与长时间球磨起着相似的作用。当样品在７５－８００℃退火处理时，饱和磁化强度Ｍｓ比矫顽力Ｈｃ受球磨条件影响更明显。     

Fe-Ti-C系燃烧合成反应的热力学分析

利用相图计算技术（ＣＡＬＰＨＡＤ）对Ｆｅ－Ｔｉ－Ｃ燃烧合成反应体系进行热力学分析,着重研究Ｆｅ含量和Ｃ／Ｔｉ原子比对体系绝热燃烧温度Ｔ_ａｄ和平衡相组成的影响．研究结果表明,Ｆｅ含量对 Ｆｅ－Ｔｉ－Ｃ三元系的平衡相组成影响不大,但对绝热燃烧温度的影响非常大．当保持Ｃ／Ｔｉ原子比接近１．０时,不管Ｆｅ含量如何变化;在２９８Ｋ下均会得到理想的平衡相组织ＴｉＣ＋Ｆｅ 随Ｆｅ含量增加,体系的绝热燃烧温度大致呈线性降低．Ｆｅ－Ｔｉ－Ｃ体系发生ＳＨＳ反应的热力学条件之一（Ｔ_ａｄ＞１８００Ｋ）是Ｆｅ＜５５ｗｔ％．而 Ｃ／Ｔｉ原子比对绝热燃烧温度的影响比较小,但对平衡相组成影响非常大,主要表现在两个方面：①石墨相的析出温度不同．随Ｃ／Ｔｉ原子比降低,析出温度也随之降低．②在各温区石墨相的含量不同．当 Ｃ／Ｔｉ在１．０～１．４变化时,石墨相含量在低温区由１％提高到１６％．     

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...     

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.     

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.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.