电阻率可调的Si—Ti—C—O纤维的研制

以Ｔｉ（ＯＢｕ）４与低分子量聚硅烷为原料合成不同含钛量的聚钛碳硅烷,经熔融纺丝、空气不熔化及高温烧结等工艺,制备出了电阻率为１０６～１０３Ω·ｃｍ的Ｓｉ－Ｔｉ－Ｃ－Ｏ纤维。通过ＩＲ、ＧＰＣ、ＶＰＯ、ＸＰＳ等分析手段,系统地研究了钛含量对纤维的制备、结构及其电性能的影响     

自生β—Si3N4棒晶增强BAS玻璃陶瓷的组织结构与力学性能

在较低的烧结温度下（１４５０℃）制备出钡长石（ＢａＡｌ２Ｓｉ２Ｏ８,ＢＡＳ）含量为２０ｗｔ％～１００ｗｔ％的Ｓｉ３Ｎ４／ＢＡＳ陶瓷基复合材料,并对其进行了组织结构分析和力学性能测试。通过ＥＤＳ研究发现无金属离子固溶入β－Ｓｉ３Ｎ４晶格。随着ＢＡＳ含量升高,Ｓｉ３Ｎ４的α→β相转变量增加。Ｓｉ３Ｎ４／ＢＡＳ复合材料的室温抗弯强度随ＢＡＳ含量增加选增后降。在１０００℃、１１００℃和１２００℃时分别测试了复合材料的高温抗弯强度。     

碳化硅渗透涂层粘胶碳纤维的制备

从粘胶纤维出发制成连续的ＳｉＣ涂层的碳纤维。在热解过程中进行聚碳硅烷溶液的ＰＳＩ处理。纤维经１０００℃高温烧成后得到Ｃ／ＳｉＣ纤维。因为碳与外表的ＳｉＣ同时在高温下生成，ＳｉＣ渗透到纤维内部，呈梯度结构。制备中使用了一种含多元胺的阻燃剂，这不仅使烧成时间大为缩短，而且使纤维的收率提高。Ｃ／ＳｉＣ纤维的收率为３５－３８％，拉伸强度为１．３－２．０ＧＰａ，弹性模量为７０－１３０ＧＰａ，纤维平均直径为４至６μ。本文还对纤维的热解动力学进行了研究，提出新的动力学模型，由此设计纤维的烧成程序。     

电沉积Ni—P,Ni—P—Si3N4非晶态合金及其结构,性能研究

研究了Ｎｉ－Ｐ、Ｎｉ－Ｐ－Ｓｉ３Ｎ４非晶态合金薄膜的是沉积工艺，通过ＳＥＭ－ＥＤＳ，ＸＲＤ，ＥＭＰＡ等微观分析方法，提出了获取８￣１４ｗｔ％Ｎｉ－Ｐ和Ｎｉ－Ｐ－Ｓｉ３Ｎ非晶合金镀层的镀液组成和电沉积参数。实验表明，Ｎｉ－Ｐ非晶态合金镀层在碱液中具有优越的耐蚀性能，在含Ｃｌ＾－１的中性盐液中有良好的耐蚀性，且不产生点蚀；Ｎｉ－Ｐ－Ｓｉ３Ｎ４非晶合金镀层，经晶化处理后，耐蚀性能提高，且与基材呈冶金结合     

管状纳米结构的合成及显微分析

自从１９９１年ＮＥＣ的Ｉｉｊｉｍａ研究员发现碳纳米管以来,管状纳米结构引起了世界范围内的物理、化学、材料等学界的广泛重视。描述了用激光蒸发法在高温氮气气氛中合成单层碳纳米管,Ｂ－Ｃ－Ｎ复合纳米管,ＢＣＮ／ＳｉＯ２／ＳｉＣ多层纳米电缆结构的工作,以及运用高分辨电子显微镜和纳米区域电子能量损失谱仪对其结构和化学组成进行分析的结果,并讨论了激光蒸发法中管状纳米结构的生成机理。     

β—SiC高性能连续纤维的研制进展

综述了β－ＳｉＣ连续纤维的制备方法，对所得纤维的性能作了评述，结合作者的研究，对今年β－ＳｉＣ纤维研制技术的发展，提出了一些观点。     

聚碳硅烷／二乙烯基苯的高温裂解

采用ＴＧ－ＤＴＡ、ＩＲ、ＸＲＤ、ＸＰＳ、ＳＥＭ等手段研究了聚碳硅烷（ＰＣＳ）／二乙烯基苯（ＤＶＢ）的高温裂解行为及其裂解产物的结构与性能。结果表明，ＰＣＳ／ＤＶＢ的裂解过程可分成５个阶段，其裂解产物主要由ＳｉＣ、ＳｉＯ２和Ｓｉ－Ｏ－Ｃ非晶网络及游离Ｃ组成，其中游离Ｃ的含量随ＤＶＢ的增加而增加，且对β－ＳｉＣ的结晶有一定的抑制作用，裂解产物的形貌为不发泡的致密结构。     

Si-Zr-B复合非催化形核涂层壳型的制备

先采用熔模铸造中的制壳工艺,在壳型内壁制备了Ｓｉ－Ｚｒ－Ｂ基底涂层Ｚ,然后利用溶胶凝胶原理,经浸涂－分级热处理以及８５０℃玻璃热处理后,在Ｚ表面制备了七层与Ｚ同成分的Ｓｉ－Ｚｒ－Ｂ玻璃薄膜涂层。ＸＲＤ和ＳＥＭ分析结果表明,Ｈ３ＢＯ３的加入起抑制Ｓｉ－Ｚｒ－Ｂ涂层析晶及对涂层表面裂纹的高温自愈合作用。因此,将Ｚ－Ｒ壳型置于１５００℃保温３０ｍｉｎ后,涂层的析晶量仅为１％～３％,其结构在高温下具有很强的稳定性。过冷实验结果表明,ＤＤ３单晶高温合金可以在该涂层壳型内获得１４０Ｋ过冷度,证明Ｓｉ－Ｚｒ－Ｂ涂层具有良好的非催化形核惰性。     

Nb镀层对c—BN—玻化陶瓷结合剂界面成分结构的影响

用ＤＴＡ、ＸＲＤ、ＳＥＭ、ＥＰＭＡ等研究了Ｎｂ镀层与ｃ－ＢＮ晶体在６００－１０００℃范围的界面反应过程、界面成分和结构特征，讨论了烧结时Ｎｂ镀层与ＳｉＯ２－Ｎａ２Ｏ－Ｂ２Ｏ３玻化结合剂的作用，结果表明：Ｎｂ镀与ｃ－ＢＮ晶体在６００℃以上发生界面反应，外延生长形成ＮｂＮ，８００℃以上形成ＮｂＢ２，它们使Ｎｂ镀层与ｃ－ＢＮ牢固结合并阻止结合剂中的碱性组分对ｃ－ＢＮ的侵蚀，镀Ｎｂ的ｃ－ＢＮ表层的Ｎｂ则作     

陶瓷材料高温断裂韧性评价

采用四点弯曲实验方法，研究了高温下不同测试方法（ＣＮ法、ＳＥＮＢ法和ＳＥＰＢ法）对工业用重结晶ＳｉＣ陶瓷材料断裂韧性的影响。通过实验发现：在低温下（Ｔ〈８００℃）不同测试方法所获得的ＫＩＣ不同，ＣＮ法测得ＫＩＣ偏大，而ＳＥＰＢ法测得的ＫＩＣ则偏小，同时，三种测试方法获得的ＫＩＣ随温度的升高变化率都不明显。在高温下（Ｔ〉８００℃），不同的测试方法其ＫＩＣ随温度的和蔼同变化趋势不同，ＣＮ法ＫＩＣ随温度的升高而增大，ＳＥＮＢ法ＫＩＣ随温度的升高而减小，ＳＥＰＢ法ＫＩＣ随温度的升高则基本无变化。     

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.