BAM稀土荧光粉的性能测试及应用

高温固相法制备了BaMgAl10O17:Eu2+(BAM)细颗粒稀土荧光粉,采用X射线衍射、粒度分布分析、光谱分析等方法,研究了BAM的晶体结构,粒度分布,热稳定性,相对亮度,光效等性能,结果表明,制备的样品为BaMgAl10O17:Eu2+(BAM),BAM细颗粒稀土荧光粉的粒度大约2μm,X50测试误差为±0.02μm;600℃,0.5h,热稳定性为7.0%~8.5%;相对亮度为101%~102%;100h的光衰5%,基本满足细颗粒灯用稀土荧光粉的要求。     

激光粒度仪的样品处理

利用激光粒度仪测粉体的粒度，需要对样品进行细致的处理，需要了解样品的物理参数，选择合适的样品量以及适应的分散剂，分散介质。并根据样品检测结果的重复性来确定样品的粒度。     

鼓泡流化床稀相空间颗粒粒度分布的时变特性

鼓泡流化床稀相空间的催化剂颗粒粒度分布一方面与流化床流化速度有关，另一方面与流化床中藏量的细小颗粒跑损有关，即随着流化床操作的连续进行，流化床系统中的细颗粒不可避免的存在跑损，进而影响到稀相空间的颗粒粒度分布。由于这种跑损是连续发生的，因此稀相的颗粒粒度分布变化具有时变特性。选用催化裂化平衡催化剂和二维流化床，在连续流化操作过程中采集稀相空间中的颗粒样品，分析颗粒的粒度分布，考察稀相空间中颗粒粒度分布随流化操作时间的变化。结果表明：随着流化床系统中细颗粒的跑损，稀相颗粒粒度分布的中位粒径和峭度逐渐增加，稀相空间的颗粒逐渐粗化，经过一段流化操作时间后颗粒粒度分布变化趋于稳定。     

水力溢流分级在超细α-Al2O3粉体中的应用研究

水力溢流分级精度较高，足目前常用的超细颗粒分级方法，本文通过水力溢流分级，研究了超声波，分散剂等因素对超细α-Al2O3，水力分级的影响，结果表明，分散剂虽然可以消除分级过程中的小颗粒现象，但是也对分级结果产生负面影响，使得分级后的产品粒度分布变宽；加入分散剂，同时超声处理后样品可以得到较好的分级结果。     

水力溢流分级在超细α-Al_2O_3粉体中的应用研究

水力溢流分级精度较高,是目前常用的超细颗粒分级方法,通过溢流分级,可以将研磨后的粉体分级成为某一特定粒度分布的粉体,以适应研磨抛光等行业对粒度分布的要求。通过水力溢流分级,研究了分散剂、超声波等因素对超细α-Al2O3水力分级的影响,结果表明,分散剂虽然可以消除分级过程中的小颗粒现象,但是也对分级结果产生负面影响,使分级后的产品粒度分布变宽;加入分散剂,同时超声处理后样品可以得到较好的分级结果,分级后的粒度分布较窄。     

水泥粒度测试--干法与湿法对比研究报告

使用济南微纳仪器有限公司生产的湿法激光粒度仪Winner2000和干法激光粒度分析仪Winner3001对水泥样品进行了测试对比实验.实验结果表明,测试参数选择得当,二者结果吻合良好.激光粒度分析仪能够满足水泥行业质量检验与工艺控制的需要.     

活性炭吸附性能与其粒度分布分形维数的关系研究

采用数字显微系统和图像处理技术算得5种活性炭样品的粒度分布分形维数值,探讨了活性炭的吸附性能与其粒度分布分形维间的关系.结果表明,活性炭样品的平衡吸附量与粒度分布分形维数值均随细颗粒活性炭含量的增加而逐渐增大.进一步的研究表明,活性炭样品的平衡吸附量与其粒度分布分形维数值存在正相关关系.     

窄粒度分布粉体产品分级的影响因素

在粉体制备的实际生产过程中，分级机是保证产品质量的重要环节，特别是在微粉窄级别物料的生产中尤为重要。这是因为窄级别物料要求产品的粒度分布很窄，即不能有大颗粒的存在，细颗粒含量也不能过多。这就要求分级机不但能去除物料中的大颗粒，而且要控制物料中的细颗粒...     

稀土永磁材料NdFeN三种粒度分析方法的比较

粉体粒度及粒度分布是粉体颗粒最重要的特性。以稀土永磁材料NdFeN为例，采用激光散射法（干法和湿法）和扫描电镜法对其粒度进行了分析，并比较了三种方法的测试结果。测试结果显示，粒度分析时样品的充分分散是准确测量的基础。将显微镜的直观与激光粒度仪的快速、准确和方便结合起来，对于保证粒度分析结果的可靠性非常有用。     

氢氧化铝粉体粒度测量技术

氧化铝生产工艺分解过程中氢氧化铝粒度检测的结果对分解系统的稳定和产品氧化铝的粒度控制有着非常重要的意义。氢氧化铝粒度的测定方法很多,目前用来监测粒度的方法有筛分法、马尔文激光粒度法、库尔特全自动颗粒粒度分析、颗粒计数器分析等,综合各种分析结果可得到氢氧化铝的全粒度分布情况。     

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.……     

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.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

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.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.