低烧超高磁导率Ni-Zn-Cu铁氧体研究

采用凝胶自燃法制备超细高活性Ｎｉ－Ｚｎ－Ｃｕ铁氧体粉。利用ＴＥＭ、ＳＥＭ、ＸＲＤ与ＨＰ４１９４Ａ研究了粉末及烧结铁氧体的显微结构、形貌、晶粒尺寸、组成相与性能的关系。所获得不加助熔剂的Ｎｉ－Ｚｎ－Ｃｕ烧结铁氧体具有低烧（≤９００℃）、高性能的特点,主要磁性能指标如下：ｕｉ８７０℃＝５００,ｕｉ９００℃＝９００,品质因数大于５,截止频率约１０ＭＨｚ。材料的磁化主要源于畴壁位移。     

不同稀土元素掺杂M型钡铁氧体超微粉末的磁性研究

利用溶胶－凝胶自蔓延高温合成法制备了4种稀土元素（La、Nd、Sm、Gd）掺杂钡铁氧体超微粉末。就烯土元素的种类、稀土掺杂量、合成工艺条件对钡铁氧体磁学性能的影响进行了较系统的研究。采用振动样品磁强计对粉末的磁学性能进行了检测。     

YSZ超细粉末的溶胶——凝胶法制备

应用溶胶－凝胶方法合成了ＹＳＺ（Ｚｒ０２＋９ｍｏｌ％Ｙ２Ｏ３）超细粉末。对凝胶形成超细粉末的热分解及晶化过程用ｘ射线衍射（ＸＲＤ）和热重一差热（ＴＧ－ＤＴＡ）等分析方法进行了研究。试验表明，溶胶－凝胶法制备ＹＳＺ超细粉末的反应过程分为：水份和有机溶剂的挥发；有机基团的燃烧和无定形Ｚｒ０２的形成；无定形Ｚｒ０２向立方要Ｚｒ０２的转变三个阶段。在４７０℃时，凝胶转变为ＹＳＺ固溶体，形成立方相Ｚｒ０２结     

M-型超微钡铁氧体粉末制备技术的最新进展

介绍了颗粒磁记录介质发展现状,着重总结、分析了钡铁氧体超细粉末制备技术最新进展,包括溶胶－凝胶法、共沉淀法、微乳液法等最新合成方法。这些方法是合成粒径小于１００ｎｍ的钡铁氧体超微粉末的有效方法。     

铁磁性Mn—Zn,Ni—Zn铁氧体与铁电性BaTiO3复合材？…

本文研究了铁磁性Ｍｎ－Ｚｎ，Ｎｉ－Ｚｎ铁氧体与铁电性ＢａＴｉＯ３复合材料在１－１０００ＭＨｚ频段内的吸波能力。结果表明；随频率升高，Ｍｎ－Ｚｎ２铁氧ＢａＴｉ／Ｏ３和Ｎｉ－Ｚｎ铁氧体／ＢａＴｉＯ３复合材料的吸波能力逐渐增加；随Ｍｎ－Ｚｎ或Ｎｉ－Ｚｎ铁氧体含量增加，这两类复合材料的吸波能力也逐渐增加；相同配比时的Ｎｉ－Ｚｎ铁氧体／ＢａＴｉＯ３复合材料吸波能力大于Ｍｎ－Ｚｎ铁氧体／ＢａＴｉＯ３。     

溶胶直接自蔓燃法制备NiZn铁氧体粉末研究

以柠檬酸铁或硝酸铁、硝酸锌、硝酸镍和柠檬酸为原料,利用溶胶直接自蔓延燃烧反应成功制备了尖晶石结构的NiZn铁氧体粉末.研究结果表明,溶胶直接自蔓延燃烧法形成的NiZn铁氧体粉末的颗粒尺寸总体较小,在含柠檬酸铁体系中晶粒平均尺寸仅为16～23nm,当柠檬酸量与金属盐总量的摩尔比为2时,形成的NiZn铁氧体粉末晶粒尺寸达最大.溶胶直接自蔓延燃烧法得到的NiZn铁氧体粉末的饱和磁化强度相对较小,约为10.54emu/g,矫顽力较大,约为412.5Oe .     

干凝胶自蔓延燃烧法制备纳米级的MnZn铁氧体

以硝酸铁、硝酸锌，硝酸锰和柠檬酸为原料，利用溶胶－凝胶法和干凝胶自蔓延燃烧工艺制备了纳米的MnZn铁氧体。利用热分析（TG－DTG）研究了干凝胶自燃烧过程，并且利用X衍射（XRD）、透射电子显微镜（TEM）研究了PH值、温度，成胶时间以及燃烧温度对MnZn铁氧体的晶体结构，晶体组成和粒径大小的关系。实验结果表明，在较低的PH值和适当的成胶时间下，通过微波外界加热维持干凝胶的自蔓燃烧可以制得粒径为10－20nm之间，晶型良好的立方尖晶石结构MnZn铁氧体。     

PZT／Ni—Zn铁氧体复合材料电磁特性研究

研究了铁电材料ＰＺＴ和铁磁材料Ｎｉ－Ｚｎ铁氧体的复合材料在１￣１０００ＭＨｚ频率范围内的电磁特性。结果表明，ＰＺＴ具有铁电与铁磁共存的双重特性。当与Ｎｉ－Ｚｎ铁氧体复合后，其复合磁导率及复合介电常数均具有可调性，由此可优化设计高吸收电磁波能力的新型复合材料。     

超临界流体干燥法制备MnZn铁氧体超细粉末：I.制备参数对粉末织？…

本文采用胶体－超临界流体干燥法制得超细ＭｎＺｎ铁氧体粉末，通过Ｘ－射线衍射技术和比表面的测定等以粉末的结构参数进行测定。其中主要考察了Ｍｎ，Ｚｎ含量，ｐＨ值，溶液浓度以及超临界流体干燥参数（温度，时间和压力等）对粉末织构的影响，并对各种凝胶粉末的织构进行了比较。     

锰锌铁氧体的制备研究进展

阐述了国内外锰锌铁氧体制备技术的研究进展,主要包括了传统的固相法、共沉淀法、水热法、溶胶-凝胶法以及自蔓延燃烧法等方法。介绍了各种方法的原理与应用,并分析了各种方法的优势与不足。其中,化学共沉淀法、溶胶凝胶法-自蔓延燃烧法制备方法应用较为普遍,而水热合成法和微乳液法在制备纳米级锰锌铁氧体晶体及相关功能化材料中有着重要的应用。分析表明锰锌铁氧体的制备还需进一步完善,并提出锰锌铁氧体与导电聚合物的复合、外加磁场制备锰锌铁氧体的研究方向。     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

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.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

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.     

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.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.