高Tc铋层状压电陶瓷结构与性能

综述了铋层状压电陶瓷的结构特点及性能研究．铋层状压电陶瓷的结构由（Ｂｉ_２Ｏ_２）^２＋层和钙钛矿层（Ａ_ｍ－１Ｂ_ｍＯ_３ｍ＋１）^２－按一定规则共生排列而成．此处 Ａ为适合干 １２配位的离子;Ｂ为适合于八面体配位的离子,ｍ为一整数,其值一般为１～５．与钛酸钡（ＢａＴｉＯ_３）或锆钛酸铅（ＰＺＴ）陶瓷相比,铋层状压电陶瓷具有以下特点：低介电常数、高Ｔ_ｃ、机电耦合系数各向异性明显、低老化率、高电阻率等． 先前研究证明,居里温度不仅与极化原子位移、自发极化强度、Ａ位Ｂｉ含量有关,而且还与取代离子的特性诸如离子半径、电负性、核外电子排布有关．压电活性低是铋层状陶瓷的本质缺点,通常发展该材料的途径为化学取代或晶粒取向技术．研究材料结构与性能之间的关系有助于发展铋层状压电陶瓷材料．     

镍内电极多层陶瓷电容器介质材料的研究

通过（ＢａＯ＋ＣａＯ）／（ＴｉＯ２＋ＺｒＯ２）略大于１的Ｂａ－ＴｉＯ３系材料进行受主离子Ｃａ＾２＋、Ｍｇ＾２＋、Ｆｅ＾３＋、Ｍｎ＾２＋和Ｚｎ＾２＋掺杂试验,使瓷料在还原性气氛中与镍电极共烧,获得介电常数为１５０００、绝缘电阻率达到１０＾１２Ω．ｃｍ的抗还原陶瓷。     

P2O3—B2O3—Al2O3—SrO—BaO玻璃中的Yb^3＋非辐射能量转移下E …

本文研究了共掺Ｅｒ＾３＋／Ｙｂ＾３Ｐ２Ｏ３－Ｂ２Ｏ３－Ａｌ２Ｏ３－ＳｒＯ－ＢａＯ玻璃的能量转移过程。实验中制备了高掺杂Ｂｂ＾３＋离子的双掺Ｅｒ＾＃＋／Ｙｂ＆＾３＋的磷酸盐玻璃样品。在Ｅｒ＾３＋／Ｙｂ＾３＋掺杂比率〉１：１８（ｍｏｌ％）时,观测到了基于Ｙｂ＾３＋离子至Ｅｒ＾３＋离子能量转移下Ｅｒ＾３＋（＾３Ｉ１３／２→＾４Ｉ１５／２）的增强发射和ｂ＾３＋（＾２Ｆ７１／→＾２Ｆ５／２）发射的减弱,当Ｂ     

立方A^4＋M^5＋2O7型化合物与新型负热膨胀材料

概述了立方Ａ＾４＋Ｍ＾５＋２Ｏ７型化合物的结构特点，讨论了ＡＶ２－ｘＰｘＯ７型（Ａ＝Ｚｒ或Ｈｆ；ｘ＝０．１～１．２）及其部分取代的Ａ＾４＋１－ｙＢ＾４＋ｙＶ２－ｘＰｘＯ７型（Ｂ＝Ｔｉ，Ｃｅ，Ｔｈ，Ｕ，Ｍｏ，Ｐｔ，Ｐｂ，Ｓｎ，Ｇｅ或Ｓｉ；ｙ＝０．１～０．４）和Ａ＾４＋１－ｙＣ＾１＋ｙＤ＾３＋ｙＶ２－ｘＰｘＯ７型（Ｃ为碱金属元素，Ｄ为稀土金属元素）材料的负热膨胀性能。     

阴离子粘土LiAl2(OH)6X·2H2O(X=OH-,1/2CO32-)的离子交换特性

本文研究了阴离子粘土ＬｉＡｌ２（ＯＨ）６－Ｘ．２Ｈ２Ｏ（Ｘ＝ＯＨ＾－，１／２ＣＯ３＾２）的离子交换特性，结构分析表明，ＬｉＡｌ２－ＬＤＨ含水分隔层内的ＯＨ和ＣＯ３＾２－离子容易与酸性溶液中的Ｃｌ、ＮＯ３等离子进行交换，且保持ＬｉＡｌ２－ＬＤＨ的水滑石型层状结构不变，其中Ｃｌ－离子型表现较高的离子交换速率，在阴离子交换的同时，氢氧化以内的Ｌｉ＾＋离子也被Ｈ离子部分取代，但交换率较低，进一步讨论说明，     

一种用于宽带温度稳定光隔离器的新型磁光材料

以Ｂｉ２Ｏ３／Ｂ２Ｏ３为主要助熔剂,用改进的高温助熔剂法生长出一种新型掺铋 事稀土铁石榴石（ＨｏＹｂＢｉ）３Ｆｅ５Ｏ１２单晶,研究了磁光性能,法拉第旋转温度和波长特性在１０－１１０℃,单昌的法拉第旋转温度系数Ｓ＝θＦ＾－１（ｄθＦ／ｄＴ）在λ＝１．５５μｍ时为４．６×１０＾－４Ｋ＾－１,比ＹＩＧ单晶的法拉第旋转温度系数小,在λ＝１．５５μｍ时,（ＨｏＹｂＢｉ）３Ｆｅ５Ｏ１２单晶的法拉第旋转波长系数     

铜离子注入对半导体BaTiO3陶瓷PTCR特性的影响

应用阻抗谱，结合阻温特性测量分析铜离子注入（１１０ＫｅＶ，６×１０＾１５和１×１０＾１７ｉｏｎｓ／ｃｍ＾２）半导体ＢａＴｉＯ３陶瓷的ＰＴＣＲ特性。结果表明，注入剂量较低时，可以提高材料的ＰＴＣＲ效应。认为注入的铜离子以Ｃｕ＾２＋和Ｃｕ＾＋同时存在于ＢａＴｉＯ３材料晶界处并发生电子转移，起着电子陷阱作用。     

X射线激发Ce^3＋掺杂硼酸盐玻璃的闪烁发光

实验研究了Ｃｅ＾３＋掺杂６４Ｂ２Ｏ３－３６ＢａＯ,７５Ｂ２Ｏ３－２５Ｌａ２Ｏ３玻璃的闪烁发光。在８０ｋＶ加速电压、阳极电流为５ｍＡ的高能Ｘ射线激发下闪烁光强为同要条件下闪烁晶体Ｎａｌ（Ｔｌ）的３％～４％。对影响闪烁光输出的因素进行了分析。结果表明,Ｃｅ＾３＋的自吸收和Ｃｅ＾４＋离子的荷移吸收是降低闪烁光输出的主要因素;含镧硼硅酸盐玻璃系统可作为发展高密度玻璃有希望的系统;闪烁玻璃的制备技术对提高闪     

纳米ZrO2的电子顺磁共振特性及其表面效应

用ＢＥＴ（氮吸附法），ＴＥ几ＸＲＤ技术测定了纳米ＺｒＯ２粉的比表面积、粒径、晶粒尺寸以及相结构随煅烧温度的变化、纳米ＺｒＯ２粉具有Ｆｓ－ｃｅｎｔｅｒ和Ｚｒ＾３＋两种电子自旋共振（ＥＳＲ）信号，Ｚｒ＾３＋是一个与体相相关的信号，而Ｆｓ－ｃｅｎｔｅｒ信号强度减弱，而Ｚｒ＾３＋信号强度增强，变化的临界尺寸为１６ｍ＾２．ｇ＾－１，当比表面积小于１６ｍ＾２．ｇ＾－１时，Ｆｓ－ｃｅｎｔｅｒ信号消失，而Ｚｒ＾３     

等离子喷涂A12O3＋13%TiO2陶瓷涂层的组织结构及其耐磨性

本文用Ｘ射线衍射、扫描电镜等研究了等离子喷涂Ａ１２Ｏ３＋１３％ＴｉＯ２（质量分数）陶瓷涂层的相结构、相组成及其组织特征。陶瓷涂层孔隙率低,致密程度较高,以亚稳相ｒ－Ａ１２Ｏ３为主要相,同时存在α－Ａ１２Ｏ３和金红石ＴｉＯ２。富Ａ１２Ｏ３区与富ＴｉＯ２区呈明显相互交迭的层状结构,且存在相互成分扩散,另外涂层设计对硬度有一定影响,ＴｉＯ２的引入提高了涂层的耐磨性。     

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 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.     

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.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.