Effects of Ultrasonic Vibration on Material Flow and Thermal Cycles in Friction Stir Welding of Dissimilar Al/Mg Alloys

Comparative experiments are performed in friction stir welding (FSW) of dissimilar Al/Mg alloys with and without assistance of ultrasonic vibration. Metallographic characterization of the welds at transverse cross sections reveals that ultrasonic vibration induces differences in plastic material flow in two conditions. In FSW, the plastic material in the peripheral area of shoulder-affected zone (SAZ) tends to flow downward because of the weakening of the driving force of the shoulder, and a plastic material insulation layer is formed at the SAZ edge. When ultrasonic vibration is exerted, the stirred zone is divided into the inner and outer shear layers, the downward material flow trend of the inner shear layer disappears and tends to flow upward, and the onion-ring structure caused by the swirl motion is avoided in the pin-affected zone. By improving the flow behavior of plastic materials in the stirred zone, ultrasonic vibration reduces the heat generation, accelerates the heat dissipation in nugget zone and changes the thermal cycles, thus inhibiting the formation of intermetallic compound layers.

     

红外测温技术在离心复合铸造轧辊生产上的应用

本文分析了离心复合铸造轧辊生产过程中离心机停机温度和时间对轧辊质量的影响 ,提出了用先进的红外测温技术来预报停机温度和时间 ,以实现微机监控适时停机 ,保证轧辊内外层熔合良好 ;同时指出了红外测温技术在离心复合铸造轧辊生产上的应用前景     

Synthesis and characterization of mechanical-alloyed Ti–xMg alloys

The synthesis and characterization of Ti–xMg (x=4, 9, 12, 15, 21, 24 at%) alloys using mechanical alloying was investigated. A nanometer-sized Ti–24Mg alloy was produced. During mechanical alloying, the height of the XRD peaks of the Mg in the Ti–9Mg alloy decreased, and then disappeared, whereas the Ti XRD peaks broadened, and the grain size decreased with increasing milling time. The Mg firstly dissolved in the grain boundaries of the Ti, and then diffused into the Ti grain interiors. The grain boundaries played an important role in enhancing the solid solubility of Mg in Ti. With increasing Mg content the volume fraction of grain boundaries increased, and a decrease in grain size occurred after mechanical alloying for 48 h.     

锻压机械打击力测量误差的加速度补偿

提出了锻压机械打击力测量中存在的问题，介绍了常用的补偿法，并通过实验验证了加速度补偿法是消除锻压机械打击力测量误差的有效途径。     

国产气相聚乙烯浆液催化剂的工业应用

本文简要阐述了北化院BCS01和上海院SLC-S两种国产气相聚乙烯浆液催化剂的性能、催化剂结构,在Unipol聚乙烯工业装置上应用结果,以及和进口同类催化剂UCAT-J的性能比较。     

高岭土在碳热还原氮化过程中的相变

系统研究了苏州高岭土碳热还原氮化合成SiAlON过程在不同温度下的相变。对试样的XRD、SEM以及EDXA分析结果表明 ,1 30 0℃之前 ,试样中没有氮化物生成 ,物相为莫来石、石英和方石英 ;1 30 0℃时 ,高岭土开始发生氮化反应 ,生成过渡型SiAlON和β SiAlON。此时 ,石英和方石英相基本消失 ;1 4 0 0℃时 ,过渡型SiAlON、β SiAlON和X SiAlON三相共存 ,β SiAlON有所增多并有少量刚玉相生成 ;从 1 4 50℃到 1 550℃ ,Z值为 3的β SiAlON成为惟一的氮化产物 ,与少量SiC和刚玉相并存。莫来石在 1 50 0℃时完全消失     

国产耐火材料在欧洲3 300t/d生产线上的整体配套

Fushe-Kruje水泥厂项目位于距阿尔巴尼亚首都地拉那市28公里处，是由黎巴嫩SEAMENT集团投资兴建的．是迄今阿尔巴尼亚最大的外商投资项目，设计能力为3300t/d新型干法水泥熟料生产线，是全套生产线由我公司设计、制造成套、施工、安装、调试及试生产的总承包项目。     

Catalytic properties of aluminated sepiolite in ethanol conversion

The aluminated sepiolite, obtained by alkaline treatment with KAlO₂, as well as the silver-exchanged aluminated sepiolite were tested in ethanol conversion. The reactions were performed at 280°C and with 50 Torr of ethanol in He. After the alumination through KA1O₂, ethanol dehydrogenation and ethanol dehydration resulted from the Lewis acidity. The dispersion of silver led to a bifunctional catalytic system and the overall catalytic activity and the selectivity towards the acetaldehyde production increased. As a result of the Prins reaction, a significant yield in butadiene was observed.     

On the membrane phospholipids and their acyl group profiles of adrenal gland

The phospholipid composition and their acyl group profiles from subcellular fractions of guinea pig adrenal gland and the same fractions from the cortex and medulla of the bovine gland were compared. The phospholipids of guinea pig adrenal were enriched in diacyl-glycerophosphocholines (GPC) which comprised over 50% of the total phospholipids, but the proportions of ethanolamine and choline plasmalogens, sphingomyelin and diacyl-glycerophosphoserine (GPS) were lower in guinea pig adrenals as compared to the bovine adrenals. In the bovine adrenal, sphingomyelin and diacyl-GPS were enriched in the medulla, whereas diacyl-glycerophosphoinositol (GPI) were enriched in the cortex. Although lysolecithin was present (up to 4.5%) in the bovine adrenal, only trace amounts of this lipid were detected in the guinea pig adrenal. Characteristic acyl group profiles were found associated with each type of the phosphoglycerides in adrenal membranes. However, acyl group profiles of the phosphoglycerides were not greatly different either between the bovine and guinea pig adrenal or with respect to the type of subcellular membranes isolated. Diacyl-GPC were enriched in 16∶0 and 18∶1, but also contained considerable amounts of 18∶0, 18∶2 and 20∶4. Diacyl-GPE were enriched in 18∶0, 18∶1 and 20∶4, while diacyl-GPI, diacyl-GPS, as well as alkenylacyl-GPE, were enriched in 20∶4. The lysolecithin from bovine adrenal membranes contained mainly 16∶0, 18∶0 and 18∶1 with only trace amounts of the polyunsaturated fatty acids. Other polyunsaturated fatty acids, such as 22∶4 and 22∶6, are apparently not prominent in the phosphoglycerides from either the bovine or the guinea pig adrenal gland.     

Preparation,characterization, and adsorption properties for metal ions of a novel chelating resin containing sulfoxide and diethylene glycol

A novel chelating resin containing sulfoxide and diethylene glycol, poly{4‐vinylbenzyl‐[2‐2‐(hydroxyethyl)ethoxyl]sulfoxide} (PVESO) was synthesized using chloromethylated polystyrene (PS‐Cl) as material. Its structure was characterized by elemental analysis, infrared spectra, and scanning electron microscopy (SEM). The adsorption capacities of the resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, and Pb²⁺ at various pH values were determined. The maximum adsorption capacities for Hg²⁺ and Ag⁺ were 1.56 and 0.75 mmol g^?1 respectively. The resin had high selectivity for Hg²⁺ and Ag⁺ over the pH range 1.0–7.0. The adsorption capacities for Hg²⁺ and Ag⁺ under competitive condition were also determined by batch experiment method. In addition, the adsorption kinetics of the resin towards Hg²⁺ at different temperatures was also investigated. The results showed that the adsorption rate was governed by film diffusion at 20°C and 25°C, by particle diffusion at 30°C and 35°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6054–6059, 2006