JOINING MECHANISMS OF β''''-Al2O3 CERAMIC AND PYREX GLASS TO Al MATRIX COMPOSITE

The bonding of β'-Al2O3 and pyrex glass to Al matrix composites by anodic bonding process is achieved. The microstructure of the bonded interface and the joining mechanisms are analyzed with scanning electron microscope (SEM), energy dispersive X-ray fluorescence spectrometer (EDX). It is observed that the bonding region across the interface consists of the metal layer, oxide transitional layer and the ceramic layer, with the transitional layer composed of surface region and sub-surface region. The bonding process can mainly be categorized into anodic bonding process and solid state diffusing process. The pile-up of the ions and its drift in the interface area are the main reasons for anode oxidation and joining of the interface. The temperature, voltage and the drift ions in the ceramic or glass during the bonding process are the essential conditions to solid state diffusing and oxide bonding at the interface. The voltages, temperature, pressure as well as the surface state are the main factors that influence the anodic bonding.     

Outage capacities and optimal power allocation for fading multiple-access channels

We derive the outage capacity region of an M-user fading multiple-access channel (MAC) under the assumption that both the transmitters and the receiver have perfect channel side information (CSI). The outage capacity region is implicitly obtained by deriving the outage probability region for a given rate vector. Given a required rate and average power constraint for each user, we find a successive decoding strategy and a power allocation policy that achieves points on the boundary of the outage probability region. We discuss the scenario where an outage must be declared simultaneously for all users (common outage) and when outages can be declared individually (individual outage) for each user.     

Ring‐opening polymerization of D,L‐lactide by rare earth 2,6‐dimethylaryloxide

Ring‐opening polymerization of D,L ‐lactide (LA) has been successfully carried out by using rare earth 2,6‐dimethylaryloxide (Ln(ODMP)₃) as single component catalyst or initiator for the first time. The effects of different rare earth elements, solvents, monomers and catalyst concentration as well as polymerization temperature and time on the polymerization were investigated. The results show that La(ODMP)₃ exhibits higher activity to prepare poly(D,L ‐lactide) (PLA) with a viscosity molecular weight of 4.5 × 10⁴ g mol^?1 and the conversion of 97 % at 100 °C in 45 min. The catalytic activity of Ln(ODMP)₃ has following sequence: La > Nd > Sm > Gd > Er > Y. A kinetic study has indicated that the polymerization is first order with respect to both monomer and catalyst concentration. The apparent activation energy of the polymerization of LA with La(ODMP)₃ is 69.6 kJ mol^?1. The analyses of polymer ends indicate that the LA polymerization proceeds according to ‘coordination–insertion’ mechanism with selective cleavage of the acyl–oxygen bond of the monomer. Copyright © 2004 Society of Chemical Industry     

遗传算法在通信网设计中的应用

由于优化问题的非线性，不能用传统的算法解决，本文利用遗传算法解决通信网设计中的优化问题，取得了良好的效果。     

镀铜／镍聚丙烯腈纤维填充复合材料电磁波屏蔽性能的研究

研究了镀铜／镍的聚丙烯腈纤维填充ＡＢＳ树脂制得的复合材料的导电性及电磁波屏蔽性能，复合材料的导电性主要与导电纤维的填加量有关，导电纤维与基体树脂间的相容状况、复合加工时某些工艺条件等对复合材料的导电性也有较大的影响，电磁波屏蔽性能随导电纤维填加量的增加而提高，加入适当的偶联剂有助于改善和复合材料的电磁波屏蔽性能。     

多目标二次规划非劣解集的理论生成及应用

本文对多目标二次规划问题非劣解集的理论生成进行了探讨,在介绍二次规划单目标问题优化解求法的基础上,提出了在决策平面上互切点,共交点轨迹的概念.由此导出了非劣解集的一般解析式(对切点解问题)和另一类交点解问题时的非劣解集求法,然后介绍了在目标平面非劣解集的解析表达式.使多目标二次规划问题整个非劣解集的推求严格、明确和方便,有理论和实际意义。文中以一个综合利用水库参数的多目标优选作为例子阐述了应用,并求出了最终的最佳协调解.     

镀镍云母导电复合材料的研究

对云母粒子化学镀镍及以LDPE为基材,镀镍云母粒子为填料制备的导电复合材料进行研究。认为此种导电复合材料只有质量轻、强度大及良好的导电等性能。     

强韧包装纸板用落叶松半化学浆的研究

主要研究一种可以替代传统硫酸盐化学木浆，来生产强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆。这种采用碱性亚硫酸盐添加蒽醌助剂的制浆方法研制的落叶松半化学浆，当纸浆得率为５６．９％时，在低打浆度情况下纸浆强度性能可以达到我国２号未漂硫酸盐化学木浆的标准，而且有可能达到１号未漂硫酸盐化学木浆的标准，纸浆得率比落叶松硫酸盐木浆得率实际指标（４３％）绝对值提高１３％以上。用于制作强韧包装纸板或瓦楞纸箱箱板纸的落叶松碱性亚硫酸盐－蒽醌半化学浆，蒸煮终点宜于控制在得率约６２％、卡伯值１００左右。     

分离有机/有机混合物的PVA、CA系列膜及其渗透汽化性能研究(Ⅱ) 成膜条件对渗透汽化性能的影响

用溶剂完全蒸发法制备了PVA复合膜 .经对MTBE/MeOH混合物的分离实验得到了PVA复合膜的最佳成膜条件 ,即 :铸膜液中PVA、马来酸浓度分别为 7%、3% ,热处理温度130～ 15 0℃ .在 1%～ 2 %丙酮水溶液中浸泡处理 4～ 8h ,CTA中空纤维RO膜被改性成渗透汽化膜 .CTA中空纤维膜的分离性能优于其它醋酸纤维素系列膜 ,PVA/CA复合膜的性能优于PVA/PAN复合膜和CA/PAN复合膜     

PAN／Ni－P纤维和碳黑填充的HIPS复合材料的导电性

研究经化学镀镍的聚丙烯腈（ＰＡＮ）导电纤维（ＰＡＮ／Ｎｉ－Ｐ）填充的高抗冲聚苯乙烯（ＨＩＰＳ）复合材料的导电性与导电填料浓度的关系及加入有机钛酸酯偶联剂的影响、为了进一步提高复合材料的导电性，在ＰＡＮ／Ｎｉ－Ｐ纤维填充的复合材料中又加入不同量的碳黑，由于碳黑粒子的加入改善了纤维间的接触状态，更有利于导电网络的形成，从而大大提高了复合材料的导电能力。