微波诱导稀土固体超强酸SO4^2-／TiO2／Ce^4＋催化合成乙酸正丁酯

本文探讨了标题合成方法中合成反应条件对酯收率的影响。其最佳反应条件为：n(醇)：n(酸)=2．5：1．0，固体超强酸用量为反应物总质量的2．0％，微波辐射功率528W，辐射时间20min，酯收率达89．5％。用IR等手段对产品进行了确证。     

SiW12/NaY固体杂多酸催化剂的微波合成及LAS降解性能研究

以微波辐射方法合成了NaY分子筛、二氧化锆和二氧化钛不同载体负载磷钨酸、磷钼酸、硅钨酸不同杂多酸的固体酸催化剂,用Hammett指示剂与紫外光谱相结合的方法测定固体杂多酸催化剂的酸度,发现SiW12/NaY酸性最强。单因子实验研究了制备条件对SiW12/NaY固体酸催化剂酸活性的影响,正交试验探讨了影响SiW12/NaY固载杂多酸活性四个因素的大小顺序为:烧结时间>烧结功率>浸泡浓度>浸泡时间,催化剂制备的优化条件为:硅钨酸水溶液浓度0.10 mol/L,浸泡时间30 h,微波功率750 W,烧结时间40 min,制得的催化剂酸度最高。应用0.050 g SiW12/NaY固载硅钨酸催化剂降解150 mg/L,pH值为3的十二烷基苯磺酸钠(LAS)溶液60 min,LAS降解率由76%提高到94.5%。固载硅钨酸催化剂对LAS的降解率明显提高。     

Variable‐frequency microwave curing of benzocyclobutene

Polymer dielectrics are widely used in the microelectronics industry for several applications including interlevel dielectrics, encapsulants, and passivating layers. To attain the desired properties, these materials need to be processed via lengthy cure cycles. Variable frequency microwave (VFM) processing has been investigated as a rapid curing alternative for the processing of thin‐film dielectrics. Previous studies on epoxies and polyimide‐based materials have shown significant reduction in cure time and improvement in properties on VFM processing. In this study, VFM curing of Dow Chemical Cyclotene? 3022 benzocyclobutene (BCB) was investigated. The kinetics of the cure reaction were studied by Fourier transform infrared (FTIR) spectroscopy. FTIR studies indicated no significant differences in chemical structure between VFM and thermally cured films. The electrical, optical, mechanical, and chemical properties of VFM‐processed films were characterized and compared with thermally processed films to determine the effectiveness of microwave processing. The results showed that VFM curing of BCB is feasible, and properties comparable to thermally cured films can be attained. The residual stress of partially cured BCB was lower for VFM processing than for traditional thermal processing. The residual stress in fully cured BCB was similar. Improvements such as shorter cure times and lower processing temperatures than conventional thermal processing can be achieved. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3055–3067, 2002; DOI 10.1002/app.10286     

微波辐射下NKC-9树脂催化合成1-萘乙酸甲酯

以NKC-9阳离子交换树脂为催化剂,在微波条件下用1-萘乙酸和甲醇合成1-萘乙酸甲酯.最佳合成条件为:醇酸摩尔比为14:1,催化剂为1-萘乙酸的80%,微波辐射时间为15分钟,微波功率为600瓦,产率为80.48%.     

常压辉光放电等离子体研究进展及聚合物表面改性

综述了常压辉光放电等离子体(APGDP)的产生机理及研究进展。介绍了难以产生稳定的APGDP 是由于辉光放电容易向细丝放电和弧光放电过渡,其解决措施是选择合适的介质板材料、电极间距、电源电压及频率、气体成分等。指出APGDP对化纤聚合物表面改性的效果与聚合物的分子结构、等离子体气体、介质板材料等因素有关,且改性效果具有时效性,要根据聚合物的分子结构选择合适的等离子体。     

吸波材料的研究现状与发展趋势

介绍了吸波材料的吸波原理，系统总结了目前各种类型吸波材料的研究和应用现状，指出了吸波材料的研究和发展趋势。     

AIN-SiC复相材料的制备及其微波衰减性能

以氮化铝、碳化硅为原料,采用热压烧结工艺,1900～2000℃、氮气氛下,制备了AlN-SiC复相材料。运用XRD,高分辨率透射电子显微镜、网络分析仪等测试手段,研究了微波衰减剂碳化硅含量及AlN-SiC部分固溶体的形成对材料微波衰减性能的影响,结果表明:AlN-SiC复相材料的频谱特性随衰减剂碳化硅含量的变化而呈现出选频衰减、宽频衰减等特性。当衰减剂SiC质量分数少于40％时,AlN-SiC复合材料具有选频衰减特性,SiC含量为40％～60％时,复合材料具有宽频衰减特性。AlN-SiC部分固溶体的形成有助于改善材料的宽频衰减特性。     

Electrochemical behaviour of the β(II)-Ni(OH)2/β(III)-NiOOH redox couple upon potentiodynamic cycling conditions

The electrochemical behaviour of pure and Co-doped Ni(OH)₂ powders is investigated under potentiodynamic cycling conditions. Evolution of some β-Ni(OH)₂ physical properties as a function of the oxidation state is followed by ex situ Surface Enhanced μ-Raman Spectroscopy and in situ Ellipsometry. Effects related to the first and second reduction steps, as well as to the sweeping rate, are qualitatively studied. When compared to the results that have been recently obtained under galvanostatic conditions [S. Deabate, F. Henn, Electrochim. Acta 50 (2005) 2823], the present work confirms that the second reduction process is strongly associated to the occurrence of a reduced phase, i.e. NiO₂H_2−?, with 0 < ? < ∼0.3, at the surface of the active mass grains. This reduced phase exhibits spectroscopic features very similar to the initial hydroxide which is known to be highly insulating in regards to both electrons and protons transfer.     

微波加热在陶瓷领域中的应用

本文对微波加热和常规加热进行了对比，分析了微波加热在陶瓷领域中应用时优于常规加热的特性，看重介绍了微波烧结陶瓷和微波焊接陶瓷技术的发展与近况。     

多孔介质微波加热厚度的确定

简述了微波加热的机理，以湿木材为研究对象，通过理论计算确定了微波在木材中的穿透深度。计算表明：随着木材含水率和微波工作频率的增加，微波在木材中的穿透深度减小；当用频率为915MHz和2450MHz的微波加热或干燥具有高含水率的多孔介质时，多孔介质的最大厚度应分别控制在16cm和6cm以内。