used－silical capillary columns containing heptakis（2、3、6－tri－o－pentyl）-β-cyclodextrinand dibenzo-18-crown-6 were prepared．By studying the selectivity of mixed stationary phases forsome solute pairs.as well a...used－silical capillary columns containing heptakis（2、3、6－tri－o－pentyl）-β-cyclodextrinand dibenzo-18-crown-6 were prepared．By studying the selectivity of mixed stationary phases forsome solute pairs.as well as comparing with the heptakis（2．3、6-tri-O-pentyl）-β-cyclodextrin and thedibenzo-18-crown-6 used as individual stationary phase、the synergistic effects were observed.These effects were affected by the column temperature．mixed ratio and linear velocity of carrier gas．展开更多
The effects of different x values on the dielectric properties in the Ba6-3xSm8+2xTi18O54 microwave dielectric ceramics(0.3≤x≤0.7) were studied. The results showed that the major crystal phase was BaSm2Ti4O12 and th...The effects of different x values on the dielectric properties in the Ba6-3xSm8+2xTi18O54 microwave dielectric ceramics(0.3≤x≤0.7) were studied. The results showed that the major crystal phase was BaSm2Ti4O12 and the sintering temperature of the ceramics was 1340 ℃ when the x value was 0.67. The dielectric properties were better: εr≈79, tanδ≈1×10-4(1 MHz); εr≈80, Q·f=9230 GHz(3.97 GHz), τf=-17 ppm·℃-1.展开更多
在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO4)电镀液中,探究了18-冠醚-6添加剂对电沉积铬的影响.紫外-可见光谱结果表明,18-冠醚-6与Cr^(3+)形成配合物,使最大吸收波长发生红移.循环伏安研究表明,Cr^(3+)的还原经历了两步.18-冠醚-6的添加...在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO4)电镀液中,探究了18-冠醚-6添加剂对电沉积铬的影响.紫外-可见光谱结果表明,18-冠醚-6与Cr^(3+)形成配合物,使最大吸收波长发生红移.循环伏安研究表明,Cr^(3+)的还原经历了两步.18-冠醚-6的添加使Cr^(3+)的峰电位和起始还原电位均正移了220 m V.能谱仪(EDS)结果显示,在18-冠醚-6的作用下镀层中铬含量有所提高.铬镀层的扫描电子显微镜(SEM)表征结果表明,加入18-冠醚-6后,所得镀层的颗粒变大.18-Crown-6/CrCl3/[BMIM]HSO4/H2O电镀液中工艺优化的结果为:在温度为50℃、pH值为3.5、电流密度为1200 A·m^(-2)、电镀时间为1.5 h的最佳工艺条件下,铬镀层的厚度达到72.5μm,电流效率为42.3%.展开更多
文摘used－silical capillary columns containing heptakis（2、3、6－tri－o－pentyl）-β-cyclodextrinand dibenzo-18-crown-6 were prepared．By studying the selectivity of mixed stationary phases forsome solute pairs.as well as comparing with the heptakis（2．3、6-tri-O-pentyl）-β-cyclodextrin and thedibenzo-18-crown-6 used as individual stationary phase、the synergistic effects were observed.These effects were affected by the column temperature．mixed ratio and linear velocity of carrier gas．
文摘The effects of different x values on the dielectric properties in the Ba6-3xSm8+2xTi18O54 microwave dielectric ceramics(0.3≤x≤0.7) were studied. The results showed that the major crystal phase was BaSm2Ti4O12 and the sintering temperature of the ceramics was 1340 ℃ when the x value was 0.67. The dielectric properties were better: εr≈79, tanδ≈1×10-4(1 MHz); εr≈80, Q·f=9230 GHz(3.97 GHz), τf=-17 ppm·℃-1.
文摘在1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO4)电镀液中,探究了18-冠醚-6添加剂对电沉积铬的影响.紫外-可见光谱结果表明,18-冠醚-6与Cr^(3+)形成配合物,使最大吸收波长发生红移.循环伏安研究表明,Cr^(3+)的还原经历了两步.18-冠醚-6的添加使Cr^(3+)的峰电位和起始还原电位均正移了220 m V.能谱仪(EDS)结果显示,在18-冠醚-6的作用下镀层中铬含量有所提高.铬镀层的扫描电子显微镜(SEM)表征结果表明,加入18-冠醚-6后,所得镀层的颗粒变大.18-Crown-6/CrCl3/[BMIM]HSO4/H2O电镀液中工艺优化的结果为:在温度为50℃、pH值为3.5、电流密度为1200 A·m^(-2)、电镀时间为1.5 h的最佳工艺条件下,铬镀层的厚度达到72.5μm,电流效率为42.3%.
