排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
The influence of hydrothermal modification on the structure and hydrodenitrogenation (HDN) activity of NiMo/γ-Al2O3catalyst was studied in the range 140~180 ℃. The experimental results indicated that the hydrodenitrogenation reaction rate of pyridine was accelerated using the NiMo/γ-Al2O3catalyst synthesized via hydrothermal route due to the change of the structure, the increase of the amount of Mo and Ni and the rise of the specific surface area. The change of the structure of catalysts was enhanced at higher hydrothermal temperature, producing NiMo/γ-Al2O3catalyst with better HDN activity. 相似文献
2.
3.
IntroductionSincethespecialsuperiorityofartificialneuralnetworkstechnologyinvariousengineeringtechniquesfields,suchasoptimization ,associativememories,patternrecognition ,signalprocessingandautomaticcontrol,therehasbeenincreasinginterestintheinvestigati… 相似文献
4.
1IntroductionConsidertheretardedLi6nard--typeequationwherehisanonnegativeconstant,fitfi,WandgarecontinuousfunctionsonR.Recently,theboundedness,stability,oscillationandperiodicityofsolutionsofwhichisEq.(1)withoutdelayandW(x)=0,hasbeenwidelyinvestigated(of[1-5]).Clearly,iffi(x)=f(x),f200=0,W(x)=0,Eq.(1)isreducedtothewell-knownretardedLi6nardequationIn1963,Krasovskii[6]gaveasufficientconditionoftheuniformasymptoticstabilityofthezerosolutionforEq.(3).Hisworkcausedmuchinterest,itisseenbythewor… 相似文献
5.
以摩擦基板间的液晶薄层为研究对象,用分子场理论研究了向列相液晶分子排列转变行为.分子质心固定在简单立方晶格的格点上.液晶由极性分子构成,与基板相接触的一层分子同时受到色散和极性两类表面作用.通过自洽的数值计算,获得3种相图,清楚地展示了摩擦基板间向列相出现的从高温沿面到低温垂面排列的转变;获得实现这类转变所需要的两类表面作用的参数范围.结果表明:基板的摩擦会改变基板表面色散作用,但不会影响基板表面极性作用;表面极性相互作用能引起基板间向列相液晶发生沿面到垂面排列转变. 相似文献
6.
7.
8.
9.
表面极化的二粒子集团理论 总被引:1,自引:1,他引:0
应用二粒子集团理论研究了基板对极性分子构成向列相液晶的作用。假定分子质心固定在简单立方晶格的格点上,分子间存在色散作用和偶极相互作用,与基板相接触的一层分子受到表面作用,在二粒集团近似下导出了分子取向分布函数所满足的方程,并用迭代方法求解,得到如下结论:在向列相液晶与固体基板相接触的界面上,会出现极化层,当基板的表面作用足够强时,界面极性序几乎独立于温度,不受体液晶相变影响。 相似文献
10.