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中孔MCM—41分子筛在微孔沸石ZSM—5上附晶生长的研究 总被引:15,自引:2,他引:15
首次在微孔沸石ZSM5表面进行了MCM41分子筛的附晶生长,并首次提出中孔材料MCM41分子筛静电组配理论的新形式(XS+I);同时利用XRD、TEM、BET等测试手段表征了合成样品,并讨论了微孔沸石表面附晶生长中孔分子筛MCM41的合成化学,考察了F离子效应、pH值及表面活性剂CTAB(十六烷基三甲基溴化铵)的影响。 相似文献
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对神府大柳塔烟煤及其300、400、500、700℃干馏产物,在75gKOH/30g试样(ad.)水溶液,氧初压为5.5MPa或6.0MPa的条件下氧化2h,其化产物水溶酸的产率及其组成随干馏温度物升高而变化,在干馏温度为400℃时水溶酸的产率达到最大(54.96%对daf.试样),并2气相色谱法进行定性、定量分析。 相似文献
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Ab initio molecular dynamics study on the local structures in Ce_(70)Al_(30) and La_(70)Al_(30) metallic glasses 下载免费PDF全文
Ab initio molecular dynamics simulations were performed to investigate the effect of similar elements on the shortto medium-range atomic packing features in Ce_(70)Al_(30) and La_(70)Al_(30) glass-forming alloys. 4 f electrons of Ce element in Ce_(70)Al_(30) alloy were properly treated in electronic calculations. The local atomic structures in both alloys are qualitatively similar. However, the local environments of Al atoms in Ce_(70)Al_(30) alloy show fluctuation with temperature in the cooling process, which could result from 4 f electrons of Ce elements. Surprisingly, the medium-range atomic packing features of Al atoms in both MGs are quite different, although Ce and La elements are similar. These findings are useful for understanding the enhanced glass-forming ability by similar element substitution in RE-based MGs from a medium-range structure perspective. 相似文献
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High Chern number phase in topological insulator multilayer structures: A Dirac cone model study 下载免费PDF全文
Yi-Xiang Wang 《中国物理 B》2022,31(9):90501-090501
We employ the Dirac cone model to explore the high Chern number (C) phases that are realized in the magnetic-doped topological insulator (TI) multilayer structures by Zhao et al. [Nature 588 419 (2020)]. The Chern number is calculated by capturing the evolution of the phase boundaries with the parameters, then the Chern number phase diagrams of the TI multilayer structures are obtained. The high-C behavior is attributed to the band inversion of the renormalized Dirac cones, along with which the spin polarization at the $varGamma$ point will get increased. Moreover, another two TI multilayer structures as well as the TI superlattice structures are studied. 相似文献
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煤及其干馏物氧化产品中苯羧酸的GC分析 总被引:2,自引:1,他引:2
煤及其干馏物氧化产品中苯羧酸的GC分析李福祥吕志平薛建伟秦梦庚(太原理工大学精细化工研究所太原030024)关键词煤氧化,苯羧酸,重氮甲烷,酯化煤及其衍生物经碱氧气或高锰酸钾等氧化后的主要产品是水溶性的羧酸混合物,它是一种吸湿性的固体,具有黄色到近... 相似文献
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一种测定氯乙酸产品中水分的方法 总被引:3,自引:0,他引:3
1 引 言 氯乙酸是一种重要的化工中间体 ,该产品的质量分析目前普遍采用国标法 (化学法 )分析 ,由于该方法的终点显色灵敏度差 ,分析的重现性不好及误差较大 ,且分析时间长 (约 1 5~ 2 0h) ,因此许多单位都在研究其更快、更好的分析方法 ,气相色谱法就是重点研究之一 ,目前有直接法和间接法两种 :直接法对仪器的损害严重 ,操作温度也高 ,不宜采用。间接法地仪器损害小 ,操作温度低 ,但如用内标法 ,分析操作麻烦 ,分析时间较长 ;若用修正面积归一法 ,虽操作简单 ,分析时间短 (约 15~ 2 0min) ,但受产品中水分含量的影响较大 (… 相似文献