In situ Heating and Thermal Effects in Auger Electron Spectroscopy for GaN

建立一套基于超高真空俄歇电子能谱的原位加热系统,对GaN薄膜进行热效应研究．随着温度的增加,Ga LMM和Ga MVV的动能减小．利用第一性原理计算,获得理论的GaMVV俄歇谱.加热过程由于晶格热膨胀以及表面原子再构引起价电子态密度发生变化,从而导致价带俄歇谱负移．An in situ heating system was built for the Auger electron spectroscopy to investigate the thermal effect of Auger lines. A GaN sample was studied in this system. The kinetic energy of Ga LMM and MVV Auger lines were observed to shift negatively with temperature increasing. By using 06 initio calculation, the theoretical Ga MVV Auger line shape was fit, which well reflects the inner property of the line. The Auger shift with heating is related with the valence electron rearrangement in the thermal expansion of the local bonds

Study on the Silicides in Cuticle of Wheat Straw Stem by Means of XPS(Ⅱ)

用X射线光电子能谱法(XPS)研究了麦秆节间不同部位皮层的硅化物组成及含量,探索皮层硅化物的碱稳定性。结果表明,在实验条件下,节间所有部位皮层中的硅化物均是由有机硅化物和无机硅化物组成;无机硅化物的含量约为有机硅化物的3倍,且种类更复杂;节间上部皮层的硅化物含量最高,下部皮层的硅化物含量最低;自外至里,上部皮层中硅化物的含量、分布具有与其他禾本科原料皮层相似的规律性,下部皮层的规律性较差。不同硅化物的碱稳定性有差别;部分无机硅化物微块由于其连接机构的碱溶解而脱落,完好地存在于黑液之中。在皮层生物结构中,硅化物的堆砌、连接方式及其碱溶机理有待进一步研究。The content and components of silicides in the cuticle of the up-part,the mid-part and the low-part on the internode of wheat straw stem were studied by means of XPS,and the alkali-stability of the silicides in the foresaid cuticle was also investigated.The results showed that,the silicides in above cuticles are all composed of organic and inorganic silicides.The content of inorganic silicides is about three times as high as organic silicides.And the sorts of inorganic silicides are more complex.Among the above three parts,the up-part has highest silicide content,and the low-part the lowest.From the outside to the inner of the cuticle,the profile of silicide content is in analogy to that of other gramieal cuticle,and the profile of silicides in the low-part cuticle has poor order.Under the experimental conditions,the alkali-stability of a sort of silicides is different from the other.A part of inorganic micro blocks of silicides with higher alkali-stability wholly remains in the black liquor after falling off from the cuticle.The mode of building and connecting as well as the alkali-degrading of the silici micro blocks will be further researched.国家自然科学基金(20277012)资助项

Study on the Silicides in Cuticle of Wheat Straw Stem by Means of XPS(Ⅰ)

进行麦秆皮层硅化物的XPS测定及分峰拟合分析。结果表明,麦秆不同部位皮层中的硅化物都是由有机硅化物和无机硅化物组成的。有机硅化物主要有线状P-METHylSIl、树脂P-PHEnylSIl、PH3SIOSIPH3、PH4SI、ET3SICl、ET2SICl2等。无机硅化物的种类更复杂,主要有硅灰石、云母、钠长石、硅线石、高岭土、分子筛A型及X型物质以及5种结晶形式的SIO2等。不同部位硅化物的组成、含量不同,将影响其在制浆等处理过程中的稳定性。The silicides in the cuticle of wheat straw stem were studied by means of XPS-peak-differenating analysis.The results showed that silicides in every part of the wheat straw stem are composed of two sorts of silicides,i.e.organic silicides and inorganic silicides.The main components of the organic silicides are P-MethylSil(linear),P-PhenylSil(resin),Ph3SiOSiPh3,Me3SiOSiMe3,Ph3SiSiPh3,Et3SiCl,Et2SiCl2 etc.The inorganic organic silicides are very complex,and the major sorts are Wollastonii,Mica,albite,Kaolinite,sillimanite,materials of Mol.Sieve A and X,SiO2(Vycor),SiO2(alpha cristobal),SiO2(guartz),H Zeoton etc.The components of silicides in different part's cuticle are different.国家自然科学基金(20277012)资助项