Fe-V-N稀合金中空位复合体特性的研究(Ⅱ)

本文利用离散变分法,集团模型和三维数值弛豫技术,研究了Fe-V-N稀合金中V-N-空位复合体的几何构型,正电子湮没特性和电子结构。根据正电子湮没寿命实验的结果和总能量极小原理,确定了V和N在V-N-空位复合体中的最佳占据位置。分析了V-N-空位复合体的成键特性和电荷转移情况。 关键词：     

Deposition of Diamond-Like carbon Films by High-Intensity Pulsed Ion Beam Ablation at Various Substrate Temperatures

Diamond-like carbon (DLC) films have been deposited on to Si substrates at substrate temperatures from 255℃ to 400O℃ by a high-intensity pulsed-ion-beam (HIPIB) ablation deposition technique. The formation of DLC is confirmed by Raman spectroscopy. According to an x-ray photoelectron spectroscopy analysis, the concentration of sp^3 carbon in the films is about 40% when the substrate temperature is below 300℃ C. With increasing substratetemperature from 25℃ to 400℃, the concentration of sp^3 carbon decreases from 43% to 8%. In other words,sp3 carbon is graphitized into sp^2 carbon when the substrate temperature is above 300℃. The results of xray diffraction and atomic force microscopy show that, with increasing the substrate temperature, the surface roughness and the friction coefficient increase, and the microhardness and the residual stress of the films decrease.     

C60的发现,制备,结构,性质及其潜在应用前景

Ｃ６０是碳的一种新的同素异型结构．本文综述了Ｃ６０的发现与制备方法，Ｃ６０形成的机制与其绪构特征，以及Ｃ６０的性质与其潜在的广阔应用前景．重点介绍用红外（ＩＲ）谱，１３Ｃ核磁共振（ＮＭＲ）谱和Ｘ射线衍射（ＸＤ）谱研究Ｃ６０结构的结果，及掺杂Ｃ６０固体的高温超导电性及其结构的最新研究进展．     

非磁杂质对高Tc超导电性的影响

本文证明了在氧化物高T_c超导体的Anderson晶格模型中,由于序参量是能量的函数,非磁掺杂也具有拆对效应,在稀掺杂情况下,求出了T_c随杂质浓度增加而线性下降的规律,与实验结果相符,文中还计算了掺杂对超导态密度中能隙的影响,结果表明,当非磁掺杂浓度增加时,零温能隙的减小比T_c的下降慢得多,从而在转变为正常态之前可能不出现类似通常BCS超导体磁性掺杂的无能隙区。 关键词：     

多孔硅制备过程中B,P杂质原子的作用

采用DV-Xα方法对多孔硅形成过程中位于表层的B和P杂质原子的作用进行研究,结果表明位于顶层硅原子层中的B和P杂质原子均可削弱其邻近的Si-Si键强度,因而可能导致出现腐蚀的突破点,再通过分析杂质对表面区势场的改变,可以认为位于顶层硅原子层中的B杂质原子产生腐蚀的突破点的可能性更大。 关键词：     

SYNTHESIS OF MACROPOROUS COPOLYMER OF VCA AND DVB

The reactivity ratios of vinyl acetate(VAc) and divinyl benzene (DVB) were calculated from the Q and e values.The possibility of the copolymerization of these two monomers was predicted and the copolymerization was carried out by suspension polymerization technique in the presence of pore producing agent (toluene and gasoine).The relative ratio of acetoxy group and benzene ring in the copolymer were monitored by IR measurement during the polymerization.The variation of pore properties,such as spectific surface area,porosity and average pore diameter,with polymerization time were determined.The copolymers at various polymerization time were alcoholyzed and thus the variation of the hydroxyl group content with polymerization time was studied.     

HL—1装置碳化和采用抽气孔栏时的可见辐射观测

本文描述了HL-1装置器壁碳化和采用抽气孔栏时,氢及杂质通量的变化情况;利用多道可见辐射的时空分布测量,得到了MARFE放电,在产生MARFE时,辐射热也相应增强。     

溶胶—凝胶法制备SiO2基片Er^3＋：Al2O3光学薄膜

用溶胶—凝胶法在SiO2基片上提拉制备了掺Er^3 ：Al2O3光学薄膜。采用扫描电子显微镜、原子力显微镜、差热—热重分析仪、X射线衍射仪研究了掺Er^3 ：Al2O3光学薄膜的肜貌和结构特性。在900℃烧结后，SiO2基片上提拉15次形成厚度8μm掺摩尔比0．01Er^3 的面心立方结构γ-Al2O3薄膜具有明显(110)择优取向，掺摩尔比0．01Er^3 对γ—Al2O3的品体结构和结晶生长过程木产生显著影响。薄膜具有均匀多孔结构，平均粒径为30～100nm，平均孔径为50～100nm，表面起伏度为10～20nm。掺摩尔比0．01Er^3 ：rAl2O3薄膜，获得了中心波长为1．534μm(半峰全宽为36nm)的光敛发光谱。