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甲基、氨基和甲胺在清洁及C(N,O)改性的Mo(100)表面的吸附 被引量:3
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作者 吕存琴 凌开成 +1 位作者 尚贞锋 王贵昌 《物理化学学报》 SCIE CAS CSCD 北大核心 2008年第8期1366-1370,共5页
采用广义梯度近似(GGA)的密度泛函理论(DFT),并结合平板模型,研究了甲基、氨基和甲胺在清洁及C(N,O)改性的Mo(100)面的吸附行为.计算结果表明,在较低覆盖度下(θ=1/6ML(monolayer)),吸附物种在不同表面上的稳定吸附位的吸附能变化不大;... 采用广义梯度近似(GGA)的密度泛函理论(DFT),并结合平板模型,研究了甲基、氨基和甲胺在清洁及C(N,O)改性的Mo(100)面的吸附行为.计算结果表明,在较低覆盖度下(θ=1/6ML(monolayer)),吸附物种在不同表面上的稳定吸附位的吸附能变化不大;而在较高覆盖度下(θ=1/4ML),其稳定的吸附位置可能发生变化,且吸附能有了明显的区别.它们在改性的Mo(100)表面吸附能较清洁表面小,并且按C、N、O的顺序降低.究其原因可归结为C、N、O改性原子的存在使得金属表面的供电子能力减弱,从而导致金属的d带中心的下移.通过对金属Mo的d带性质的分析,发现d带中心只能笼统地说明改性原子对于清洁表面的性质有一定的影响,不能很好地体现C、N、O对于清洁表面性质影响的差异,而dz2轨道的能量中心却能很好地反映出吸附物种在改性表面上的吸附能按C、N、O的顺序依次减小这一规律. 展开更多
关键词 DFT—GGA 平板模型 吸附 Mo(100) C(N O)改性的Mo(100)
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甲胺在清洁及磷改性Mo(100)表面的解离 被引量:2
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作者 吕存琴 凌开成 王贵昌 《物理化学学报》 SCIE CAS CSCD 北大核心 2009年第11期2336-2342,共7页
采用广义梯度近似(GGA)的密度泛函理论(DFT)(DFT-GGA)并结合平板模型,研究了甲胺在清洁及磷(P)改性的Mo(100)表面(P-Mo(100))发生C—N键断裂的反应历程(CH3NH2→CH3+NH2).优化了裂解过程中反应物、过渡态和产物的几何构型,获得了反应路... 采用广义梯度近似(GGA)的密度泛函理论(DFT)(DFT-GGA)并结合平板模型,研究了甲胺在清洁及磷(P)改性的Mo(100)表面(P-Mo(100))发生C—N键断裂的反应历程(CH3NH2→CH3+NH2).优化了裂解过程中反应物、过渡态和产物的几何构型,获得了反应路径上各物种的吸附能及反应的活化能数据.计算结果表明,在清洁和磷改性的Mo(100)表面,甲胺均稳定吸附在顶位,甲基和氨基最稳定的吸附位置均为桥位.甲胺的C—N键在P-Mo(100)表面裂解的活化能为2.39eV,高于其在清洁表面的活化能(1.99eV).这表明Mo(100)表面被预吸附的P原子钝化了.电子结构分析表明,改性P原子使得金属Mo的供电子能力减弱,导致它的d带中心下移,从而降低了该表面的反应活性,提高了甲胺的C—N键裂解的活化能.活化能的分解表明,C—N键在P-Mo(100)与Mo(100)表面裂解的活化能的差异主要体现在初态到过渡态时甲胺的结构变化引起的能量变化(△ECdHef3NH2)、过渡态仅有甲基存在时的吸附能(ECTHS3)和过渡态甲基和氨基的相互作用(ECinHt3…NH2).△ECdHef3NH2和ECTHS3使活化能升高幅度大于ECinHt3…NH2使活化能降低幅度,最终导致甲胺的C—N键在P-Mo(100)表面裂解的活化能要高于在Mo(100)表面裂解的活化能. 展开更多
关键词 密度泛函理论 甲胺 解离 Mo(100) 磷改性的Mo(100) 广义梯度近似 平板模型
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Mo同位素分离技术研究
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作者 孙永刚 曾红梅 刘子辉 《甘肃科技纵横》 2011年第6期50-51,共2页
钼元素的稳定同位100Mo在测量双中微子双Beta的衰变和无中微子双Beta的衰变中具有很重要的作用,对无中微子双Beta的衰变和研究中微子性质有很重要的意义。丰度在90%以上的100Mo做成的CaMoO4晶体在双Beta衰变中有很好的应用前景。本论述... 钼元素的稳定同位100Mo在测量双中微子双Beta的衰变和无中微子双Beta的衰变中具有很重要的作用,对无中微子双Beta的衰变和研究中微子性质有很重要的意义。丰度在90%以上的100Mo做成的CaMoO4晶体在双Beta衰变中有很好的应用前景。本论述重点介绍了钼的物理化学性质、探讨了100Mo的分离方法。 展开更多
关键词 100mo 六氟化钼 转化 钼酸钙
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Decomposition of methylamine on Mo(100) surface: A DFT study 被引量:1
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作者 Jianhong Liu Cunqin Lü +1 位作者 Dongli Du Yong Guo 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第2期132-137,共6页
The initial decomposition of methylamine on Mo(100) surface has been investigated by self-consistent (GGA-PW91) density functional theory combined with periodic slab model. The adsorption energies of possible spec... The initial decomposition of methylamine on Mo(100) surface has been investigated by self-consistent (GGA-PW91) density functional theory combined with periodic slab model. The adsorption energies of possible species and the activation energies for possible elementary reactions involved are obtained in the present work. Our results indicate that the barriers decreased with the order of C-NN-HC-H. In addition, metastable adsorption of the abstracted hydrogen atom on the hollow site in the final state is also considered for the N-H and C-H bond breaking. For the C-H bond cleavage, the reaction barrier that the abstracted hydrogen located on the hollow site in the final state is lower than that on the bridge site. However, for the N H bond breaking, the barriers are alike for the abstracted hydrogen on both hollow and bridge sites in the final state. 展开更多
关键词 METHYLAMINE DECOMPOSITION Mo(100) DFT calculations slab model
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A STUDY OF INCOMMENSURATE STRUCTURE ON Mo(100) SURFACE BY DOMAIN MODULATION MODEL
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作者 FENG Kean WU Naijuan ZHAO Lihua 《Chinese Physics Letters》 SCIE CAS 1986年第6期261-264,共4页
By introducing mass density waves,we have determined the positions and intensities of a quartet of spots around the(±1/2,±1/2)positions on a clean Mo(100)surface at low temperature.lt is shown that the Mo(10... By introducing mass density waves,we have determined the positions and intensities of a quartet of spots around the(±1/2,±1/2)positions on a clean Mo(100)surface at low temperature.lt is shown that the Mo(100)-C(2x2)*incomensurate surface structure is a stable one and can be described in terms of a C(2x2)superlattice modulated by square-like-domains.The domain size and the direction of the domain structure relative to Mo(100)lattice are also discussed. 展开更多
关键词 TEMPERATURE Mo(100) POSITIONS
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Adsorption and Reaction of CO on Mo(100)-c(2×2)-N Surface Studied by HREELS
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作者 Jun Fa ZHU.,ian Chang GUO, Run Sheng ZHAI, Xin He BAO, Shu Xian ZHUANG ( National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 Department of Chemical Physics. University of Science and Technology of China 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第3期275-278,共4页
High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) l... High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) layer to form isocyanate (NCO) surface species was found in addition to CO adsorbed on the molybdenum atoms at 120 K. indicating that both Mo and N atoms of the Mo(100)-c(2×2)-N surface are of high reactivities for CO adsorption. 展开更多
关键词 HREELS ADSORPTION REACTION Mo(100)-c(2×2)-N CO.
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HREELS Studies on Adsorption and Decomposition of ^(15)NO on Mo(100)-c(2×2)N Surface
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作者 Jun Fa ZHU Shu Xian ZHUANG +3 位作者 Jian Chang GUO Run Sheng ZHAI Yu Ming CAO Xin He BAO(Department of Chemical Physics, University of Science and Technology of China, Hefei 230026)(State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chine 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第7期667-670,共4页
High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorPtion and decomposition of 15NO on the Mo(100)-c(2×2)14N surface. At 140K, the 15NO molecu1e could adsorb associati... High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorPtion and decomposition of 15NO on the Mo(100)-c(2×2)14N surface. At 140K, the 15NO molecu1e could adsorb associatively on atop sites of the Mo and l4N atoms in the nitride layers. On the other hand, a small amount of dissociatCd 15NO also exists. The dissociation of surface nitric oxides species at elevated temperatures caused the oxidation of the surface Mo. 展开更多
关键词 HREELS ADSORPTION DECOMPOSITION Mo(100)-c(2 symb2)N nitric oxides
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Description of the properties of the low-lying energy states in ^(100)Mo with IBM2 被引量:2
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作者 ZHANG DaLi DING BinGang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第3期447-452,共6页
The properties of the low-lying energy states for the l00 Mo isotope is investigated within the framework of the proton-neutron interacting model IBM2. By considering the relative energy of the d proton boson to be di... The properties of the low-lying energy states for the l00 Mo isotope is investigated within the framework of the proton-neutron interacting model IBM2. By considering the relative energy of the d proton boson to be different from that of the neutron boson and taking into account the dipole interacting among like-boson Lπ·Lπ and Lπ·Lπ, the low-lying energy spectrum is reproduced well. Particularly, the relative position of the energies for 2+1, 0+2, 2+2 and 4+1 states shifted correctly fit the experimental data. The electromagnetic properties, including the key observable B(E2) reduced transition branching ratios and the E2 reduced matrix elements of the experimental data, are well described. Our calculations show possible shape coexistence in the l00Mo nucleus. 展开更多
关键词 100mo shape coexistence low-ling energy states IBM2.
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W6Mo5Cr4V2/A100复合材料的制备及摩擦性能
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作者 季琳琳 李长生 +2 位作者 孙建荣 苟州 张号 《金属热处理》 CAS CSCD 北大核心 2021年第9期42-46,共5页
为了提高A100钢的摩擦学性能,采用气雾化法制备纯A100钢粉末及分别添加10%、17%、23%W6Mo5Cr4V2高速钢的W6Mo5Cr4V2/A100合金粉末,再利用粉末冶金工艺制备W6Mo5Cr4V2/A100复合材料。研究不同含量W6Mo5Cr4V2钢对复合材料力学性能和摩擦... 为了提高A100钢的摩擦学性能,采用气雾化法制备纯A100钢粉末及分别添加10%、17%、23%W6Mo5Cr4V2高速钢的W6Mo5Cr4V2/A100合金粉末,再利用粉末冶金工艺制备W6Mo5Cr4V2/A100复合材料。研究不同含量W6Mo5Cr4V2钢对复合材料力学性能和摩擦性能的影响,并探讨其磨损机理。结果表明,随着W6Mo5Cr4V2钢含量的增加,复合材料的硬度先上升后下降,且摩擦因数和磨损率都有不同程度的降低,但是材料的密度和韧性都略微下降。当W6Mo5Cr4V2钢含量为17%时,复合材料的摩擦性能最优,这与其优异的微观结构和力学性能有着密不可分的关系。 展开更多
关键词 W6Mo5Cr4V2/A100复合材料 粉末冶金 摩擦性能
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