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Research of caged dynamics of clusters center atoms in Pd_(82)Si_(18) amorphous alloy
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作者 邓永和 陈贝 +5 位作者 祁清华 李兵兵 高明 文大东 王小云 彭平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期623-629,共7页
To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research objec... To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research object to further elucidate the underlying mechanism of caged dynamics from multiple perspectives,including the cage's lifetime,atomic local environment,and atomic potential energy.The results reveal that Si atoms exhibit a pronounced cage effect due to the hindrance of Pd atoms,resulting in an anomalous peak in the non-Gaussian parameters.An in-depth investigation was conducted on the caged dynamics differences between fast and slow Si atoms.In comparison to fast Si atoms,slow Si atoms were surrounded by more Pd atoms and occupied lower potential energy states,resulting in smaller diffusion displacements for the slow Si atoms.Concurrently,slow Si atoms tend to be in the centers of smaller clusters with coordination numbers of 9 and 10.During the isothermal relaxation process,clusters with coordination numbers 9 and 10 have longer lifetimes,suggesting that the escape of slow Si atoms from their cages is more challenging.The findings mentioned above hold significant implications for understanding the caged dynamics. 展开更多
关键词 caged dynamics pd_(82)Si_(18) amorphous alloy fast and slow atoms clusters lifetime
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Advances of Synergistic Electrocatalysis Between Single Atoms and Nanoparticles/Clusters
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作者 Guanyu Luo Min Song +6 位作者 Qian Zhang Lulu An Tao Shen Shuang Wang Hanyu Hu Xiao Huang Deli Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期377-412,共36页
Combining single atoms with clusters or nanoparticles is an emerging tactic to design efficient electrocatalysts.Both synergy effect and high atomic utilization of active sites in the composite catalysts result in enh... Combining single atoms with clusters or nanoparticles is an emerging tactic to design efficient electrocatalysts.Both synergy effect and high atomic utilization of active sites in the composite catalysts result in enhanced electrocatalytic performance,simultaneously provide a radical analysis of the interrelationship between structure and activity.In this review,the recent advances of single-atomic site catalysts coupled with clusters or nanoparticles are emphasized.Firstly,the synthetic strategies,characterization,dynamics and types of single atoms coupled with clusters/nanoparticles are introduced,and then the key factors controlling the structure of the composite catalysts are discussed.Next,several clean energy catalytic reactions performed over the synergistic composite catalysts are illustrated.Eventually,the encountering challenges and recommendations for the future advancement of synergistic structure in energy-transformation electrocatalysis are outlined. 展开更多
关键词 Single atoms NANOPARTICLES clusters Synergistic composite catalysts Synergistic effect
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Ni Single Atoms and Ni Phosphate Clusters Synergistically Triggered Surface-Functionalized MoS_(2)Nanosheets for High-performance Freshwater and Seawater Electrolysis 被引量:2
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作者 Min Sung Kim Duy Thanh Tran +3 位作者 Thanh Hai Nguyen Van An Dinh Nam Hoon Kim Joong Hee Lee 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2022年第4期1340-1349,共10页
Two-dimensional metal dichalcogenides have been evidenced as potential electrocatalysts for hydrogen evolution reaction(HER);however,their application is limited by a poor oxygen evolution reaction(OER)activity due to... Two-dimensional metal dichalcogenides have been evidenced as potential electrocatalysts for hydrogen evolution reaction(HER);however,their application is limited by a poor oxygen evolution reaction(OER)activity due to insufficient number/types of multi-integrated active sites.In this study,we report a novel bifunctional catalyst developed by simultaneous engineering of single nickel atoms(Ni_(SA)) and nickel phosphate clusters(Ni_(Pi)) to synergistically trigger surface-functionalized MoS_(2) nanosheets(NSs)resulting in high reactivities for both HER and OER.The Ni_(SA)-Ni_(Pi)/MoS_(2)NSs material exhibits a fairly Pt-like HER behavior with an overpotential of 94.0 mV and a small OER overpotential of 314.0 mV to reach 10 mA cm^(-2) in freshwater containing 1.0 M KOH.Experimental results of the catalyst are well supported by theoretical study,which reveals the significant modulation of electronic structure and enrichment of electroactive site number/types with their reasonably adjusted free adsorption energy.For evaluating practicability,the Ni_(SA)-Ni_(Pi)/MoS_(2)NSs-based electrolyzer delivers effective operation voltage of 1.62,1.52,and 1.66 V at 10 mA cm^(-2) and superior long-term stability as compared to Pt/C//RuO_(2) system in freshwater,mimic seawater,and natural seawater,respectively.The present study indicates that the catalyst is a promising candidate for the practical production of green hydrogen via water electrolysis. 展开更多
关键词 bifunctional electrocatalyst freshwater and seawater electrolysis nickel phosphate clusters nickel single atoms surface-functionalized-MoS_(2)nanosheets
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Magnetism of Metals, Alloys and of Clusters of Transition Metal Atoms 被引量:1
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作者 N.H.March Oxford University, Oxford, England Department of Physics, University of Antwerp (RUCA), Groenenborgerlaan 171, B-2020 Antwerp, Belgium 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第6期581-589,共9页
A condition for local moment formation in metals derived by Stoddart and March (Ann. Phys. NY 1972 64, 174) is first used to discuss the ferromagnetism of body-centred-cubic Fe. A less detailed discussion is also ... A condition for local moment formation in metals derived by Stoddart and March (Ann. Phys. NY 1972 64, 174) is first used to discuss the ferromagnetism of body-centred-cubic Fe. A less detailed discussion is also added on Ni and Co. This leads into a treatment of the non- linear response of such 3d ferromagnets to dilute substitutional impurities. Antiferromagnets responding to local changes in the exchange field caused by such impurities are also studied, Mn in Cr being one such system discussed. The paper concludes with a brief summary of clusters of transition metal atoms, with most attention devoted to Cr and to Mn. 展开更多
关键词 NICR Alloys and of clusters of Transition Metal atoms Magnetism of Metals
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Experimental and Theoretical Study of Hydrogen Atom Abstraction from C2H6 and C4H10 by Zirconium Oxide Clusters Anions 被引量:1
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作者 马嘉璧 吴晓楠 +2 位作者 赵艳霞 丁迅雷 何圣贵 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第2期133-137,I0001,共6页
The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H... The reactions of anionic zirconium oxide clusters ZrxOy- with C2H6 and C4H10 are investi-gated by a time of flight mass spectrometer coupled with a laser vaporization cluster source.Hydrogen containing products Zr2O5H- and Zr3O7H- are observed after the reaction. Den-sity functional theory calculations indicate that the hydrogen abstraction is favorable in the reaction of Zr2O5- with C2H6, which supports that the observed Zr2O5H- and Zr3O7H- are due to hydrogen atom abstraction from the alkane molecules. This work shows a newpossible pathway in the reaction of zirconium oxide cluster anions with alkane molecules. 展开更多
关键词 Time of flight mass spectrometry Zirconium oxide cluster anion Reactivity Density functional theory Hydrogen atom abstraction
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Iron Atom-Cluster Strategy Synthesis of Hierarchically Porous Fe-N-C Catalysts for Proton Exchange Membrane Fuel Cells 被引量:1
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作者 Wenhao Qiu Qing Han +1 位作者 Xiaogang Yu Zhonghua Xiang 《Transactions of Tianjin University》 EI CAS 2023年第6期453-461,共9页
Developing nonprecious metal-nitrogen-doped carbon(M-N-C)catalysts with high activity and stability is critical to their widespread use in fuel cells;however,these catalysts still face considerable challenges.Herein,a... Developing nonprecious metal-nitrogen-doped carbon(M-N-C)catalysts with high activity and stability is critical to their widespread use in fuel cells;however,these catalysts still face considerable challenges.Herein,a novel iron atom-cluster strategy for the synthesis of iron-based N-C catalyst comprising Fe nanoparticles(Fe NPs)surrounded by Fe-N_(x) sites is developed for oxygen reduction reactions in an acidic fuel cell.Iron oxide NPs were incorporated into zeolitic imidazolate framework-8(ZIF-8)-derived carbon materials and pyrolyzed at high temperatures using NaCl as a modifi er to produce Fe NPs and Fe-N_(x) composite active sites.The half-wave potential of the optimized Fe_(NP)/FeNC-NaCl material was substantially improved to 0.81 V.Furthermore,even after 15,000 cycles,the half-wave potential of the catalyst remained essentially unchanged.As a cathode catalyst for fuel cells,it realized a high peak power density of 436 mW/cm^(2)under a practical H_(2)-air atmosphere.Therefore,this study presents a new approach for designing and synthesizing electrocatalytic materials with high catalytic activity and stability. 展开更多
关键词 Oxygen reduction reaction Fuel cell Fe-N-doped carbon IRON atom clusters PYROLYSIS synthesis
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Preparation of Cluster States for Many Atoms in Cavity QED 被引量:3
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作者 ZHAN Zhi-Ming School of Physics & Information Engineering,Jianghan University,Wuhan 430056,China 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第7期83-86,共4页
We propose a scheme for the generation of the cluster states for many atoms in cavity QED.In our scheme,the atoms are sent through nonresonant cavity fields in the vacuum states.The cavity fields are only virtually ex... We propose a scheme for the generation of the cluster states for many atoms in cavity QED.In our scheme,the atoms are sent through nonresonant cavity fields in the vacuum states.The cavity fields are only virtually excitedand no quantum information will be transferred from the atoms to the cavity fields.The advantage is that the cavitiesare suppressed during the procedure.The scheme can also be generalized to the ion trap system. 展开更多
关键词 cluster cavity QED atom
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Simultaneous integration of Fe clusters and NiFe dual single atoms in nitrogen-doped carbon for oxygen reduction reaction 被引量:1
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作者 Jirong Bai Yuebin Lian +5 位作者 Yaoyao Deng Mei Xiang Peng Xu Quanfa Zhou Yawen Tang Yaqiong Su 《Nano Research》 SCIE EI CSCD 2024年第4期2291-2297,共7页
Atomically-dispersed iron-based electrocatalysts are promising substitutes for noble metal electrocatalysts because of excellent performance in oxygen reduction reaction(ORR).Rationally modulating the local coordinati... Atomically-dispersed iron-based electrocatalysts are promising substitutes for noble metal electrocatalysts because of excellent performance in oxygen reduction reaction(ORR).Rationally modulating the local coordination environment of the Fe site and optimizing the binding energy of oxygen reduction intermediates are effective strategies to optimize ORR activity.Herein,we report a new method in which Ni is introduced to construct NiFe dual single atoms and iron nanoclusters loaded on the nitrogen-doped carbon with a highly porous structure.This design plays a synergistic role of dual single atoms and clusters,optimizes the 3d orbital and Fermi level of Fe,breaks the symmetrical structure of Fe-N_(4),and effectively improves the adsorption/desorption behavior of the oxygen-containing intermediates.Electrochemical tests show FeNCs/NiFeSAs-NC has an excellent intrinsic activity.Theoretical calculations show the oxygen-containing species on the Ni active site will move to the middle of NiFe(bridge site connection)after optimization and that the key step is OH desorption,with a reaction energy of 0.27 eV.The electron exchange between NiFe-N6 and Fe-cluster is very strong,further indicating the introduction of Ni species and Fe clusters has a regulatory effect on the electronic structure of Fe-N_(4). 展开更多
关键词 NiFe dual single atoms Fe clusters OH*adsorption energy oxygen reduction reaction
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Rapid synthesis of Pd single‐atom/cluster as highly active catalysts for Suzuki coupling reactions 被引量:2
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作者 Hehe Wei Xiaoyang Li +7 位作者 Bohan Deng Jialiang Lang Ya Huang Xingyu Hua Yida Qiao Binghui Ge Jun Ge Hui Wu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第4期1058-1065,共8页
Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annea... Palladium(Pd)‐based catalysts are essential to drive high‐performance Suzuki coupling reactions,which are powerful tools for the synthesis of functional organic compounds.Herein,we developed a solution‐rapid‐annealing process to stabilize nitrogen‐mesoporous carbon supported Pd single‐atom/cluster(Pd/NMC)material,which provided a catalyst with superior performance for Suzuki coupling reactions.In comparison with commercial palladium/carbon(Pd/C)catalysts,the Pd/NMC catalyst exhibited significantly boosted activity(100%selectivity and 95%yield)and excellent stability(almost no decay in activity after 10 reuse cycles)for the Suzuki coupling reactions of chlorobenzenes,together with superior yield and excellent selectivity in the fields of the board scope of the reactants.Moreover,our newly developed rapid annealing process of precursor solutions is applied as a generalized method to stabilize metal clusters(e.g.Pd,Pt,Ru),opening new possibilities in the construction of efficient highly dispersed metal atom and sub‐nanometer cluster catalysts with high performance. 展开更多
关键词 pd single‐atom/cluster catalyst Suzuki coupling reactions Solution rapid annealing Energy barrier High yield
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Exploring the Interactions of Atomic Oxygen on Silver Clusters with Hydrogen
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作者 曹西子 殷保祺 +1 位作者 王亭亭 邢小鹏 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第6期685-690,I0002,共7页
The interactions between AgnO- (n=1-8) and H2 (or D2) were explored by combination of the mass spectroscopy experiments and density function theory (DFT) calculations. The experiments found that all oxygen atoms... The interactions between AgnO- (n=1-8) and H2 (or D2) were explored by combination of the mass spectroscopy experiments and density function theory (DFT) calculations. The experiments found that all oxygen atoms in AgnO- (n--1-8) are inert in the interactions with H2 or D2 at the low temperature of 150 K, which is in contrast to their high reactivity with CO under the same condition. These observations are parallel with the preferential oxidation (PROX) of CO in excess hydrogen catalyzed by dispersed silver species in the condensed phase. Possible reaction paths between AgnO- (n=1-8) and H2 were explored using DFT calculations. The results indicated that adsorption of H2 on any site of AgnO- (n=1-8) is extremely weak, and oxidation of H2 by any kind of oxygen in AgnO- (n=1-8) has an apparent barrier strongly dependent on the adsorption style of the "O". These experiments and theoretical results about cluster reactions provided molecule-level insights into the activity of atomic oxygen on real silver catalysts. 展开更多
关键词 Silver clusters atomic oxygen HYDROGEN Mass spectroscopy Density functiontheory calculations
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Unveiling the early stage evolution of local atomic structures in the crystallization process of a metallic glass
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作者 马琳 杨晓东 +2 位作者 杨锋 周鑫嘉 武振伟 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期58-64,共7页
The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal s... The early stage evolution of local atomic structures in a multicomponent metallic glass during its crystallization process has been investigated via molecular dynamics simulation.It is found that the initial thermal stability and earliest stage evolution of the local atomic clusters show no strong correlation with their initial short-range orders,and this leads to an observation of a novel symmetry convergence phenomenon,which can be understood as an atomic structure manifestation of the ergodicity.Furthermore,in our system we have quantitatively proved that the crucial factor for the thermal stability against crystallization exhibited by the metallic glass is not the total amount of icosahedral clusters,but the degree of global connectivity among them. 展开更多
关键词 metallic glass CRYSTALLIZATION molecular dynamics simulation local atomic clusters
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Controllable selective anchoring of subnanometric Ru clusters or single-atoms/clusters on tungsten nitride for the hydrogen oxidation
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作者 Qijiao Sun Chuanqiang Wu +7 位作者 Yiqiang Sun Yuan Shen Lei Zhao Xiaodong Yang Li Yang Yunxiang Lin Keke Mao Kun Xu 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第11期3749-3756,共8页
The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms(SAs) into the substrate. However, the question of whether the introduction of SAs will further impr... The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms(SAs) into the substrate. However, the question of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction(HOR) remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires(RuC/WN) show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters(NCs)-coupled catalyst anchored on WN nanowires system(RuC,S/WN). Notably, the RuC/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 m A mg^(-1)PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that RuC/WN owns an optimized H^(*)and OH^(*) reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance. 展开更多
关键词 hydrogen oxidation reaction Ru cluster catalyst Ru single atoms and nanoclusters coupled catalyst tungsten nitride substrate
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Interaction of intense laser pulses with hydrogen atomic clusters
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作者 杜洪川 王慧巧 +4 位作者 刘作业 孙少华 李露 马玲玲 胡碧涛 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期367-373,共7页
The interaction between intense femtosecond laser pulses and hydrogen atomic clusters is studied by a simplified Coulomb explosion model. The dependences of average proton kinetic energy on cluster size, pulse duratio... The interaction between intense femtosecond laser pulses and hydrogen atomic clusters is studied by a simplified Coulomb explosion model. The dependences of average proton kinetic energy on cluster size, pulse duration, laser intensity and wavelength are studied respectively. The calculated results indicate that the irradiation of a femtosecond laser of longer wavelength on hydrogen atomic clusters may be a simple, economical way to produce highly kinetic hydrogen ions. The phenomenon suggests that the irradiation of femtosecond laser of longer wavelength on deuterium atomic clusters may be easier than that of shorter wavelength to drive nuclear fusion reactions. The product of the laser intensity and the squared laser wavelength needed to make proton energy saturated as a function of the squared cluster radius is also investigated. The proton energy distribution calculated is also shown and compared with the experimental data. Our results are in agreement with the experimental results fairly well. 展开更多
关键词 femtosecond laser pulse Coulomb explosion hydrogen atomic cluster
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Preparation of Highly Dispersed Supported Metal Catalysts via Solvated Metal Atom Impregnation ( V) --The Effects of Hydroxyl Group on the Surface Concentrations of SiO2 on the Properties of Supported Fe Clusters
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作者 Wu Shihua, Yang Shujun, Huang Weiping and Wang Xukun (Department of Chemistry and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1990年第1期47-55,共9页
Two kinds of small iron clusters supported on SiO2-200 (dehydroxylated at 200℃ and SiO2-600 (de-hydroxylated at 600℃) were prepared by Solvated Metal Atom Impregnation (SMAI) techniques. The iron atom precursor comp... Two kinds of small iron clusters supported on SiO2-200 (dehydroxylated at 200℃ and SiO2-600 (de-hydroxylated at 600℃) were prepared by Solvated Metal Atom Impregnation (SMAI) techniques. The iron atom precursor complex, bis (toluene) iron(0) formed in the metal atom reactor, was impregnated into SiO2 having different concentrations of surface hydroxyl groups to study the effect of surface hydroxylation on the crucial stage of iron cluster formation. Catalysts prepared in this way were characterized by THM, Mosbauer and chemisorption measurements, and the resules show that higher concentration of surface hydroxyl groups of SiO2-200 favours the formation of more positively charged support iron cluster Fen/SiO2-200 and the lower concentration of surface hydroxyl groups of SiO2-600 favours the formation of basically neutral supported iron cluster Fe2/SiO2-600. The measured results also indicate that the higher concentration of surface hydroxyl groups causes the precursor complex,bis(toluene) fron(0), to decompose more rapidly, and favours the formation of relatively large iron cluster. As a consequence, these two kinds of catalysts show different catalytic properties in Fischer-Tropsch reaction. The catalytic pattern of Fe/SiO2-200 in F-T reaction is similar to that of the unreduced a-Fe2O2, while Fe2/SiO2 -600 is similar to that of reduced α-Fe2O2. 展开更多
关键词 Iron clusters Solvated metal atom impregnation. Iron atom precursor complex
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Clusters Deposition on Surface an Atomic Scale Study by Computer Simulation Method
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作者 Akbarali Rasulov Nodirbek Ibroximov 《Journal of Applied Mathematics and Physics》 2019年第10期2303-2314,共12页
The investigation is generalized to clusters with sizes up to 3000 atoms, covering this way the range of sizes experimentally available for low energy cluster beam deposition. The atomic scale modeling is carried on b... The investigation is generalized to clusters with sizes up to 3000 atoms, covering this way the range of sizes experimentally available for low energy cluster beam deposition. The atomic scale modeling is carried on by both Molecular Dynamics and Metropolis Monte Carlo. This represents a huge series of simulations (175 cases) to which further calculations are added by spot when finer tuning of the parameters is necessary. Analyzing the results is a major task which is still in progress. This way, not only a realistic range of sizes is covered, but also the whole range of compositions and the temperature range relevant to the solid and the liquid states. 展开更多
关键词 COMPUTER Simulation Low Energy cluster DEPOSITION Slowing down Molecular Dynamics PARALLELIZATION Embedded atom Model
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Ionization Potentials and Electron Affinities of Cu_n Atomic Clusters
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作者 Senyying LIU Rongze HU and Chongyu WANG(Central Iron and Steel Research Institute, Beijing, 100081, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1994年第1期71-74,共4页
Ionization potentials and electron affinities of Cux (n = 2-7) atomic clusters with the optimal geom etries have been calculated by use of SC F-Xa-SW method and Slater's transition state theory. Theo retical calc... Ionization potentials and electron affinities of Cux (n = 2-7) atomic clusters with the optimal geom etries have been calculated by use of SC F-Xa-SW method and Slater's transition state theory. Theo retical calcuIations show that the ionization potentiaIs and electron affinities of Cu. (n = 2-7) atom ic clusters have a sharp even / odd alternation with increasing their sizes, which are related to the electronic structure of Cun atomic clusters. The theoretical results are consistent with the related ex perimental ones. 展开更多
关键词 CU REV Ionization Potentials and Electron Affinities of Cu_n atomic clusters FIGURE
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Studies of Atomic Structure and Physical Properties of Metal Clusters in MgO by HREM and Nano-probe Methods
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作者 Nobuo Tanaka (Dept. of Applied Physics, School of Engineering, Nagoya University, Nagoya, 464-01, Japan) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1997年第4期265-270,共6页
Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area el... Nanometer-sized metal clusters were prepared inside single crystalline MgO films by vacuum co-deposition of metals and MgO. The atomic structure was studied by high-resolution electron microscopy (HREM) and nm-area electron diffraction. The size of the clusters is ranging from 1 nm to 3 nm without those larger than 5 nm, and most of them have definite epitaxial orientations with the MgO matrix films. The character of the composite films is very much useful for the studies of various kinds of physical properties with anisotroPy. The physical properties such as electric transport, magnetic, optical absorption, sintering and catalytic ones were thus measured on the same samples analyzed by HREM by using high sensitivity apparatus with interest of clarifying the retationship between the atomic structure and physical properties 展开更多
关键词 FIGURE NANO Studies of atomic Structure and Physical Properties of Metal clusters in MgO by HREM and Nano-probe Methods HREM MGO
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Irregular phenomenon induced by Ag atomic segregation during the heating process of Ag Pd cluster
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作者 肖绪洋 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期376-380,共5页
This paper studies the melting of icosahedral Ag-Pd bimetallic clusters by using molecular dynamics with the embedded atom method. It finds that the mixed Ag-Pd cluster shows an irregular phenomenon before melting, i.... This paper studies the melting of icosahedral Ag-Pd bimetallic clusters by using molecular dynamics with the embedded atom method. It finds that the mixed Ag-Pd cluster shows an irregular phenomenon before melting, i.e., the atomic energy decreases with the increase of temperature. It indicates that the segregation of Ag atoms results in this phenomenon by analysing atomic radius distribution. Since the surface energy of Ag is lower than that of Pd, this leads to the result that the decreased energy by the Ag atomic segregation is larger than the increased energy by the heating. This provides a new method to obtain irregular thermodynamic properties. 展开更多
关键词 bimetallic cluster HEATING Ag-pd molecular dynamics
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火试金-电感耦合等离子体原子发射光谱法测定硅藻土中Pt、Pd含量
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作者 苏婧 陈潮炎 《中国资源综合利用》 2024年第7期13-16,共4页
硅藻土凭借独特的理化性质,被广泛用作助滤剂。火试金法是经典的贵金属富集方法,电感耦合等离子体原子发射光谱法(Inductively Coupled Plasma Atomic Emission Spectrometry,ICP-AES)可以简单、准确和快速地测定贵金属含量。试验采用... 硅藻土凭借独特的理化性质,被广泛用作助滤剂。火试金法是经典的贵金属富集方法,电感耦合等离子体原子发射光谱法(Inductively Coupled Plasma Atomic Emission Spectrometry,ICP-AES)可以简单、准确和快速地测定贵金属含量。试验采用火试金法富集硅藻土中的Pt、Pd,并在灰吹过程中加入银作为保护剂,形成合粒,经硝酸、盐酸溶解合粒后采用ICP-AES测定溶液中Pt、Pd含量。其间开展条件试验,得出最佳试验条件,从而消除基体干扰。试验结果表明,火试金-电感耦合等离子体原子发射光谱法可用于测定硅藻土中Pt、Pd含量,消除ICP-AES直接测定硅藻土中Pt、Pd时的基体干扰,测定结果稳定,方法操作简便快速。 展开更多
关键词 火试金-电感耦合等离子体原子发射光谱法 硅藻土 PT pd 测定
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Study of Structures and Electronic Properties of Pd_(n–1)Pb and Pd_n (n≤8) Clusters
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作者 方芳 朱瑜 +2 位作者 赵倩 蒋刚 王红艳 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第9期1092-1096,共5页
Geometric and electronic properties of Pdn–1Pb and Pdn (n≤8) clusters have been studied by using density functional theory with effective core potentials, focusing on the differences between mono- and bimetallic c... Geometric and electronic properties of Pdn–1Pb and Pdn (n≤8) clusters have been studied by using density functional theory with effective core potentials, focusing on the differences between mono- and bimetallic clusters. The average bond length of Pdn–1Pb (n≤8) bimetallic clusters is longer than that of pure palladium clusters except for n = 2 and 3. The most stable structure of Pdn–1Pb (n≤7) is the singlet where there is at least a Pd or Pb atom on its excited state. The energy gaps of Pd–Pb binary clusters are narrower than those of Pdn clusters, and then the chemical activity is strengthened when Pdn clusters are doped with Pb. 展开更多
关键词 pd-Pb bimetallic clusters equilibrium geometries bonding energy electron affinity Ionization potential HOMO-LUMO gap
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