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Optimizing geometric configuration of single Zn-N_(4) sites for boosting reciprocal transformation between aromatic alcohols and aldehydes

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Nano Research 2023年第7期16卷 9132-9141页

作者： Shengjie Wei Yucheng Jin Chunlin Lv Chao Lian Zheng Chen Xiao Liang Qinghua Zhang Xin Chen Dongdong Qi Zhi Li School of Materials Science and Engineering Nankai UniversityTianjin 300350China Department of Chemistry Tsinghua UniversityBeijing 100084China Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials Department of ChemistryUniversity of Science and Technology BeijingBeijing 100083China School of Pharmacy and Center on Translational Neuroscience Minzu University of ChinaBeijing 100081China Department of Chemistry School of ScienceBeijing Jiaotong UniversityBeijing 100091China School of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083China College of Chemistry Beijing Normal UniversityBeijing 100875China

It is significant to optimize geometric configuration of metal catalytic sites and boost their catalytic ***,we synthesized isolated single Zn-N_(4)sites on N-doped carbon(Zn-CN)by pyrolyzing zeolite imidazole framework-8(ZIF-8)at different *** the reciprocal transformation between benzyl alcohol and benzaldehyde,the catalytic activities of Zn-CN catalysts exhibited a volcano-like trend as the pyrolysis temperatures *** optimal catalyst was Zn-CN-900,with outstanding catalytic activity exceeding commercial 20 wt.%Pd/C and 20 wt.%Pt/C,promising to substitute the noble metalbased catalysts.X-ray absorption near-edge structure(XANES)measurements and density functional theory(DFT)calculation revealed the gradual transformation from tetrahedral ZnN_(4)sites of ZIF-8 into planar ZnN_(4)sites above 700℃,with the maximum planar ZnN_(4)sites in *** stronger adsorption between reactants and planar ZnN_(4)sites facilitated the activation of reactants compared with tetrahedral ZnN_(4)*** work will provide valuable insight into rational design of efficient catalysts by optimizing geometric configuration of catalytic sites.

关键词： geometric configuration single Zn-N_(4)sites benzyl alcohol oxidation hydrogen transfer reaction

Sliding and damming properties of granular debris with different geometric configurations and grain size distributions

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Journal of Mountain Science 2024年第3期21卷 932-951页

作者： HE Ligeng TAN Longmeng YANG Xingguo ZHOU Jiawen LIAO Haimei College of Civil Engineering Guizhou UniversityGuiyang 550025China Quality Supervision and Law Enforcement Detachment of Guizhou Province Traffic Construction Engineering Guiyang 550081China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

Granular debris plays a significant role in determining damming deposit characteristics. An indepth understanding of how variations in grain size distribution(GSD) and geometric configurations impact the behavior of granular debris during the occurrence of granular debris is essential for precise assessment and effective mitigation of landslide hazards in mountainous terrains. This research aims to investigate the impact of GSD and geometric configurations on sliding and damming properties through laboratory experiments. The geometric configurations were categorized into three categories based on the spatial distribution of maximum volume: located at the front(Type Ⅰ), middle(Type Ⅱ), and rear(Type Ⅲ) of the granular debris. Our experimental findings highlight that the sliding and damming processes primarily depend on the interaction among the geometric configuration, grain size, and GSD in granular debris. Different sliding and damming mechanisms across various geometric configurations induce variability in motion parameters and deposition patterns. For Type Ⅰ configurations, the front debris functions as the critical and primary driving component, with energy dissipation primarily occurring through inter-grain interactions. In contrast, Type Ⅱ configurations feature the middle debris as the dominant driving component, experiencing hindrance from the front debris and propulsion from the rear, leading to complex alterations in sliding motion. Here, energy dissipation arises from a combination of inter-grain and grain-substrate interactions. Lastly, in Type Ⅲ configurations, both the middle and rear debris serve as the main driving components, with the rear sliding debris impeded by the front. In this case, energy dissipation predominantly results from grainsubstrate interaction. Moreover, we have quantitatively demonstrated that the inverse grading in damming deposits, where coarse grain moves upward and fine grain moves downward, is primarily caused by grain sortin

关键词： Landslide dam geometric configuration Energy dissipation Inverse grading Physical experiment

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Construction of pH-universal hydrogen evolution freeway in MoO_(3)-MoNi_(4)@Cu core-shell nanowires via synergetic electronic and geometric effect

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Nano Research 2023年第10期16卷 12253-12262页

作者： Xiaodong Chen Shoufu Cao Xiaojing Lin Xiaofei Wei Zhaojie Wang Hongyu Chen Chengcheng Hao Siyuan Liu Shuxian Wei Daofeng Sun Xiaoqing Lu School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580China College of Science China University of Petroleum(East China)Qingdao 266580China

Both the adsorption/dissociation of water molecules and hydrogen intermediate(H*)are the major limitations to hydrogen evolution reaction(HER).Herein,the modulation of electronic structure and geometric configuration are combined to design onedimensional electrocatalyst with outstanding HER activity in a wide pH *** catalyst was composed of molybdenum trioxide doped molybdenum nickel alloy supported by copper nanowires(MoO_(3)-MoNi_(4)@Cu NWs).As revealed by the experimental characterizations and theoretical calculations,Cu NWs act as the electron donator to MoNi4,resulting in up shift of the d-band center in MoNi4,thus expediting H_(2)O adsorption and ***,the introduction of amorphous MoO_(3) sets up a unique geometric configuration on MoNi4 for the accelerated H*transfer via hydrogen-bond and hydrogen *** work provides a synergetic route for constructing HER freeway and promotes further investigations on more versatile electrocatalysis involving H_(2)O or H*.

关键词： pH-universal hydrogen evolution reaction(HER) electronic structure geometric configuration hydrogen-bond hydrogen spillover

Studying on the increasing temperature in IT-SOFC:Effect of heat sources

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第9期8卷 1500-1504页

作者： ZITOUNI Bariza BEN MOUSSA Hocine OULMI Kafia Laboratore d'étude des Systèmes énergétiques Industriels (LESEI) Faculty of EngineeringUniversity of BatnaBatnaAlgeria Laboratoire de Chimie et de Chimie de L'environnement Faculty of ScienceUniversity of BatnaBatnaAlgeria

The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell,is due to the over potential of activation (transfer of load),the over potential Ohmic (resistance of polarization),the over potential of reaction (heat released by the chemical reaction) and the over potential of diffusion. In this paper,we studied the thermo-electrical performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) with electrode supported. The aim of this work is to study this increasing temperature of a single cell of an IT-SOFC under the influence of the following parameters: heat sources,functioning temperature and voltages of the cell,geometric configuration and materials type. The equation of energy in one dimension is numerically resolved by using the method of finite volumes. A computing program (FORTRAN) is developed locally for this purpose in order to obtain fields of temperature in every element of the cell.

关键词： IT-SOFC Thermo-electrical Joule effect Activation energy Temperature Voltage geometric configuration

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Density functional investigations for geometric and electronic properties of In_4M and In_(12)M (M=C,Si,In) clusters

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Chinese Physics B 2008年第8期17卷 2951-2955页

作者：李志坚李锦茴 Mathematics and science department Hunan first normal college

First-principle calculations are performed to study geometric and electronic properties of both neutral and anionic In4M and In12M （M = C, Si, In） clusters. In4C and In4Si are found to be tetrahedral molecules. The icosahedral structure is found to be unfavourable for In12M. The most stable structure for In12C is a distorted buckled biplanar structure while for In12Si it is of an In-cage with the Si located in the centre. Charge effect on the structure of In12M is discussed. In4C has a significantly large binding energy and an energy gap between the highest-occupied molecularorbital level and the lowest unoccupied molecular-orbital level, a low electron affinity, and a high ionization potential, which are the characters of a magic cluster, enriching the family of doped-group-IIIA metal clusters for cluster-assembled materials.

关键词： atomic cluster geometric configuration electronic properties stability

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Structure and stability of neutral and cationic AlnO clusters

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Chinese Physics B 2007年第4期16卷 1014-1019页

作者：杨鹏葛建华姜振益 ISN National Key Laboratory Xidian University Xi'an 710071 China state Key Laboratory of Electrical Insulation for Power Equipment Xi'an Jiaotong University Xi'an 710049 China Multidisciplinary Materials Research Center Xi'an Jiaotong University Xi'an 710049 China

In this paper various structural possibilities for AlnO neutral and cationic isomers were investigated by using the B3LYP/6-311G（3df） method. Calculations of this paper predicted the existence of a number of previously unknown isomers. The stabilities of the AlnO （n = 2 - 7） clusters with even n are greater than those with odd n, however the stabilities Of cationic ions have the opposite odd-even alternation. The mass spectra observations of Al17O^＋ and Al19O^＋ ions support our theoretical predictions on their stabilities.

关键词： AlnO clusters geometric configuration ionization potentials stability

Review of Fiber-Optic Localized Surface Plasmon Resonance Sensors:Geometries,Fabrication Technologies,and Bio-Applications

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Photonic Sensors 2024年第2期14卷 31-56页

作者： Mengdi LU Chen WANG Ruizhi FAN Ming LIN Jianye GUANG Wei PENG Affiliated Cancer Hospital Dalian University of TechnologyShenyang 110042China School of Physics Dalian University of TechnologyDalian 116024China

Localized surface plasmon resonance(LSPR)biosensors,which enable nanoscale confinement and manipulation of light,offer the enhanced sensitivity and electromagnetic energy *** integration of LSPR with the fiber-optic technology has led to the development of compact and versatile sensors for miniaturization and remote *** comprehensive review explores various sensor configurations,fiber types,and geometric shapes,highlighting their benefits in terms of sensitivity,integration,and performance *** techniques such as focused non-chemical bonding strategies and self-assembly of nanoparticles are discussed,providing control over nanostructure morphology and enhancing sensor ***-applications of fiber-optic LSPR(FOLSPR)sensors are detailed,specifically in biomolecular interactions and analysis of proteins,pathogens and cells,nucleic acids(DNA and RNA),and other small molecules(organic compounds and heavy metal ions).Surface modification and detection schemes are emphasized for their potential for label-free and real-time *** challenges and prospects of FOLSPR sensors are addressed,including the developments in sensitivity,fabrication techniques,and measurement *** with emerging technologies such as nanomaterials is highlighted as a promising direction for future ***,this review provides insights into the advancements and potential applications of FOLSPR sensors,paving the way for sensitive and versatile optical biosensing platforms in various fields.

关键词： Fiber-optic localized surface plasmon resonance biosensor nanoparticles geometric configuration fabrication technology

Photochromatic Behavior of the Graft Copolymer of Starch and Azo-dye

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Chemical Research in Chinese Universities 2001年第Z1期17卷 236-237页

作者： FU ZhengSheng Department of chemistry Northwest Normal University Guangzhou Institute of Chemical Chinese Academy of sciences

Photoisomerization (trans-cis) of azoaromatic compounds has been investigated extensively using absorption spectroscopy since 1950s[1]. By irradiation with light of wavelength λ1 or λ 2 ,the geometric configuration of the azo bond in azobenzene based compounds can be reversibly switched from trans to cis. The two states have distinct absorption spectra. This feature would allow reversible storage of data on the basis of cis and trans states with the aid of λ 1 and λ 2 . However, the cis state is thermodynamically unstable with respect to the trans state, therefore a thermal relaxation process occurs in the dark (at room temperature). This thermal back-reaction strongly limits the lifetime of the cis state, and it is influenced by the substituent R1 and R2, catalysts, temperature, and environment (solvent polarity, type of polymer matrix)[2].

关键词： geometric configuration absorption spectroscopy relaxation process absorption spectra room temperature