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Reduction of dinitrogen to ammonia on doped three-atom clusters Nb_(2)M(M=Sc to Cu & y to Ag)

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Rare Metals 2024年第8期43卷 3810-3818页

作者： Ran Cheng Chao-nan Cui Zhi-Xun Luo Beijing National Laboratory for Molecular Science(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Science University of Chinese Academy of SciencesBeijing 100049China

Catalytic reduction of dinitrogen to ammonia under mild conditions remains an attractive topic for the purpose of lowering energy ***-atom metal clusters have been proved an ideal model to explore highly efficient catalysts taking advantage of unique geometric/electronic structures and cooperative active *** a study of N2 activation and reduction on seventeen bimetallic Nb_2M(M=Sc to Cu,and y to Ag) clusters was *** key processes for ammonia fixation(namely nitrogen activation,hydrogenation,and ammonia desorption) are fully studied,and three preferred systems(Nb_2Ni,Nb_2Rh and Nb_2Pd) are highlighted with outstanding catalytic *** d-σ and d-π~* orbital hybridizations between these metal clusters and N_(2) were demonstrated and the internal association with the N≡N bond activation was *** examining the ammonia synthesis on four chosen Nb_(2)M clusters(M=Fe,Ni,Rh and Pd),it can be elucidated that the distal pathway is more favorable than the alternative pathway in these *** work not only clarifies the N_(2) reduction on the bimetallic Nb_(2)M clusters,but also guides efficient bimetallic catalyst design.

关键词： Three-atom cluster catalysis Three-criteria strategy Nitrogen fixation Ammonia synthesis Theoretical calculations

Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 72-89页

作者： yingjie Ma nan Zhang Jie Li Cuiwen Cao Centre for Process Integration Department of Chemical Engineering and Analytical ScienceSchool of EngineeringThe University of ManchesterManchester M139PLUK Key Laboratory of Advanced Control and Optimization for Chemical Processes(Ministry of Education) East China University of Science and TechnologyShanghai 200237China

The extractive dividing-wall column(EDWC)is one of the most efficient technologies for separation of azeotropic or close boiling-point mixtures,but its design is fairly *** this paper we extend the hybrid feasible path optimisation algorithm(Ma y,McLaughlan M,Zhang N,Li ***&Chemical Engineering,2020,143:107058)for such optimal *** tolerances-relaxation integration method is refined to allow for long enough integration time that can ensure the solution of the pseudo-transient continuation simulation close to the steady state before the required tolerance is *** ensure the gradient and Jacobian information available for optimisation,we allow a relaxed tolerance for the simulation in the sensitivity analysis mode when the simulation diverges under small *** addition,valid lower bounds on purity of the recycled entrainer and the vapour flow rate in column sections are imposed to improve computational *** computational results demonstrate that the extended hybrid algorithm can achieve better design of the EDWC compared to those in *** energy consumption can be reduced by more than 20%compared with existing literature *** addition,the optimal design of the heat pump assisted EDWC is achieved using the improved hybrid algorithm for the first time.

关键词： design extractive dividing-wall column equation-oriented optimisation pseudo-transient continuation model hybrid algorithm

Oxidation Mechanism of Ni-0.5y Microcrystal Coating Sputtered by Magnetron at 1 000 ℃

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Journal of Iron and Steel Research International 2004年第5期11卷 59-62页

作者： JINHuiming ZHANGLin-nan LIUXiao-jun yangzhouUniversity Yangzhou225009China NortheasternUniversity Shenyang110025China

The isothermal and cyclic oxidation behaviors of bulk pure nickel and its Ni-0.5ymicrocrystal coating sputtered by magnetron at 1 000 ℃in air were *** scanning electronic microscopy(SEM)and transmission electronic microscopy(TEM)were used to examine the structures of the coating and the NiO oxide *** laser Raman spectrum was also used to measure the stress level in NiO films formed on bulk nickel and the *** is found that the Ni-0.5y microcrystal coating has lower oxidation rate,and the grain size of NiO formed on Ni-0.5ycoating is also relatively smaller than that formed on bulk ***,the compressive stress level of oxide film formed on Ni-0.5ycoating was lower than that formed on bulk nickel,and the high temperature plasticity of oxide film was much improved in coating *** improvements of anti-oxidation properties of the sputtered Ni-0.5ycoating are due to the microcrystal structure and yttrium.

关键词： magnetron sputtering coating oxidation laser Raman yttrium

Single thiolate replacement of metal nanoclusters

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Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen yue Zhou Wanmiao Gu Qing you Liang Fang Guoqing Bian nan yan nan Xia Zhikun Wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

Surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal ***,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted ***,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption ***,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted *** bond length-related stability was also ***,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

Theoretical study of interactions between human adult hemoglobin and acetate ion by polarizable force field and fragmentation quantum chemistry methods

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Science China Chemistry 2009年第11期52卷 1925-1931页

作者： yAN XiuFen JIANG nan MA Jing School of Chemistry and Chemical Engineering Institute of Theoretical and Computational ChemistryKey Laboratory of Mesoscopic Chemistry of MOENanjing UniversityNanjing 210093China

A series of theoretical approaches,including conventional FF03 and FF03-based polarization model,as well as the generalized energy-based fragmentation(GEBF) quantum chemistry method,have been applied to investigate the interactions between acetate ion(CH3COO-) and the α-subunit of human adult hemoglobin(designated as Hb-α) at four binding sites(Lys16,Lys90,Arg92,and Lys127),*** FF03-based polarizable force fields show that the interaction energies between the CH3COO-group and Hb-α follow the trend of Arg92>Lys127>Lys90>*** complexation of CH3COO-with Hb-α is governed by the long-range electrostatic interactions and steric effect.

关键词： polarization model fragmentation QM method hemoglobin interaction

Ginzburg-Landau Vortex and Mean Curvature Flow with External Force Field

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Acta Mathematica Sinica,English Series 2006年第6期22卷 1831-1842页

作者： Huai yu JIAN yan nan LIU Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China

This paper is devoted to the study of the vortex dynamics of the Cauchy problem for a parabolic Ginzburg Landau system which simulates inhomogeneous type II superconducting materials and three-dimensional superconducting thin films having variable thickness. We will prove that the vortex of the problem is moved by a codimension k mean curvature flow with external force field. Besides, we will show that the mean curvature flow depends strongly on the external force, having completely different phenomena from the usual mean curvature flow.

关键词： system of parabolic equations Ginzburg-Landau vortex mean curvature flow

A Discrete Tire Model for Cornering Properties Considering Rubber Friction

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Automotive Innovation 2020年第2期3卷 133-146页

作者： nan Xu yiyang yang KonghuiGuo State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025Jilin ProvinceChina Pan Asia Technical Automotive Center Co. LtdPudong 201208ShanghaiChina

In this paper,a discrete tire model of comering properties for road vehicles relating to tire grip performance,which is important for driving stability and safety,is *** proposed tire model combines realistic rubber friction related to velocity and tire grip performance with deformation of the *** model can describe the stress and strain of the carcass and tread,and the rubber friction coefficient at each point of the contact patch,which is affected by the di stribution of the slip ***,the model incorporates the effects of the viscoelastic rubber material and power spectrum of the road,which are explicitly reflected in the rubber friction ***,an improved rubber friction model based on the Persson theory of rubber friction is introduced in this paper.A discrete analytical tire model,which considers carcass compliance and the discretization of the tread,is then *** addition,important phenomena of tire properties arising from the carcass compl iance and rubber friction are analyzed and the effectiveness of the discrete analytical tire model is validated *** proposed model provides a new way to optimize the grip performance of a tire by adjusting the tire or rubber physical parameters even before the tire is made.

关键词： Road vehicle Tire model Grip performance Rubber friction Running velocity

Existence of Solutions to Generalized Vector Quasi-Equilibrium Problems with Discontinuous Mappings

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1127-1132页

作者： ya Ping FANG nan Jing HUANG Department of Mathematics Sichuan University Chengdu 610064 P. R. China

Let X, y be two finite-dimensional topological vector spaces, Z a Hausdorff topological vector space, K C X and D C Z be two nonempty sets, C be a pointed, closed, and convex cone in y with int C ≠θ Let S ： K → 2^K and T ： K → 2^D be two multivalued mappings, and φ ： K × D × K → y be a trifunction. In this paper, we consider the generalized vector quasi-equilibrium problem, which is formulated by finding X∈ K and y∈ T（x） such that x∈ E S（x） and φ（x,y, u）（∈/） -int C for all u ∈ S（x）. We establish an existence result in which T is not supposed to have any continuity property. Our results extend and improve the corresponding results of Cubiotti, yao and Guo.

关键词： Generalized vector quasi-equilibrium problem Upper semi-continuity Lower semi-continuity Fixed point Existence

SCHEDULING ALGORITHM BASED ON FOLLOW-UP SHARING CHARACTER FOR POST-EVENT RESPONSE RESOURCE DISTRIBUTION IN LARGE-SCAL DISASTERS

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Journal of Systems Science and Systems Engineering 2016年第1期25卷 77-101页

作者： yong ye nan Liu Guiping Hu Shalei Zhan Department of Management College of Humanities and Management Wenzhou Medical University Wenzhou 325035 P.R. China Department of Management Sciences & Engineering School of Management Zhejiang University Hangzhou 310058 P.R. China Industrial and Manufacturing Systems Engineering 3014 Black Engineering Iowa State University Ames IA 50011 School of Computer Science and Information Engineering Zhejiang Gongshang University Hangzhou 310058 P.R. China

Post-event response planners must develop effective and efficient plans for the proper allocation and distribution of resources to impacted areas （IAs） within a critical time window. To determine the effectiveness and efficiency of distribution plans, this study addresses resource allocation effectiveness losses （RAEL, or losses caused by the mismatch between supply and demand in IAs） and emergency logistics time costs （ELTC, or transportation time of logistics processes under emergency conditions）. Moreover, this study examines a follow-up sharing character （FSC） that coordinates resources among different phases. This research proposes an integrated model （IM） based on this character. This model aims to minimize RAEL and ELTC. Furthermore, the IM combines the time dimension model （TDM）, which coordinates the demands and supplies of all phases in the planning horizon, and the space dimension model （SDM）, which generates a specific distribution plan for the first phase. An analytical solution is obtained for the TDM as per the definition of FSC, after which the SDM is solved through a single-objective linear programming model. After solving the IM effectively, we fred that the proposed methodology fits the emergency circumstance well. Insights derived from the model are also presented in the conclusion.）

关键词： Emergency management humanitarian logistics decision-making resource distribution