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Exploring the Nanomechanical Properties of a Coordination-bond Based Supramolecular Polymer

Chinese Journal of Polymer Science 2022年第12期40卷 1613-1622,I0008页

作者： Rui-Xiang Yao Jun-Juan shi ke-Huan Li xin Liu Hou-Yu Zhang Ming Wang Wen-ke Zhang State key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130012China

Due to their dynamic nature and strength tunability,metallo-supramolecular polymers have been introduced into various *** mechanical strength of the metallo-supramolecular polymers in the system directly influences the mechanical properties(e.g.,the toughness)of the ***,it is necessary to explore the mechanical behavior of the metallo-supramolecular ***,we present a single-molecule method to systematically explore the chain structure and mechanical properties of metallo-supramolecular polymer by using a loop protected ***,we found that the mechanical stability of the individual chain,which is determined by the strength of terpyridine-Fe^(2+) -terpyridine(tpy-Fe^(2+)-tpy)bonds,was about 0.6–1.0 nN,depending on the pulling *** value is around three times higher than those measured using old *** addition,the unique loop protected structure further reduces the interference of non-specific polymer-AFM tip(or polymer-substrate)interactions on the quantification of the actual strength and kinetic parameter of noncovalent interactions in supramolecular ***,the single chain flexibility of the metallo-supramolecular polymer was investigated and found to be comparable to the corresponding covalent *** findings provide a new way to explore the force response of supramolecular polymers composed of metal-ligand interactions and will be useful for the design of metallo-supramolecular polymer-based functional materials with tailored mechanical properties.

关键词： Supramolecular polymer Single-molecule force spectroscopy Coordination chemistry Polymer mechanochemistry

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Deformation Behavior of Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd Alloy in β/Quasi-β Forging Process

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Journal of Iron and Steel Research International 2016年第12期23卷 1297-1302页

作者： ke-lu WANG shi-qiang LU Xian-juan DONG xin LI De-lai OUYANG School of Aeronautical Manufacturing Engineering Nanchang Hangkong University

The hot deformation behavior of Ti 5.6Al-4.8Sn-2.0Zr-1.0Mo 0.35Si 0.85Nd alloy in β/quasi-β forging process was studied using isothermal compression tests over temperature range from 1040℃ to 1 100 ℃ and strain rates form 0. 001 s-1 to 70 s -1. The results show that the flow stress and mierostrueture are sensitive to thermomechanical parameters. The processing maps based on the dynamic materials model at strain of 0.3 and 0.7 were established. The optimum deformation thermomechanical parameters at a strain of 0.7 have two regions that exhibit the peak of power dissipation efficiency. One is the region of 1062-1100 ℃ and 10- 3 10-1.5 s -1 ; and another which represents dynamic recrystallization is 1040-1045 ℃ and 10-1.8 10- 0.5 s -1. The instable region is located where the strain rate is larger than 1 s 1 which corresponds to the mechanical instability.

关键词： titanium alloy β/quasi-β forging deformation behavior processing map process parametersoptim ization

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Hot deformation behavior and process parameters optimization of Ti-6Al-7Nb alloy using constitutive modeling and 3D processing map

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Journal of Iron and Steel Research International 2021年第7期28卷 862-873页

作者： Ming-jun Zhong ke-lu Wang shi-qiang Lu xin Li Xuan Zhou Rui Feng School of Aeronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063JiangxiChina

The isothermal compression test for Ti-6Al-7Nb alloy was conducted by using Gleeble-3800 thermal *** hot deformation behavior of Ti-6Al-7Nb alloy was investigated in the deformation temperature ranges of 940-1030℃and the strain rate ranges of 0.001-10 s^(-1).Meanwhile,the activation energy of thermal deformation was *** results show that the flow stress of Ti-6Al-7Nb alloy increases with increasing the strain rate and decreasing the deformation *** activation energy of thermal deformation for Ti-6Al-7Nb alloy is much greater than that for self-diffusion ofα-Ti andβ-*** the influence of strain on flow stress,the strain-compensated Arrhenius constitutive model of Ti-6Al-7Nb alloy was *** error analysis shows that the model has higher accuracy,and the correlation coefficient r and average absolute relative error are 0.9879 and 4.11%,*** processing map(PM)of Ti-6Al-7Nb alloy was constructed by the dynamic materials model and Prasad instability *** to PM and microstructural observation,it is found that the main form of instability zone is local flow,and the deformation mechanisms of the stable zone are mainly superplasticity and dynamic *** optimal processing parameters of Ti-6Al-7Nb alloy are determined as follows:960-995℃/0.01-0.18 s^(-1)and 1000-1030℃/0.001-0.01 s^(-1).

关键词： Ti-6Al-7Nb alloy Hot deformation behavior Strain-compensated Arrhenius constitutive model Processing map Process parameters optimization

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Tensile properties of structural I clathrate hydrates:Role of guest-host hydrogen bonding ability

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Frontiers of physics 2021年第3期16卷 125-134页

作者： Yue xin Qiao shi ke Xu Zhi-Sen Zhang Jian-Yang Wu Department of Physics Research Institute for Biomimetics and Soft MatterJiujiang Research Institute and Fujian Provincial Key Laboratory for Soft Functional Materials ResearchXiamen UniversityXiamen361005China

Clathrate hydrates(CHs)are one of the most promising molecular structures in applications of gas capture and storage,and gas *** knowledge of mechanical characteristics of CHs is of crucial importance for assessing gas storage and separations at cold conditions,as well as understanding their stability and formation ***,the tensile mechanical properties of structural I CHs encapsulating a variety of guest species(CH_(4),NH_(3),H_(2)S,CH_(2)O,CH_(3)OH,and CH_(3)SH)that have different abilities to form hydrogen(H-)bonds with water molecule are explored by classical molecular dynamics(MD)*** investigated CHs are structurally stable clathrate *** mechanical properties of CHs including tensile limit and Young’s modulus are dominated by the H-bonding ability of host-guest molecules and the guest molecular *** containing small CH_(4),CH_(2)O and H_(2)S guest molecules that possess weak H-bonding ability are mechanically robust clathrate structures and mechanically destabilized via brittle failure on the(101)***,those entrapping CH3SH,CH3OH,and NH3 that have strong H-bonding ability are mechanically weak molecular structures and mechanically destabilized through ductile failure as a result of gradual global dissociation of clathrate cages.

关键词： mechanical properties clathrate hydrates hydrogen bonding

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Identifying the dynamic behaviors in complete reconstruction of Co-based complex precatalysts during electrocatalytic oxygen evolution

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Journal of Energy Chemistry 2025年第1期100卷 226-233页

作者： Jingfang Zhang Danyang Wu Linke Cai Youluan Lu Fanpeng Cheng Lijuan shi Qun Yi Yao Liu Yi Huang key Laboratory of Green Chemical Engineering Process of Ministry of Education Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education Hubei Key Laboratory of Novel Reactor and Green Chemical Technology School of Chemical Engineering & Pharmacy Wuhan Institute of Technology key Laboratory of Pesticide & Chemical Biology of Ministry of Education Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction of Ministry of Education College of Chemistry Central China Normal University College of Materials Science and Engineering Fuzhou University

Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction（OER）. Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under operating conditions of OER process. However, most of them undergo incomplete reconstruction with limited thickness of reconstruction layer, leading to low component utilization and arduous exploration of real catalytic mechanism. Herein, we identify the dynamic behaviors in complete reconstruction of Co-based complexes during OER. The hollow phytic acid（PA） cross-linked CoFe-based complex nanoboxes with porous nanowalls are designed because of their good electrolyte penetration and mass transport ability, in favor of the fast and complete reconstruction. A series of experiment characterizations demonstrate that the reconstruction process includes the fast substitution of PA by OH-to form Co（Fe）(OH)xand subsequent potential-driven oxidation to Co（Fe）OOH. The obtained CoFeOOH delivers a low overpotential of 290 mV at a current density of 10 mA cm-2and a long-term *** experiment results together with theory calculations reveal that the Fe incorporation can result in the electron rearrangement of reconstructed CoFeOOH and optimization of their electronic structure,accounting for the enhanced OER activity. The work provides new insights into complete reconstruction of metal-based complexes during OER and offers guidelines for rational design of high-performance electrocatalysts.

关键词： Complete reconstruction Co-based complex Precatalysts Oxygen evolution reaction

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Boosting hydrocarbon conversion via Cu-doping induced oxygen vacancies on CeO2 in CO2 electroreduction

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Journal of Energy Chemistry 2025年第1期100卷 66-76页

作者： Lei Xue Tong shi Chenhui Han Heng Zhang Fenrong Liu Haorun Li Yan Wang Xiaojun Gu Shanghong Zeng Inner Mongolia key Laboratory of Chemistry and Physics of Rare Earth Materials School of Chemistry and Chemical Engineering Inner Mongolia University State key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Institute of Catalysis Department of Chemistry Zhejiang University National key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths

Conversion of CO2back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as ***,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based ***,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO2nanorods were effectively created,with adjustable vacancy/Cu *** resulting optimum catalyst shows up to 79% catalytic current density to hydrocarbons （excluding CO）,with 49% faradaic efficiency to *** and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to *** findings may spur new insights for designing and developing more controllable chemical process relevant to CO2utilization.

关键词： Oxygen vacancy Hydrocarbon production Reaction mechanism

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Escaped and Trapped Emission of Organic Light-Emitting Diodes

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Chinese Physics Letters 2012年第2期29卷 108-111页

作者： LIANG shi-Xiong WU Zhao-xin ZHAO Xuan-ke HOU Xun key Laboratory of Photonics Technology for Information Key Laboratory for Physical Electronics and Devices(Ministry of Education)School of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049

By locating the emitters around the first and second antinode of the metal electrode,the escaped and trapped emission of small molecule based bottom emission organic light-emitting diodes is investigated by using an integrating sphere,a fiber spectrometer and a glass *** is found that the external coupling ratio by locating the emitters at the second antinode (at a distance of 220 nm from the cathode) is 70%,which is higher than that of an emitter at the first antinode (60nm from the cathode) in theory and *** the "half-space" dipole model by taking the dipole radiation pattern into account,we also calculate the optical coupling efficiency for the emitter at both the first and second *** experimental and theoretical results will benefit the optimization of device structures for the higher out-coupling efficiency.

关键词： emitter coupling locating

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CONVERGENCE OF AN IMMERSED INTERFACE UPWIND SCHEME FOR LINEAR ADVECTION EQUATIONS WITH PIECEWISE CONSTANT COEFFICIENTS I:L^1-ERROR ESTIMATES

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Journal of Computational Mathematics 2008年第1期26卷 1-22页

作者： xin Wen shi Jin LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Department of Mathematics University of Wisconsin Madison WI 53706 USAand Department of Mathematical Sciences Tsinghua University Beijing 100084 China

We study the L^l-error estimates for the upwind scheme to the linear advection equations with a piecewise constant coefficients modeling linear waves crossing interfaces. Here the interface condition is immersed into the upwind scheme. We prove that, for initial data with a bounded variation, the numerical solution of the immersed interface upwind scheme converges in L^l-norm to the differential equation with the corresponding interface condition. We derive the one-halfth order L^l-error bounds with explicit coefficients following a technique used in [25]. We also use some inequalities on binomial coefficients proved in a consecutive paper [32].

关键词： Linear advection equations Immersed interface upwind scheme Piecewise constant coefficients Error estimate Half order error bound

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Bifurcation analysis and stability design for aircraft longitudinal motion with high angle of attack

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Chinese Journal of Aeronautics 2015年第1期28卷 250-259页

作者： xin Qi shi Zhongke School of Automation Northwestern Polytechnical University

Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

关键词： bifurcation longitudinal aircraft saddle continuation stabilization scheduling unstable stationary exponent

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Revealing and predicting the long-term biomechanical response of orthokeratology by developing a patient-specific computational model

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 156-168页

作者： Yifeng Li Zhuoran Yang Ziming Yan Huibin shi Zhanli Liu Kaijie Wang Department of Engineering Mechanics School of Aerospace Engineering Tsinghua University Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing Ophthalmology & Visual Sciences Key Lab

Orthokeratology(OK) is widely used for effective myopia correction and control. However, the incomplete understanding of its biomechanical mechanisms makes OK lens fitting rely heavily on clinician judgment, complicating accurate predictions of treatment outcomes. In this paper, we performed clinical experiments and numerical analysis to study corneal deformation modes and long-term changes in central corneal thickness. Clinical experiments were conducted on 194 Chinese myopic patients under OK treatment for 3 months. Based on the experimental data, a patient-specific computational biomechanical model for OK was established and validated. Specifically, the anisotropic mechanical properties of the cornea were incorporated into the model to describe the significant difference between its shear modulus(29.5 kPa) and tensile modulus(768.4 kPa). Additionally, a viscohyperelastic material model with a prolonged corneal relaxation time of 5.6 h was developed to capture the long-term deformation response. The results show that corneal thickness reduction in OK is primarily due to out-of-plane shear deformation,influenced by the cornea's low shear resistance. Modeling the extended corneal relaxation time is crucial for predicting long-term biomechanical responses. The computational model effectively captures long-term changes in central corneal thickness, potentially improving OK lens fitting accuracy.

关键词： orthokeratology computational biomechanical model long-term viscoelasticity myopia correction

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