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Tunable chiroptical application by encapsulating achiral lanthanide complexes into chiral MOF thin films

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Nano Research 2022年第2期15卷 1102-1108页

作者： Rui Zhai Yihong Xiao Zhigang gu jian Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China University of Chinese Academy of Sciences Beijing 100049China

Chiral metal-organic frameworks(chirMOFs)have been widely considered on enantioselective adsorption/separation,asymmetric catalysis,biological and nonlinear optical ***,chirMOFs are facing a great challenge in development of chiroptical thin films with circularly polarized luminescence(CPL)***,we first report CPL thin films by encapsulating achiral lanthanide complexes Ln(acac)_(3)(Ln=Eu_(a)Tb_(b)Gd_(c))into the pores of surface-coordinated chirMOF thin films(SURchirMOF)[Zn_(2)(cam)_(2)dabco]_(n) with layer by layer(Ibl)encapsulation *** to the unique combination of chiral porous MOF and adjustable luminescent complexes in the host-guest thin films,the obtained Ln(acac)_(3)@SURchirMOF possess strong and tunable CPL property with high dissymmetry *** compared CPL and fluorescent lifetime results show that the advantage of this preparation strategy can effectively achieve energy transfer from Ln(acac)_(3) to SURchirMOF,resulting in an excellent CPL *** study not only provides a novel strategy to develop new types of chiral thin films but also offers an efficient approach for tunable chiroptical applications.

关键词： metal-organic frameworks lanthanide complexes thin films encapsulation chiral optical application

Suppressing nonlinear aeroelastic response of laminated composite panels in supersonic airflows using a nonlinear energy sink

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Chinese Journal of Aeronautics 2021年第2期34卷 376-385页

作者： jian ZHOU Minglong XU Zhichun YANG Yingsong gu State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi'an Jiaotong UniversityXi'an 710049China School of Aeronautics Northwestern Polyteclmical UniversityXi'an 710072China

This paper proposes using a Nonlinear Energy Sink(NES) to suppress the nonlinear aeroelastic response of laminated composite panels in supersonic airflows. Relevant aeroelastic equations are established using Hamilton’s principle and a finite element approach, drawing upon Von Karman’s large deflection theory and first order piston theory. The idea of the NES suppression region is proposed and the effects of NES parameters on the NES suppression region are studied in detail. The results show that the nonlinear aeroelastic responses of the panel can be completely suppressed by the Transient Resonance Capture(TRC);the appropriate NES parameter values can increase the critical dynamic pressure for flutter and suppress the nonlinear aeroelastic response effectively. Increasing the mass ratio of the NES can improve the NES suppression region;the nonlinear stiffness coefficient and damping of the NES within a specific range can suppress the nonlinear aeroelastic response. The most effective installation position for a NES is in a specific region behind the center-line of the panel in the direction of the airflow.

关键词： Aeroelasticity Laminated composite panel Nonlinear dynamics Nonlinear energy sink Panel flutter Passive suppression

Effect of strain rate on the compressive deformation behaviors of lotus-type porous copper

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International Journal of Minerals,Metallurgy and Materials 2014年第7期21卷 687-695页

作者： xin-hua Liu Hai-you Huang jian-xin Xie Institute for advanced Materials and Technology University of Science and Technology Beijing Key Laboratory for Advanced Materials Processing(MOE) University of Science and Technology Beijing

Lotus-type porous copper was fabricated by unidirectional solidification, and compressive experiments were subsequently conducted in the strain rate range of 10-3-2400 s-1 with the compressive direction parallel to the pores. A GLEEBLE-1500 thermal-mechanical simulation system and a split Hopkinson pressure bar （SHPB） were used to investigate the effect of strain rate on the compressive deforma-tion behaviors of lotus-type porous copper. The influence mechanism of strain rate was also analyzed by the strain-controlling method and by high-speed photography. The results indicated that the stress-strain curves of lotus-typed porous copper consist of a linear elastic stage, a plateau stage, and a densification stage at various strain rates. At low strain rate （〈1.0 s^-1）, the strain rate had little influence on the stress-strain curves; but when the strain rate exceeded 1.0 s^-1, it was observed to strongly affect the plateau stage, showing obvious strain-rate-hardening characteristics. Strain rate also influenced the densification initial strain. The densification initial strain at high strain rate was less than that at low strain rate. No visible inhomogeneous deformation caused by shockwaves was observed in lotus-type porous copper during high-strain-rate deformation. However, at high strain rate, the bending deformation characteristics of the pore walls obviously differed from those at low strain rate, which was the main mechanism by which the plateau stress exhibited strain-rate sensitivity when the strain rate exceeded a certain value and exhibited less densification initial strain at high strain rate.

关键词： porous materials copper directional solidification strain rate sensitivity deformation modes stress-strain curves

Circulating tumor cells:from new biological insights to clinical practice

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Signal Transduction and Targeted Therapy 2024年第10期9卷 4178-4212页

作者： Xuyu gu Shiyou Wei xin Lv Department of Oncology Shanghai Pulmonary HospitalSchool of MedicineTongji UniversityShanghaiChina Department of Anesthesiology Shanghai Pulmonary HospitalSchool of MedicineTongji UniversityShanghaiChina

The primary reason for high mortality rates among cancer patients is metastasis,where tumor cells migrate through the bloodstream from the original site to other parts of the *** advancements in technology have significantly enhanced our comprehension of the mechanisms behind the bloodborne spread of circulating tumor cells(CTCs).One critical process,DNA methylation,regulates gene expression and chromosome stability,thus maintaining dynamic equilibrium in the *** hypomethylation and locus-specific hypermethylation are examples of changes in DNA methylation patterns that are pivotal to *** comprehensive review first provides an overview of the various processes that contribute to the formation of CTCs,including epithelial-mesenchymal transition(EMT),immune surveillance,and *** then conduct an in-depth analysis of how modifications in DNA methylation within CTCs impact each of these critical stages during CTC dissemination.

关键词： mortality metastasis insight

A Coupled Thermomechanical Crack Propagation Behavior of Brittle Materials by Peridynamic Differential Operator

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 339-361页

作者： Tianyi Li xin gu Qing Zhang College of Architectural Engineering Jiangsu Open UniversityNanjing210036China Department of Engineering Mechanics Hohai UniversityNanjing211100China

This study proposes a comprehensive,coupled thermomechanical model that replaces local spatial derivatives in classical differential thermomechanical equations with nonlocal integral forms derived from the peridynamic differential operator(PDDO),eliminating the need for calibration *** model employs a multi-rate explicit time integration scheme to handle varying time scales in multi-physics *** simulations conducted on granite and ceramic materials,this model demonstrates its *** successfully simulates thermal damage behavior in granite arising from incompatible mineral expansion and accurately calculates thermal crack propagation in ceramic slabs during *** account for material heterogeneity,the model utilizes the Shuffle algorithm andWeibull distribution,yielding results that align with numerical simulations and experimental *** coupled thermomechanical model shows great promise for analyzing intricate thermomechanical phenomena in brittle materials.

关键词： Peridynamic differential operator thermomechanical coupling heterogeneity numerical simulation

A practical iterative two-view metric reconstruction with uncalibrated cameras

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1614-1623页

作者： ZHOU Yong-jun KOU xin-jian School of Naval Architecture. Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

This paper presents a practical iterative algorithm for two-view metric reconstruction without any prior knowledge about the scene and motion in a nonsingular geometry configuration. The principal point is assumed to locate at the image center with zero skew and the same aspect ratio, and the interior parameters are fixed, so the self-calibration becomes focal-length cali- bration. Existing focal length calibration methods are direct solutions of a quadric composed of fundamental matrix, which are sensitive to noise. A quaternion-based linear iterative Least-Square Method is proposed in this paper, and one-dimensional searching for optimal focal length in a constrained region instead of solving optimization problems with inequality constraints is applied to simplify the computation complexity, then unique rotational matrix and translate vector are recovered. Experiments with simulation data and real images are given to verify the algorithm.

关键词： Close-range photogrammetry Computer vision General relative orientation Unit quaternion Metric reconstruction

Tau in Alzheimer’s Disease:Pathological Alterations and an Attractive Therapeutic Target

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Current Medical Science 2020年第6期40卷 1009-1021页

作者： jian-lan gu Fei LIU Department of Biochemistry and Molecular Biology School of MedicineNantong UniversityNantong 226001China Key Laboratory of Neuroregeneration and Ministry of Education of jiangsu Co-innovation Center of NeuroregenerationNantong 226001China Department of Neurochemistry Inge Grundke-Iqbal Research FloorNew York State Institute for Basic Research in Developmental DisabilitiesStaten IslandNY 10314USA

Alzheimer’s disease(AD)is an age-related neurodegenerative disease with two major hallmarks:extracellular amyloid plaques made of amyloid-β(Aβ)and intracellular neurofibrillary tangles(NFTs)of abnormally hyperphosphorylated *** number of NFTs correlates positively with the severity of dementia in AD ***,there is still no efficient therapy available for AD treatment and prevention so far.A deeper understanding of AD pathogenesis has identified novel strategies for the generation of specific therapies over the past few *** studies have suggested that the prion-like seeding and spreading of tau pathology in the brain may be a key driver of *** protein is considered as a promising candidate target for the development of therapeutic interventions due to its considerable pathological role in a variety of neurodegenerative *** tau hyperphosphorylation plays a detrimental pathological role,eventually leading to *** the present review,we describe the recent research progresses in the pathological mechanisms of tau protein in AD and briefly discuss tau-based therapeutic strategies.

关键词： Alzheimer’s disease tau protein hyperphosphorylation propagation of tau pathology

Study on dynamic response of multi-degree-of-freedom explosion vessel system under impact load

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Defence Technology（防务技术） 2020年第4期16卷 777-786页

作者： Yun-hao Hu Wen-bin gu jian-qing Liu Jing-lin Xu xin Liu Yang-ming Han Zhen-xiong Wang College of Field Engineering Army Engineering University of PLANanjing 210007China Unit No.78102 of PLA Chengdu 610031China Unit No.31696 of PLA Jinzhou 121017China Research Institute of Chemical Defense Beijing 102205China

In order to study the dynamic response and calculate the axial dynamic coefficient of the monolayer cylindrical explosion vessel,the wall of vessel is simplified as a multi-degree-of-freedom(MDoF) undamped elastic foundation *** the coupled motion equation and using Duhamel's integrals,the solutions in generalized coordinates of the equations under exponentially decaying loads,square wave loads and triangular wave loads are *** solutions are consistent in form with the solutions of single-degree-of-freedom(SDoF) undamped forced vibration simplified *** on the model,equivalent MDoF design method(also called MDoF dynamic coefficient method) of cylindrical explosion vessel is *** traditional method can only predict the dynamic coefficient of torus portion around the explosion center,but this method can predict that of the vessel wall at any axial n dividing point *** is verified that the prediction accuracy of this model is greatly improved compared with the SDoF model by comparing the results of this model with SDoF model and numerical simulation in different working ***,the prediction accuracy decreases as the scaled distance decreases and approaches the end of the vessel,which is related to the accuracy of the empirical formula of the implosion load,the simplification of the explosion load direction,the boundary conditions,and the loading time difference.

关键词： Explosion vessel Dynamic response Vibration analysis Dynamic coefficient Load feature

On the correction of the boundary deficiency in SPH for the frictional contact simulation

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Science China(Technological Sciences) 2014年第1期57卷 86-100页

作者： WANG jian HUA Hui gu ChongShi National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University College of Water Conservancy and Hydropower Engineering Hohai University

Smoothed particle hydrodynamics(SPH)is a mesh-free method which is powerful for large deformation computation of ***,the algorithm for the simulation of frictional contact which is common in geotechnical engineering is still quite immature due to the boundary *** this study,the cause of boundary deficiency in the SPH simulation for frictional contact is ***,based on mathematical derivation,the method to correct boundary deficiency related to frictional contact is discussed theoretically,where the frictional contact algorithm is established by dividing the computational domain into several subdomains according to the existing contact boundaries and by using contact forces as bridges of these subdomains to fulfil problem solving,and the value of correction coefficient is obtained by comparing the SPH outcome of the contact particles with that calculated through Newton’s second law of *** the same time,from the perspective of numerical computation,an optimized value for the correction coefficient is proposed,and a thorough investigation is performed on the cubic spline kernel function and quintic spline kernel function,whose correction coefficients are found to be 2.0 and[2.0,2.16],***,numerical tests are carried out to verify the proposed *** outcome of the study is helpful to providing theoretical support for the research of frictional contact simulation within the framework of SPH.

关键词： smoothed particle hydrodynamics (SPH) frictional contact boundary deficiency correction