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Focusing on the Focus： What Else beyOnd the Master Switches for Polar Cell Growth？

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Molecular Plant 2015年第4期8卷 582-594页

作者： yuan qin Juan dong Center for Genomics and Biotechnology College of Crop Science Fujian Agriculture and Forestry University Fuzhou 350002 Fujian Province China Waksman Institute of Microbo ogy Rutgers the State University of New Jersey Piscataway NJ 08854 LISA The Department of Plant Biology and Pathology Burgers the State University of New Jersey New Brunswick NJ 08901 USA

Cell polarity, often associated with polarized cell expansion/growth in plants, describes the uneven distribution of cellular components, such as proteins, nucleic acids, signaling molecules, vesicles, cytoskeletal elements, and organelles, which may ultimately modulate cell shape, structure, and function. Pollen tubes and root hairs are model cell systems for studying the molecular mechanisms underlying sustained tip growth. The formation of intercalated epidermal pavement cells requires excitatory and inhibitory pathways to coordinate cell expansion within single cells and between cells in contact. Strictly controlled cell expansion is linked to asymmetric cell division in zygotes and stomatal lineages, which require integrated processes of pre-mitotic cellular polarization and division asymmetry. While small GTPase ROPs are recognized as fundamental signaling switches for cell polarity in various cellular and developmental processes in plants, the broader molecular machinery underpinning polarity establishment required for asymmetric division remains largely unknown. Here, we review the widely used ROP signaling pathways in cell polar growth and the recently discovered feedback loops with auxin signaling and PIN effluxers. We discuss the conserved phosphorylation and phospholipid signaling mechanisms for regulating uneven distribution of proteins, as well as the potential roles of novel proteins and MAPKs in the polarity establishment related to asymmetric cell division in plants.

关键词： cell expansion cytoskeleton polarity polarity determination signal transduction

Characterization of Nanocrystalline Intermetallic Compound NiAl Synthesized by Condensation

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Journal of Materials Science & Technology 1996年第6期12卷 461-463页

作者： qin, y.qin, Xy Zhang, LD Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

Nanocrystalline intermetallic compound NiAl was synthesized by evaporating NiAl master alloy in inert-gas followed by in situ compaction, and its structure was studied by means of X-ray diffractometry and transmission electron microscope. Experimental results reveal that the as-synthesized nanocrystalline sample has a mean grain size of less than 10 nm and it is dominantly composed of the cubic structure phase NiAl. However, nanocrystalline Ni3Al as a trace phase mixed in NiAl phase, was also detected by transmission electron microscope observation.

关键词： Intermetallics

A multi-scale model for CO_(2) sequestration enhanced coalbed methane recovery

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Frontiers of Chemical Science and Engineering 2009年第1期3卷 20-25页

作者： G.X.WANG X.R.WEI V.RUDOLPH C.T.WEI y.qin School of Engineering University of QueenslandSt Lucia Qld 4072Australia School of Resources and Geoscience China University of Mining&TechnologyXuzhou 221008China

This paper presents a multi-scale model to simulate the multicomponent gas diffusion andﬂow in bulk coals for CO_(2) sequestration enhanced coalbed methane *** model is developed based on a bi-dispersed structure model by assuming that coal con-sists of microporous micro-particles,meso/macro-pores and open *** bi-disperse diffusion theory and the Maxwell-Stefan approach were incorporated in the model,providing an improved simulation of the CH4-CO_(2)/CH4-N2 counter diffusion *** the model,the counter diffusion process is numerically coupled with theﬂow of the mixture gases occurring within macro-pores or fractures in coal so as to account for the interaction between diffusion andﬂow in gas transport through *** model was validated by both experimental data from literature and our CO_(2)ﬂush tests,and shows an excellent agreement with the *** results reveal that the gas diffusivities,in particular the micro-pore diffusivities are strongly concentration-dependent.

关键词： multi-scale model gas transport coal coalbed methane CO_(2)sequestration

Parallelization strategies for resolved simulations of fluid-structure-particle interactions

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 857-872页

作者： Jianhua qin Fei LIAO Guodan dong Xiaolei yANG The State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China Interdisciplinary Center for Fundamental and Frontier Sciences Nanjing University of Science and TechnologyJiangyin 214443Jiangsu ProvinceChina School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China

Fluid-structure-particle interactions in three spatial dimensions happen in many environmental and engineering *** paper presents the parallel algorithms for the hybrid diffuse and sharp interface immersed boundary(IB)method developed in our previous *** the moving structure modeled using the sharp interface IB method,a recursive box method is developed for efficiently classifying the background grid *** the particles modeled using the diffuse interface IB method,a‘master-slave’approach is *** the particle-particle interaction(PPI)and particle-structure interaction(PSI),a fast algorithm for classifying the active and inactive Lagrangian points,which discretize the particle surface,is developed for the‘dry’contact *** results show that the proposed recursive box method can reduce the classifying time from 52seconds to 0.3 *** parallel efficiency is obtained for cases with different particle ***,the lubrication model is utilized when a particle approaches a wall,enabling an accurate simulation of the rebounding phenomena in the benchmark particle-wall collision *** last,the capability of the proposed computational framework is demonstrated by simulating particle-laden turbulent channel flows with rough walls.

关键词： particle-resolved direct numerical simulation particle-laden flow complex geometry resolved fluid-structure-particle interaction(RFSPI) immersed boundary(IB)method

Two-layer formation-containment fault-tolerant control of fixed-wing UAV swarm for dynamic target tracking

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1375-1396页

作者： qin Boyu ZHANG dong TANG Shuo XU yang School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Aerospace Flight Vehicle Design Key Laboratory Xi’an 710072China School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072China

This paper tackles the formation-containment control problem of fixed-wing unmanned aerial vehicle(UAV)swarm with model uncertainties for dynamic target tracking in three-dimensional space in the faulty case of UAVs’actuator and *** fixed-wing UAV swarm under consideration is organized as a“multi-leader-multi-follower”structure,in which only several leaders can obtain the dynamic target information while others only receive the neighbors’information through the communication *** simultaneously realize the formation,containment,and dynamic target tracking,a two-layer control framework is adopted to decouple the problem into two subproblems:reference trajectory generation and trajectory *** the upper layer,a distributed finite-time estimator(DFTE)is proposed to generate each UAV’s reference trajectory in accordance with the control ***,a distributed composite robust fault-tolerant trajectory tracking controller is developed in the lower layer,where a novel adaptive extended super-twisting(AESTW)algorithm with a finite-time extended state observer(FTESO)is involved in solving the robust trajectory tracking control problem under model uncertainties,actuator,and sensor *** proposed controller simultaneously guarantees rapidness and enhances the system’s robustness with fewer chattering ***,corresponding simulations are carried out to demonstrate the effectiveness and competitiveness of the proposed two-layer fault-tolerant cooperative control scheme.

关键词： fixed-wing unmanned aerial vehicle(UAV)swarm two-layer control formation-containment dynamic target tracking

GGC:Gray-Granger Causality Method for Sensor Correlation Network Structure Mining on High-Speed Train

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Tsinghua Science and Technology 2022年第1期27卷 207-222页

作者： Jie Man Honghui dong Limin Jia yong qin the State Key Laboratory of Rail Traffic Control and Safety and Beijing Research Center of Urban Traffic Information Sensing and Service TechnologiesBeijing Jiaotong UniversityBeijing 100044China

Vehicle information on high-speed trains can not only determine whether the various parts of the train are working normally,but also predict the train’s future operating *** to obtain valuable information from massive vehicle data is a difficult ***,we divide the vehicle data of a high-speed train into 13 subsystem datasets,according to the functions of the collection ***,according to the gray theory and the Granger causality test,we propose the Gray-Granger Causality(GGC)model,which can construct a vehicle information network on the basis of the correlation between the collection *** using the complex network theory to mine vehicle information and its subsystem networks,we find that the vehicle information network and its subsystem networks have the characteristics of a scale-free *** addition,the vehicle information network is weak against attacks,but the subsystem network is closely connected and strong against attacks.

关键词： vehicle information network structure mining gray theory Granger causality theory complex network theory high-speed train

Preparation of nano-compounded polyolefin materials through in situ polymerization technique:status quo and future prospects

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Chinese Science Bulletin 2009年第1期54卷 38-45页

作者： qin yaWei dong Jinyong CAS Key Laboratory of Engineering Plastics and Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Nano-compounding of polyolefins,an economical yet very effective route to high-performance poly-olefin materials,has received considerable attention in recent years. Unlike most of the other polymers,polyolefins are chemically inert,which dictates that nano-compounding of polyolefins has to be con-ducted via in situ polymerization. In this review,a technological progress of the nano-compounding of polyolefins via in situ polymerization technique was summarized thoroughly,with emphasis laid on the current research status of polyolefin/montmorillonite (MMT) nanocomposites. A clear perspective for future researches on this specific family of materials was envisaged.

关键词：聚烯烃纳米复合材料聚合反应蒙脱石

Influence of Metal Material Properties on Heat and Mass Transfer into Thermal Protection Surface with Phenomenological Catalytic Model

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Journal of Thermal Science 2023年第3期32卷 993-1006页

作者： LI qin yANG Xiaofeng dong Wei DU yanxia School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000China

Surface heterogeneous catalysis in a high-enthalpy dissociated environment leads to a remarkable enhancement of aerodynamic heating into the thermal protection surface of hypersonic *** more accurately predict this catalytic heating,a kinetic catalytic model was *** model involved four elementary reactions,the rates of which were determined on mean-field approximation and surface steady-state reaction *** coupling this model into the viscous wall boundary condition of computational fluid dynamics(CFD)solver,the influences of metal material catalytic properties on heat and mass transfer into thermal protection materials were numerically *** results showed that atomic oxygen recombination catalyzed by surface material accounts for a major contribution to aerodynamic heating and thus variation in recombination rates from different materials leads to the significant difference in surface heat *** a comparative analysis of various materials,the catalytic activity increases from the inert platinum(Pt)to nickel(Ni)and finally to the active copper(Cu).As a result,the catalytic heating on Cu surface was more than twice of that on Pt *** parametrical research revealed that the proper layout of inert material at the nose of aircraft could prevent stagnation catalytic heating from thermal damage by carrying near-wall dissociated atoms from the stagnation zone *** material-relied heterogeneous catalysis mechanism in this study provides some technical support for the thermal protection system design of hypersonic aircraft.

关键词： aerodynamic heating chemical non-equilibrium flow heterogeneous catalysis phenomenological model high-temperature interface effects

Investigation on halogen-doped n-type SnTe thermoelectrics

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Rare Metals 2022年第11期41卷 3803-3814页

作者： Chang-Rong Guo Bing-Chao qin dong-yang Wang Li-dong Zhao School of Materials Science and Engineering Beihang UniversityBeijing100191China

Recent theoretical predictions and experimental findings on the transport properties of n-type SnTe have triggered extensive researches on this simple binary compound,despite the realization of n-type SnTe being a great ***,Cl as a donor dopant can effectively regulate the position of Fermi level in Sn_(0.6)Pb_(0.4)Te matrix and successfully achieve the n-type transport behavior in *** outstanding power factor of~14.7μW·cm^(-1)·K^(-2) at 300 K was obtained for Cl-doped Sn_(0.6)Pb_(0.4)Te *** combining the experimental analysis with theoretical calculations,the transport properties of n-type SnTe thermoelectrics doped with different halogen dopants(Cl,Br,and I)were then systematically investigated and *** results demonstrated that Br and I had better doping efficiencies compared with Cl,which contributed to the well-optimized carrier concentrations of~1.03×10^(19)and~1.11×10^(19)cm^(-3)at 300 K,*** improved n-type carrier concentrations effectively lead to the significant enhancement on the thermoelectric performance of n-type *** study further promoted the experimental progress and deep interpretation of the transport features in n-type SnTe *** present results could also be crucial for the development of n-type counterparts for SnTe-based thermoelectric devices.

关键词： Thermoelectric performance n-type SnTe Halogen doping Doping efficiency