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Cellular response to titanium discs coated with polyelectrolyte multilayer films

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International Journal of Minerals,Metallurgy and Materials 2014年第9期21卷 925-933页

作者： Jing Zhan Qiao-jie luo Ying Huang Xiao-dong Li Department of Stomatology Sir Run Run Shaw Hospital College of Medicine Zhejiang University Department of Oral and Maxillofacial Surgery the Affiliated Stomatology Hospital College of Medicine Zhejiang University

The purpose of this study was to investigate the effects ofpolyelectrolyte multilayer （PEM） coatings on the biological behavior of titanium （Ti） substrates. Collagen type I/hyaluronic acid （Col/HA） and chitosan/hyaluronic acid （Chi/HA） multilayer PEM coatings were introduced onto Ti substrates using layer-by-layer assembly. Contact angle instruments and quartz crystal microbalance were used for film characterization. The results obtained showed that both Col/HA and Chi/HA surfaces had high hydrophilicity and promoted cell adhesion in MC3T3-E1 pre-osteoblast and human gingival fibroblast cells. In addition, the synthesis of function-related proteins and gene expression levels in both MC3T3-E1 and fibroblast cells was higher for the Col/HA coating compared with the Chi/HA coating, indicating better cellular response to the Col/HA coating.

关键词： titanium surface modification polyelectrolytes multilayer films cellular response

Electrically manipulating magnetization reversal via energy band engineering

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Science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 181-187页

作者： Junwei Tong Yanzhao Wu Feifei luo Fubo Tian Xianmin Zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität BerlinBerlin 14195Germany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Realization of a magnetization reversal by an external electric field is vital for developing ultra-low-power spintronic *** this report,starting from energy band engineering,a general design principle is proposed for achieving electrical manipulation of a nonvolatile 180°magnetization reversal.A half semiconductor(HSC)and a bipolar magnetic semiconductor(BMS)are selected as the model of magnetic layers,whose conduction-band minimum and valence-band maximum are in the same and opposite spin states,*** on the analysis of virtual hopping and tight-binding models,the interlayer coupling of HSC/insulator/BMS devices is successfully tuned between ferromagnetic and antiferromagnetic interactions by varying electric field ***,the interlayer coupling nearly disappears after removing the electric field,proving the nonvolatile magnetization *** first-principles calculations,the feasibility of present design strategy is further confirmed by a representative device with the structure of CrBr3/h-BN/2H-VSe_(2).This design guideline and physical phenomena may open an avenue to explore magnetoelectric coupling mechanisms and develop next-generation spintronic devices.

关键词： magnetic semiconductor magnetization reversal energy band engineering

Molecular dynamics simulation of cylindrical Richtmyer-Meshkov instability

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Science China(Physics,Mechanics & Astronomy) 2018年第11期61卷 61-71页

作者： Zhenhong Wu Shenghong Huang Juchun Ding Weirong Wang Xisheng luo Department of Modern Mechanics University of Science and Technology of China

The microscopic-scale Richtmyer-Meshkov(RM) instability of a single-mode Cu-He interface subjected to a cylindrically converging shock is studied through the classical molecular dynamics simulation. An unperturbed interface is first considered to examine the flow features in the convergent geometry, and notable distortions at the circular inhomogeneity are observed due to the atomic fluctuation. Detailed processes of the shock propagation and interface deformation for the single-mode interface impacted by a converging shock are clearly captured. Different from the macroscopic-scale situation, the intense molecular thermal motions in the present microscale flow introduce massive small wavelength perturbations at the single-mode interface, which later significantly impede the formation of the roll-up structure. Influences of the initial conditions including the initial amplitude,wave number and density ratio on the instability growth are carefully analyzed. It is found that the late-stage instability development for interfaces with a large perturbation does not depend on its initial amplitude any more. Surprisingly, as the wave number increases from 8 to 12, the growth rate after the reshock drops gradually. The distinct behaviors induced by the amplitude and wave number increments indicate that the present microscopic RM instability cannot be simply characterized by the amplitude over wavelength ratio(η). The pressure history at the convergence center shows that the first pressure peak caused by the shock focusing is insensitive to η, while the second one depends heavily on it.

关键词： molecular dynamics simulation Richtmyer-Meshkov instability converging shock

Object-Based Classification Method for PolSAR Images with Improved Scattering Powers and Contextual Features

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Chinese Journal of Electronics 2017年第4期26卷 803-809页

作者： YUAN zhengwu CHEN Ran CHEN Cuiping luo Xiaobo LIU Minghao College of computer science and technology Chongqing University of Posts and Telecommunications

This paper proposes a new object-based classification method for Polarimetric synthetic aperture radar(Pol SAR) images, which considers scattering powers from an improved model-based polarimetric decomposition approach, as well as the spatial and textural features. With the decomposition, the scattering ambiguities between oriented buildings and vegetation are reduced. Furthermore,various contextual features are extracted from the object and incorporated into the K-nearest neighbors(k-NN)based classification. To reduce the feature redundancy, a new Supervised locally linear embedding(S-LLE) dimensionality reduction method is introduced to map the high dimensional polarimetric signatures into the most compact low-dimensional structure for classification. Experimental results with Airborne synthetic aperture rada(AIRSAR)C-band Pol SAR image demonstrate the superior performance to other methods.

关键词： Object-based Polarimetric decomposi tion Contextual features Supervised locally linear embed ding(S-LLE) Polarimetric synthetic aperture radar(PolSAR)

Evaluation of simulation-based training for aircraft carrier marshalling with learning cubic and Kirkpatrick's models

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Chinese Journal of Aeronautics 2015年第1期28卷 152-163页

作者： Tian Yongliang Liu Hu Yin Jiao luo Mingqiang Wu Guanghui School of Aeronautic Science and Engineering Beihang University Chengdu Aircraft Design Institute Commercial Aircraft Corporation of China Ltd.

Simulation-based training is a promising way to train a carrier flight deck crew because of the complex and dangerous working environment. Quantitative evaluation of simulation-based training quality is vital to make simulation-based training practical for aircraft carrier *** paper develops a personal computer-based aircraft carrier marshalling simulation system and a cave automatic virtual environment（CAVE）-based immersive environment. In order to compare the training effectiveness of simulation-based training and paper-based training, a learning cubic model is proposed and a contrast experiment is carried out as well. The experimental data is analyzed based on a simplified Kirkpatrick＇s model. The results show that simulation-based training is better than paper-based training by 26.80% after three rounds of testing, which prove the effectiveness of simulation-based aircraft carrier marshalling training.

关键词： aircraft cubic dangerous simplified questionnaire vital train deviation pyramid judge

Dynamic temperature prediction of electronic equipment under high altitude long endurance conditions

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Chinese Journal of Aeronautics 2018年第6期31卷 1189-1197页

作者： Liping PANG Miao ZHAO Kun luo Yongli YIN Zhou YUE School of Aeronautic Science and Engineering Beihang University Beijing 100083 China National Key Laboratory of Human Factors Engineering China Astronaut Research and Training Center Beijing 100094 China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration. Nanjing 211102 China

Unmanned Aerial Vehicle（UAV） is developing towards the direction of High Altitude Long Endurance（HALE）. This will have an important influence on the stability of its airborne electronic equipment using passive thermal management. In this paper, a multi-node transient thermal model for airborne electronic equipment is set up based on the thermal network method to predict their dynamic temperature responses under high altitude and long flight time conditions. Some relevant factors are considered into this temperature prediction model including flight environment,radiation, convection, heat conduction, etc. An experimental chamber simulating a high altitude flight environment was set up to survey the dynamic thermal responses of airborne electronic equipment in a UAV. According to the experimental measurement results, the multi-node transient thermal model is verified without consideration of the effects of flight speed. Then, a modified way about outside flight speed is added into the model to improve the temperature prediction performance. Finally, the corresponding simulation code is developed based on the proposed model. It can realize the dynamic temperature prediction of airborne electronic equipment under HALE conditions.

关键词： Airborne electronic equipment High altitude long endurance Multi-node transient thermal model Node thermal network Temperature prediction

CFD simulation with enhancement factor of sulfur dioxide absorption in the spray scrubber

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1601-1613页

作者： Xiang GAO Wang HUO Zhong-yang luo Ke-fa CEN State Key Laboratory of Clean Energy Utilization Institute for Thermal Power Engineering Zhejiang University Hangzhou 310027 China

A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A con- tinuous concentration change of H+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value of pH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.

关键词： SO2 absorption Limestone dissolution Enhancement factor Mass transfer Concentration profile

Simultaneous manipulations of thermal expansion and conductivity in symbiotic ScTaO_(4)/SmTaO_(4) composites via multiscale effects

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Journal of Advanced Ceramics 2023年第8期12卷 1625-1640页

作者： Lin Chen Jiankun Wang Baihui Li Keren luo Jing Feng Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

Effective manipulations of thermal expansion and conductivity are significant for improving operational performances of protective coatings,thermoelectric,and *** work uncovers determinant mechanisms of the thermal expansion and conductivity of symbiotic ScTaO_(4)/SmTaO_(4) composites as thermal/environmental barrier coatings(T/EBCs),and we consider the effects of interface stress and thermal *** weak bonding and interface stress among composite grains manipulate coefficient of thermal expansion(CTE)stretching from 6.4×10^(−6) to 10.7×10^(−6) K^(−1) at 1300℃,which gets close to that of substrates in T/EBC *** multiscale effects,including phonon scattering at the interface,mitigation of the phonon speed(vp),and lattice point defects,synergistically depress phonon thermal transports,and we estimate the proportions of different *** interface thermal resistance(R)reduces the thermal conductivity(k)by depressing phonon speed and scattering phonons because of different acoustic properties and weak bonding between symbiotic ScTaO_(4) and SmTaO_(4) ceramics in the *** study proves that CTE of tantalates can be artificially regulated to match those of different substrates to expand their applications,and the uncovered multiscale effects can be used to manipulate thermal transports of various materials.

关键词： thermal management coefficient of thermal expansion(CTE) interface thermal resistance(R) thermal stress(σ) thermal/environmental barrier coatings(T/EBCs)

Metal salts with highly electronegative cations as efficient catalysts for the liquid-phase nitration of benzene by NO2 to nitrobenzene

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Frontiers of Chemical Science and Engineering 2017年第2期11卷 205-210页

作者： Shenghui Zhou Kuiyi You zhengming Yi Pingle Liu Hean luo School of Chemical Engineering Xiangtan University Xiangtan 411105 China National & Local United Engineering Research Center for Chemical Process Simulation and Intensification Xiangtan University Xiangtan 411105 China

Metal salts with highly electronegative cations have been used to effectively catalyze the liquid-phase nitration of benzene by NO2 to nitrobenzene under solventfree conditions. Several salts including FeCl3, ZrCl4, AlCl3, CuCl2, NiCl2, ZnCl2, MnCl2, Fe（NO3）3-9H2O, Bi （NO3）3·5H2O, Zr（NO3）4-SH2O, Cu（NO3）2.6H2O, Ni （NO3）2·6H2O, Zn（NO3）2·6H2O, Fe2（SO4）3, and CuSO4 were examined and anhydrous FeCl3 exhibited the best catalytic performance under the optimal reaction conditions. The benzene conversion and selectivity to nitrobenzene were both over 99%. In addition, it was determined that the metal counterion and the presence of water hydrates in the salt affects the catalytic activity. This method is simple and efficient and may have potential industrial application prospects.

关键词： metal salts electronegativity nitrobenzene NO2 catalytic nitration