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Synthesis of GaPO_4-GaN Coaxial Nanowires

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Journal of Materials Science & Technology 2010年第1期26卷 15-19页

作者： Lutang Fu zhigang chen Hongtao Cong Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences 72 Wenhua Road Shenyang 110016 China

GaPO4-GaN coaxial nanowires were synthesized by two-step chemical vapor deposition method using H2 and NH3 as reactant gas in turn at 950℃. The morphology and microstructures of the GaPO4-GaN coaxial nanowires were studied by scanning elctron microscopy （SEM）, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The nanowires have an average diameter of -15 nm and length of hundreds of nanometers. The core is GaPO4 crystal and the outer shell is GaN crystal. The formation mechanism was discussed and the key factors controlling the growth are temperature and the concentration of reactant gases. These coaxial nanowires may have potential application for piezoluminescence nano-devices, and the two-step synthetic technique could be used to grow rationally other 1D GaN-based nanowire heterostructures.

关键词： GaN GAPO4 Coaxial nanowires

Experimental study on double-stage on-line jet mixing apparatus

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第3期13卷 1-19页

作者： zhigang chen Pengcheng Wang School of Electrical and Information Engineering Jiangsu University Jiangsu Province Zhenjiang 212013P.R.China JingJiang College of Jiangsu University Jiangsu Province Zhenjiang 212013 P.R.China

With the accelerated development of agricultural intelligence and mechanization,the traditional premixed pesticide mixing method has been unable to meet people’s needs for safe,environmental and efficient agricultural ***,an in-depth study on a variety of new pesticide mixing methods has been conducted at home and *** single-stage on-line jet mixing method has been increasingly used because of its advantages of safety and high efficiency,which,however,proved to have some disadvantages such as difficulty in controlling the pesticide mixing ratio and poor mixing *** this experiment,a set of double-stage online jet mixing apparatus was designed to solve some shortcomings of single-stage online jet mixing apparatus,and the influence of jet nozzle parameters in the main jet mixing apparatus and the radiation flow mixing apparatus on the final pesticide mixing effect were studied for this apparatus,and the most appropriate jet nozzle parameters were selected.

关键词： Mixing of pesticide double-stage jet jet nozzle

Special Issue on “Topological photonics and beyond:novel concepts and recent advances”

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Light(Science & Applications) 2020年第1期9卷 31-35页

作者： zhigang chen Hrvoje Buljan Daniel Leykam TEDA Applied Physics Institute and School of Physics Nankai UniversityTianjin 300457China Department of Physics and Astronomy San Francisco State UniversitySan FranciscoCA 94132USA Department of Physics Faculty of ScienceUniversity of ZagrebBijenicka cesta 3210000 ZagrebCroatia Centre for Quantum Technologies National University of Singapore3 Science Drive 2Singapore 117543Singapore

The discovery of topological phases and topological insulators has revolutionized several fields of natural science,including condensed matter physics,materials science,and *** concepts have been implemented in a variety of materials and in a broad range of wave systems ranging from electronic,atomic,photonic,plasmonic,polaritonic,to microwave,acoustic,and mechanical waves.

关键词： topological microwave condensed

Reducing energy consumption optimization selection of path transmission routing algorithm in opportunistic networks

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High Technology Letters 2015年第3期21卷 321-327页

作者：吴嘉 Yi Xi chen zhigang School of Software Central South University

Opportunistic networks are random networks and do not communicate with each other among respective communication *** situation leads to great difficulty in message *** paper proposes a reducing energy consumption optimal selection of path transmission(OSPT) routing algorithm in opportunistic *** algorithm designs a dynamic random network topology,creates a dynamic link,and realizes an optimized selected *** algorithm solves a problem that nodes are unable to deliver messages for a long time in opportunistic *** to the simulation experiment,OSPT improves deliver ratio,and reduces energy consumption,cache time and transmission delay compared with the Epidemic Algorithm and Spray and Wait Algorithm in opportunistic networks.

关键词： opportunistic networks routing algorithm deliver ratio energy consumption transmission delay cache time

Global cultivated land mapping at 30 m spatial resolution

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Science China Earth Sciences 2016年第12期59卷 2275-2284页

作者： CAO Xin chen XueHong ZHANG WeiWei LIAO AnPing chen LiJun chen zhigang chen Jin State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University National Geomatics Center of China College of Geomatics Anhui University of Science and Technology

Cultivated land is one of the most important types of land cover in the global mapping of land cover, and its variation influences economic development, food security, and ecological environment protection. Existing products of global cultivated land mapping have a low resolution, and high spatial resolution products are in demand. This study uses global remote sensing image datasets in 2000/2010 with a spatial resolution of 30 m(Landsat TM/ETM+, HJ-1), MODIS 250 m NDVI time-serial data, and many types of reference data. An three-layer extraction method based on pixels, objects, and knowledge(POK) was adopted to ease cultivated land extraction in global-scale 30 m images, i.e., cultivated land classification based on pixel-scale multi-feature optimization, cultivated land automatic identification based on objects, and interactive object processing based on information service and priori knowledge. Global 30 m cultivated land mapping was accomplished for the two reference years(2000 and 2010), and statistical analysis was conducted on the data. Results showed that the total cultivated land area was 1.903 billion ha and 1.960 billion ha, respectively. Accuracy assessments showed that overall accuracy of global cultivated land mapping are higher than 92% for both the two reference years. The global cultivated land products in 2000/2010 developed in this research are superior to their international counterparts in terms of spatial resolution and classification accuracy. They also provide significant basic data on global food security, ecological environment supervision, and global change.

关键词： Cultivated land global 30 m resolution Remote sensing mapping NDVI time series

Interfacial Bonding Strength of TiN Film Coated on Si_3N_4 Ceramic Substrate

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Journal of Materials Science & Technology 2007年第4期23卷 487-490页

作者： Dejun KONG Yongkang ZHANG zhigang chen Jinzhong LU Jiangsu Key Laboratory of Oil ＆： Gas Storage and Transportation Technology Jiangsu Polytechnic University Changzhou 213016 China Department of Materials Science and Engineering Jiangsu Polytechnic University Changzhou 213016 China School of Mechanical Engineering Jiangsu University Zhenjiang 212013 China

The fraction of TiN/Si3N4 in the cross section was observed with scanning electric microscope （SEM）, and residual stresses of TiN coated on the surface of Si3N4 ceramic were measured with X-ray diffraction （XRD）.The hardness of TiN film was measured, and bonding strength of TiN film coated on Si3N4 substrate was measured by scratching method. The formed mechanism of residual stress and the failure mechanism of the bonding interface in the film were analyzed, and the adhesion mechanism of TiN film was investigated preliminarily. The results show that residual stresses of TiN film are all behaved as compressive stress, and TiN film is represented smoothly with brittle fracture, which is closely bonded with Si3N4 substrate. TiN film has high hardness and bonding strength of about 500 MPa, which could satisfy usage requests of the surface of cutting Si3N4 ceramic.

关键词： TiN film Bonding strength X-ray diffraction (XRD) Residual stress ceramic substrate

Effect of titanium based complex catalyst and carbon nanotubes on hydrogen storage performance of magnesium

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Science China Chemistry 2013年第4期56卷 451-458页

作者： KADRI Atikah JIA Yi chen zhigang YAO XiangDong ARC Centre of Excellence for Functional Nanomaterials The University of Queensland Faculty of Chemical Engineering Universiti Teknologi Mara (UiTM) 40000 Shah Alam Selangor Queensland Microand Nanotechnology Centre (QMNC) Griffith University

Mg （MgH2）-based composites, using carbon nanotubes （CNTs） and pre-synthesized titanium based complex （TCat） as the cat- alysts, were prepared by high energy ball milling technique. The use of both catalysts demonstrated markedly improved the hydrogen storage performance, e.g. a significant increase of hydrogen release rate and decrease of desorption temperature. The synthesized composites can absorb almost 6 wt% of hydrogen within 3 min at 200 ~C and desorb 6 wt% hydrogen in 10 min at 310 ~C. The influence of CNTs and TCat on desorption temperature was also investigated by using temperature programmed desorption （TPD）. The TPD results reveal that the peak desorption temperature and the onset temperature can be lowered by 109 ~C and 155 ~C, respectively, compared to the non-catalyzed MgH2. The reaction enthalpy and entropy of hydrogen de- sorption for the synthesized MgH2-based composites are calculated by the van＇t Hoff analysis to be 73.1 kJ/mol H2 and 130.2 J/mol H2 K, respectively.

关键词： hydrogen storage magnesium hydride carbon nanotubes titanium compound catalysts mechanical milling

MICROBIOLOGICALLY INFLUENCED CORROSION ON WELD OF STAINLESS STEEL 304L

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Chinese Journal of Mechanical Engineering 1998年第2期11卷 80-85页

作者： chen, zhigang Guempel, P. Kaesser, M. Jiangsu Univ of Science and Technology China

The influence of welding defects on MIC (microbiologically influenced corrosion) was *** open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a higher level when the system was inoculated with bacteria and it decreased dramatically when MIC started. Among a series of welding defects golden heat tint was found the most susceptible to MIC. The tubercles over pitting were observed with SEM. Some elements inside of the tubercles were analysed with EDXA. Microbiological analysis of a corroded and a non-corroded sample revealed no significant difference between them with the exception of the number of the manganeseoxidising bacteria.

关键词： Microbiologically influenced corrosion Stainless steel Weld

Electromagnetic Force Balanced Single-Wheel Robot

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Chinese Journal of Electronics 2016年第3期25卷 441-447页

作者： ZHU Xiaoqing RUAN Xiaogang chen zhigang WEI Ruoyan XIAO Yao College of Electronic Information and Control Engineering Beijing University of Technology Center for Intelligent Machines McGill University

It is a challenging task to carry on the research concerning the lateral stabilization of Single wheel robot(SWR). The lateral dynamics of earlier flywheel stabilizing SWR is derived to explain the shortcomings of such a mechanism, and the recovery torque proportional to the acceleration and moment of inertia of the flywheel is proved. But as the motor being a speed server system,it is difficult to control its acceleration to actuate the flywheel to provide recovery torque for SWR; and the moment of inertia of the flywheel must be large enough to produce adequate recovery torque, which makes such a system rather cumbersome. We proposed a new mechanism to solve the problem by introducing an electromagnetic force. The proposed mechanism is described briefly, and the dynamic analyses of such a new SWR is given, then the stability analysis is also done. Three-dimensional(3D)multi-body simulation, numerical simulation and physical invented pendulum prototype experiments were conducted to verify the proposed mechanism. The experiment results verified that the proposed mechanism is feasible and have some advantages over the flywheel balanced SWR.

关键词： Single-wheel robot(SWR) Electromagnetic force Lateral stabilization mechanism Dynamic analyses Stability analysis