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High-performance phosphate supported on HZSM-5 catalyst for dehydration of glycerol to acrolein

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1031-1040页

作者： Feng Zhang Xin Ren He huang jun huang Medak Sudhakar Licheng Liu Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences

The purpose of this study is to increase acrolein yield and capability of coking resistance in the reaction of glycerol dehydration to acrolein by assembling metal phosphate supported on HZSM-5 catalyst. The as-prepared catalysts were characterized by XRD, SEM, EDS, BET, NH_3-TPD, CO_2-TPD and Py-IR techniques. It was found that metal phosphate species were incorporated into the porous structure of HZSM-5 zeolites, thus influencing the surface and textural physico-chemical properties of the supporters. The alkaline-treated HZSM-5 catalyst promoted the dispersion of phosphate species on the carriers. Moreover, the amount of strong acidity was tremendously improved by adding the different metal hydrophosphates and the catalysts show high catalytic activity. In this present work, the Sn1/4 H_2PO_4/HZSM-5 catalyst exhibited good performance in the catalytic activity and coking resistant ability, which resulted in a high acrolein yield of 83% initially and acrolein yield of 68% after 30 h. The acidity, especially the ratio of strong to weak acid, plays an important role in promoting acrolein yield and stability simultaneously.

关键词： JHZSM-5 Metal hydrophosphate Glycerol dehydration Coking resistance

Influence of aircraft surface distribution on electromagnetic scattering characteristics

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Chinese Journal of Aeronautics 2017年第2期30卷 759-765页

作者： Liu Dawei huang jun Song Lei Ji Jinzu School of Aeronautic Science and Engineering Beihang University Beijing 100083 China

In this paper,two typical stealth aircraft concepts（wing fuselage blended and flyingwing） were *** three gradually changed surface distribution models with the same planform for each concept were *** on the multilevel fast multipole algorithm（MLFMA）,the vertical polarization transmitting/vertical polarization receiving（VV） and horizontal polarization transmitting/horizontal polarization receiving（HH） radar cross section（RCS） characteristics were simulated with five frequencies between 0.1 and 1.0 *** influences and mechanisms of aircraft surface distribution on electromagnetic scattering characteristics were *** results show that for the wing fuselage blended concept,the W RCS of this frequency range is higher than the HH RCS in most cases,while it is just the opposite for the flying-wing *** for the two aircraft concepts,the RCS levels of HH and W both decrease with the frequency increasing,but the HH RCS has a faster downward *** surface distribution has little influence on HH RCS *** the contrary,it has a significant impact on W RCS characteristics,and the amplitude of the VV RCS increases with the surface thickness.

关键词： Aircraft concept Electromagnetic scattering characteristic Horizontal polarization MLFMA Stealth Surface distribution Vertical polarization

Analysis of the Flow Rate Characteristics of Valveless Piezoelectric Pump with Fractal-like Y-shape Branching Tubes

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 628-634页

作者： huang jun ZHANG Jianhui WANG Shouyin LIU Weidong State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences

Microchannel heat sink with high heat transfer coefficients has been extensively investigated due to its wide application prospective in electronic cooling. However, this cooling system requires a separate pump to drive the fluid transfer, which is uneasy to minimize and reduces their reliability and applicability of the whole system. In order to avoid these problems, valveless piezoelectric pump with fractal-like Y-shape branching tubes is proposed. Fractal-like Y-shape branching tube used in microchannel heat sinks is exploited as no-moving-part valve of the valveless piezoelectric pump. In order to obtain flow characteristics of the pump, the relationship between tube structure and flow rate of the pump is studied. Specifically, the flow resistances of fractal-like Y-shape branching tubes and flow rate of the pump are analyzed by using fractal theory. Then, finite element software is employed to simulate the flow field of the tube, and the relationships between pressure drop and flow rate along merging and dividing flows are obtained. Finally, valveless piezoelectric pumps with fractal-like Y-shape branching tubes with different fractal dimensions of diameter distribution are fabricated, and flow rate experiment is conducted. The experimental results show that the flow rate of the pump increases with the rise of fractal dimension of the tube diameter. When fractal dimension is 3, the maximum flow rate of the valveless pump is 29.16 mL/min under 100 V peak to peak （13 Hz） power supply, which reveals the relationship between flow rate and fractal dimensions of tube diameter distribution. This paper investigates the flow characteristics of valveless piezoelectric pump with fractal-like Y-shape branching tubes, which provides certain references for valveless piezoelectric pump with fractal-like Y-shape branching tubes in application on electronic chip cooling.

关键词： piezoelectric pump valveless fractal-like Y-shape branching tube

Linear random search and engineering estimation of sinkage for launching carrier aircraft

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Science China(Technological Sciences) 2019年第6期62卷 996-1002页

作者： ZHONG Guo huang jun ZHOU ZeYang YI MingXu School of Aeronautic Science and Engineering Beijing University of Aeronautics and Astronautics

A linear random search algorithm(LRSA) is developed to determine the critical value of takeoff weight limited to the safe flight track sinkage and an engineering estimation method(EEM) is proposed to calculate the sinkage of carrier aircraft launch in real time. Based on the analysis of free flight after leaving the carrier, the equations are established to participate into engineering estimation of flight track sinkage. Thanks to the proposed search algorithm, the maximum takeoff weight of carrier aircraft with safe catapult launch flight track sinkage is generated in few steps. The results of sinkage estimation and the search algorithm are in good agreement with that of aircraft catapult launch simulation. The main contribution of this manuscript is the establishment of simple and accurate engineering estimation for carrier aircraft launch flight track sinkage and the development of robust and efficient search algorithm for the critical value with safe catapult criteria.

关键词： carrier aircraft launch flight track sinkage engineering estimation linear random search simulation

3D FEM Analyses on Flow Field Characteristics of the Valveless Piezoelectric Pump

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Chinese Journal of Mechanical Engineering 2016年第4期29卷 825-831页

作者： huang jun ZHANG Jianhui SHI Weidong WANG Yuan National Research Center of Pumps Jiangsu University School of Mechanical and Electric Engineering Guangzhou University State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics College of Communication Engineering PLA University of Science and Technology

Due to the special transportation and heat transfer characteristics,the fractal-like Y-shape branching tube is used in valveless piezoelectric pumps as a no-moving-part ***,there have been little analyses on the flow resistance of the valveless piezoelectric pump,which is critical to the performance of the valveless piezoelectric pump with fractal-like Y-shape branching *** field of the piezoelectric pump is analyzed by the finite element method,and the pattern of the velocity streamlines is revealed,which can well explain the difference of total flow resistances of the piezoelectric ***,simplified numerical method is employed to calculate the export flow rate of piezoelectric pump,and the flow field of the piezoelectric pump is *** FEM computation shows that the maximum flow rate is 16.4 m L/*** with experimental result,the difference between them is just 55.5%,which verifies the FEM *** reasons of the difference between dividing and merging flow resistance of the valveless piezoelectric pump with fractal-like Y-shape branching tubes are also investigated in this *** proposed research provides the instruction to design of novel piezoelectric pump and a rapid method to analyse the pump flow rate.

关键词： piezoelectric pump valveless fractal-like Y-shape branching tube FEM

Theory and Experimental Verification on Valveless Piezoelectric Pump with Multistage Y-shape Treelike Bifurcate Tubes

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Chinese Journal of Mechanical Engineering 2013年第3期26卷 462-468页

作者： huang jun ZHANG Jianhui XUN Xianchao WANG Shouyin State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Precision Driving Laboratory Nanjing University of Aeronautics and Astronautics State Key Lab of Digital Manufacturing Equipment & Technology Huazhong University of Science and Technology Foundation Department Aviation University of Air Force Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences

Among most traditional piezo water cooling systems, piezoelectric valve pumps are adopted as their driving sources. The valves in these pumps induce problems of shock and vibration and also make their structure complicated, which is uneasy to minimize and reduce their reliability and applicability of the whole system. In order to avoid these problems caused by valve structure, a novel valveless piezoelectric pump is developed, which integrates both functions of transforming and cooling. The pump’s Y-shape tree-like construction not only increases the efficiency of cooling but also the system reliability and applicability. Firstly, a multistage Y-shape treelike bifurcate tube is proposed, then a valveless piezoelectric pump with multistage Y-shape treelike bifurcate tubes is designed and its working principle is analyzed. Then, the theoretical analysis of flow resistance characteristics and the flow rate of the valveless piezoelectric pump are performed. Meanwhile, commercial software CFX is employed to perform the numerical simulation for the pump. Finally, this valveless piezoelectric pump is fabricated, the relationship between the flow rates and driving frequency, as well as the relationship between the back pressure and the driving frequency are experimentally investigated. The experimental results show that the maximum flow rate is 35.6 mL/min under 100 V peak-to-peak voltage (10.3 Hz) power supply, and the maximum back pressure is 55 mm H2O under 100 V (9 Hz) power supply, which validates the feasibility of the valveless piezoelectric pump with multistage Y-shape treelike bifurcate tubes. The proposed research provides certain references for the design of valveless piezoelectric pump and improves the reliability of piezo water cooling systems.

关键词： piezoelectric pump valveless Y-shape tube treelike bifurcate

A recursive model for static empty container allocation

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Frontiers of Computer Science 2011年第4期5卷 486-495页

作者： Zijian GUO Wenyuan WANG Guolei TANG jun huang Faculty of Infrastructure Engineering Dalian University of Technology Dalian 116023 China Transport Planning and Research Institute Ministry of Communications Beijing 100028 China

Backlogged empty containers have gradually turned into a serious burden to shipping networks. Empty container allocation has become an urgent settlement issue for the container shipping industry on a global scale. Therefore, this paper proposes an improved immune algorithm based recursive model for optimizing static empty container allocation which integrates with the global maritime container shipping network. This model minimizes the operating and capital costs during container shipping considering 0-1 mixed-integer programming. So an immune algorithm procedure based on a special two- dimensional chromosome encoding is proposed. Finally, computational experiments are performed to optimize a 10-port static empty container shipping system. The results indicate that the proposed recursive model for static empty container allocation is effective in making an optimal strategy for empty container allocation.

关键词： immune algorithm shipping network emptycontainer allocation

Prediction models of burst strength degradation for casing with considerations of both wear and corrosion

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Petroleum Science 2024年第1期21卷 458-474页

作者： Jie-Li Wang Wen-jun huang De-Li Gao MOE Key Laboratory of Petroleum Engineering China University of PetroleumBeijing102249China State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China

Casing wear and casing corrosion are serious problems affecting casing integrity failure in deep and ultra-deep *** paper aims to predict the casing burst strength with considerations of both wear and ***,the crescent wear shape is simplified into three categories according to common mathematical ***,based on the mechano-electrochemical(M-E)interaction,the prediction model of corrosion depth is built with worn depth as the initial condition,and the prediction models of burst strength of the worn casing and corroded casing are ***,the accuracy of different prediction models is validated by numerical simulation,and the main influence factors on casing strength are *** last,the theoretical models are applied to an ultra-deep well in Northwest China,and the dangerous well sections caused by wear and corrosion are predicted,and the corrosion rate threshold to ensure the safety of casing is *** results show that the existence of wear defects results in a stress concentration and enhanced M-E interaction on corrosion depth *** accuracy of different mathematical models is different:the slot ring model is most accurate for predicting corrosion depth,and the eccentric model is most accurate for predicting the burst strength of corroded *** burst strength of the casing will be overestimated by more than one-third if the M-E interaction is neglected,so the coupling effect of wear and corrosion should be sufficiently considered in casing integrity evaluation.

关键词： Deep well Casing integrity Casing wear Casing corrosion Burst strength

Energy harvester array using piezoelectric circular diaphragm for rail vibration

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Acta Mechanica Sinica 2014年第6期30卷 884-888页

作者： Wei Wang Rong-Jin huang Chuan-jun huang Lai-Feng Li State Key Laboratory of Technologies in Space Cryogenic Propellants Technical Institute of Physics and ChemistryChinese Academy of Sciences

Generating electric energy from mechanical vibration using a piezoelectric circular membrane array is presented in this *** electrical characteristics of the functional array consisted of three plates with varies tip masses are examined under dynamic *** an optimal load resistor of 11 k,an output power of 21.4 m W was generated from the array in parallel connection at 150 Hz under a pre-stress of 0.8 N and a vibration acceleration of9.8 m/***,the broadband energy harvesting using this array still can be realized with different tip *** obvious output power peaks can be obtained in a frequency spectra of 110 Hz to 260 *** results show that using a piezoelectric circular diaphragm array can increase significantly the output of energy compared with the use of a single *** by optimizing combination of tip masses with piezoelectric elements in array,the frequency range can be tuned to meet the broadband *** array may possibly be exploited to design the energy harvesting for practical applications such as future high speed rail.

关键词： Energy harvesting Array Piezoelectric material Rail vibration