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Numerical Investigation of Inlet Distortion on an Axial Flow Compressor Rotor with Circumferential Groove Casing Treatment

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Chinese Journal of Aeronautics 2008年第6期21卷 496-505页

作者： huang Jian wu hu School of Power and Energy Northwestern Polytechnieal University Xi' an 710072 China

On the base of an assumed steady inlet circumferential total pressure distortion, three-dimensional time-dependent numerical simulations are conducted on an axial flow subsonic compressor rotor. The performances and flow fields of a compressor rotor, either casing treated or untreated, are investigated in detail either with or without inlet pressure distortion. Results show that the circumferential groove casing treatment can expand the operating range of the compressor rotor either with or without inlet pressure distortion at the expense of a drop in peak isentropic efficiency. The casing treatment is capable of weakening or even removing the tip leakage vortex effectively either with or without inlet distortion. In clean inlet circumstances, the enhancement and forward movement of tip leakage vortex cause the untreated compressor rotor to stall. By contrast, with circumferential groove casing, the serious flow separation on the suction surface leads to aerodynamic stalling eventually. In the presence of inlet pressure distortion, the blade loading changes from passage to passage as the distorted inflow sector is traversed. Similar to the clean inlet circumstances, with a smooth wall casing, the enhancement and forward movement of tip leakage vortex are still the main factors which lead to the compressor rotor stalling eventually. When the rotor works trader near stall conditions, the blockage resulting from the tip leakage vortex in all the passages is very serious. Especially in several passages, flow-spillage is observed. Compared to the clean inlet circumstances, circumferential groove casing treatment can also eliminate the low energy zone in the outer end wall region effectively.

关键词： axial flow compressor inlet distortion casing treatment aerodynamic stability numerical simulation

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Microstructure evolution of an ultra-high strength metal alloy with tempering temperature

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Rare Metals 2012年第5期31卷 442-445页

作者： wu Sujun hu Bin HAN Bo School of Materials Science and Engineering Beijing University of Aeronautcs and Astronautics Beijing 100191 China

Optical microscopy (OM) and transmission electron microscopy (TEM) were used to investigate the effect of tempering temperature on the experimental extra-high carbon steels. It is found that tempering reaction can reduce austenite content and influence the stability of the austenite. As-normalized microstructure is a mixture of twinned martensite and retained austenite. Tempered at 250 °C for 2 h, lath martensite can occasionally be found nearby the diffusionally decomposed austenite area. It also is found that tempering at 650 °C for 2 h, nanoparticles of carbides precipitate in the martensite and decomposed austenite. © The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg 2012.

关键词： Austenite Carbides Carbon steel High strength alloys Martensite Microstructure Optical microscopy Transmission electron microscopy

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Effect of forging temperature on the microstructures and mechanical properties of the SiC_p/AZ91 magnesium matrix composite

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Acta Metallurgica Sinica(English Letters) 2010年第2期23卷 99-105页

作者： Kun wu Kunkun DENG Hai CHANG Yewei wu Xiaoshi hu Mingyi ZHENG School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

In this paper, 10 vol. pct SiCp/AZ91 magnesium matrix composite was fabricated by stir casting technology. The ingots were forged at temperatures of 320, 370 and 420 ℃, respectively. XRD, OM and SEM were used to characterize microstructure of the＇composites. It was shown that the clusters of particles in the as-cast composite were largely eliminated, and that the tensile strength was improved obviously.

关键词： Magnesium matrix composite Forging Mechanical properties

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A Study of Surfactant-Induced Growth of Ag on Ag (111)

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Communications in Theoretical Physics 2008年第12期50卷 1439-1442页

作者： wu Li-Li hu Juan-Mei wu Feng-Min College of Mathematics and Physics Information Engineering Zhejiang Normal University Jinhua 321004 China

A new growth model is introduced to describe surfactant-induced growth of Ag on Ag （111） with realistic physical parameters. In this model, the A-S exchange mechanism is considered for the first time. Using the Monte Carlo simulations, the influence of exchange mechanism, surface temperature T, the exchange barrier Eεx, and the coverage of surfactant θM on the growth mode and morphology during multilayer film growth of Ag/Ag （111） are studied in detail Both the referenced value of surfactant coverage and the method to obtain perfect layer-by-layer film in surfactantinduced Ag/Ag （111） system are provided. Our simulation results are consistent with many experimental observations for surfactant-induced growth of Ag on Ag （111）.

关键词： surfactant surface roughness exchange Monte Carlo simulation

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Multi-view recognition of fruit packing boxes based on features clustering angle

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High Technology Letters 2021年第2期27卷 200-209页

作者： Li Xinning wu hu Yang Xianhai School of Mechanical Engineering Shandong Universily of TechnologyZibo 255000P.R.China

In order to realize the intelligent mechanization of the last process of the fruit industry chains,the identification of fruit packing boxes is researched.A multi-view database is established to describe the omnidirectional attitudes of the fruit packing *** order to reduce the data redundancy caused by multi-view acquisition,a new binary multi-view kernel principal component analysis network(BMKPCANet) is built,and a multi-view recognition method of fruit packing boxes is proposed based on the BMKPCANet and support vector machine(SVM).The experimental results show that the recognition accuracy of proposed BMKPCANet is 12.82% higher than PCANet and3.51% higher than KPCANet on *** time consumption of proposed BMKPCANet is 7.74%lower than PCANet and 29.01% lower than KPCANet on *** work has laid a theoretical foundation for multi-view recognition of 3 D objects and has a good practical application value.

关键词： boxes recognition kernel principal component analysis(KPCA) binary hashing and clustering multi-view clustering(MVC)

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Nonepitaxial growth of a (001) textured L1_0 Fe-Pt film in H_2 and N_2 annealing atmospheres

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Rare Metals 2006年第3期25卷 260-264页

作者： wu Peiwen hu Xuerang QIAN Jun YUAN Jun Electron Microscope Laboratory Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

A nonepitaxial （001） textured Fe-Pt alloyed film was obtained by annealing Fe/Pt multilayers in H2. No Such nonepitaxial （001） texture was observed for similar multilayers annealed in N2 atmosphere. Sensitive electron energy loss spectroscopy and the left shift of the L10 FePt （111） diffr cfion peak indicate oxidation in the N2 annealed samples. The oxidation dramatically degrades the （001） texture of the Fe-Pt fdm and induces the composition change in the alloyed layer. The relation between the texture formation and oxidation was discussed.

关键词： metal (001) textured FePt annealing oxidation shift of diffraction peak

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Model optimization method and connected-pipe experiment of a liquid fuel ramjet engine

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航空动力学报 2013年第6期28卷 1277-1285页

作者： MA Qian-rong GUO Xin wu hu CHOU Qian School of Power and Energy Northwest Polytechnical University Aero-Engine Altitude Simulated Key Laboratory China Gas Turbine EstablishmentAviation Industry Corporation of China

The optimization method of a mathematical model and connected-pipe experimental technique for a test in altitude test facility (ATF) of a liquid fuel ramjet engine was *** optimization of the simple mathematical model was divided into two ***,using the test engine's geometry configuration size data,a preliminary adjustment was ***,using experimental test data,the components' experiential coefficients were modified *** was laid on the simulation technique of flight condition and parameters measurement *** experimental technique was applied to a ramjet ATF test *** comparison results show that the optimized-model has higher precision and the nozzle gross thrust difference drops from 12% to about 4%.

关键词： ramjet engine model optimization altitude test facility(ATF) connected-pipe experiment simulation technique

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Synthesis and Crystal Structure of a Co(II) Complex with Schiff Base and Imidazole Ligand

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Chinese Journal of Structural Chemistry 2006年第5期25卷 567-571页

作者： wu Lian-Bin hu Zi-Qiang LAI Guo-Qiao Key Laboratory of Organosilicon Chemistry and Material Technology of Education Ministry Hangzhou Teachers University Hangzhou 310012 China

The title compound, [Co（C3H4N2）2（C22H18N2O4）]·5H2O （Mr = 659.56）, has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n, a = 9.6808（2）, b = 26.7204（5）, c = 12.7993（3） A, β = 100.9340（10）°, V= 3250.75（12） A^3, Z = 4, Dc = 1.348 g/cm^3,μ = 0.586 mm^-1, F（000） = 1380, S = 1.131, R = 0.0689 and wR = 0.1883 for 4782 observed reflections （Ⅰ 〉 2σ（Ⅰ））. The title crystal consists of Co（Ⅱ） complex and lattice water molecules. The Co（Ⅱ） complex assumes a distorted octahedral coordination geometry, formed by one Schiff base dianion phenylenediamine-3-methoxysali-cylaldehyde and two imidazole ligands. The π-π stacking interaction occurs between nearly parallel benzene rings of the neighboring complexes.

关键词： cobalt(Ⅱ) complex Schiff base crystal structure π-π stacking

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Simple method to rapidly fabricate chain-like carbon nanotube films and its field emission properties

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 371-375页

作者： Zhi-yuan wu Shuang-qi hu Zhi-qian Wang Chemical Industry and Ecology Institute North University of China Taiyuan 030051 China

A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.

关键词： carbon nanotube (CNT) chain-like film microwave plasma-enhanced chemical vapor deposition (MPCVD) field emission

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RELATIONSHIP OF FIRST STEP HEIGHT,STEP SLOPE AND CAVITY IN X-SHAPED FLARING GATE PIERS

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Journal of Hydrodynamics 2007年第3期19卷 349-355页

作者： WANG Bo wu Chao hu Yao-hua MO Zheng-yu State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China.

The energy dissipation of X-shaped flaring gate piers ahead of a stepped spillway was adopted in the Suofengying Hydroplant. Under the circumstance that the first step is higher than others, at the step surface an aerated cavity occured behind piers. The interaction of the weir head, the elevation difference between crest and chamber outlet, the first step height, the slopes of weir end and step, and the size of cavity, was investigated, the expression was derived to characterize their relationship, and the corresponding curves were plotted. The comparison of the calculated and simulated results with the measured data was performed. When the slopes of step and weir end are equivalent, the relative height difference between the first and second steps becomes the main factor influencing the aerated cavity. These findings may be useful in practical applications.

关键词： X-shaped flaring gate pier first step height slope of weir end step slope size of cavity

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