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复形范畴的两个函子

湖北大学学报(自然科学版) 1988年第2期 1-8页

作者：邓宏钧胡耀华湖北大学数学系

本文构造了复形范畴的两个函子Hom与,它们类似于模范畴中相应的函子,在此基础上利用长正合列定理证明了几个长正合列的图形交换性。

关键词：正合列定理交换图复形范畴函子

Kinetic models of peroxidase activity in potato leaves infected with late blight based on hyperspectral data

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International Journal of Agricultural and Biological Engineering 2019年第2期12卷 160-165页

作者： Qinyu Li yaohua hu College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100China Key Laboratory of Agricultural Internet of Things Ministry of AgricultureYangling 712100China Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service Yangling 712100China

Potato late blight,which is caused by Phytophthorainfestans(Mont.)de Bary,is a worldwide devastating disease for *** decreased yields of potato and caused unpredictable losses all over the *** simple statistical methods and forecasting models have been developed to predict and manage potato late ***,there is a rising need to develop prediction models reflecting peroxidase(POD)activity,which is an important health index that varies with infection and correlated with stress resistance in ***,the aim of this research was to develop kinetic models to predict POD ***-induced changes in potato leaves stored in an artificial climate chest at 25°C were analyzed using *** prediction models were developed by using linear partial least squares(PLS)and nonlinear support vector machine(SVM)methods based on the full spectrum and effective *** effective wavelengths were selected by the successive projection algorithm(SPA).In this study,the prediction model developed by means of SPA-SVM method obtained the best performance,with a Rp(correlation coefficient of prediction)value of 0.923 and a RMSEp(root mean square error of prediction)value of ***-order kinetics models according to the prediction model were developed,and late blight disease can be predicted using this *** study provided a theoretical basis for the prediction of latencies of late blight.

关键词： POD(peroxidase)activity kinetic model potato leaves late blight hyperspectral data latency prediction

Application of modified quartz crystal sensors:Detection of isobutyl alcohol,ethyl acetate and ethylene

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International Journal of Agricultural and Biological Engineering 2014年第5期7卷 71-77页

作者： Hou Juncai hu yaohua Guo Kangquan College of Mechanical and Electronic Engineering Northwest A&F UniversityYangling 712100China

Aroma volatilization is one of the very important attributes of agricultural products during *** of aroma compounds experience changes over products’different ripening *** paper aimed to develop a detection system based on modified quartz crystal sensors to detect volatile organic compounds(VOCs).By drop-coating on sensors’surface,four sensors were made using quartz crystal resonators coated with four different absorbable materials:ethyl cellulose,cellulose acetate,1,2-dioleoyl-sn-glycero-3-[phosphor-L-serine],and galactosyl *** the diversely coated sensors,three VOCs:isobutyl alcohol,ethyl acetate and ethylene were detected at ppm *** investigate the structure influence of the coated sensing films on VOCs absorption,the topography of films was imaged in 3D using atomic force microscopy(AFM)in tap mode for qualitative analysis of gas *** selectivity and sensitivity were investigated when sensors were exposed to VOCs with increasing *** results showed that the frequency shift of sensors was linear to the concentrations of all three VOCs in the range of 5-25 *** values reaching over 4.5 Hz/ppm,the sensitivity of cellulose acetate coated sensor to three VOCs was similar,higher than that of sensors with other *** high sensitivity of the cellulose acetate coated sensor might be due to the film’s rough surface and porous *** results may help further research on detection of fruits’organic volatiles during the ripening stage.

关键词： quartz crystal sensor atomic force microscopy detection selectivity sensitivity volatile organic compounds

A study on boundary integral equations for dynamic elastoplastic analysis for the plane problem by TD-BEM

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Acta Mechanica Sinica 2021年第4期37卷 662-678,I0003页

作者： hongjun Li Weidong Lei Rui Chen Qiang hu Urban and Rural Construction Institute Hebei Agricultural UniversityBaoding 071001China School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China China Academy of Railway Sciences Corporation Limited Beijing 100081.China

The equivalent stress fundamental solution for the elastoplastic dynamic plane strain problem is proposed to transform the virtual work in the third direction to the ***,based on Betti reciprocal theorem,by adopting the time dependent fundamental solutions in terms of displacement,traction and equivalent stress,the boundary integral equations for dynamic elastoplastic analysis for the plane strain problem are *** establishment procedures for the displacement and the stress boundary integral equations,together with the stress equation at boundary points,are presented in details,while the standard discretization both in time and space under the frame of time domain boundary element method(TD-BEM)and the solution of the algebraic equations are also briefly *** verification examples are presented from different viewpoints,for elastic and elastoplastic analysis,for 1-D and 2-D geometries,and for finite and infinite *** TD-BEM formulation for dynamic elastoplastic analysis is presented for the plane strain problem as an example,where the formulation is also applicable for the plane stress problem by properly transforming the elastic constants and adopting the corresponding fundamental solutions.

关键词： Time domain boundary element method Dynamic elastoplastic analysis Equivalent stress fundamental solution Boundary integral equation

Effects of heat treatment on the microstructure and mechanical properties of ZA84 magnesium alloy

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Journal of University of Science and Technology Beijing 2008年第6期15卷 747-752页

作者： Mingbo Yang Liang Bai Fusheng Pan hongjun hu School of Materials Science and Engineering Chongqing Institute of Technology Chongqing 400050 China School of Materials Science and Engineering Chongqing University Chongqing 400030 China

The effects of heat treatment on the microstructure and mechanical properties of ZA84 （Mg-8Zn-4Al-0.25Mn） alloy were investigated. The results indicate that the as-cast microstructure of the alloy is mainly composed of α-Mg matrix and two different morphologies of precipitates （continuous and quasi-continuous Mg32（Al,Zn）49 phases and isolated Mg5Al2Zn2 phases）. After solid solution treatment at 345℃, the Mg32（Al,Zn）49 phases change from continuous and quasi-continuous net to disconnected acute angle shape, and parts of second phases sphericize. The optimum heat treatment condition for the alloy is solution treatment at 345℃ for 48 h and water quenching, then aging treatment at 200℃ for 12 h and atmosphere cooling. Under the optimum condition, the ulti- mate tensile strength and yield strength of the alloy can be imoroved, but the elongation is not effected much bv heat treatment.

关键词： ZA84 magnesium alloy heat treatment microstructure mechanical properties precipitates

Analysis of the cracks formation on surface of extruded magnesium rod based on numerical modeling and experimental verification

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Acta Metallurgica Sinica(English Letters) 2009年第5期22卷 353-364页

作者： hongjun hu Dingfei ZHANG Fusheng PAN Mingbo YANG College of Materials Science and Engineering Chongqing University Chongqing 400045 China National Engineering Research Center for Magnesium Alloys Chongqing 400044 China College of Material Science and Engineering Chongqing University of Technology Chongqing 400050 China

To reduce the surface cracks of extrusion rod for AZ31 magnesium caused by nonhomogeneous metal flow in extrusion process, 3D computer finite element （FE） simulations of extruding a wrought magnesium alloy AZ31 into rods have been performed and the results have been verified in extrusion experiments under identical conditions. The tendency to generate the dead zone is decreased by employing the die angle 60° at the cone-shaped die comparing with the die angle 180°. The surface additional tensile stresses of the rod at the die exit are decreased greatly so that the surface cracks caused are avoided by using the die angle 60°. The extrusion die with die angle 180° would increase the higher temperature rise and possibility of crack formation on the rod surface that caused by die angle 60° and temperature rise decrease tensile strength of the AZ31 rod. The experimental results show that die angle 180° could cause continuous cracks on the surface of the extruded rod. The extrusion force required is reduced approximately 15 ton by employing the die angle 60°. Theoretical results obtained by the DeformTM-3D simulation agreed well with the experiments. The obtained results provide the fundamental and also practical guidelines for the design and correction of dies to produce magnesium rod with good surface quality.

关键词： Extrusion Finite element Magnesium alloy Cracks Experimental validation

Effect of Electropulsing on Recrystallization and Mechanical Properties of Silicon Steel Strips

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Journal of Materials Science & Technology 2011年第11期27卷 1034-1038页

作者： Guoliang hu yaohua Zhu Guoyi Tang Chanhung Shek Iianan Liu Materials Department and Advanced Materials Institute Tsinghua University Shenzhen 518055 China Department of Industrial and Systems Engineering Hong Kong Polytechnic University Kowloon Hong Kong China Department of Physics and Materials Science City University of Hong Kong 83 Tat Chee Avenue Kowloon Tong Honk Kong China

Electropulsing-induced recrystallization and its effect on mechanical properties of oriented silicon steel strips （Fe-3.0%Si） were studied by optical microscopy, scanning electron microscopy and electron back-scatter diffraction. The results indicated that electropulsing accelerated recrystallization, and decreased the temperature of recrystallization. Electropulsing favors refinement of the grain structure of the alloy. Effects of electropulsing on strength and elongation of the alloy were discussed from the point view of dislocation dynamics, microstructural changes, and electropulsing kinetics.

关键词： Recrystallization Electropulsing Oriented silicon steel strip

Nitrogen removal and simultaneous nitrification and denitrification in a fluidized bed step-feed process

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Journal of Environmental Sciences 2012年第2期24卷 303-308页

作者： BingWang Wei Wang hongjun Han Hongbo hu Haifeng Zhuang State Key Laboratory of Urban Water Resources and Environment （SKLUWRE） Harbin Institute of Technology Harbin 150090 China Municipal ＆ Environmental Engineering College Shenyang Jianzhu University Shenyang 110168 China School of Civil and Hydraulic Engineering Hefei University of Technology Hefei 230009 China

For urban wastewater treatment,we conducted a novel four-stage step-feed wastewater treatment system combined with a fluidized bed laboratory experiment to investigate chemical oxygen demand（COD）,NH4＋-N,and total nitrogen（TN） removal *** removal rates of COD,NH4＋-N and TN were 88.2%,95.7%,and 86.4% with e？uent concentrations of COD,NH4＋-N and TN less than 50,8,and 10 mg/L,*** and bacterial activities were also measured,with results showing more nitrobacteria in the activated sludge than in the biofilm;however,bacterial activity of the biofilm biomass and the activated sludge were *** concentrations during the process were also detected,with simultaneous nitrification and denitrification found to be obvious.

关键词： denitrification fluidized bed step-feed simultaneous nitrification and denitrification

Taxonomy and ultrastructure of five species of Tetraselmis (Prasinophyceae) isolated from China seas

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Acta Oceanologica Sinica 2002年第4期21卷 557-579页

作者： Zhang Chengwu hu hongjun The Key Laboratory of Molecular Medical Biotechnology College of Life SciencesNanjing Normal UniversityNanjing 210097China Wuhan Institute of Botany Chinese Academy of SciencesWuhan 430074China

Comparative ultrastructural investigations on twenty-three isolates of Tetraselmis from the South China Sea, East China Sea and huanghai Sea, have revealed that these isolates belong to:(1)Tetraselmis chui Butcher; (2)T. cordiformis (H. J. Carter) Stein; (3)T. helgolandica Kylin; (4)T. suecica (Kylin) Butcher; (5)T. guangdongensis sp. nov. Except T. helgolandica, the others are new records in China. T. guangdongensis sp. nov. is a new species. Its external and anatomical features closely resemble those of T. impellucida McLachlan et Parke. As in that species the pyrenoid is penetrated from many directions by cytoplasmic channels delimited by a double membrane. The protoplast withdraws from the apical portion of the theca, that portion which overlaid the trough inverts and pops out in the form of a teat. But unlike that species a starch sheath is present; pyrenoid matrix is surrounded by thylakoids which intervenes between the matrix and the starch sheath surrounding pyrenoid; the theca is stratified.

关键词： Taxonomy ultrastructure Tetraselmis pyrenoid