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Study on magnetic memory signals of medium carbon steel specimens with surface crack precut during loading process

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Rare Metals 2006年第z1期25卷 431-435页

作者： dong lihong XU Binshi dong Shiyun YE Minghui CHEN Qunzhi Basic Department Ordnance Engineering College Shijiazhuang 050003 China National Key Laboratory for Remanufacturing of Armored Force Engineering Institute Beijing 100072 China National Key Laboratory for Remanufacturing of Armored Force Engineering Institute Beijing 100072 China National Key Laboratory for Remanufacturing of Armored Force Engineering Institute Beijing 100072 China Basic Department Ordnance Engineering College Shijiazhuang 050003 China Beijing Aeronautical Technology Research Center Beijing 100076 China

Static tensile test and tensile-tensile fatigue test of medium carbon steel sheet specimens with surface crack precut were performed on MTS810 hydraulic testing machine to clear the meaning of the point of Hp(y) value zero. Magnetic memory signals were measured during the test process. The results show that only one point of Hp(y) zero value exists in all measured magnetic signal curves during the loading process, which should be a sign of intersection of positive-negative magnetic poles after magnetic ordered state appears and does not indicate the position of surface crack precut. The analysis shows that the surface crack precut can not interrupt the magnetic ordered state occurred during the test completely, hence its Hp(y) value is not zero. However, the crack extending to a penetrated defect at the instant of specimen′s fracture leads to the discontinuance of magnetic ordered state.

关键词： metal magnetic memory ferromagnetic materials surface crack precut Hp(y) zero value magnetic ordered state

EFFECT OF TENSILE STRESS AND RESIDUAL STRESS ON THE SPONTANEOUS STRAY FIELD SIGNALS FROM THE SURFACE OF 0.45%C STEEL

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Chinese Journal of Mechanical Engineering 2007年第6期20卷 29-32页

作者： dong lihong XU Binshi dong ShiYun CHEN Qunzhi WANG Dan YIN Dawei National Key Laboratory for Remanufactudng Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory TOr Remanufacturing Academy of Armored Force Engineering Beijing 100072 China Aeronautical Technology Research Center Beijing 100076 China

In order to explore the quantitative method of metal magnetic memory testing（MMMT） and clarify the relationship between Hp（y）, the normal component of spontaneous stray field, and applied stress or residual stress, the static tensile tests of 0.45%C steel sheet specimens are carried out on a servo hydraulic MTS810 machine. Hp（y） values are measured during the test process by an EMS-2003 metal magnetic memory diagnostic apparatus and a non-magnetic electric control displacement instrument. Residual stresses of some points on the surface of a specimen are measured by a Stress Tech X-Stress 3000 X-ray diffraction instrument. The results show that the same variation rules of Hp（y） value versus applied tensile stress are presented under the different conditions of load-on and load-off. However, the same rule does not exist between the Hp（y） value and residual stress. The variation of Hp（y） value reflects the history of applied tensile stress.

关键词： Metal magnetic memory Spontaneous stray field Tensile stress Residual stress

Fatigue features study on the crankshaft material of 42CrMo steel using acoustic emission

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Frontiers of Mechanical Engineering 2016年第3期11卷 233-241页

作者： Yue SHI lihong dong Haidou WANG Guolu LI Shenshui LIU School of Materials Science and Engineering Hebei University ofTechnology Tianjin 300130 China National Key Laboratory for Remanufacturing Academy of ArmoredForces Engineering Beijing 100072 China

Crankshaft is regarded as an important component of engines, and it is an important application of remanufacturing because of its high added value. However, the fatigue failure research of remanufactured crankshaft is still in its primary stage. Thus, monitoring and investigating the fatigue failure of the remanufacturing crankshaft is crucial. In this paper, acoustic emission （AE） technology and machine vision are used to monitor the four-point bending fatigue of 42CrMo, which is the material of crankshaft. The specimens are divided into two categories, namely, pre-existing crack and non-pre- existing crack, which simulate the crankshaft and crank- shaft blank, respectively. The analysis methods of para- meter-based AE techniques, wavelet transform （WT） and SEM analysis are combined to identify the stage of fatigue failure. The stage of fatigue failure is the basis of using AE technology in the field of remanufacturing crankshafts. The experiment results show that the fatigue crack propagation style is a transgranular fracture and the fracture is a brittle fracture. The difference mainly depends on the form of crack initiation. Various AE signals are detected by parameter analysis method. Wavelet threshold denoising and WT are combined to extract the spectral features of AE signals at different fatigue failure stages.

关键词： acoustic emission fatigue failure remanufac- turing crankshaft wavelet analysis

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

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Frontiers of Mechanical Engineering 2016年第3期11卷 250-257页

作者： Runbo MA lihong dong Haidou WANG Shuying CHEN Zhiguo XING National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China

This work discusses the interactive effects between every two of argon flow rate, voltage, and spray distance on in-flight particles by plasma spray and constructs models that can be used in predicting and analyzing average velocity and temperature. Results of the response surface methodology show that the interactive effects between voltage and spray distance on particle in- flight properties are significant. For a given argon flow rate, particle velocity and temperature response surface are obviously bending, and a saddle point exists. With an increase in spray distance, the interactive effects between voltage and argon flow rate on particle in-flight properties appear gradually and then weaken. With an increase in voltage, the interactive effects between spray distance and argon flow rate on particle in-flight properties change from appearing to strengthening and then to weakening.

关键词： particle velocity particle temperature interactive effects response surface

Double Constructions of Frobenius Hom-Algebras and Connes Cocycles

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Journal of Mathematical Research with Applications 2020年第6期40卷 577-595页

作者： Shuangjian GUO lihong dong School of Mathematics and Statistics Guizhou University of Finance and Economics College of Mathematics and Information Science Henan Normal University

In this paper, we give an explicit and systematic study on the double constructions of Frobenius Hom-algebras and introduce the close relations between O-operators and Homdendriform algebras. Furthermore, we study the double constructions of Connes cocycles in terms of Hom-dendriform algebras. Finally, we give a clear analogy between antisymmetric infinitesimal Hom-bialgebras and Hom-dendriform D-bialgebras.

关键词： Frobenius Hom-algebras Hom-dendriform algebras $\mathcal{O}$-operators antisymmetric infinitesimal Hom-bialgebras Hom-dendriform $D$-bialgebras

Synthesis, spectral properties of aluminum polymeric phthalocyanine carboxyl with low aggregation in aqueous solution

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Chinese Science Bulletin 2008年第20期53卷 3159-3163页

作者： ZHAO Peng NIU lihong ZHONG Cheng dong SiDa ZHANG FuShi The Key Laboratory of Organic Photoelectrons and Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China

A water soluble poly-[tetrakis-(2,3-dicarboxylate phenoxy) methyl methan] aluminum phthalocyanine (AlPPc.(COOH)x) has been synthesized from the cyclization of tetranuclear phthalonitrile and successive hydrolysis of cyano in alkaline solution. The absorption spectra showed low aggregation of this compound in pH 9.18 buffer than that of existing water soluble phthalocyanine compounds. With the addition of Triton X 100, an enhancement of fluorescence emission with quantum yield from 0.4 to 0.83 was observed; contrarily, it was thoroughly quenched by the addition of CATB in suit. A longer life time of singlet state was also detected in presence of Triton X 100. The result indicates that AlPPc.(COOH)x is desired to investigate in fluorescent probe or in fluorescence imaging diagnose.

关键词：铝酞菁染料聚合体水溶性荧光性合成

Novel Wind Power Grid-connection System Using Inductive Filtering Technology

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Chinese Journal of Electrical Engineering 2022年第3期8卷 102-111页

作者： Juan Ni Sijia Hu Yong Li Jinjie Lin Qianyi Liu Peiyao Liu lihong dong College of Electrical and Information Engineering Hunan UniversityChangsha 410082China School of Automation Central South UniversityChangsha 410083China

Herein,a novel wind power grid-connection system based on inductive filtering is proposed to improve grid-connection compatibility,and is implemented in a 50-MW real ***,the topology and wiring configuration of the proposed system are ***,an equivalent circuit and mathematical model are established to reveal the filtering characteristics and resonance damping mechanism of the proposed ***,a 50-MW wind farm-based experimental study,which is conducted to validate the effectiveness and availability of the system is *** experimental results show that the main harmonics,power factor,voltage fluctuation,and flicker satisfy national standards.

关键词： Wind power generation inductive filtering method grid-connection compatibility power quality

Discovery of possible hepatoprotective components from lychee pulp phenolic extract by online knockout methods

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Food Bioscience 2022年第6期50卷 587-593页

作者： Xuchao Jia lihong dong Yejie Wen Fei Huang Jianwei Chi Ruifen Zhang Sericultural&Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products ProcessingGuangzhou510610PR China

Lychee pulp phenolic extract (LPPE) possessed protective effects against nonalcoholic fatty liver disease (NAFLD), while the specific components concerned were unclear. In this study, twelve major components in LPPE were identified by LC-MS and prepared by on line knockout methods. Two antioxidant methods companied with hepatocyte steatosis assay were used to evaluate the contribution of twelve components to the hepatoprotective effects of LPPE. The identified components include four procyanidins and eight flavonoids, they all play active roles in the oxygen radical absorbance capacity of LPPE, while only B-type procyanidin trimer and quercetin 3-O -rutinoside-7-O -rhamnoside exert positive effects on cellular antioxidant activity of LPPE. Six components including procyanidin B2, epicatechin, two quercetin glycosides, and two procyanidin trimers are considered as contributors to lipid accumulation inhibitory effects of LPPE with B-type procyanidin trimer being identified as the main contributor. All the twelve components were recognized as hepatoprotective components against NAFLD in LPPE.

关键词： Lychee pulp phenolic extract Hepatocyte steatosis Antioxidant Online knockout

Microstructure,magnetic domain and dynamic loss of surface-textured Fe-based nanocrystalline alloy

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Journal of Materials Science & Technology 2022年第25期120卷 1-7页

作者： Aina He Jiawei Li Mingkun Wang Anding Wang Yao Xiao Yaqiang dong Hai Guo Rongrong Jiang Weixing Xia lihong dong Haidou Wang Jianya Ge CAS Key Laboratory of Magnetic Materials and Devices Zhejiang Province Key Laboratory of Magnetic Materials and Application TechnologyNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China Ningbo Zhongke B Plus New Materials Technology Co. LtdNingbo 315201China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China Jinhua Polytechnic Jinhua 321007China

Heterogeneous coarse surface crystallites induced in the industrial Fe-rich nanocrystalline alloy is an obstacle for high-frequency and high-power commercial ***,the phase,crystal orientation,nanostructure and magnetic domain evolution of the surface-crystallized Fe-rich alloy were systematically *** and inverse pole figures analysis confirms that the DOordered dendriticcrystallites bear-oriented fiber texture before and after annealing at the free surface,while ultrafine nanocrystals are randomly oriented in the interior and wheel surface after *** compared to zero magnetic-field-annealing,the transverse magnetic-field-annealing induces weakly oriented fiber texture and relatively uniform dendritic-crystallites at the surface,and uniform anisotropy in the interior and surface,which promotes smooth wall motion at the surface and magnetization rotation in the *** synergetic effect reduces the excess loss and leads reduction in dynamic loss at 1.0 T and10 kHz by 36%.

关键词： Nanocrystalline alloy Crystallization Texture Magnetic domain Dynamic loss