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Microstructural characteristics and deformation of magnesium alloy AZ31 produced by continuous variable cross-section direct extrusion

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Journal of Materials Science & Technology 2017年第6期33卷 573-579页

作者： hongwei jiang Feng Li Xiang Zeng School of Materials Science and Engineering Harbin University of Science and Technology

Magnesium（Mg） alloy AZ31 was produced by continuous variable cross-section direct extrusion（CVCDE）to study its deformation behavior. Metallographic microscopy（OM）, transmission electron microscopy（TEM）, and scanning electron microscopy（SEM） were used to observe the variations in microstructure and fracture morphology of Mg alloy AZ31 as a function of processing methods. The results reveal that grains of Mg alloy AZ31 were refined and their microstructure was homogenized by CVCDE. The recrystallization in Mg alloy AZ31 produced by CVCDE with 2 interim dies was more complete than that produced by conventional extrusion（CE） and CVCDE with 1 interim die, and the grains were finer and more *** of the AZ31 alloy was improved. Fracture mode was evolved from a combination of ductility and brittleness to a sole ductile form. In summary, a CVCDE mold structure with 2 interim dies can improve microstructure, plasticity, and toughness of Mg alloy AZ31.

关键词： Continuous variable cross-section direct extrusion(CVCDE) Magnesium alloys Microstructural characteristics Plastic deformation

Enzymatic Promiscuity：＂Amano＂ Lipase AS-catalysed Synthesis of Naphthopyran Derivatives in Anhydrous Media

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Chemical Research in Chinese Universities 2014年第3期30卷 396-399页

作者： jiang Ling YU hongwei Department of Chemical and Biological Engineering Zhejiang University Hangzhou 310007 P. R. China

＂Amano＂ lipase AS（lipase from Aspergillus niger）, which naturally hydrolyzes triglycerides, was found promiscuously to catalyze multi-component reactions of aromatic aldehydes with malononitrile and β-naphthol to... 详细信息

关键词： "Amano" lipase AS Catalytic promiscuity Multi-component reaction Naphthopyran derivative

Enzymatic Promiscuity： Escherichia coli BioH Esterase-catalysed Aldol Reaction and Knoevenagel Reaction

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Chemical Research in Chinese Universities 2014年第2期30卷 289-292页

作者： jiang Ling YU hongwei Department of Chemical and Biological Engineering Zhejiang University Hangzhou 310007 P.R.China

Esterase BioH,which is obligatory for biotin synthesis in Escherichia coli,was found to exhibit a promiscuous ability to catalyse Aldol and Knoevenagel reactions with moderate to good *** reaction conditions including organic solvent,molar ratio of ketone to aldehyde,enzyme amount,and reaction time were investigated to evaluate the effect of different reaction conditions on *** compounds were afforded in the best yield of 91.2％ for Aldol reaction and 54.7％ for Knoevenagel *** addition,because the enzyme could be prepared with a low cost,this protocol could provide an economic route to conduct Aldol and Knoevenagel reactions,which expand the field of enzymatic promiscuity.

关键词： Escherichia coli BioH esterase Catalytic promiscuity Aldol reaction Knoevenagel reaction

Bayesian synthetic evaluation of multistage reliability growth with instant and delayed fix modes

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1287-1294页

作者： Yan Zhiqiang Li Xinxin Xie hongwei jiang Yingjie Coll. of Mechatronic Engineering and Automation National Univ. of Defense Technology Changsha 410073 P. R. China

In the multistage reliability growth tests with instant and delayed fix modes, the failure data can be assumed to follow Weibull processes with different parameters at different stages. For the Weibull process within a stage, by the proper selection of prior distribution form and the parameters, a concise posterior distribution form is obtained, thus simplifying the Bayesian analysis. In the multistage tests, the improvement factor is used to convert the posterior of one stage to the prior of the subsequent stage. The conversion criterion is carefully analyzed to determine the distribution parameters of the subsequent stage＇s variable reasonably. Based on the mentioned results, a new synthetic Bayesian evaluation program and algorithm framework is put forward to evaluate the multistage reliability growth tests with instant and delayed fix modes. The example shows the effectiveness and flexibility of this method.

关键词： reliability growth Bayesian analysis improvement factor multistage test Weibull process

Numerical Simulation of Magnetic Pressure in Tube-electromagnetic Bulging with Die

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Journal of Materials Science & Technology 2003年第Z1期19卷 129-132页

作者： hongwei jiang Chunfeng LI Haiping YU Zhiheng ZHAO School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Calculation of magnetic pressure is the basis of application of electromagnetic forming (EMF). This paper carries out a numerical simulation of magnetic pressure under the influence of die by means of finite element method. The analysis model of electromagnetic bulging with die is created by using ANSYS, and the distribution of magnetic pressure acting on the tube and the die is obtained. The differences between EMF and other technologies and the effect of die on tube formability are analyzed. The die has important influence upon the calculation accuracy. The simulating conclusions with different discharge energy and current frequency are verified through the technologic tests. The distribution of magnetic pressure acting on the tube agrees well with the measurements of the deformed tube.

关键词： Electromagnetic bulging, Numerical simulation, Magnetic pressure, Deformation

Microstructure evolution and mechanical anisotropy of M50 steel ball bearing rings during multi-stage hot forging

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Chinese Journal of Aeronautics 2021年第11期34卷 254-266页

作者： hongwei jiang Yanran SONG Yucheng WU Debin SHAN Yingying ZONG National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China AECC Harbin Bearing Co. LtdHarbin 150070China

This study aimed to explore the evolution of flow lines and microstructures of M50-steel bearing ring and the anisotropy of its tensile mechanical properties after Multi-Stage Hot Forging(MSHF) and subsequent spheroidizing annealing(MSHFA). To this end, the present study mainly employed stereo microscopy, Optical Metallurgical Microscopy(OMM), Scanning Electron Microscopy(SEM), and Electron Backscatter Diffraction(EBSD) to characterize and analyze the workpiece at each processing stage of MSHF while performing microhardness measurement and uniaxial tensile experiment to test and analyze the mechanical properties of the workpiece. Macro-structure observation showed that the simulation results of flow lines at each stage were consistent with the experimental results. Microscopic observation showed that, after MSHF, deformation gradually became less significant along the outward radial direction of the bearing ring. After MSHFA,the microstructures of the bearing ring became uniform, whereas primary carbides did not *** mechanical properties were better in the axial direction(AD) than in the radial(RD) and circumferential directions(CD) after MSHF due to the smaller grain width. After MSHFA, the mechanical properties in the ADs and CDs were better than those in the RDs, which was due to the large cross-sectional area of carbides along the flow-line direction.

关键词： Bearing ring Flow lines Forging Mechanical anisotropy Microstructure evolution

Revolutionizing tumor immunotherapy:unleashing the power of progenitor exhausted T cells

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Cancer Biology & Medicine 2024年第6期21卷 499-512页

作者： Zhang Fang Xinyi Ding Hao Huang hongwei jiang Jingting jiang Xiao Zheng Department of Tumor Biological Treatment The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China jiangsu Engineering Research Center for Tumor Immunotherapy The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China Institute for Cell Therapy of Soochow University The Third Affiliated Hospital of Soochow UniversityChangzhou 213003China

In exploring persistent infections and malignancies, a distinctive subgroup of CD8^(+) T cells, progenitor exhausted CD8^(+) T(Tpex) cells, has been identified. These Tpex cells are notable for their remarkable self-renewal and rapid proliferation abilities. Recent strides in immunotherapy have demonstrated that Tpex cells expand and differentiate into responsive exhausted CD8^(+) T cells, thus underscoring their critical role in the immunotherapeutic retort. Clinical examinations have further clarified a robust positive correlation between the proportional abundance of Tpex cells and enhanced clinical prognosis. Tpex cells have found noteworthy applications in the formulation of inventive immunotherapeutic approaches against tumors. This review describes the functions of Tpex cells in the tumor milieu, particularly their potential utility in tumor immunotherapy. Precisely directing Tpex cells may be essential to achieving successful outcomes in immunotherapy against tumors.

关键词： Progenitor exhausted CD8^(+)T cells TCF-1 immunotherapy tumor microenvironment cellular crosstalk

Relationship between Formation Water Rate,Equivalent Penetration Rate and Volume Flow Rate of Air in Air Drilling

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Petroleum Science 2007年第4期4卷 62-65页

作者： Wang Kexiong Zhang Laibin jiang hongwei School of Petroleum Engineering China University of Petroleum Beijing 102249 China School of Mechanical and Electronic Engineering China University of Petroleum Beijing 102249 China

Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during air drilling. Formation water could be circulated out of the wellbore through increasing the gas injection rate. In this paper, the Angel model was modified by introducing Nikurade friction factor for the flow in coarse open holes and translating formation water rate into equivalent penetration rate. Thus the distribution of annular pressure and the relationship between minimum air injection rate and formation water rate were obtained. Real data verification indicated that the modified model is more accurate than the Angel model and can provide useful information for air drilling.

关键词： Air drilling Angel model modified model formation water rate minimum volume flow rate equivalent penetration rate

Relationship between giant magnetoresistance of NiFe/Cu multilayers and their microstructures

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Chinese Science Bulletin 1998年第15期43卷 1268-1271页

作者： hongwei jiang Guangming Luo Zhenhong Mai Wuyan Lai Chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China

The (111)_orientated NiFe/Cu multilayers were prepared by magnetron sputtering method. At room temperature, saturation magnetoresistances of NiFe/CU multilayers oscillate as a function of Cu spacer layer thickness. Two peak GMR values of 19 4%, 11 6% and 11 2%, 1% appear, respectively, at Cu sublayer thickness of t Cu =1 0, 2 2 nm while the deposition pressures are 0 25 and 0 45 Pa. X_ray small_angle reflections and diffuse scattering at Cu K_edge (8 979 keV) by synchrotron radiation source were used to characterize the interfacial roughness. Diffraction anomalous fine_structure scattering (DAFS) was performed to investigate the local structure of NiFe and Cu sublayers. Results show that the deposition pressure has effect on interfacial roughness of the samples obviously, and the interfacial roughness also affects the GMR values of the samples strongly.

关键词： multilayer GMR synchrotron radiation interface roughness.