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Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

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Journal of Iron and Steel Research International 2004年第5期11卷 44-49页

作者： LEI jun-xiang University of Shanghai for Science and Technology

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model,the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle *** to the fracture model,the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture *** the criterion for stamping without wrinkle with that without fracture,the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping *** the stainless steel0Cr18Ni9(SUS304)sheet and the square box stamped part as examples,the limit diagram was given to predict and control the wrinkle,fracture and stamping *** is suitable for the deep drawing without flange,the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane *** limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined,and the appropriate BHF(blank holder force)and the deep-drawing force can be *** provide a reference for the technology planning,the die and mold design and the equipment determination,and a new criterion evaluating sheet stamping formability,which predicts and controls the stamping process,can be applied to the deep drawing under constant or variable BHF conditions.

关键词： regular polygonal box stamped part wrinkle fracture stamping criterion predic-tion control

An Effective Platform for SARS-CoV-2 Prevention by Combining Neutralization and RNAi Technology

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Chinese Journal of Polymer Science 2023年第3期41卷 327-333,I0005页

作者： jun-xiang Zhou Xue Yin Hao-jun Liang Department of Polymer Science and Engineering Hefei National Research Center for Physical Sciences at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) University of Science and Technology of China

At present,the coronavirus disease 2019(COVID-19)pandemic is a global health *** all over the globe are urgently looking forward to an effective solution to prevent the spread of the epidemic and avoid more casualties at an early *** this study,we establish an effective platform for the prevention of SARS-CoV-2 by combining the neutralization strategy and RNAi *** protect normal cells from infection,the customized cells are constructed to stably express viral antigenic receptor ACE2 on the cell *** modified cells are used as bait for inducing the viral *** transcription and replication activities of viral genome are intercepted subsequently by the intracellular sh RNAs,which are complementary to the viral gene fragments.A pseudotyped virus reconstructed from the HIV lentivirus is utilized as a virus model,by which we validate the feasibility and effectiveness of our strategy in *** work establishes an initial model and lays the foundation for future prevention and treatment of various RNA viruses.

关键词： SARS-CoV-2 Neutralization ACE2 RNAi Pseudotypedvirus

Recovery of PET-quenched Fluorescent Conjugated Polymers with Aza-15-crown-5 as Pendant Groups on Interaction with Ions

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Chinese Journal of Polymer Science 2014年第3期32卷 371-376页

作者：曹靖 jun-xiang Feng 吴诗 College of Chemistry Xiangtan University School of Pharmacy Hubei University of Science and Technology

Novel conjugated polymers with aza-15-crown-5 as pendant groups, P1 were synthesized by the Sonogashira coupling reaction. The polymer P1 was found to show fluorescence en-hancement response towards Ba2＋. The gradual recovery and turning-point of emission intensity of polymers appeared in the addition of Ba2＋, which provided good evidence for the fluorescence amplification mechanism of conjugated polymers.

关键词： Conjugated polymer Fluorescence recovery,

Analysis of structural response under blast loads using the coupled SPH-FEM approach

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第9期9卷 1184-1192页

作者： jun-xiang XU Xi-la LIU Department of Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

A numerical model using the coupled smoothed panicle hydrodynamics-finite element method （SPH-FEM） approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for free field explosive and the other for structural response under blast loads, are performed to model the whole processes from the propagation of the pressure wave to the response of structures. Based on the simulation, it is concluded that this model can be used for reasonably accurate explosive analysis of structures. The resulting information would be valuable for protecting structures under blast loads.

关键词： Smoothed particle hydrodynamics (SPH) Finite element method (FEM) Reinforced concrete structure Explosion

Advances in phase relationship for high Nb-containing TiAl alloys

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Rare Metals 2016年第1期35卷 15-25页

作者： Yong-Feng Liang xiang-jun Xu jun-Pin Lin State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Materials and Chemistry School Zhongyuan University of Technology

γ-TiAl alloys,including two categories（the conventional TiAl and the high Nb-containing TiAl（high Nb-TiAl））,are technologically intriguing because of their applications at high ***,the service temperature of the high Nb-TiAl alloys is 60-100℃higher than that of conventional TiAl *** developed TiAl alloys,for example TNB,TNM,β-γ alloys,belong to the high Nb-TiAl alloys,displaying similar behavior in phase transformation,strengthening,oxidation at high temperatures,and relationships between composition,microstructure,and mechanical *** work presents an in-depth review of the high Nb-TiAl alloys regarding the advances in phase diagram,formation mechanism of the new γ_1 phase,microsegregation induced by adding a high content of alloying element Nb,and the mechanism of the B2/ω phase *** challenges in developing the high Nb-TiAl alloys are also discussed.

关键词： TiAl alloy Nb addition Phase diagram Microsegregation Microstructure

Chemical mixing by turbulent convection in the overshooting region below the convective envelope of RGB stars

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Research in Astronomy and Astrophysics 2011年第11期11卷 1351-1370页

作者： xiang-jun Lai Yan Li National Astronomical Observatories / Yunnan Observatory Chinese Academy of SciencesKunming 650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy ofSciences Kunming 650011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Based on the turbulent convection model （TCM）, we investigate chemical mixing in the bottom overshooting region of the convective envelope of intermediatemass stars, focusing on its influence on the formation and extension of blue loops in the Hertzsprung-Russell （HR） diagram. A diffusive mixing model is adopted during the Red Giant Branch （RGB） phase. The properties of the blue loop are changed by modification of the element profiles above the H-burning shell, which results from the incomplete mixing in the bottom overshooting region when the stellar model evolves up along the RGB. Such modification of the element profiles will lead to an increase of opacity in the region just above the H-burning shell and a decrease of opacity in the outer homogeneous convection zone, which will result in a quick decrease of the H-shell nuclear luminosity LH when the stellar model evolves from the RGB tip to its bottom and, finally, a much weaker and smaller convection zone will be obtained in the stellar envelope. This helps to form a longer blue loop. The extension of the blue loop is very sensitive to the parameters （Cx and αTCM） of the diffusive mixing model and of the TCM. The results mainly show that： 1） comparing the results of the classical model with the mixing-length theory, the lengths of the obtained blue loops with different combinations of the values of Cx and αTCM are all increased and the length of the blue loop increases with the values of parameters Cx and αTCM; 2） the diffusive mixing model can significantly extend the time of stellar models lingering on the blue side of the HR diagram, even though the length of the blue loop for the 7M⊙ star has a less prominent difference between the classical and diffusive mixing model; 3） both the observations referring to the location of the Cepheid instability strip and the number ratio NB/NR of blue to red evolved stars in the Galactic open clusters can confine the two parameters in a range of 0.5 ≤ αLTCM ≤ 0.9 and 10-5 ≤

关键词： stars convection-star interiors-star HR diagram-blue loops-Cepheids-Galactic open clusters

Characteristics of convection and overshooting in RGB and AGB stars

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Research in Astronomy and Astrophysics 2011年第10期11卷 1143-1157页

作者： xiang-jun Lai Yan Li National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy ofSciences Kunming 650011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China.

Based on the turbulent convection model （TCM） of Li ＆ Yang, we have studied the characteristics of turbulent convection in the envelopes of 2 and 5M⊙ stars at the red giant branch and asymptotic giant branch phases. The TCM has been successfully applied over the entire convective envelopes, including the convective unstable zone and the overshooting regions. We find that the convective motions become progressively stronger when the stellar models are located farther up along the Hayashi line. In the convective unstable zone, we find that the turbulent correlations are proportional to functions of a common factor （V - V^d）T, which explains similar distributions in those correlations. For the TCM we find that if the obtained stellar temperature structure is close to that of the mixing length theory （MLT）, the convective motion will have a much larger velocity and thus be more violent. However, if the turbulent velocity is adjusted to be close to that of the MLT, the superadiabatic convection zone would be much more extended inward, which would lead to a lower effective temperature of the stellar model. For the overshooting distance, we find that the e-folding lengths of the turbulent kinetic energy k in both the top and bottom overshooting regions decrease as the stellar model is progressively located farther up along the Hayashi line, but both the extents of the decrease are not obvious. The overshooting distances of the turbulent correlation /u＇rT＂ are almost the same for the different stellar models with the same set of TCM parameters. For the decay modes of the kinetic energy k, we find that they are very similar for different stellar models based on the same set of TCM parameters, and there is a nearly linear relationship between lg k and In P for different stellar models. When Cs or α increases while the other parameters are fixed, the obtained linearly decaying distance will become longer.

关键词： stars RGB and AGB -- convection of stars -- turbulent convection model convective overshooting

Effects of Ce^(3+) doping on the structure and magnetic properties of Mn-Zn ferrite fibers

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Rare Metals 2009年第2期28卷 151-155页

作者： xiang, jun Shen, xiangqian Zhu, Yongwei School of Materials Science and Engineering Jiangsu University Zhenjiang 212013 China School of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Ce3+-doped Mn-Zn ferrite fibers were successfully prepared by the organic gel-thermal decomposition method from metal salts and citric acid. The composition,structure,and magnetic properties of these ferrite fibers were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),and vibrating sample magnetometer (VSM). The results show that Mn0.2Zn0.8Fe2-xCexO4 (x = 0-0.04) fibers are featured with an average grain size of 11.6-12.7 nm,with diameters ranging between 1.0 to 3.5 μm and a high ...

关键词： ceramic fibers Mn-Zn ferrite thermal decomposition magnetic properties Ce3+-doped

Effect of casting speed on dendrite arm spacing of Mn13 steel continuous casting slab

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Journal of Iron and Steel Research International 2020年第6期27卷 665-672页

作者： Jian-min Li Mao-fa Jiang jun-xiang Ning jun Zhai Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina Shanxi Taigang Stainless Steel Co. Ltd.Taiyuan 030003ShanxiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The dendrite arm spacing in the continuous casting slab of Mn13 steel under different casting speeds was measured using the metallographic microscope. Meanwhile, a heat transfer model was established by the Pro-cast software. The relationship between the dendrite arm spacing and casting speed in continuous casting slab of Mn13 steel was studied and described by a function expression. The results provide an important theoretical basis for the development and optimization of con-tinuous casting production process of high-manganese steel and help to improve the quality of continuous casting slab of high-manganese steel. Under the experimental conditions, the suitable casting speed is about 0.9 m/min. The secondary dendrite spacing maintains a relatively stable low-amplitude increase trend, and it is beneficial to obtain a higher proportion of equiaxed crystals.

关键词： High-manganese steel Dendrite arm spacing Continuous casting Casting speed