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Your search keyword '"Qin Ming-Hui"' showing total 20 results
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20 results on '"Qin Ming-Hui"'

1. Dynamics of asymmetrically deformed skyrmion driven by internal forces and strain force in a flower-shaped magnetic nanostructure

Author

Tan, Zhen-Yu, Chen, Ji-Pei, Shi, Yu-Ke, Chen, Yuan, Qin, Ming-Hui, Gao, Xing-Sen, and Liu, Jun-Ming

Subjects
Condensed Matter - Materials Science
Abstract

Magnetic skyrmions emerge as promising quasi-particles for encoding information in nextgeneration spintronic devices. Their innate flexibility in shape is essential for the applications although they were often ideally treated as rigid particles. In this work, we investigated the voltagecontrolled uniform strain mediated dynamics of deformed skyrmions in heterostructures with a flower-shaped magnetic nanostructure, using micromagnetic simulations. The simulated results revealed the possible states of isolated skyrmion nucleated in the nanostructure, which can be mutually switched by applying suitable in-plane strain pulses. In addition, it was found that the skyrmion motions are driven by the emerging internal forces and strain force, which originate from the asymmetric deformation of skyrmion structures. Furthermore, an analytical model of deformed skyrmions was proposed to interpret the dependences of internal forces and strain force on the asymmetric deformation of skyrmion, with some formulae derived for these forces in a semi-analytical approach. Further calculations based on these formulae verified the forces appearing in the skyrmion motion, with the resulting forces showing consistence with the simulated data. This suggested that our semi-analytical model successfully captures the main physics responsible for the motion of deformed skyrmion in the nanostructure. Our work extends the understanding of the mechanics emerging in deformed skyrmion, and provides an effective approach for deterministic manipulation of deformed skyrmion motion via strain forces and internal forces, which may be instructive to design of skyrmion-based spintronic devices.

Published
2024

6. Characterization of the oriC region of Mycobacterium smegmatis

Author

Qin, Ming-Hui, Madiraju, Murty V.V.S., Zachariah, Sunny, and Rajagopalan, Malini

Subjects
Mycobacterium -- Research, Mycobacteria -- Research, Chromosome replication -- Research, Biological sciences
Abstract

The research study which was aimed at characterizing the chromosomal origin of replication (oriC) region of Mycobacterium smegmatis (M smegtatis) was conducted. The methods used were the recombinant DNA techniques, analysis of oriC activity, construction of oriC plasmids, site-directed mutagenesis, oriC copy number determination and stability experiments. Results suggested that M smegtatis oriC replication could involve interactions of DnaA protein with DnaA boxes and the DnaA boxes and AT nucleotide rich cluster are important to oriC activity.

Published
1997

7. Mycobacterium smegmatis dnaA region and autonomous replication activity

Author

Rajagopalan, Malini, Qin, Ming-Hui, Nash, Donald R., and Madiraju, Murty V.V.S.

Subjects
Mycobacterium -- Genetic aspects, Chromosome replication -- Research, Biological sciences
Abstract

A 4-kb chromosomal DNA fragment from Mycobacterium smegmatis that has a dnaA gene was studied to analyze mycobacteria's method of starting replication. Analysis of the nucleotide sequence showed homologies with the rpmH gene, which encodes the ribosomal protein L34, the dnaA gene, which encodes the replication initiator protein DnaA, and the 5' end of the dnaN gene, which encodes the beta subunit of DNA polymerase III.

Published
1995

13. Tailoring the structural and magnetic properties of Cu-doped ZnO by ±b c -axis pressure

Author

Liu Jun-Ming, Zeng Min, Gong Ji-Jun, Wu Hao, Gao Xingsen, Chen Ji-Pei, Zhang Fei, and Qin Ming-Hui

Subjects
Condensed Matter::Materials Science, Nuclear magnetic resonance, Materials science, Field (physics), Condensed matter physics, Ferromagnetism, General Physics and Astronomy, Condensed Matter::Strongly Correlated Electrons, Structural transition, Cu doped, Instability, Wurtzite crystal structure
Abstract

The structural and magnetic properties of the Cu-doped ZnO (ZnO:Cu) under c-axis pressure were studied using first-principle calculations. It was found that the ZnO:Cu undergoes a structural transition from Wurtzite to Graphite-like structure at a c-axis pressure of 7–8 GPa. This is accompanied by an apparent loss of ferromagnetic stability, indicating a magnetic transformation from a ferromagnetic state to a paramagnetic-like state. Further studies revealed that the magnetic instability is closely related to the variation in crystalline field originated from the structural transition, which is in association with the overlapping of spin–charge density between the Cu2+ and adjacent O2-.

Published
2015

19. Dynamic resistive switching in a three-terminal device based on phase separated manganites.

Author

Qin Ming-Hui, Gao Xing-Sen, Wang Zhi-Qiang, Yan Zhi-Bo, and Liu Jun-Ming

Subjects
*NONVOLATILE random-access memory, *ELECTRIC resistance, *SWITCHING theory, *PHASE separation, *DIELECTROPHORESIS, *MANGANITE, *MONTE Carlo method
Abstract

A three-terminal device based on electronic phase separated manganites is suggested to produce high performance resistive switching. Our Monte Carlo simulations reveal that the conductive filaments can be formed/annihilated by reshaping the ferromagnetic metal phase domains with two cross-oriented switching voltages. Besides, by controlling the high resistance state (HRS) to a stable state that just after the filament is ruptured, the resistive switching remains stable and reversible, while the switching voltage and the switching time can be greatly reduced. [ABSTRACT FROM AUTHOR]

Published
2015
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20. Tailoring the structural and magnetic properties of Cu-doped ZnO by ±bc-axis pressure.

Author

Chen Ji-Pei, Zhang Fei, Wu Hao, Qin Ming-Hui, Zeng Min, Gong Ji-Jun, Gao Xing-Sen, and Liu Jun-Ming

Subjects
DILUTED magnetic semiconductors, ZINC oxide, SEMICONDUCTOR doping, FERROMAGNETISM, CONDUCTION electrons, ANTIFERROMAGNETIC materials, DENSITY functional theory, AXIOMS
Abstract

The structural and magnetic properties of the Cu-doped ZnO (ZnO:Cu) under c-axis pressure were studied using first-principle calculations. It was found that the ZnO:Cu undergoes a structural transition from Wurtzite to Graphite-like structure at a c-axis pressure of 7–8 GPa. This is accompanied by an apparent loss of ferromagnetic stability, indicating a magnetic transformation from a ferromagnetic state to a paramagnetic-like state. Further studies revealed that the magnetic instability is closely related to the variation in crystalline field originated from the structural transition, which is in association with the overlapping of spin–charge density between the Cu2+ and adjacent O2-. [ABSTRACT FROM AUTHOR]

Published
2015
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