If βN exceeds βNno-wall, the plasma will be unstable because of external kink and resistive wall mode （RWM）. In this article, the effect of the passive structure and the toroidal rotation on the RWM stability in t...If βN exceeds βNno-wall, the plasma will be unstable because of external kink and resistive wall mode （RWM）. In this article, the effect of the passive structure and the toroidal rotation on the RWM stability in the experimental advanced superconducting tokamak （EAST） are simulated with CHEASE and MARS codes. A model using a one-dimensional （1D） surface to present the effect of the passive plate is proved to be credible. The no wall fiN limit is about 3li, and the ideal wall βN limit is about 4.5li on EAST. It is found that the rotation near the q = 2 surface and the plasma edge affects the RWM more.展开更多
Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-...Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-DYNA was employed for the simulation of hypervelocity impact on the double-wall structure. By using elementary shock wave theory, the experimental results above are analyzed. The analysis can provide an explanation for the penetration mechanism of hypervelocity projectile impact on double-wall structure about the effect of front wall thickness and impact velocity..展开更多
The stability of a backfill wall is critical to implement gob-side entry driving technology in which a small coal pillar is substituted by a waste backfill wall. Based on features of surrounding rock structures in the...The stability of a backfill wall is critical to implement gob-side entry driving technology in which a small coal pillar is substituted by a waste backfill wall. Based on features of surrounding rock structures in the backfill wall, we propose a mechanical model on the structural effect of a soft-hard backfill wall using theory analysis, physical experiments and a numerical simulation. The results show thatChe deformation of the structure of the soft-hard backfill wall is coordinated with the roof and floor. The soft structure on the top of the backfill wall can absorb the energy in the roof by its large deformation and adapt to the given deformation caused by the rotation and subsidence of a key rock block. The hard structure at the bottom of the backfill wall can absorb the strong supporting resistance from the top surrounding rock. The soft structure on the top protecting the hard bottom structure by its large deformation contributes to the stability of the entire backfill wall. An application indicated that the stress in the backfill wall effec- tively decreased and its deformation was significantly reduced after the top coal remained. This ensured the stability of the backfill wall.展开更多
Due to the upcoming demands of next-generation electronic/magnetoelectronic devices with low-energy consumption,emerging correlated materials（such as superconductors,topological insulators and manganites） are one of...Due to the upcoming demands of next-generation electronic/magnetoelectronic devices with low-energy consumption,emerging correlated materials（such as superconductors,topological insulators and manganites） are one of the highly promising candidates for the applications.For the past decades,manganites have attracted great interest due to the colossal magnetoresistance effect,charge-spin-orbital ordering,and electronic phase separation.However,the incapable of deterministic control of those emerging low-dimensional spin structures at ambient condition restrict their possible applications.Therefore,the understanding and control of the dynamic behaviors of spin order parameters at nanoscale in manganites under external stimuli with low energy consumption,especially at room temperature is highly desired.In this review,we collected recent major progresses of nanoscale control of spin structures in manganites at low dimension,especially focusing on the control of their phase boundaries,domain walls as well as the topological spin structures（e.g.,skyrmions）.In addition,capacitor-based prototype spintronic devices are proposed by taking advantage of the above control methods in manganites.This capacitor-based structure may provide a new platform for the design of future spintronic devices with low-energy consumption.展开更多
We establish a theoretical bimodal model for the complex permeability of flaky soft magnetic composite materials to explain the variability of their initial permeability.The new model is motivated by finding the two n...We establish a theoretical bimodal model for the complex permeability of flaky soft magnetic composite materials to explain the variability of their initial permeability.The new model is motivated by finding the two natural resonance peaks to be inconsistent with the combination of the domain wall resonance and the natural resonance.In the derivation of the model,two relationships are explored:the first one is the relationship between the number of magnetic domains and the permeability,and the second one is the relationship between the natural resonance and the domain wall resonance.This reveals that the ball milling causes the number of magnetic domains to increase and the maximum initial permeability to exist after 10 h of ball milling.An experiment is conducted to demonstrate the reliability of the proposed model.The experimental results are in good agreement with the theoretical calculations.This new model is of great significance for studying the mechanism and applications of the resonance loss for soft magnetic composite materials in high frequency fields.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program of China(Grant Nos.2012GB105000,2011GB101000,2011GB107000,and 2013013GB102000)the National Natural Science Foundation of China(Grant Nos.10725523,10721505,10090212,111005037,and 11205199)
文摘If βN exceeds βNno-wall, the plasma will be unstable because of external kink and resistive wall mode （RWM）. In this article, the effect of the passive structure and the toroidal rotation on the RWM stability in the experimental advanced superconducting tokamak （EAST） are simulated with CHEASE and MARS codes. A model using a one-dimensional （1D） surface to present the effect of the passive plate is proved to be credible. The no wall fiN limit is about 3li, and the ideal wall βN limit is about 4.5li on EAST. It is found that the rotation near the q = 2 surface and the plasma edge affects the RWM more.
文摘Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-DYNA was employed for the simulation of hypervelocity impact on the double-wall structure. By using elementary shock wave theory, the experimental results above are analyzed. The analysis can provide an explanation for the penetration mechanism of hypervelocity projectile impact on double-wall structure about the effect of front wall thickness and impact velocity..
基金Financial supports for this work, provided by the New Century Excellent Talents in University (No.NCET-05-0480)the Research Fund of the State Key Laboratory of Coal Resources and Mine Safety of CUMT (No.09KF06)the Scientific Research Fund of CUMT (No.OA090239)
文摘The stability of a backfill wall is critical to implement gob-side entry driving technology in which a small coal pillar is substituted by a waste backfill wall. Based on features of surrounding rock structures in the backfill wall, we propose a mechanical model on the structural effect of a soft-hard backfill wall using theory analysis, physical experiments and a numerical simulation. The results show thatChe deformation of the structure of the soft-hard backfill wall is coordinated with the roof and floor. The soft structure on the top of the backfill wall can absorb the energy in the roof by its large deformation and adapt to the given deformation caused by the rotation and subsidence of a key rock block. The hard structure at the bottom of the backfill wall can absorb the strong supporting resistance from the top surrounding rock. The soft structure on the top protecting the hard bottom structure by its large deformation contributes to the stability of the entire backfill wall. An application indicated that the stress in the backfill wall effec- tively decreased and its deformation was significantly reduced after the top coal remained. This ensured the stability of the backfill wall.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB920902)the National Natural Science Foundation of China(Grant Nos.61306105 and 51572278)+1 种基金the Information Science and Technology(TNList)Cross-discipline Foundation from Tsinghua National Laboratory,Chinathe Fund from the State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China
文摘Due to the upcoming demands of next-generation electronic/magnetoelectronic devices with low-energy consumption,emerging correlated materials（such as superconductors,topological insulators and manganites） are one of the highly promising candidates for the applications.For the past decades,manganites have attracted great interest due to the colossal magnetoresistance effect,charge-spin-orbital ordering,and electronic phase separation.However,the incapable of deterministic control of those emerging low-dimensional spin structures at ambient condition restrict their possible applications.Therefore,the understanding and control of the dynamic behaviors of spin order parameters at nanoscale in manganites under external stimuli with low energy consumption,especially at room temperature is highly desired.In this review,we collected recent major progresses of nanoscale control of spin structures in manganites at low dimension,especially focusing on the control of their phase boundaries,domain walls as well as the topological spin structures（e.g.,skyrmions）.In addition,capacitor-based prototype spintronic devices are proposed by taking advantage of the above control methods in manganites.This capacitor-based structure may provide a new platform for the design of future spintronic devices with low-energy consumption.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11564024,51731001,and 11574122)the Fundamental Research Funds for the Central Universities,China(Grant No.lzujbky-2019-kb06).
文摘We establish a theoretical bimodal model for the complex permeability of flaky soft magnetic composite materials to explain the variability of their initial permeability.The new model is motivated by finding the two natural resonance peaks to be inconsistent with the combination of the domain wall resonance and the natural resonance.In the derivation of the model,two relationships are explored:the first one is the relationship between the number of magnetic domains and the permeability,and the second one is the relationship between the natural resonance and the domain wall resonance.This reveals that the ball milling causes the number of magnetic domains to increase and the maximum initial permeability to exist after 10 h of ball milling.An experiment is conducted to demonstrate the reliability of the proposed model.The experimental results are in good agreement with the theoretical calculations.This new model is of great significance for studying the mechanism and applications of the resonance loss for soft magnetic composite materials in high frequency fields.
