An experimental system has been built to produce and measure the magnetic field in the backward ejected matter during hypervelocity impact. The designs of measurement system and coil, the choice of associated equipmen...An experimental system has been built to produce and measure the magnetic field in the backward ejected matter during hypervelocity impact. The designs of measurement system and coil, the choice of associated equipment, and the system calibration are also described in detail. The measurement of magnetic induction intensity for different given coil positions and azimuth angles are performed with two-stage light-gas gun. On condition that impact velocities are approximately equal and incidence angles are 45°, 60° and 90° respectively, the relationship between average magnetic induction intensity and impact angle at different time spans is obtained. Experimental results show that the average magnetic induction intensity with incidence angle of 90° is larger than those with incidence angles of 45°and 60°.展开更多
In order to control the shape and distribution of hardening phase in plasma surfacing deposit, a longitudinal DC magnetic field was applied during plasma surfacing of nickel-based alloy Ni60. Hardness, wearing resista...In order to control the shape and distribution of hardening phase in plasma surfacing deposit, a longitudinal DC magnetic field was applied during plasma surfacing of nickel-based alloy Ni60. Hardness, wearing resistance, microstructure and phase coastitnent of the plasma surfacing layer were investigated. It was revealed that the hardness and wearing resistance of the Ni60 plasma surfacing layer could gotten significantly enhanced through introducing magnetic field. The mechanical properties of the surfacing deposit were optimal when magnetic field current is 1 A. The metallurgical analysis showed that the microstructure of the Ni60 plasma surfacing layer was mainly composed of γ solid solution and some hardening phase particles such as Cr7C3 with an application of the magnetic field.展开更多
INTRODUCTIONInflammatory pseudotumor of the liver ,a rare benign lesion ,is often confused with the malignant tumors .Until 1998,less than 80 cases had been reported in the world [1,2].The accuracy of the pre-surgica...INTRODUCTIONInflammatory pseudotumor of the liver ,a rare benign lesion ,is often confused with the malignant tumors .Until 1998,less than 80 cases had been reported in the world [1,2].The accuracy of the pre-surgical diagnosis was low p[3,4] ,and very few materials on the diagnosis using dynamic MRI were reported [5-7] .We collected thirteen cases of inflammatory pseudotumor of the liver were collected and roved by pathology with MRI studies .Our purpose is to describe and analyze the MRI findings of this lesion and find out the valuable signs suggesting the diagnosis so as to avoid unnecessary operations.展开更多
Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomen...Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomena such as chiral magnetic,chiral separation,chiral electric separation,and chiral vortical effects as well as the spin polarization of hadrons.These phenomena provide us with experimentally feasible means to study the nontrivial topological sector of quantum chromodynamics,the possible parity violation of strong interaction at high temperature,and the subatomic spintronics of quark–gluon plasma.These studies,both in theory and in experiments,are strongly connected with other subfields of physics such as condensed matter physics,astrophysics,and cold atomic physics,and thus form an emerging interdisciplinary research area.We give an introduction to the aforementioned phenomena induced by the EM field and vorticity and an overview of the current status of experimental research in heavy-ion collisions.We also briefly discuss spin hydrodynamics as well as chiral and spin kinetic theories.展开更多
In the Large Helical Device （LHD）, two different divertor configurations, i.e. helical divertor （HD） and local island divertor （LID）, are utilized to control the edge plasma. The HD with two X-points is an intri...In the Large Helical Device （LHD）, two different divertor configurations, i.e. helical divertor （HD） and local island divertor （LID）, are utilized to control the edge plasma. The HD with two X-points is an intrinsic divertor for heliotron devices, accompanied with a relatively thick ergodic layer outside the confinement region. Edge and divertor plasma behavior from low density to high density regimes is presented, referring to the divertor detachment. The effect of the ergodic layer on the edge transport is also discussed. On the other hand, the LID is an advanced divertor concept which realizes a high pumping efficiency by the combination of an externally induced magnetic island and a closed pumping system. Experimental results to confirm the fundamental divertor performance of the LID are presented.展开更多
In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates...In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y＇-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft （ideal） ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.展开更多
In this paper, we consider the application of the equation of non-classical mathematical physics to magneto-hydrodynamic equilibrium (in the case of a mixed magnetic field) for magnetic stars. First, we give the neces...In this paper, we consider the application of the equation of non-classical mathematical physics to magneto-hydrodynamic equilibrium (in the case of a mixed magnetic field) for magnetic stars. First, we give the necessary concepts about the equation of non-classical mathematical physics and the possibility of their applicability to astrophysical problems. The conditions of magneto-hydrodynamic equilibrium are determinate, and self-consistence provides the means to derive the corresponding partial differential equations describing this equilibrium in a magnetosphere magnetic star. Namely, this process is to the non-classical equations of mathematical physics in cases of types. Keldysh-Tricomi, a common case equation of non-classical type, is at first introduced by the author. Using the two main physical efficiencies of MHD. A mathematical model of a poloidal-toroidal mixed magnetic field for magnetic stars is constructed, and this model is classified with respect to degenerating case equations. According to Hopf’s theorem, Maxwell’s equation and the magnetic force balance equation constructed equilibrium conditions of the poloidal-toroidal of the magnetic field for a magnetic star. At the same time, the taken example, which is the self-consistency of this model by observation dates, is investigated. At first, in an application, the method of straight lines for recurrent formulas of calculation of magnetic flux and stream functions is used. The physical means, the corresponding singular point of the sonic line, cutoff, and resonance phenomena are considered. In this case, a general solution equation is found, which is interpreted by this phenomenon as a cutoff, resonance. Finally, this obtained solution gives the conditions of magneto-hydrodynamic equilibrium on the magnetosphere of magnetic stars. Methodology and obtained equations are new approaches that are at first considered.展开更多
As one of the most spectacular energy release events in the solar system,solar flares are generally powered by magnetic reconnection in the solar corona.As a result of the re-arrangement of magnetic field topology aft...As one of the most spectacular energy release events in the solar system,solar flares are generally powered by magnetic reconnection in the solar corona.As a result of the re-arrangement of magnetic field topology after the reconnection process,a series of new looplike magnetic structures are often formed and are known as flare loops.A hot diffuse region,consisting of around 5–10 MK plasma,is also observed above the loops and is called a supra-arcade fan.Often,dark,tadpole-like structures are seen to descend through the bright supra-arcade fans.It remains unclear what role these so-called supra-arcade downflows(SADs)play in heating the flaring coronal plasma.Here we show a unique flare observation,where many SADs collide with the flare loops and strongly heat the loops to a temperature of 10–20 MK.Several of these interactions generate clear signatures of quasi-periodic enhancement in the full-Sun-integrated soft X-ray emission,providing an alternative interpretation for quasi-periodic pulsations that are commonly observed during solar and stellar flares.展开更多
基金National Natural Science Foundation of China (10772028)Talent Resources Development Special Funds of Shenyang (20081400103009)Doctoral Initiation Special Fund of Shenyang Ligong University
文摘An experimental system has been built to produce and measure the magnetic field in the backward ejected matter during hypervelocity impact. The designs of measurement system and coil, the choice of associated equipment, and the system calibration are also described in detail. The measurement of magnetic induction intensity for different given coil positions and azimuth angles are performed with two-stage light-gas gun. On condition that impact velocities are approximately equal and incidence angles are 45°, 60° and 90° respectively, the relationship between average magnetic induction intensity and impact angle at different time spans is obtained. Experimental results show that the average magnetic induction intensity with incidence angle of 90° is larger than those with incidence angles of 45°and 60°.
文摘In order to control the shape and distribution of hardening phase in plasma surfacing deposit, a longitudinal DC magnetic field was applied during plasma surfacing of nickel-based alloy Ni60. Hardness, wearing resistance, microstructure and phase coastitnent of the plasma surfacing layer were investigated. It was revealed that the hardness and wearing resistance of the Ni60 plasma surfacing layer could gotten significantly enhanced through introducing magnetic field. The mechanical properties of the surfacing deposit were optimal when magnetic field current is 1 A. The metallurgical analysis showed that the microstructure of the Ni60 plasma surfacing layer was mainly composed of γ solid solution and some hardening phase particles such as Cr7C3 with an application of the magnetic field.
文摘INTRODUCTIONInflammatory pseudotumor of the liver ,a rare benign lesion ,is often confused with the malignant tumors .Until 1998,less than 80 cases had been reported in the world [1,2].The accuracy of the pre-surgical diagnosis was low p[3,4] ,and very few materials on the diagnosis using dynamic MRI were reported [5-7] .We collected thirteen cases of inflammatory pseudotumor of the liver were collected and roved by pathology with MRI studies .Our purpose is to describe and analyze the MRI findings of this lesion and find out the valuable signs suggesting the diagnosis so as to avoid unnecessary operations.
基金supported by National Natural Science Foundation of China(Nos.11535012 and 11675041)。
文摘Relativistic heavy-ion collisions create hot quark–gluon plasma as well as very strong electromagnetic(EM)and fluid vortical fields.The strong EM field and vorticity can induce intriguing macroscopic quantum phenomena such as chiral magnetic,chiral separation,chiral electric separation,and chiral vortical effects as well as the spin polarization of hadrons.These phenomena provide us with experimentally feasible means to study the nontrivial topological sector of quantum chromodynamics,the possible parity violation of strong interaction at high temperature,and the subatomic spintronics of quark–gluon plasma.These studies,both in theory and in experiments,are strongly connected with other subfields of physics such as condensed matter physics,astrophysics,and cold atomic physics,and thus form an emerging interdisciplinary research area.We give an introduction to the aforementioned phenomena induced by the EM field and vorticity and an overview of the current status of experimental research in heavy-ion collisions.We also briefly discuss spin hydrodynamics as well as chiral and spin kinetic theories.
基金supported by NIFS under Grant(No.NIFS05ULPP506)in part by the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusion
文摘In the Large Helical Device （LHD）, two different divertor configurations, i.e. helical divertor （HD） and local island divertor （LID）, are utilized to control the edge plasma. The HD with two X-points is an intrinsic divertor for heliotron devices, accompanied with a relatively thick ergodic layer outside the confinement region. Edge and divertor plasma behavior from low density to high density regimes is presented, referring to the divertor detachment. The effect of the ergodic layer on the edge transport is also discussed. On the other hand, the LID is an advanced divertor concept which realizes a high pumping efficiency by the combination of an externally induced magnetic island and a closed pumping system. Experimental results to confirm the fundamental divertor performance of the LID are presented.
文摘In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y＇-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft （ideal） ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.
文摘In this paper, we consider the application of the equation of non-classical mathematical physics to magneto-hydrodynamic equilibrium (in the case of a mixed magnetic field) for magnetic stars. First, we give the necessary concepts about the equation of non-classical mathematical physics and the possibility of their applicability to astrophysical problems. The conditions of magneto-hydrodynamic equilibrium are determinate, and self-consistence provides the means to derive the corresponding partial differential equations describing this equilibrium in a magnetosphere magnetic star. Namely, this process is to the non-classical equations of mathematical physics in cases of types. Keldysh-Tricomi, a common case equation of non-classical type, is at first introduced by the author. Using the two main physical efficiencies of MHD. A mathematical model of a poloidal-toroidal mixed magnetic field for magnetic stars is constructed, and this model is classified with respect to degenerating case equations. According to Hopf’s theorem, Maxwell’s equation and the magnetic force balance equation constructed equilibrium conditions of the poloidal-toroidal of the magnetic field for a magnetic star. At the same time, the taken example, which is the self-consistency of this model by observation dates, is investigated. At first, in an application, the method of straight lines for recurrent formulas of calculation of magnetic flux and stream functions is used. The physical means, the corresponding singular point of the sonic line, cutoff, and resonance phenomena are considered. In this case, a general solution equation is found, which is interpreted by this phenomenon as a cutoff, resonance. Finally, this obtained solution gives the conditions of magneto-hydrodynamic equilibrium on the magnetosphere of magnetic stars. Methodology and obtained equations are new approaches that are at first considered.
基金The authors thank the SDO,GOES,and RHESSI teams for providing the data,and Shinsuke Takasao for helpful discussion.This work was supported by NSFC grants 11825301 and 11790304,Strategic Priority Research Program of CAS(grant XDA17040507)NASA LWS grant 80NSSC19K0069,NSF grants AST-1735405 and AGS-1723436 to New Jersey Institute of Technology(NJIT)NASA grant 80NSSC18K0732 and NASA's SDO/AIA contract(NNG04EA00C)to the Lockheed Martin Solar and Astrophysics Laboratory.AIA is an instrument onboard the SDO,a mission for NASA's Living With a Star program.
文摘As one of the most spectacular energy release events in the solar system,solar flares are generally powered by magnetic reconnection in the solar corona.As a result of the re-arrangement of magnetic field topology after the reconnection process,a series of new looplike magnetic structures are often formed and are known as flare loops.A hot diffuse region,consisting of around 5–10 MK plasma,is also observed above the loops and is called a supra-arcade fan.Often,dark,tadpole-like structures are seen to descend through the bright supra-arcade fans.It remains unclear what role these so-called supra-arcade downflows(SADs)play in heating the flaring coronal plasma.Here we show a unique flare observation,where many SADs collide with the flare loops and strongly heat the loops to a temperature of 10–20 MK.Several of these interactions generate clear signatures of quasi-periodic enhancement in the full-Sun-integrated soft X-ray emission,providing an alternative interpretation for quasi-periodic pulsations that are commonly observed during solar and stellar flares.
