In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurat...In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurately describing the equilibrium is challenging due to the presence of 3D structures,magnetic islands,and chaotic regions.It is difficult to obtain a balance between the available diagnostic and the real equilibrium structure.To address this issue,we introduce KTX3DFit,a new 3D equilibrium reconstruction code specifically designed for the Keda Torus eXperiment(KTX)RFP.KTX3DFit utilizes the stepped-pressure equilibrium code(SPEC)to compute 3D equilibria and uses polarimetric interferometer signals from experiments.KTX3DFit is able to reconstruct equilibria in various states,including axisymmetric,doubleaxis helical(DAx),and single-helical-axis(SHAx)states.Notably,this study marks the first integration of the SPEC code with internal magnetic field data for equilibrium reconstruction and could be used for other 3D configurations.展开更多
The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tok...The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tokamak discharges.This model was used to calculate the trajectory and penetration parameters of CT injections by applying both perpendicular and tangential injection schemes in both HL-2A and ITER tokamaks.For perpendicular injection along the tokamak's major radius direction from the outboard,CTs with the same injection parameters exhibited a 0.08 reduction in relative penetration depth when injected into HL-2A and a 0.13reduction when injected into ITER geometry when considering the vacuum magnetic field region compared with cases where this region was not considered.In addition,we proposed an optimization method for determining the CT's initial injection velocity to accurately calculate the initial injection velocity of CTs for central fueling in tokamaks.Furthermore,this paper discusses schemes for the tangential injection of CT into tokamak discharges.The optimal injection angle and CT magnetic moment direction for injection into both HL-2A and ITER were determined through numerical simulations.Finally,the kinetic energy loss occurring when the CT penetrated the vacuum magnetic field region in ITER was reduced byΔEk=975.08 J by optimizing the injection angle for the CT injected into ITER.These results provide valuable insights for optimizing injection angles in fusion experiments.Our model closely represents actual experimental scenarios and can assist the design of CT parameters.展开更多
Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study a...Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation.展开更多
Genetic factors play a key role in determination of the structure of the cloacal flora for newborn Chinese Alligators.We collected the cloacal microbiomes for 24 newborn Chinese Alligators from three different genetic...Genetic factors play a key role in determination of the structure of the cloacal flora for newborn Chinese Alligators.We collected the cloacal microbiomes for 24 newborn Chinese Alligators from three different genetic backgrounds for 16S gene amplicon sequencing.The number of cloacal flora for the Chinese Alligators from different groups was comparable but differed structurally.There were variations in proportions of floral compositions at the phylum and family levels;however,the main difference was at the genus level.There were two significant differences in richness and evenness among the three groups.Non-metric multidimensional scaling NMDS analysis revealed that the 24 samples could be clearly divided into three categories based on their genetic backgrounds(stress=0.0244).Thus,we postulated that newborn Chinese Alligators with different genetic backgrounds have different immune strengths,which affects individual responses to environmental microorganisms.In summary,newborn Chinese Alligators from different genetic backgrounds exhibit variations in cloacal microbiome.展开更多
难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti...难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti3Zr1.5Nb((1-x))-MoxVAl_(0.25)(x=0.1,0.3,0.5,标记为Mo0.1,Mo0.3和Mo0.5)合金,这些合金都具有良好的拉伸延展性和低于6 g cm^(-3)的密度.高剪切模量Mo元素的引入促进了晶格畸变,从而提高了合金中的晶格摩擦应力以及屈服强度.铸态Mo0.3和Mo0.5合金均表现出超过1100 MPa的拉伸屈服强度,以及大于15%的断裂延伸率.Labusch模型计算结果表明,原子尺寸和剪切模量失配引起的固溶强化对屈服强度的影响最为显著.通过观察变形微观组织发现,由于存在高密度的位错界面,扭折带、位错壁以及泰勒晶格的形成能有效提高合金的应变硬化能力,使合金在展现高强度的同时保持足够的延展性.该研究为开发具有高强韧的单相难熔高熵合金提供了新的见解.展开更多
A new compact torus injector(KTX-CTI)has been built for injection experiments on the Keda Torus eXperiment(KTX)reversed field pinch(RFP).The aim is to study the fundamental physics governing the compact torus(CT)centr...A new compact torus injector(KTX-CTI)has been built for injection experiments on the Keda Torus eXperiment(KTX)reversed field pinch(RFP).The aim is to study the fundamental physics governing the compact torus(CT)central fueling processes.In experiments conducted under the sole influence of a 0.1 T toroidal magnetic field,the injected CT successfully penetrated the entire toroidal magnetic field,reaching the inner wall of the KTX vacuum vessel.Upon reaching the inner wall,the CT diffused both radially outward and toroidally within the vessel at a discernible diffusion speed.Moreover,the inherent helicity within the CT induced a modest KTX plasma current of 200 A,consistent with predictions based on helicity conservation.CT injection demonstrated the capability to initiate KTX discharges at low loop voltages,suggesting its potential as a pre-ionization and current startup technique.During RFP discharges featuring CT injection,the central plasma density was found to exceed the Greenwald density limit,with more peaked density profiles,indicating the predominant confinement of CT plasma within the core region of the KTX bulk plasma.展开更多
Combining high strength and good ductility is an urgent requirement for traditional structural materials,but yet a challenge.Newly emerging ductile Ti_(3)Zr_(1.5)VNbAl_(x)(x=0,0.25,0.5,0.75) refractory complex concent...Combining high strength and good ductility is an urgent requirement for traditional structural materials,but yet a challenge.Newly emerging ductile Ti_(3)Zr_(1.5)VNbAl_(x)(x=0,0.25,0.5,0.75) refractory complex concentrated alloys(RCCAs) with high specific strength were designed and synthesized via vacuum arc-melting.Alloying effects of Al on microstructure and mechanical properties were systematically investigated.It was found that the phase composition in this alloy system changes from the single disordered body-centered cubic(BCC) phase to a nano-scale mixture of co-continuous disordered BCC and ordered B2 phases with the increase of Al concentration.This structure transition results in a remarkable increase in the yield strength of the RCCAs,i.e.,from 790 to 1118 MPa,leading to a superior specific yield strength of 199.4 MPa cm^(3)g^(-1)for the Al0.75 alloy,meanwhile,the tension plasticity maintained at~10%.TEM observation demonstrates that cell-forming structure and HDDWs induced by wave slip play a crucial role of considerable plasticity in Al0.25 alloy,whereas in Al0.5 alloy,microbands induced by planar slip dominant deformation behavior.The current work is important not only for providing novel high strength and tough structural materials with low density,but also sheds light on designing highperformance lightweight alloys with tunable microstructure.展开更多
基金supported by National Natural Science Foundation of China(Nos.12175227 and 12375226)the National Magnetic Confinement Fusion Program of China(No.2022YFE03100004)+1 种基金the Fundamental Research Funds for the Central Universities(No.USTC 20210079)the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP022)。
文摘In the reversed field pinch(RFP),plasmas exhibit various self-organized states.Among these,the three-dimensional(3D)helical state known as the“quasi-single-helical”(QSH)state enhances RFP confinement.However,accurately describing the equilibrium is challenging due to the presence of 3D structures,magnetic islands,and chaotic regions.It is difficult to obtain a balance between the available diagnostic and the real equilibrium structure.To address this issue,we introduce KTX3DFit,a new 3D equilibrium reconstruction code specifically designed for the Keda Torus eXperiment(KTX)RFP.KTX3DFit utilizes the stepped-pressure equilibrium code(SPEC)to compute 3D equilibria and uses polarimetric interferometer signals from experiments.KTX3DFit is able to reconstruct equilibria in various states,including axisymmetric,doubleaxis helical(DAx),and single-helical-axis(SHAx)states.Notably,this study marks the first integration of the SPEC code with internal magnetic field data for equilibrium reconstruction and could be used for other 3D configurations.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2022YFE03100004 and 2022YFE03060003)National Natural Science Foundation of China(Nos.12375226,12175227 and 11875255)the China Postdoctoral Science Foundation(No.2022M723066).
文摘The trajectory of the compact torus(CT)within a tokamak discharge is crucial to fueling.In this study,we developed a penetration model with a vacuum magnetic field region to accurately determine CT trajectories in tokamak discharges.This model was used to calculate the trajectory and penetration parameters of CT injections by applying both perpendicular and tangential injection schemes in both HL-2A and ITER tokamaks.For perpendicular injection along the tokamak's major radius direction from the outboard,CTs with the same injection parameters exhibited a 0.08 reduction in relative penetration depth when injected into HL-2A and a 0.13reduction when injected into ITER geometry when considering the vacuum magnetic field region compared with cases where this region was not considered.In addition,we proposed an optimization method for determining the CT's initial injection velocity to accurately calculate the initial injection velocity of CTs for central fueling in tokamaks.Furthermore,this paper discusses schemes for the tangential injection of CT into tokamak discharges.The optimal injection angle and CT magnetic moment direction for injection into both HL-2A and ITER were determined through numerical simulations.Finally,the kinetic energy loss occurring when the CT penetrated the vacuum magnetic field region in ITER was reduced byΔEk=975.08 J by optimizing the injection angle for the CT injected into ITER.These results provide valuable insights for optimizing injection angles in fusion experiments.Our model closely represents actual experimental scenarios and can assist the design of CT parameters.
基金supported by the National Natural Science Foundation of China(Nos.32000355,32170525,32370561)Anhui Science and Technology Major Project(202003a06020028).
文摘Chinese alligator hatchlings in captivity are fragile and have a high mortality rate within first year.The body mass gain of reptile animals is closely related to their feeding behavior and gut microbiota.This study analyzed the intrinsic factors influencing the allometric growth of Chinese alligator hatchlings based on their body mass gain,feeding behavior,and gut microbiota.This information would enhance the health management of Chinese alligator hatchlings.There was a significant correlation between the total distance moved,the average number of conspecifics nearby,and body mass gain.Chinese alligator hatchlings with a greater growth rate showed greater activity and more independent behavior during feeding than those with a lower growth rate.Moreover,after feeding started,some functions of the gut microbiota showed significant relationships with growth rate and feeding activity.Chinese alligator hatchlings with a greater growth rate showed greater levels of heme biosynthesis than those with a lower growth rate,and feeding activity was inhibited by long-chain fatty acid biosynthesis.These results elucidate the relationships between health,feeding behavior,and the gut microbiota of Chinese alligator hatchlings.Understanding the intrinsic factors of their health and feeding behavior can improve the health management of Chinese alligator hatchlings in captivity for conservation.
基金supported by National Natural Science Foundation of China(No.32000355 and No.32370561)Research start-up funds of Anhui Normal University(No.751865)Anhui Forestry Science and Technology Innovation Project(AHLYCX-2021-01).
文摘Genetic factors play a key role in determination of the structure of the cloacal flora for newborn Chinese Alligators.We collected the cloacal microbiomes for 24 newborn Chinese Alligators from three different genetic backgrounds for 16S gene amplicon sequencing.The number of cloacal flora for the Chinese Alligators from different groups was comparable but differed structurally.There were variations in proportions of floral compositions at the phylum and family levels;however,the main difference was at the genus level.There were two significant differences in richness and evenness among the three groups.Non-metric multidimensional scaling NMDS analysis revealed that the 24 samples could be clearly divided into three categories based on their genetic backgrounds(stress=0.0244).Thus,we postulated that newborn Chinese Alligators with different genetic backgrounds have different immune strengths,which affects individual responses to environmental microorganisms.In summary,newborn Chinese Alligators from different genetic backgrounds exhibit variations in cloacal microbiome.
基金supported by the National Natural Science Foundation of China (52074257)Chinese Academy of Sciences (ZDBS-LY-JSC023)。
文摘难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti3Zr1.5Nb((1-x))-MoxVAl_(0.25)(x=0.1,0.3,0.5,标记为Mo0.1,Mo0.3和Mo0.5)合金,这些合金都具有良好的拉伸延展性和低于6 g cm^(-3)的密度.高剪切模量Mo元素的引入促进了晶格畸变,从而提高了合金中的晶格摩擦应力以及屈服强度.铸态Mo0.3和Mo0.5合金均表现出超过1100 MPa的拉伸屈服强度,以及大于15%的断裂延伸率.Labusch模型计算结果表明,原子尺寸和剪切模量失配引起的固溶强化对屈服强度的影响最为显著.通过观察变形微观组织发现,由于存在高密度的位错界面,扭折带、位错壁以及泰勒晶格的形成能有效提高合金的应变硬化能力,使合金在展现高强度的同时保持足够的延展性.该研究为开发具有高强韧的单相难熔高熵合金提供了新的见解.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2022YFE03100000 and 2017YFE0301701)National Natural Science Foundation of China(Nos.12375226,11875255,11635008,11375188 and 11975231)the Fundamental Research Funds for the Central Universities(No.wk34200000022)。
文摘A new compact torus injector(KTX-CTI)has been built for injection experiments on the Keda Torus eXperiment(KTX)reversed field pinch(RFP).The aim is to study the fundamental physics governing the compact torus(CT)central fueling processes.In experiments conducted under the sole influence of a 0.1 T toroidal magnetic field,the injected CT successfully penetrated the entire toroidal magnetic field,reaching the inner wall of the KTX vacuum vessel.Upon reaching the inner wall,the CT diffused both radially outward and toroidally within the vessel at a discernible diffusion speed.Moreover,the inherent helicity within the CT induced a modest KTX plasma current of 200 A,consistent with predictions based on helicity conservation.CT injection demonstrated the capability to initiate KTX discharges at low loop voltages,suggesting its potential as a pre-ionization and current startup technique.During RFP discharges featuring CT injection,the central plasma density was found to exceed the Greenwald density limit,with more peaked density profiles,indicating the predominant confinement of CT plasma within the core region of the KTX bulk plasma.
基金financially supported by the National Key Research and Development Program (No.2018YFB0703402)the National Natural Science Foundation of China (Grant No.52074257)Chinese Academy of Sciences (No.ZDBS-LY-JSC023)。
文摘Combining high strength and good ductility is an urgent requirement for traditional structural materials,but yet a challenge.Newly emerging ductile Ti_(3)Zr_(1.5)VNbAl_(x)(x=0,0.25,0.5,0.75) refractory complex concentrated alloys(RCCAs) with high specific strength were designed and synthesized via vacuum arc-melting.Alloying effects of Al on microstructure and mechanical properties were systematically investigated.It was found that the phase composition in this alloy system changes from the single disordered body-centered cubic(BCC) phase to a nano-scale mixture of co-continuous disordered BCC and ordered B2 phases with the increase of Al concentration.This structure transition results in a remarkable increase in the yield strength of the RCCAs,i.e.,from 790 to 1118 MPa,leading to a superior specific yield strength of 199.4 MPa cm^(3)g^(-1)for the Al0.75 alloy,meanwhile,the tension plasticity maintained at~10%.TEM observation demonstrates that cell-forming structure and HDDWs induced by wave slip play a crucial role of considerable plasticity in Al0.25 alloy,whereas in Al0.5 alloy,microbands induced by planar slip dominant deformation behavior.The current work is important not only for providing novel high strength and tough structural materials with low density,but also sheds light on designing highperformance lightweight alloys with tunable microstructure.