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Gyrofluid Simulation of Ion-Scale Turbulence in Tokamak Plasmas

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Communications in Computational Physics 2008年第10期4卷 1245-1257页

作者： jiquan li Y.Kishimoto Graduate School of Energy Science Kyoto UniversityUjiKyoto 611-0011Japan Institute for Fusion Theory and Simulation ZhejiangUniversityHangzhouChina

An improved three-field gyrofluid model is proposed to numerically simulate ion-scale turbulence in tokamak plasmas,which includes the nonlinear evolution of perturbed electrostatic potential,parallel ion velocity and ion pressure with adiabatic electron *** is benchmarked through advancing a gyrofluid toroidal global(GFT G)code as well as the local version(GFT L),with the emphasis of the collisionless damping of zonal *** nonlinear equations are solved by using Fourier decomposition in poloidal and toroidal directions and semi-implicit finite difference method along radial *** numerical implementation is briefly explained,especially on the periodic boundary condition in GFT L *** a numerical test and also practical application,the nonlinear excitation of geodesic acoustic mode(GAM),as well as its radial structure,is investigated in tokamak plasma turbulence.

关键词： Geodesic acoustic mode(GAM) zonal flow ion temperature gradient(ITG)turbulence gyrofluid simulation tokamak

Effect of electronic stimulation at Neiguan(PC 6) acupoint on gene expression of adenosine triphosphate-sensitive potassium channel and protein kinases in rats with myocardial ischemia

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Journal of Traditional Chinese Medicine 2015年第5期35卷 577-582页

作者： Wang Wei li jiquan Meng Xiangyu Chen Yiguo College of Acupuncture and Massage Liaoning University of Traditional Chinese Medicine

OBJECTIVE:To investigate the effects of electronic stimulation at acupoints Neiguan(PC 6) and lieque(LU 7) on the gene expression of the adenosine triphosphate(ATP)-Sensitive potassium channel(KATP:Kir6.1,Kir6.2,SUR2 A,and SUR2B) and protein kinases(PKA,PKG,and PKCβ2) in myocardial cells of rats with myocardial ischemia(Ml) induced by isoproterenol(ISO).METHODS:Rats were randomly divided into a control,model,Neiguan(PC 6),lieque(LU 7),and non-acupoint *** Ml model was established by injecting rats with ***-acupuncture treatment was given to the acupuncture groups,once a day for 7 *** expression was analyzed with real-time ***:The gene expression of KATP and protein kinases in the model group was higher than those in the control group(P lieque(LU 7) groups compared with the model group[P lieque(LU 7) group(P 0.05).CONCLUSION:Our findings suggest that electronic needling of Neiguan(PC 6) can both reduce the gene expression of KATP and protein kinases in rats with ISO-induced Ml.

关键词： Point PC6(Neiguan) Acupuncture Electric stimulation KATP Channels Protein Kinases Myocardial ischemia

Machine learning of turbulent transport in fusion plasmas with neural network

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Plasma Science and Technology 2021年第11期23卷 9-17页

作者： Hui li Yanlin FU jiquan li Zhengxiong WANG Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Physics.Dalian University of TechnologyDalian 116024People's Republic of China Southwestern Institute of Physics Chengdu 610041People's Republic of China School of Physics Dalian University of TechnologyDalian 116024People's Republic of China

Turbulent transport resulting from drift waves,typically,the ion temperature gradient(ITG)mode and trapped electron mode(TEM),is of great significance in magnetic confinement *** is also well known that turbulence simulation is a challenging issue in both the complex physical model and huge CPU cost as well as long computation *** this work,a credible turbulence transport prediction model,extended fluid code(ExFC-NN),based on a neural network(NN)approach is established using simulation data by performing an ExFC,in which multi-scale multi-mode fluctuations,such as ITG and TEM turbulence are *** show that the characteristics of turbulent transport can be successfully predicted including the type of dominant turbulence and the radial averaged fluxes under any set of local gradient ***,a global NN model can well reproduce the radial profiles of turbulence perturbation intensities and fluxes much faster than existing codes.A large number of comparative predictions show that the newly constructed NN model can realize rapid experimental analysis and provide reference data for experimental parameter design in the future.

关键词： neural network plasma turbulence transport properties plasma simulation

Role of the zonal flow in multi-scale multi-mode turbulence with small-scale shear flow in tokamak plasmas

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Chinese Physics B 2022年第6期31卷 549-556页

作者： Hui li jiquan li Zhengxiong Wang Lai Wei Zhaoqing Hu Key Laboratory of Materials Modification by Beams of the Ministry of Education School of PhysicsDalian University of TechnologyDalian 116024China Southwestern Institute of Physics Chengdu 610041China

The structural characteristics of zonal flows and their roles in the nonlinear interaction of multi-scale multi-mode turbulence are investigated numerically via a self-consistent Landau-fluid *** multi-mode turbulence here is composed of a shorter wavelength electromagnetic(EM)ion temperature gradient(ITG)mode and a Kelvin-Helmholtz(KH)instability with long wavelengths excited by externally imposed small-scale shear *** strong shear flow,a prominent periodic intermittency of fluctuation intensity except for dominant ITG component is revealed in turbulence evolution,which onset time depends on the ion temperature gradient and the shear flow amplitudes corresponding to different KH *** is identified that the intermittency phenomenon results from the zonal flow dynamics,which is mainly generated by the KH mode and back-reacts on *** is demonstrated that the odd symmetric components of zonal flow(same symmetry as the external flow)make the radial parity of the KH mode alteration through adjusting the drift velocities at two sides of the resonant surface so that the KH mode becomes bursty ***,the ITG intermittency follows due to nonlinear mode *** dependences of the features of the intermittency are ***,associated turbulent heat transport is evaluated.

关键词： drift waves turbulence nonlinear phenomena plasma simulation

Magnetic-island-induced ion temperature gradient mode： Landau damping, equilibrium magnetic shear and pressure flattening effects

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Plasma Science and Technology 2018年第7期20卷 77-85页

作者： Wei WANG Zhengxiong WANG jiquan li Yasuaki KISHIMOTO Jiaqi DONG Shu ZHENG Key Laboratory of Materials Modification by Beams of the Ministry of Education School of PhysicsDalian University of TechnologyDalian 116024People＇s Republic of China Graduate School of Energy Science Kyoto UniversityGokasyoUjiKyoto 611-0011Japan Southwestern Institute of Physics Chengdu 610041People＇s Republic of China Institute for Fusion Theory and Simulation Zhejiang UniversityHangzhou 310027People＇s Republic of China

Characteristics of the magnetic-island-induced ion temperature gradient （MITG） mode are studied through gyrofluid simulations in the slab geometry, focusing on the effects of Landau damping, equilibrium magnetic shear （EMS）, and pressure flattening. It is shown that the magnetic island may enhance the Landau damping of the system by inducing the radial magnetic field. Moreover, the radial eigenmode numbers of most MITG poloidal harmonics are increased by the magnetic island so that the MITG mode is destabilized in the low EMS regime. In addition, the pressure profile flattening effect inside a magnetic island hardly affects the growth of the whole MITG mode, while it has different local effects near the O-point and the X-point regions. In comparison with the non-zero-order perturbations, only the quasi-linear flattening effect due to the zonal pressure is the effective component to impact the growth rate of the mode.

关键词： magnetic island magnetic shear Landau damping MITG

Gyro-Landau-fluid simulations of impurity effects on ion temperature gradient driven turbulence transport

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Plasma Science and Technology 2024年第1期26卷 8-15页

作者：刘逸飞李继全 Southwestern Institute of Physics Chengdu 610041People’s Republic of China

The effects of impurities on ion temperature gradient(ITG)driven turbulence transport in tokamak core plasmas are investigated numerically via global simulations of microturbulence with carbon impurities and adiabatic *** simulations use an extended fluid code(ExFC)based on a four-field gyro-Landau-fluid(GLF)*** multispecies form of the normalized GLF equations is presented,which guarantees the self-consistent evolution of both bulk ions and *** parametric profiles of the cyclone base case,well-benchmarked ExFC is employed to perform simulations focusing on different impurity density *** a fixed temperature profile,it is found that the turbulent heat diffusivity of bulk ions in a quasi-steady state is usually lower than that without impurities,which is contrary to the linear and quasilinear *** evolutions of the temperature gradient and heat diffusivity exhibit a fast relaxation process,indicating that the destabilization of the outwardly peaked impurity profile is a transient state ***,the impurity effects from different profiles can obviously influence the nonlinear critical temperature gradient,which is likely to be dominated by linear *** results suggest that the improvement in plasma confinement could be attributed to the impurities,most likely through adjusting both heat diffusivity and the critical temperature gradient.

关键词： gyro-Landau-fluid simulation impurity effects ion temperature gradient mode turbulence transport

城市建筑生态位原理探析及其生态位策略研究——日本东京中城规划设计案例分析

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城市发展研究 2012年第8期19卷 28-35页

作者：李积权福建工程学院

如同自然生物体的产生、生长、成熟和衰亡一样,一栋城市建筑通常要经历从材料的开采、加工运输、规划设计、建造、使用维修、更新改造,直到最后拆除、废弃物处置的整个"生命周期"过程。城市中的建筑活动涉及材料、技术、能源、社会、经... 详细信息

如同自然生物体的产生、生长、成熟和衰亡一样,一栋城市建筑通常要经历从材料的开采、加工运输、规划设计、建造、使用维修、更新改造,直到最后拆除、废弃物处置的整个"生命周期"过程。城市中的建筑活动涉及材料、技术、能源、社会、经济、文化等诸多因素,是一个复合生态系统。以城市建筑为生态元,视影响城市建筑的各种自然和社会要素为生态因子,引入生态位概念,探析城市建筑生态位原理,构建城市建筑生态位;举例分析,从自然与社会两方面探讨可持续发展的城市建筑生态位策略,为建设低碳生态城市提供一种新的思路和实践方法,从而打开研究城市建筑规划设计的新视角。

关键词：生态位城市建筑生态位生态位策略东京中城

Semi-analytic Modeling of Tokamak Particle Transport

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中国核科技报告 1999年第S3期 3-5页

作者： SHI Bingren LONG Yongxin li jiquan

Plasma particle transport is one of the most fundamental and important issues relevant to the global energy confinement time due not only to its effect on total energy storage but also to that the profile of the particle density is critical to the confinement mode. The study of particle transport generally includes the working particles like H, D and impurities. This paper is an extension of that described in Ref. [1]. Assuming the operator in transport equation is linear, we express the solution in a form based on the Green function or, equivalently, in generalized Fourier expansion. For space-dependent diffusion coefficient and convection, it is necessary to do some numerical calculation

关键词： Particle transport Complementarity Generalized Fourier expansion

Gyrokinetic simulation of magnetic-island-induced electric potential vortex mode

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Plasma Science and Technology 2024年第1期26卷 34-41页

作者：王丰李继全曲洪鹏彭晓东 Southwestern Institute of Physics Chengdu 610041People’s Republic of China

Ion temperature gradient(ITG)-driven turbulence with embedded static magnetic islands is simulated by utilizing a gyrokinetic theory-based global turbulence transport code(GKNET)in this *** from the traditional equilibrium circular magnetic-surface average(EMSA)method,an advanced algorithm that calculates the perturbed magnetic-surface average(PMSA)of the electric potential has been developed to precisely deal with the zonal flow component in a non-circular magnetic surface perturbed by magnetic *** show that the electric potential vortex structure inside islands induced by the magnetic islands is usually of odd parity when using the EMSA *** is found that the odd symmetry vortex can transfer into an even one after a steep zonal flow gradient,*** flow shear has been built in the vicinity of the magnetic islands by adopting the PMSA *** phase of the potential vortex in the poloidal cross section is coupled with the zonal flow *** an electric potential vortex mode may be of essential importance in wide topics,such as the turbulence spreading across magnetic islands,neoclassical tearing mode physics,and also the interaction dynamics between the micro-turbulence and MHD activities.

关键词： magnetic islands electric vortex ITG perturbed magnetic flux surface average