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Effect of passive structure and toroidal rotation on resistive wall mode stability in the EAST tokamak

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Chinese Physics B 2014年第7期23卷 523-528页

作者：刘广君万宝年孙有文刘钺强郭文峰郝广周丁斯晔沈飙肖炳甲钱金平 Institute of Plasma Physics Chinese Academy of Sciences Luoyang Optoelectro Technology Development Center Euratom/UKAEA Fusion Association Culham Science CentreAbingdonOX14 3DBUnited Kingdom Southwestern Institute of Physics

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.

关键词： resistive wall mode passive structure rotation

Numerical investigation of plane Couette flow with weak spanwise rotation

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Science China(Physics,Mechanics & Astronomy) 2019年第4期62卷 71-83页

作者： YuHan Huang ZhenHua Xia MinPing Wan YiPeng Shi ShiYi Chen State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Department of Engineering Mechanics Zhejiang University Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang University Department of Mechanics and Aerospace Engineering Southern University of Science and Technology

Direct numerical simulation of rotating plane Couette flow(RPCF) at Re_w= 1300 and Ro = 0.02 was performed with different mesh resolutions and different sizes of computation domain. Our results showed that a grid resolution in wall units with ?x^+=8.51, ?z^+= 4.26, ?y^+|_(min)= 0.0873 and ?y^+|_(max)= 3.89 is fine enough to simulate the problem at the present parameters. The streamwise length Lxand spanwise length Lzof the computational box have different impacts on the flow statistics, where the statistics were converged if Lxis longer than 8πh, while no converged results were obtained for different Lz. More importantly,our results with very long simulation time showed that a state transition would happen if L_x≥ 8πh, from a state with four pairs of roll cells to a state with three pairs of roll cells with L_z= 6πh. Each state could survive for more than 1500 h/U_w, and the flow statistics were different.

关键词： plane Couette flow span wise rotation state transition

A Note on rotation Symmetric S-boxes

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Journal of Systems Science & Complexity 2019年第5期32卷 1460-1472页

作者： GAO Guangpu LIN Dongdai LIU Wenfen State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou 450002China State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing 100093China State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing 100093China Guangxi Key Laboratory of Cryptogpraphy and Information Security Guilin University of Electronic TechnologyGuilin 541004China

This paper is twofold. The first is devoted to study a class of quadratic rotation symmetric S-boxes(RSSBs) which was presented by Gao G, et al., Constructions of quadratic and cubic rotation symmetric bent functions, IEEE Transactions on Information Theory, vol. 58, no. 7, pp. 4908 –4913, 2012, by decomposing a class of cubic rotation symmetric bent functions. The authors obtain its nonlinearity and differential uniformity of such class of S-boxes. In particular, the compositional inversion of the class of rotation symmetric S-boxes is also presented. Then the authors introduce a steepest-descent-like search algorithm for the generation of RSSBs. The algorithm finds 5,6,7,8-bit RSSBs with very good cryptographic properties which can be applied in designing cryptographical algorithms.

关键词： Dual Keccak permutation rotation symmetry S-box

Thomson and rotation effects during photothermal excitation process in magnetic semiconductor medium using variable thermal conductivity

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Applied Mathematics and Mechanics(English Edition) 2020年第6期41卷 909-926页

作者： K.LOTFY A.K.KHAMIS A.A.EL-BARY M.H.AHMED Department of Mathematics Faculty of ScienceZagazig UniversityZagazig 44519Egypt Department of Mathematics Faculty of ScienceTaibah UniversityAl-Madinah 30002Saudi Arabia Department of Mathematics Faculty of ScienceNorthern Border UniversityArar 91431Saudi Arabia Arab Academy for Science Technology and Maritime TransportAlexandria 1029Egypt

This study investigates a strong magnetic field acting over an elastic rotator semiconductor medium.The Thomson effect due to the magnetic field during the photothermal transport process is studied,and the thermoelectricity theory is used to explain the behavior of waves in the homogenous and isotropic medium under the effect of variable thermal conductivity.The variable thermal conductivity is considered as a linear function of the temperature.The two-dimensional deformation equations are used to describe the overlaps among plasma,electrical,thermal,and magneto-elastic waves.The charge density of inertia-particles is considered as a function of time for studying the induced electric current.The normal mode analysis is used to obtain the exact solutions of the physical field distributions as part of this phenomenon.To obtain the complete solutions of the physical field quantities,the certain mechanical loads,electromagnetic effects,thermal effects,and plasma recombination process are applied herein.The results of the physical distributions are graphically depicted and discussed in consideration of the internal heat source,rotation,and Peltier coefficient.

关键词： photothermal thermal conductivity Thomson effect rotation magnetic field Peltier coefficient

Effects of rice or wheat residue retention on the quality of milled japonica rice in a rice–wheat rotation system in China

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The Crop Journal 2015年第1期3卷 67-73页

作者： Pengfu Hou Yanfeng Ding Guofa Zhang Quan Li Shaohua Wang She Tang Zhenghui Liu Chengqiang Ding Ganghua Li College of Agronomy Nanjing Agricultural University/Key Laboratory of Crop Physiology Ecology and Production ManagementMinistry of Agriculture Daqing Normal University

In rice–wheat rotation systems, crop straw is usually retained in the field at land preparation in every, or every other, season. We conducted a 3-year-6-season experiment in the middle–lower Yangtze River Valley to compare the grain qualities of rice under straw retained after single or double seasons per year. Four treatments were designed as: both wheat and rice straw retained(WR), only rice straw retained(R), only wheat straw retained(W), and no straw retained(CK). The varieties were Yangmai 16 wheat and Wuyunjing 23 japonica rice. The results showed contrasting effects of W and R on rice quality. Amylopectin content, peak viscosity, cool viscosity, and breakdown viscosity of rice grain were significantly increased in W compared to the CK, whereas gelatinization temperature,setback viscosity, and protein content significantly decreased. In addition, the effect of WR on rice grain quality was similar to that of W, although soil fertility was enhanced in WR due to straw being retained in two cycles. The differences in protein and starch contents among the treatments might result from soil nitrogen supply. These results indicate that wheat straw retained in the field is more important for high rice quality than rice straw return, and straw from both seasons is recommended for positive effects on soil fertility.

关键词： Japonica rice Crop straw Grain quality Paddy–upland rotation

Modeling and analysis of solar Doppler difference bias with arbitrary rotation axis

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Chinese Journal of Aeronautics 2020年第12期33卷 3331-3343页

作者： Jin LIU Yangyang LI Xiaolin NING Xiao CHEN Zhiwei KANG College of Information Science and Engineering Wuhan University of Science and TechnologyWuhan 430081China College of Instrument Science and Optoelectronic Engineering Beihang UniversityBeijing 100191China Shanghai Institution of Satellite Engineering Shanghai 200240China College of Information Science and Engineering Hunan UniversityChangsha 410082China

The solar rotation causes the solar Doppler difference bias,which leads to the decline of the velocity measurement accuracy.Modeling and compensation are an effective solution.The limited model with specific geometric direction,where the solar rotation axis is perpendicular to the plane through the Sun,the Earth and Mars,was established.However,in fact,the geometric relationship among the Sun,Mars and the spacecraft is not fully in line with the hypothesis of the model due to the spacecraft orbital angle and the solar rotation axis drift.Thus,this model is not consistent with the fact.In order to solve this problem,a universal solar Doppler difference bias model,which provides the expression with arbitrary rotation axis,is established in this paper.In this method,for any point at the solar surface,four variables including the direction of the solar rotation linear velocity at this point,the distance from this point to the rotation axis,the vector from this point to Mars,and the vector from this point to the spacecraft are calculated.Based on these four variables,the solar Doppler difference bias corresponding to this point is obtained.The theoretical analysis and simulation results demonstrate that the solar Doppler difference bias model with the actual rotation axis is different from that with one of the specific rotation axes.Therefore,it is indispensable to build the proposed model for compensation.Besides,the direction of the solar rotation axis,the spacecraft-Mars-Sun angle and the spacecraft-to-Mars distance are important impact factors for the proposed model.

关键词： Bias Doppler navigation Measurement Modeling rotation

Change monitoring of earth rotation parameter with Maglev gyroscope precessional torque

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中国有色金属学会会刊：英文版 2011年第S3期21卷 589-593页

作者： YANG Zhi-qiang, GONG Yun, SHI Zhen, LI Yun Geological Engineering and Geomatics Institute, Chang’an University, Xi’an 710054, China Geological Engineering and Geomatics Institute Chang'an University Xi'an 710054 China

Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT Maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology.

关键词： Maglev gyroscope earth rotation parameters (ERP) precessional torque pole motion length of day

Influence of the Earth's rotation on measurement of gravitational constant G with the time-of-swing method

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Chinese Physics B 2020年第2期29卷 137-141页

作者：罗杰董涛邵成刚谈玉杰张惠捷 School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics PGMF and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074China

In the measurement of the Newtonian gravitational constant G with the time-of-swing method,the influence of the Earth's rotation has been roughly estimated before,which is far beyond the current experimental precision.Here,we present a more complete theoretical modeling and assessment process.To figure out this effect,we use the relativistic Lagrangian expression to derive the motion equations of the torsion pendulum.With the correlation method and typical parameters,we estimate that the influence of the Earth's rotation on G measurement is far less than 1 ppm,which may need to be considered in the future high-accuracy experiments of determining the gravitational constant G.

关键词： the Earth's rotation relativistic Lagrangian G measurement time-of-swing method

Cluster rotation in an Unmagnetized Dusty Plasma

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Chinese Physics Letters 2013年第11期30卷 128-132页

作者：黄峰刘艳红陈朝阳王龙叶茂福 College of Science China Agricultural UniversityBeijing 100083 School of Physics and Optoelectronic Engineering Ludong UniversityYantai 264025 Department of Physics Beijing University of Chemical TechnologyBeijing 100029 Institute of Physics Chinese Academy of SciencesBeijing 100190

rotation of dust clusters in an unmagnetized dusty plasma under different gas pressures is experimentally studied.Clusters containing different numbers of charged dust grains are found in different horizontal planes.The mechanism behind the dust rotation is investigated by using molecular dynamics simulations.The experimental and simulation results show that the radial confinement potential plays an important role in determining the properties of the cluster rotation under given gas pressure or temperature.

关键词： temperature rotation determining