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纤维形态参数及测量 被引量:50
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作者 王丹枫 《中国造纸》 CAS 北大核心 2000年第1期36-39,共4页
介绍了造纸用纤维和纸浆中纤维形态参数(长度、粗度、卷曲、扭结等) 的意义及自动测量原理、测量方法, 并介绍了纤维形态参数在制浆造纸工业生产与控制中的应用前景。
关键词 长度分布 卷曲 扭结 测量 形态参数 造纸纤维
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Two new types of bounded waves of CH-γ equation 被引量:12
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作者 GUO Boling & LIU Zhengrong Institute of Applied Physics and Computational Mathematics, Beijing 100088, China School of Mathematical Sciences and Center for Nonlinear Science Studies, South China University of Technology, Guangzhou 510640, China 《Science China Mathematics》 SCIE 2005年第12期1618-1630,共13页
In this paper, the bifurcation method of dynamical systems and numerical approach of differential equations are employed to study CH-γ equation. Two new types of bounded waves are found. One of them is called the com... In this paper, the bifurcation method of dynamical systems and numerical approach of differential equations are employed to study CH-γ equation. Two new types of bounded waves are found. One of them is called the compacton. The other is called the generalized kink wave. Their planar graphs are simulated and their implicit expressions are given. The identity of theoretical derivation and numerical simulation is displayed. 展开更多
关键词 CH-γ equation compactons generalized kink waves.
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膝褶、膝褶带、共轭膝褶带——一种可能的新型油气构造样式 被引量:9
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作者 张波 李生福 +2 位作者 张进江 郑亚东 张仲培 《天然气工业》 EI CAS CSCD 北大核心 2010年第2期32-39,71,共9页
受控于最大有效力矩准则的共轭膝褶带,是各向异性岩石中较为常见的构造变形样式,依据大量国、内外学者的研究资料及勘探实践成果,结合膝褶带几何学、形成机制以及地球物理资料解释成果等综合分析认为,大型膝褶带和共轭膝褶带可能被误解... 受控于最大有效力矩准则的共轭膝褶带,是各向异性岩石中较为常见的构造变形样式,依据大量国、内外学者的研究资料及勘探实践成果,结合膝褶带几何学、形成机制以及地球物理资料解释成果等综合分析认为,大型膝褶带和共轭膝褶带可能被误解释为"两断夹一隆"的构造形态,原先一些构造样式被解释为高角度逆冲断层的地方更可能是膝褶的枢纽带。研究结果认为,膝褶带具备形成油气构造圈闭的物质条件,可形成有利油气聚集区;膝褶带和共扼膝褶带作为非主造山期构造在油气勘探和构造解释上应引起石油地质学家和地球物理学家的重视;结合野外地质构造观测,利用地球物理资料准确识别和区分膝褶带构造与断裂构造是寻找油气构造圈闭的新思路和新方法。 展开更多
关键词 膝褶 膝褶带 共扼膝褶带 褶皱 最大有效力矩 含油气构造 构造圈闭 油气聚集区
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Effect of the Plasma Pressure on Magnetohydrodynamic Kink Instability in a Cylindrical Geometry 被引量:10
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作者 代玉杰 刘金远 王学慧 《Plasma Science and Technology》 SCIE EI CAS CSCD 2009年第3期269-273,共5页
A semi-analytical method is introduced to study kink instability in cylindrical plasma with line-tied boundary conditions. The method is based on an expansion for magnetohydrodynamics (MHD) equations in one-dimensio... A semi-analytical method is introduced to study kink instability in cylindrical plasma with line-tied boundary conditions. The method is based on an expansion for magnetohydrodynamics (MHD) equations in one-dimensional (1D) radial eigenvalue problems by using Fourier transforms. The MHD equations then become an ordinary differential equation. This method is applicable to both ideal and non-ideal MHD problem. The effect of plasma pressure (P0) on kink instability is studied in a cylindrical geometry. Complex discrete spectra are pre- sented. Two-dimensional (2D) eigenfunctions with the line-tied boundary conditions are obtained. The growth rate and radial eigenfunctions are different in the two cases of P0 = 0 and P0 ≠ 0, which indicate that the effect of plasma pressure can not be ignored if it is large enough. This method allows us to understand the role of individual radial eigenfunctions, and is also computationally efficient compared to direct solutions of the MHD equations by the finite difference method. 展开更多
关键词 plasma pressure Fourier transforms MHD kink instability
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等离子体压强对Line-tied扭曲不稳定性增长率和本征函数的影响 被引量:9
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作者 代玉杰 刘金远 王学慧 《核聚变与等离子体物理》 CAS CSCD 北大核心 2010年第4期306-311,共6页
应用半解析方法,研究了直圆柱位形下等离子体压强P0分别为P0=0、P0=常数和P0=f(r)时Line-tied扭曲不稳定性的增长率和二维径向本征函数的演化规律。结果表明,P0=0和P0=常数时的轴向波数k的范围相同,但P0=常数时的增长率比P0=0时的小。P0... 应用半解析方法,研究了直圆柱位形下等离子体压强P0分别为P0=0、P0=常数和P0=f(r)时Line-tied扭曲不稳定性的增长率和二维径向本征函数的演化规律。结果表明,P0=0和P0=常数时的轴向波数k的范围相同,但P0=常数时的增长率比P0=0时的小。P0=f(r)时的轴向波数k的范围和增长率则都比P0=0时的大,同时磁流体的速度变化也较大。因此,P0=f(r)更接近实际的物理模型(例如日冕的喷射问题)。 展开更多
关键词 等离子体 压强 扭曲 不稳定性增长率 径向本征函数 kink 常数 半解析方法 轴向 演化规律 物理模型 速度变化 波数 磁流体 圆柱 问题 位形 日冕 喷射 结果
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Bifurcations of Travelling Wave Solutions for a Two-Component Camassa-Holm Equation 被引量:6
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作者 Ji Bin LI Yi Shen LI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2008年第8期1319-1330,共12页
By using the method of dynamical systems to the two-component generalization of the Camassa-Holm equation, the existence of solitary wave solutions, kink and anti-kink wave solutions, and uncountably infinite many bre... By using the method of dynamical systems to the two-component generalization of the Camassa-Holm equation, the existence of solitary wave solutions, kink and anti-kink wave solutions, and uncountably infinite many breaking wave solutions, smooth and non-smooth periodic wave solutions is obtained. Under different parametric conditions, various sufficient conditions to guarantee the existence of the above solutions are given. Some exact explicit parametric representations of travelling wave solutions are listed. 展开更多
关键词 solitary wave kink wave solution periodic wave solution breaking wave solution smooth- ness of wave
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Compressive failure analysis of unidirectional carbon/epoxy composite based on micro-mechanical models 被引量:6
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作者 Wei SUN Zhidong GUAN +2 位作者 Zengshan LI Mi ZHANG Yongjie HUANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第6期1907-1918,共12页
A 2D micro-mechanical model was proposed to study the compressive failure of Uni Directional(UD) carbon/epoxy composite. Considering the initial imperfection and strength distribution of the fiber, the plasticity an... A 2D micro-mechanical model was proposed to study the compressive failure of Uni Directional(UD) carbon/epoxy composite. Considering the initial imperfection and strength distribution of the fiber, the plasticity and ductile damage of the matrix, the failure of T300/914 UD composite under longitudinal compression and in-plane combined loads was simulated by this model. Simulation results show that the longitudinal compressive failure of the UD composite is caused by the plastic yielding of the matrix in kink band, and the fiber initial imperfection is the main reason for it. Under in-plane combined loads, the stress state of the matrix in kink band is changed, which affects the longitudinal compressive failure modes and strength of UD composite.The failure envelope of r_1–s_(12) and r_1–r_2 are obtained by the micro-mechanical model. Meanwhile,the compressive failure mechanism of the UD composite is analyzed. Numerical results agree well with the experimental data, which verifies the validity of the micro-mechanical model. 展开更多
关键词 Micro-mechanical model Unidirectional composite Initial imperfection Matrix plasticity Ductile damage kink band
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Rolling reduction-dependent deformation mechanisms and tensile properties in aβtitanium alloy 被引量:7
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作者 Zhaoxin Du Qiwei He +6 位作者 Ruirun Chen Fei Liu Jingyong Zhang Fei Yang Xueping Zhao Xiaoming Cui Jun Cheng 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第9期183-193,共11页
This work investigated the dependence of deformation mechanisms and mechanical properties on cold rolling reductions of the metastable TB8 titanium alloy.Results shown that the crystal orientation of the matrix change... This work investigated the dependence of deformation mechanisms and mechanical properties on cold rolling reductions of the metastable TB8 titanium alloy.Results shown that the crystal orientation of the matrix changes with the increasing level of reduction,leading to the activation of complex deformation mechanisms in the matrix.When the rolling reduction is 10%,the deformation mechanisms are dominated by dislocations and{332}<113>deformation twins.As the reductions increase to 20%-50%,the secondary deformation twinning(SDT)is triggered in primary deformation twins besides the primary kink band is activated.Meanwhile,the secondary kink bands and{332}<113>twins have be observed in the primary kink bands.When the reduction reaches to 60%,the deformation mechanisms are dominated by dislocations and deformation twins.Furthermore,the matrix refined by crisscrossing among the twins,kink bands and other deformation mechanisms during cold rolling,which shortens the dislocation mean free path and then affects the strength and shape of the alloy.The dynamic Hall-Petch effect and the interaction between multi-scale deformed structures control the work hardening behavior of the alloy. 展开更多
关键词 TB8 titanium alloy Deformation mechanisms kink band variants TWINNING Mechanical properties
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An improved ASM-HEMT model for kink effect on GaN devices
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作者 WANG Shuai CHENG Ai-Qiang +3 位作者 GE Chen CHEN Dun-Jun LIU Jun DING Da-Zhi 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2024年第4期520-525,共6页
With the analysis of experiment and theory on GaN HEMT devices under DC sweep,an improved model for kink effect based on advanced SPICE model for high electron mobility transistors(ASM-HEMT)is pro⁃posed,considering th... With the analysis of experiment and theory on GaN HEMT devices under DC sweep,an improved model for kink effect based on advanced SPICE model for high electron mobility transistors(ASM-HEMT)is pro⁃posed,considering the relationship between the drain/gate-source voltage and kink effect.The improved model can not only accurately describe the trend of the drain-source current with the current collapse and kink effect,but also precisely fit different values of drain-source voltages at which the kink effect occurs under different gatesource voltages.Furthermore,it well characterizes the DC characteristics of GaN devices in the full operating range,with the fitting error less than 3%.To further verify the accuracy and convergence of the improved model,a load-pull system is built in ADS.The simulated result shows that although both the original ASM-HEMT and the improved model predict the output power for the maximum power matching of GaN devices well,the im⁃proved model predicts the power-added efficiency for the maximum efficiency matching more accurately,with 4%improved. 展开更多
关键词 ASM-HEMT DC current collapse kink effect
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Exact Traveling Wave Solutions and Bifurcations in a Nonlinear Elastic Rod Equation 被引量:3
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作者 Ji-bin Li Tian-lan He 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2010年第2期283-306,共24页
The exact parametric representations of the traveling wave solutions for a nonlinear elastic rod equation are considered. By using the method of planar dynamical systems, in different parameter regions, the phase port... The exact parametric representations of the traveling wave solutions for a nonlinear elastic rod equation are considered. By using the method of planar dynamical systems, in different parameter regions, the phase portraits of the corresponding traveling wave system are given. Exact explicit kink wave solutions, periodic wave solutions and some unbounded wave solutions are obtained. 展开更多
关键词 kink wave solution periodic wave solution qualitative method BIFURCATION elliptic function
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Integrable peakon systems with weak kink and kink-peakon interactional solutions 被引量:2
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作者 Zhijun QIAO Baoqiang XIA 《Frontiers of Mathematics in China》 SCIE CSCD 2013年第5期1185-1196,共12页
We report two integrable peakon systems that have weak kink and kink-peakon interactional solutions. Both peakon systems are guaranteed integrable through providing their Lax pairs. The peakon and multi-peakon solutio... We report two integrable peakon systems that have weak kink and kink-peakon interactional solutions. Both peakon systems are guaranteed integrable through providing their Lax pairs. The peakon and multi-peakon solutions of both equations are studied. In particular, the two-peakon dynamic systems are explicitly presented and their collisions are investigated. The weak kink solution is studied, and more interesting, the kink-peakon interactional solutions are proposed for the first time. 展开更多
关键词 Integrable system Lax pair PEAKON weak kink kink-peakon
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Three-Dimensional Simulation of Plasma Deformation During Contact Opening in a Circuit Breaker,Including the Analysis of Kink Instability and Sausage Instability 被引量:3
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作者 Vahid ABBASI Ahmad GHOLAMI Kaveh NIAYESH 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第11期996-1001,共6页
A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric cur... A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm's law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere's law, Ohm's law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl'amework of time-dependent magnetohydrodynamic (MHD) equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma (these phenomena are related tO pinch effects and electromagnetic fields). The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations. 展开更多
关键词 magnetohydrodynamic (MHD) plasma deformation electromagnetic force kink instability sausage instability
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Gapped topological kink states and topological corner states in honeycomb lattice 被引量:5
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作者 Yuting Yang Ziyuan Jia +4 位作者 Yijia Wu Rui-Chun Xiao Zhi Hong Hang Hua Jiang X.C.Xie 《Science Bulletin》 SCIE EI CAS CSCD 2020年第7期531-537,M0003,共8页
Based on the tight-binding calculations on honeycomb lattice and photonic experimental visualization on artificial graphene(AG), we report the domain-wall-induced gapped topological kink states and topological corner ... Based on the tight-binding calculations on honeycomb lattice and photonic experimental visualization on artificial graphene(AG), we report the domain-wall-induced gapped topological kink states and topological corner states. In honeycomb lattice, domain walls(DWs) with gapless topological kink states could be induced either by sublattice symmetry breaking or by lattice deformation. We find that the coexistence of these two mechanisms will induce DWs with gapped topological kink states. Significantly, the intersection of these two types of DWs gives rise to topological corner state localized at the crossing point.Through the manipulation of the DWs, we show AG with honeycomb lattice structure not only a versatile platform supporting multiple topological corner modes in a controlled manner, but also possessing promising applications such as fabricating topological quantum dots composed of gapped topological kink states and topological corner states. 展开更多
关键词 Topological corner states Topological kink states Topological quantum dot Honeycomb photonic crystal Domain-wall-induced topological states
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2-D Theoretical Model for Current–Voltage Characteristics in AlGaN/GaN HEMT’s 被引量:2
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作者 Manel Charfeddine Hafedh Belmabrouk +1 位作者 Mohamed Ali Zaidi Hassen Maaref 《Journal of Modern Physics》 2012年第8期881-886,共6页
A threshold-voltage-based 2-D theoretical model for the Current–Voltage characteristics of the AlGaN/GaN high electron mobility transistors (HEMT’s) is developed. The present work proposes an improved charge-control... A threshold-voltage-based 2-D theoretical model for the Current–Voltage characteristics of the AlGaN/GaN high electron mobility transistors (HEMT’s) is developed. The present work proposes an improved charge-control model by employing the Robin boundary condition when introduced the solution of the 2-D Poisson’s equation in the density of charge depleted in the AlGaN layer. The dependence of 2-DEG sheet carrier concentration on the aluminum composition and AlGaN layer thickness has been investigated in detail. Current–voltage characteristics developed from the 2-DEG model in order to take into account the impact of gate lengths. The relation between the kink effect and existing deep centers has also been confirmed by using an electrical approach, which can allow to adjust some of electron transport parameters in order to optimize the output current. 展开更多
关键词 ALGAN/GAN High ELECTRON Mobility TRANSISTORS Two-Dimensional ELECTRON Gas Sheet Charge Density Current–Voltage Characteristics kink Effect
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An improved EEHEMT model for kink effect on AlGaN/GaN HEMT 被引量:2
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作者 曹梦逸 卢阳 +5 位作者 魏家行 陈永和 李卫军 郑佳欣 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期452-456,共5页
In this paper, a new current expression based on both the direct currect (DC) characteristics of the A1GaN/GaN high election mobility transistor (HEMT) and the hyperbolic tangent function tanh is proposed, by whic... In this paper, a new current expression based on both the direct currect (DC) characteristics of the A1GaN/GaN high election mobility transistor (HEMT) and the hyperbolic tangent function tanh is proposed, by which we can describe the kink effect of the A1GaN/GaN HEMT well. Then, an improved EEHEMT model including the proposed current expression is presented. The simulated and measured results of Ⅰ-Ⅴ, S-parameter, and radio frequency (RF) large-signal characteristics are compared for a self-developed on-wafer A1GaN/GaN HEMT with ten gate fingers each being 0.4-μm long and 125-p-m wide (Such an A1GaN/GaN HEMT is denoted as A1GaN/GaN HEMT (10 × 125 μm)). The improved large signal model simulates the Ⅰ-Ⅴ characteristic much more accurately than the original one, and its transconductance and RF characteristics are also in excellent agreement with the measured data. 展开更多
关键词 A1GaN/GaN HEMT kink effect tanh EEHEMT model
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Spatio-Temporal Deformation of Kink-Breather to the (2+1)-Dimensional Potential Boiti–Leon–Manna–Pempinelli Equation 被引量:2
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作者 宋莉莉 蒲志林 戴正德 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第5期493-497,共5页
In the paper, the rational breather soliton and kink solitary wave solution of the (2+1)-dimensional PBLMP equation are obtained by adopting Hirota bilinear method and selecting different test functions. Furthermore, ... In the paper, the rational breather soliton and kink solitary wave solution of the (2+1)-dimensional PBLMP equation are obtained by adopting Hirota bilinear method and selecting different test functions. Furthermore, it has been found that the fusion and degeneration of the kink solitary wave occur when interaction between the rational breather soliton and the kink solitary wave happens. These phenomena are very helpful in researching soliton dynamical complexity in the higher dimensional systems. 展开更多
关键词 the (2+1)-dimensional PBLMP equation the Hirota bilinear method the kink solitary wave the rational breather soliton fusion DEGENERATION
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三维复Ginzburg-Landau方程的一些精确解 被引量:4
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作者 罗森月 杨荣晖 钟澎洪 《肇庆学院学报》 2010年第2期6-8,共3页
通过辅助函数法与齐次平衡原理,得到了三维复Ginzburg-Landau方程的一些精确周期波和扭结波解.
关键词 Ginzburg—Landau 辅助函数法 周期波 扭结
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Observation of Doppler shift f_(D) modulated by the internal kink mode using conventional reflectometry in the EAST tokamak
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作者 李恭顺 张涛 +18 位作者 耿康宁 文斐 叶凯萱 徐立清 朱翔 张学习 钟富彬 周振 杨书琪 周子强 喻琳 兰婷 王守信 提昂 张寿彪 刘海庆 李国强 高翔 the EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期1-9,共9页
In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence sp... In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_(D)during the internal kink mode(IKM)rotation phase.This Doppler shift f_(D)is the target measurement of Doppler reflectometry,but captured by conventional reflectometry.Results show that the Doppler shift f_(D)is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal,but not by plasma turbulence.The fishbone mode and saturated long-lived mode are typical IKMs,and this modulation phenomenon is observed in both cases.Moreover,the value of the Doppler shift f_(D)is positively correlated with the amplitude of the IKM,even when the latter is small.However,the positive and negative frequency components of the Doppler shift f_(D)can be asymmetric,which is related to the plasma configuration.A simulated analysis is performed by ray tracing to verify these observations.These results establish a clear link between f_(D)and IKM rotation,and are helpful for studying the characteristics of IKM and related physical phenomena. 展开更多
关键词 microwave reflectometry Doppler shift internal kink mode
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Advantages of rapid solidification over casting of Mg-0.4Zn-1Y alloy
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作者 Drahomír Dvorský Shin-Ichi Inoue +7 位作者 Ayami Yoshida JiríKubásek Jan Duchon Esther de Prado Andrea Školáková Klára Hosová Petr Svora Yoshihito Kawamura 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第7期2847-2862,共16页
The Mg-Y-Zn magnesium alloy system is commonly recognized for its remarkable combination of high strength and ductility,achieved even with minimal amounts of alloying elements.This exceptional performance is attribute... The Mg-Y-Zn magnesium alloy system is commonly recognized for its remarkable combination of high strength and ductility,achieved even with minimal amounts of alloying elements.This exceptional performance is attributed to its unique microstructure,which includes Long-Period Stacking Ordered(LPSO)phases or the distinctive microstructure derived from the LPSO phase,referred to as the Mille-Feuille structure(MFS).This study systematically compares the traditional ingot metallurgy method with the rapid solidification technique,coupled with diverse heat treatments and extrusion processes.Microscopic analyses reveal variations in the presence of LPSO phases,Mille-Feuille structure,and grain size,leading to divergent mechanical and corrosion properties.The rapid solidification approach stands out,ensuring superior mechanical properties alongside a reasonable corrosion rate. 展开更多
关键词 Rapid solidification LPSO kink EXTRUSION Corrosion Ignition temperature
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Exact Traveling Wave Solutions of Nano-Ionic Solitons and Nano-Ionic Current of MTs Using the exp(-φ (ξ ))-Expansion Method
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作者 Emad H. M. Zahran 《Advances in Nanoparticles》 2015年第2期25-36,共12页
In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to... In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. The validity and reliability of the method are tested by its applications to Nano-ionic solitons wave’s propagation along microtubules in living cells and Nano-ionic currents of MTs which play an important role in biology. 展开更多
关键词 The exp(-φ )) -Expansion Method Nano-Solitons of IONIC Wave’s Propagation along Microtubules in Living Cells Nano-Ionic Currents of MTS Traveling WAVE SOLUTIONS kink and Anti kink WAVE SOLUTIONS
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