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Experimental study of the time-resolved reflectivity of chromium film 被引量:1
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作者 武腾飞 周常河 +1 位作者 戴恩文 谢金 《Chinese Optics Letters》 SCIE EI CAS CSCD 2009年第7期653-655,共3页
The transient time-resolved reflectivity of chromium film is studied by femtosecond pump-probe technique with a 70-fs laser. Experimental results show that the reflectivity change increases with the power of the pump ... The transient time-resolved reflectivity of chromium film is studied by femtosecond pump-probe technique with a 70-fs laser. Experimental results show that the reflectivity change increases with the power of the pump laser. The fast decrease of the reflectivity occurs between 0-200 fs which is mainly due to the electron-electron interaction. Subsequencely, the slower recovery of the reflectivity between 200-900 fs is mainly due to the electron-phonon coupling process. The reflectivity after 900 fs rises little to a near-constant value for the thermal equilibrium of the system. The experimental results can be explained properly with numerical simulation of the two-temperature model. It is helpful for understanding of the electron ultrafast dynamics in chromium film. 展开更多
关键词 CHROMIUM Computer simulation electron electron interactions electronS Metal recovery Metallic films PHONONS Pumping (laser) PUMPS
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Impact of propagation effects on intersubband Rabi flopping in semiconductor quantum wells
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作者 周旭升 崔妮 +1 位作者 祖继锋 龚尚庆 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第9期689-692,共4页
We investigate intersubband Rabi flopping in modulation-doped semiconductor quantum wells with and without the propagation effects, respectively. It is shown that propagation effects have a larger impact on Rabi flopp... We investigate intersubband Rabi flopping in modulation-doped semiconductor quantum wells with and without the propagation effects, respectively. It is shown that propagation effects have a larger impact on Rabi flopping than the nonlinearities rooted from electron-electron interactions in multiple quantum wells. By using ultrashort rr pulses, an almost complete population inversion exists if the propagation effects are not considered; while no complete population inversion occurs in the presence of propagation effects. Furthermore, the magnitude of the impact of propagation effects may be controlled by varying the carrier density. 展开更多
关键词 Electric conductivity electron electron interactions Laser pulses MODULATION Semiconductor materials Semiconductor quantum wires WELLS
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用正电子湮没技术研究Cr和Nb对TiAl合金中缺陷和d-d电子相互作用的影响 被引量:2
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作者 祝莹莹 邓文 +4 位作者 孙顺平 江海峰 黄宇阳 曹名洲 熊良钺 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2009年第2期271-274,共4页
测量Al,Si,Ti,Cr,Nb等纯元素以及Ti50Al50,Ti50Al48Cr2,Ti50Al48Nb2合金的符合正电子湮没辐射多普勒展宽谱和寿命谱,获得金属及合金中d电子和缺陷的信息。结果表明,二元TiAl合金的电子密度和3d电子的信号较低,晶界缺陷的开空间较大。在T... 测量Al,Si,Ti,Cr,Nb等纯元素以及Ti50Al50,Ti50Al48Cr2,Ti50Al48Nb2合金的符合正电子湮没辐射多普勒展宽谱和寿命谱,获得金属及合金中d电子和缺陷的信息。结果表明,二元TiAl合金的电子密度和3d电子的信号较低,晶界缺陷的开空间较大。在TiAl合金中加入Cr或Nb,合金中的d-d电子作用增强,基体和晶界处的电子密度均增加。Ti50Al48Cr2合金的多普勒展宽谱的d电子信号高于Ti50Al48Nb2合金。讨论了Cr和Nb对TiAl合金中缺陷和d-d电子相互作用的影响。 展开更多
关键词 TIAL合金 d-d电子相互作用 缺陷 正电子湮没技术
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轨道选择性相变——多轨道物理中一类独特的现象 被引量:2
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作者 张宇钟 《物理》 CAS 北大核心 2014年第5期309-318,共10页
金属—绝缘体相变是凝聚态物理中被大量研究并有广泛应用前景的一种物理现象。通常具有巡游性的电子由于受到各种因素(如无序或电子相互作用等)的影响发生局域化,从而形成了金属—绝缘体相变。然而在实际材料中,由于电子还具有轨道属性... 金属—绝缘体相变是凝聚态物理中被大量研究并有广泛应用前景的一种物理现象。通常具有巡游性的电子由于受到各种因素(如无序或电子相互作用等)的影响发生局域化,从而形成了金属—绝缘体相变。然而在实际材料中,由于电子还具有轨道属性而使该相变的发生变得更加复杂。文章简要回顾了一类考虑电子轨道自由度后发生的较为特殊的金属—绝缘体相变——轨道选择性相变,即由于电子相互作用的影响而在同一原子壳层中出现局域化的电子和巡游电子共存的现象,并讨论了其形成机理和相关的实验。 展开更多
关键词 金属-绝缘体相变 轨道自由度 电子相互作用 多轨道哈巴德模型 动力学平均场
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Microscopic energy transport through photon-electron-phonon interactions during ultrashort laser ablation of wide bandgap materials Part Ⅰ: photon absorption 被引量:6
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作者 Lan Jiang Lishan Li +1 位作者 Sumei Wang Hai-Lung Tsai 《中国激光》 EI CAS CSCD 北大核心 2009年第4期779-789,共11页
The new phenomena induced by femtosecond lasers lead to the new area of ultrafast science.It is a significantchallenge to explain the phenomena associated with complex non-equilibrium and non-linear processes.Although... The new phenomena induced by femtosecond lasers lead to the new area of ultrafast science.It is a significantchallenge to explain the phenomena associated with complex non-equilibrium and non-linear processes.Althoughthere is a growing body of experimental observation,a comprehensive model remains undeveloped.We reviewthe challenges in understanding the photon absorption stage mainly for the femtosecond ablation of wide bandgap materialsat the intensities of 10^(13)~10^(14) W/cm^2.Major opinions and challenges in ionization mechanisms are presentedby primarily considering multiphoton ionization and avalanche ionization. 展开更多
关键词 激光导致 电离 光子 激光技术
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Evaluation of electron-electron interactions in coupled quantum dots by using far-infrared spectra
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作者 董庆瑞 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第4期1400-1404,共5页
We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the inter... We have studied the far-infrared spectra of two-electron vertically coupled quantum dots in an axial magnetic field by exact diagonalization. The calculated results show an obvious difference in role between the interactions for spin S = 1 and for spin S = O. The results support the possibility to evaluate the interactions by far-infrared spectroscopy in vertically coupled quantum dots. 展开更多
关键词 coupled quantum dots electron-electron interactions far-infrared spectra
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Interaction Effects on the Density of States in a Disordered Metallic Film
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作者 杨永宏 《Journal of Southeast University(English Edition)》 EI CAS 1996年第2期126-129,共4页
The interaction theory is generalized to the case of anisotropic disordered electronic systems. The interaction correction to the density of states near Fermi surface in a disordered metallic film is calculated in the... The interaction theory is generalized to the case of anisotropic disordered electronic systems. The interaction correction to the density of states near Fermi surface in a disordered metallic film is calculated in the weakly localized regime, and the dime 展开更多
关键词 DISORDERED SYSTEMS THIN FILMS electron electron interactions
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黄-里斯因子及其在阐释固体有关光学性质的关键作用 被引量:2
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作者 徐士杰 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第16期15-25,共11页
1950 年黄昆先生与A. Rhys(里斯,黄昆先生夫人,中文名李爱扶)发表了F-中心的光吸收与非辐射跃迁理论的论文,这一论文被公认为是处理电子-声子互作用在固体缺陷光吸收的先驱开创性量子理论工作,其中首先由黄昆先生所推导和明确的一个用... 1950 年黄昆先生与A. Rhys(里斯,黄昆先生夫人,中文名李爱扶)发表了F-中心的光吸收与非辐射跃迁理论的论文,这一论文被公认为是处理电子-声子互作用在固体缺陷光吸收的先驱开创性量子理论工作,其中首先由黄昆先生所推导和明确的一个用于表征电子-声子耦合强度的无量纲因子,被广泛采用和推崇为黄-里斯因子(Huang-Rhys factor),也被简称为S 因子.本文试图总结黄-里斯因子的物理内涵,以及它在阐释几种固体有关光学性质中的关键作用,包括在深缺陷中心发光以及带边浅杂质束缚激子发光中的支配作用.研究发现,在不同性质的固体材料中,电子(激子)-声子耦合强度可以分为极弱耦合(黄-里斯因子远远小于1)、中等耦合(黄-里斯因子在1—5 之间)以及强耦合(黄-里斯因子远远大于1)等几种情况.限于篇幅及个人理解,本文仅讨论GaN 各种带边激子、二维单原子层半导体激子、无机卤族钙钛矿纳米晶片激子以及金刚石单晶中NV 复合中心等极弱及中等强度耦合等几种情况,以纪念黄昆先生诞辰百周年. 展开更多
关键词 声子-电子互作用 黄-里斯因子 固体光学性质 发光
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电子——电子相互作用和Hubbard模型
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作者 解士杰 赵明文 田茂盛 《山东大学学报(自然科学版)》 CSCD 1992年第4期434-439,共6页
采用屏蔽库仑势形式,通过计算—维体系中电子——电子相互作用的U,V,W,X 各项值,分析了Hubbard 模型、KSSH 模型等的不足,并给出它们适用范围的参考标准。
关键词 相互作用 电子 HUBBARD模型
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电子 -电子相互作用对电致发光高分子极化特性的影响(英文) 被引量:1
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作者 傅柔励 郭光宇 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2000年第4期259-265,共7页
用同时计入电子 -电子相互作用 ,外电场及电子 -晶格相互作用的理论模型研究分析了电致发光高分子的极化特性 ,发现在位电子相互作用和相邻格点间电子的相互作用明显增加高分子中双激子态的反向极化 .
关键词 电子-电子相互作用 极化 电致发光高分子
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电子-电子相互作用对trion静态性质的影响
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作者 苗文丹 张亚琳 王亚东 《河北师范大学学报(自然科学版)》 CAS 北大核心 2014年第6期584-588,共5页
基于一维紧束缚SSH模型和扩展的Hubbard模型,采用非绝热分子动力学方法,在非限制性Hartree-Fock(HF)平均场近似下,研究了三粒子复合体trion的静态性质.trion比极化子、双极化子具有更大的束缚能、稳定性和有效质量;电子-声子耦合和电子... 基于一维紧束缚SSH模型和扩展的Hubbard模型,采用非绝热分子动力学方法,在非限制性Hartree-Fock(HF)平均场近似下,研究了三粒子复合体trion的静态性质.trion比极化子、双极化子具有更大的束缚能、稳定性和有效质量;电子-声子耦合和电子间相互作用均增强trion的局域度,并导致其有效质量增大,稳定性增强. 展开更多
关键词 聚合物 TRION 电子-电子相互作用
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混合金属卤化物中的电荷转移
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作者 李宏 《曲阜师范大学学报(自然科学版)》 CAS 1999年第2期58-60,共3页
采用双带Peierls_Hubbard模型研究混合金属卤化物PtXxX′1-x,发现电荷会穿过界面在两单体内自发转移,从而导致极化子的生产.随着电子-电子(e-e)相互作用强度的增加。
关键词 金属卤化物 电子-电子 相互作用 电荷转移
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极性晶体膜中的强耦合磁极化子 被引量:2
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作者 花修坤 顾世洧 彭飞 《上海交通大学学报》 EI CAS CSCD 北大核心 1999年第6期703-705,共3页
应用变分法研究了极性晶体膜中强耦合磁极化子的性质,给出基态和激发态的系统能量,重点研究了系统处于基态和激发态时的电子-表面声子相互作用能.计算结果表明,在磁场强度一定的条件下(B=9T),电子-表面声子相互作用能随着... 应用变分法研究了极性晶体膜中强耦合磁极化子的性质,给出基态和激发态的系统能量,重点研究了系统处于基态和激发态时的电子-表面声子相互作用能.计算结果表明,在磁场强度一定的条件下(B=9T),电子-表面声子相互作用能随着膜厚的增加而减小;在一定膜厚的条件下(W=3nm),电子-表面声子相互作用能随着磁场强度的增加先增大而后缓慢减小,当B=30T时,|Ve-SO(1)|和|Ve-SO(0)|之间的差最大. 展开更多
关键词 强耦合 磁极化子 电子-声子作用 极性晶体
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The effect of interface hopping on inelastic scattering of oppositely charged polarons in polymers
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作者 邸冰 王亚东 +1 位作者 张亚琳 安忠 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期512-517,共6页
The inelastic scattering of oppositely charge polarons in polymer heterojunctions is believed to be of fundamental importance for the light-emitting and transport properties of conjugated polymers. Based on the tight-... The inelastic scattering of oppositely charge polarons in polymer heterojunctions is believed to be of fundamental importance for the light-emitting and transport properties of conjugated polymers. Based on the tight-binding SSH model, and by using a nonadiabatic molecular dynamic method, we investigate the effects of interface hopping on inelastic scattering of oppositely charged polarons in a polymer heterojunction. It is found that the scattering processes of the charge and lattice defect depend sensitively on the hopping integrals at the polymer/polymer interface when the interface potential barrier and applied electric field strength are constant. In particular, at an intermediate electric field, when the interface hopping integral of the polymer/polymer heterojunction material is increased beyond a critical value, two polarons can combine to become a lattice deformation in one of the two polymer chains, with the electron and the hole bound together, i.e., a self-trapped polaron-exciton. The yield of excitons then increases to a peak value. These results show that interface hopping is of fundamental importance and facilitates the formation of polaron-excitons. 展开更多
关键词 POLARONS electron-phonon interactions EXCITON POLYMERS
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Injection and transport of electric charge in a metal/copolymer structure
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作者 李冬梅 袁晓娟 +1 位作者 马嘉赛 刘德胜 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期438-445,共8页
The dynamical processes of the electric charge injection and transport from a metal electrode to the copolymer are investigated by using a nonadiabatic dynamic approach. The simulations are performed within the framew... The dynamical processes of the electric charge injection and transport from a metal electrode to the copolymer are investigated by using a nonadiabatic dynamic approach. The simulations are performed within the framework of an extended version of the one-dimensional Su-Schrieffer-Heeger (SSH) tight-binding model. It is found that the electric charge can be injected into the copolymer by increasing the applied voltage. For different structures of the copolymer, the critical voltage biases are different and the motion of the injected electric charge in the copolymer varies obviously. For the copolymer with a barrier-well-barrier configuration, the injected electric charge forms a wave packet due to the strong electron-lattice interaction in the barrier, then comes into the well and will be confined in it under a weak electric field. Under a medium electric field, the electric charge can go across the interface of two homopolymers and enter into the other potential barrier. For the copolymer with a well-barrier-well configuration, only under strong enough electric field can the electric charge transfer from the potential well into the barrier and ultimately reach a dynamic balance. 展开更多
关键词 injection and transport electron-lattice interactions potential barrier potential well
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Dynamical study on charge injection and transport in a metal/polythiophene/metal structure
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作者 李冬梅 刘晓静 +5 位作者 李元 李海宏 胡贵超 高馄 刘德胜 解士杰 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期3067-3076,共10页
The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene (PT)/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found tha... The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene (PT)/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger. 展开更多
关键词 metal/polythiophene/metal structure electron-phonon interactions carriers transport wave packet
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Oscillatory electron phonon coupling in Pb/Si(111)deduced by temperature-dependent quantum well states
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作者 张艳锋 贾金锋 +4 位作者 韩铁柱 唐喆 沈全通 郭阳 薛其坤 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第9期1910-1914,共5页
Photoemission study of atomically flat Pb films with a thickness from 15 to 24 monolayers (ML) have been performed within a temperature range 75-270K. Well-defined quantum well states (QWSs) are observed, which ex... Photoemission study of atomically flat Pb films with a thickness from 15 to 24 monolayers (ML) have been performed within a temperature range 75-270K. Well-defined quantum well states (QWSs) are observed, which exhibit interesting temperature-dependent behaviours. The peak position of the QWSs shifts towards higher binding energy with increasing substrate temperature, whereas the peak width broadens linearly due to enhanced electron-phonon coupling strength (λ). An oscillatory A with a period of 2ML is deduced. Preliminary analysis shows that the oscillation can be explained in terms of the interface induced phase variations, and is thus a manifestation of the quantum size effects. 展开更多
关键词 Pb thin films PHOTOEMISSION quantum well states electron-phonon interactions
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磁场下量子点中二电子系统的自旋振荡 被引量:1
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作者 杨健君 王旭 《内蒙古大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第2期149-153,共5页
研究了磁场下量子点中二电子系统的低激发态能谱 ,考察了电子 -声子相互作用对能谱的影响 .以 In Sb半导体材料为对象进行了数值计算 ,并将结果与他人的二维简化模型的结果进行了对比 .发现在此三维系统中仍可出现自旋振荡现象 ,但能级... 研究了磁场下量子点中二电子系统的低激发态能谱 ,考察了电子 -声子相互作用对能谱的影响 .以 In Sb半导体材料为对象进行了数值计算 ,并将结果与他人的二维简化模型的结果进行了对比 .发现在此三维系统中仍可出现自旋振荡现象 ,但能级随磁场的增大要比二维结果变化缓慢 ,且基态能级交替点向强磁场方有向明显移动 . 展开更多
关键词 量子点 磁场 自旋态 电子-声子相互作用 二电子系统 自旋振荡 低激发态能谱
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电子-晶格耦合非线性项对极化子性质的影响 被引量:1
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作者 宋瑞 刘晓静 +2 位作者 王亚东 邸冰 安忠 《物理学报》 SCIE EI CAS CSCD 北大核心 2010年第5期3461-3465,共5页
基于一维紧束缚SSH模型,讨论了电子晶格耦合二阶项对极化子静态和动力学性质的影响:随着二阶项系数β的增加,二聚化常数越来越大,能隙越来越宽,极化子的局域性不断增强,但带宽几乎没有变化.动力学方面由于二阶项的引入增强了电声相互作... 基于一维紧束缚SSH模型,讨论了电子晶格耦合二阶项对极化子静态和动力学性质的影响:随着二阶项系数β的增加,二聚化常数越来越大,能隙越来越宽,极化子的局域性不断增强,但带宽几乎没有变化.动力学方面由于二阶项的引入增强了电声相互作用,随着β值的增大,极化子的运动速度减小,并且极化子的解离电场不断增大. 展开更多
关键词 SSH模型 电-声耦合二阶项 极化子
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电子-声子相互作用非对称双势垒共振隧穿的影响(英文)
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作者 闫祖威 梁希侠 班士良 《内蒙古大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第5期520-526,共7页
理论研究了非对称双势垒结构中光学声子发射率和光学声子辅助隧穿电流 .对Alx Ga1-x As/Ga As/Aly Ga1-y As结构作了数值计算 ,得到对声子辅助隧穿实验电流峰的一种新的理论上的合理辨认 .对宽量子阱理论上只有一个声子辅助峰 ,且接近阱... 理论研究了非对称双势垒结构中光学声子发射率和光学声子辅助隧穿电流 .对Alx Ga1-x As/Ga As/Aly Ga1-y As结构作了数值计算 ,得到对声子辅助隧穿实验电流峰的一种新的理论上的合理辨认 .对宽量子阱理论上只有一个声子辅助峰 ,且接近阱内 LO声子的能量 .发现界面光学 ( IO)声子辅助隧穿是主要的 . 展开更多
关键词 声子辅助隧穿 电子-声子相互作用 非对称双势垒结构 共振隧穿 宽量子阱理论 光学声子
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