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Dynamic evolution of outer radiation belt electrons driven by superluminous R-X mode waves

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science china(Technological sciences) 2010年第10期53卷 2734-2738页

作者： xiao fuliang1,2, chen liangxu1, he yihua1 & yang chang1 1 school of physics and electronic sciences, changsha university of science and technology, changsha 410004, china 2 State Key Laboratory of Space Weather, Chinese Academy of sciences, Beijing 100190, china school of physics and electronic sciences Changsha University of Science and Technology Changsha China State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing China

We present initial results on the temporal evolution of the phase space density (PSD) of the outer radiation belt energetic electrons driven by the superluminous R-X mode waves. We calculate diffusion rates in pitch angle and momentum assuming the standard Gaussian distributions in both wave frequency and wave normal angle at the location L=6.5. We solve a 2D momentum-pitch-angle Fokker-Planck equation using those diffusion rates as inputs. Numerical results show that R-X mode can produce significant acceleration of relativistic electrons around geostationary orbit,supporting previous findings that superluminous waves potentially contribute to dramatic variation in the outer radiation belt electron dynamics.

关键词： wave-particle interaction superluminous R-X waves phase space density evolution radiation belt electrons

Quasi-linear modeling of gyroresonance between different MLT chorus and geostationary orbit electrons

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science china(Information sciences) 2012年第11期55卷 2624-2634页

作者： ZHANG ZeLong1,2,xiao fuliang1,2,he yihua1,2,he ZhaoGuo1,2,yang chang1,ZHOU xiaoPing1 & TANG LiJun1 1school of physics and electronic sciences,changsha university of science and technology,changsha 410004,china 2Key Laboratory of Basic Plasma physics,Chinese Academy of sciences,hefei 230026,china school of physics and electronic sciences Changsha University of Science and Technology Changsha China Key Laboratory of Basic Plasma physics Chinese Academy of Sciences Hefei China

The contributions of dayside and nightside gyroresonance of chorus waves to electron radiation belt evolution at L = 6.6 are detailedly differentiated via fully solving the two-dimensional Fokker-Plank *** numerical results show that the chorus waves at different regions play signiffcantly different *** dayside chorus waves can cause obvious loss of energetic electrons at lower pitch angles and weak energization at larger pitch *** nightside chorus waves can yield significant energization at larger pitch angles,but cannot efficiently resonate with the energetic electrons at lower pitch *** to the numerical difficulty in fully solving Fokker-Planck equation,the cross diffusion terms are often ignored in the previous *** the effect of cross diffiusion at different regions is further *** the dayside,ignoring cross diffusion overestimates the electron phase space density by several orders of magnitude at lower pitch angles,and consequently the dayside chorus waves are incorrectly regarded as an effective energization *** the nightside,ignoring cross diffusion overestimates the electron phase space density(PSD) by about one order of magnitude at larger pitch *** numerical results suggest that cross diffusion terms can significantly affect gyroresonance of chorus waves on both the dayside and nightside,which should be included in the future radiation belt models.

关键词： geostationary orbit chorus waves wave-particle interaction

Atomistic understanding of capacity loss in LiNiO_(2)for high-nickel Li-ion batteries:First-principles study

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Chinese physics B 2024年第5期33卷 625-629页

作者：彭率陈丽娟何长春杨小宝 school of physics and Optoelectronics South China University of TechnologyGuangzhou 510000China Center of Excellence for Advanced Materials Dongguan 523808China

Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of Li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are *** understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and Li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically *** can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.

关键词： Li-ion battery ground state formation energy oxygen vacancy Li/Ni antisite

Utilizing quantum coherence in Cs Rydberg atoms for high-sensitivity room-temperature terahertz detection: a theoretical exploration

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Photonics Research 2024年第7期12卷 1583-1592页

作者： LEI HOU JUNNAN WANG QIHUI he SUGUO chen LEI yang SUNCHAO HUANG WEI SHI Department of physics Xi’an University of TechnologyXi’an 710048China school of Electrical Engineering Xi’an University of TechnologyXi’an 710048China school of Electrical and electronic Engineering Nanyang Technological UniversitySingapore 610101Singapore

In recent years,terahertz (THz) technology has made significant progress in numerous applications;however,the highly sensitive,room-temperature THz detectors are still rare,which is one of the bottlenecks in THz *** this paper,we proposed a room-temperature electrometry method for THz detection by laser spectroscopy of cesium(^(133)Cs) Rydberg atoms,and conducted a comprehensive investigation of the five-level system involving electromagnetically induced transparency (EIT),electromagnetically induced absorption (EIA),and Autler–Townes (AT) splitting in^(133)Cs *** solving the Lindblad master equation,we found that the influence of the THz electric field,probe laser,dressing laser,and Rydberg laser on the ground state atomic population as well as the coherence between the ground state and the Rydberg state,plays a crucial role in the transformation and amplitude of the EIT and EIA *** and the atomic vapor cell’s dimensions affect the number of^(133)Cs atoms involved in the detection,and ultimately determine the *** predicted the proposed quantum coherence THz detection method has a remarkable sensitivity of as low as 10^(-9)V m^(-1)Hz^(-1/2).This research offers a valuable theoretical basis for implementing and optimizing quantum coherence effects based on Rydberg atoms for THz wave detection with high sensitivity and room-temperature operation.

关键词： quantum Rydberg dimensions

MOF-derived Se doped MnS/Ti_(3)C_(2)T_(x) as cathode and Zn-Ti_(3)C_(2)T_(x) membrane as anode for rocking-chair zinc-ion battery

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Nano Research 2024年第4期17卷 2781-2789页

作者： Kaisheng Sun Zemao xiao Yunfei Shen heng Lv Jianpeng Zhu Jianxiang Pang yang Zheng Wenwen Kong Long chen school of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering Shihezi UniversityShihezi 832003China CAS Key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Key Laboratory of Electronic Information Materials and DevicesCenter of Materials Science and Optoelectronics EngineeringXinjiang Technical Institute of Physics and Chemistry of CASUrumqi 830011China

Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage ***,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of ***,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is *** tests show that Se-doped could generate S defects and enhance the electrochemical activity of *** the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of *** the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during *** the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate *** addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the *** 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.

关键词： rocking-chair zinc-ion battery MnS Zn-Ti_(3)C_(2)T_(x) membrane Se doped Ti_(3)C_(2)T_(x) composite

Giant magnetoimpedance effect of multilayered structure(F/SiO_2)_3/Ag/(SiO_2/F)_3 films deposited in a longitudinal magnetic field

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science china(Technological sciences) 2010年第3期53卷 287-292页

作者： chen WeiPing1,2,SHAO XianYi1,2,FENG ShangShen1,2,xiao ShuQin3 & LIU yihua3 1 school of physics and electronics Engineering,Zhejiang Taizhou university,Taizhou 318000,china 2 Institute of Function Materials for electronic Information,Zhejiang Taizhou university,Taizhou 318000,china 3 school of physics,Shandong university,Jinan 250100,china school of physics and electronics Engineering Zhejiang Taizhou University Taizhou China Institute of Function Materials for electronic Information Zhejiang Taizhou University Taizhou China school of physics Shandong University Jinan China

The soft magnetic properties and giant magnetoimpedance(GMI) effect of the multilayered structure(F/SiO2)3/Ag/(SiO2/F)3(F≡Fe71.5Cu1Cr2.5V4Si12B9) films,which were prepared by radio frequency sputtering without and with a longitudinal magnetic field of about 72 kA/m,are *** results show that the GMI effect almost cannot be detected in the samples deposited without field,whereas,a longitudinal magnetic field applied during deposition process obviously optimizes the soft magnetic properties of the films,and noticeable GMI effect is *** maximum values of the longitudinal and transverse GMI ratios are 45% and 44% at the frequency of 6.81 MHz,*** addition,the dependence of magnetoimpedance ratio,magnetoresistance ratio,magnetoreactance ratio and effective permeability ratio on the frequency has been *** found that the GMI spectrum curves in the longitudinal and transverse cases almost overlap for the field-deposited *** GMI effect is mainly a giant magnetoinductive effect at low *** f >9 MHz,magnetoreactance ratio changes to a negative,i.e.,the property of reactance changes from inductive to capacitive.

关键词： Fe-based soft magnetic alloy as-deposited multilayered films giant magnetoimpedance effect effective permeability magnetic anisotropy

Revolution in thermoelectric cooling using PbSe thermoelectrics by grid plainification

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science china Materials 2024年第5期67卷 1672-1673页

作者： xiao-Lei Shi Qingfeng Liu Zhi-Gang chen school of Chemistry and physics ARC Research Hub in Zero-emission Power Generation for Carbon Neutralityand Centre for Materials ScienceQueensland University of TechnologyBrisbaneQueensland4000Australia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev... 详细信息

关键词： enable thermoelectric constrained

Knockout reaction mechanism studied by ~6he projectile

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science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 136-140页

作者： Lü LinHui1, YE YanLin1, JIANG DongXing1, HUA Hui1, ZheNG Tao1, LI ZhiHuan1, GE Yucheng1, LI XiangQing1, LOU JianLing1, CAO ZhongXin1, SONG YuShou1, xiao Jun1, LI QiTe1, QIAO Rui1, YOU HaiBo1, chen RuiJiu1, XU HuShan2, WANG JianSong2, GUO ZhongYan2, ZHANG XueYing2, LI chen2, HU ZhengGuo2, chen RuoFu2, WANG Meng2, XU ZhiGuo2, YUE Ke2, TANG Bin2, ZANG YongDong2, ZHANG Xueheng2, YAO XiangWu2, chen JinDa2 & BAI Zhen2 1 school of physics and State Key Laboratory of Nuclear physics and technology, Peking university, Beijing 100871, china 2 Institute of Modern physics, Chinese Academy of sciences, Lanzhou 730000, china school of physics and State Key Laboratory of Nuclear physics and technology Peking University Beijing China Institute of Modern physics Chinese Academy of Sciences Lanzhou China

Knockout reaction experiment was carried out by using the 6he beams at 61.2 MeV/u impinging on a CH2 target. The α core fragments at forward angles were detected in coincidence with the recoiled protons at larger angles. From this exclusive meas urement the valence nucleon knockout mechanism and the core knockout mechanism can be distinguished by the relation be tween the polar angles of the core fragments and the recoiled protons, respectively. It is demonstrated that the core knockout mechanism may result in some strong contamination to the real invariant mass spectrum.

关键词： exotic nuclei knockout reaction reaction mechanism invariant mass spectra

Butterfly distribution of Earth＇s radiation belt relativistic electrons induced by dayside chorus

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science china(Technological sciences) 2018年第2期61卷 212-218页

作者： jin yuyue yang chang he yihua liu si zhou qinghua xiao fuliang school of physics and electronic sciences changsha university of science and technologyChangsha 410004China

Previous theoretical studies have shown that dayside chorus can produce butterfly distribution of energetic electrons in the Earth＇s radiation belts by preferentially accelerating medium pitch angle electrons, but this requires the further confirmation from high- resolution satellite observation. here, we report correlated Van Allen Probes data on wave and particle during the 1 I-13 April, 2014 geomagnetic storm. We find that a butterfly pitch angle distribution of relativistic electrons is formed around the location L = 4.52, corresponding to the presence of enhanced dayside chorus. Using a Gaussian distribution fit to the observed chorus spectra, we calculate the bounce-averaged diffusion rates and solve two-dimensional Fokker-Planck equation. Numerical results demonstrate that acceleration by dayside chorus can yield the electron flux evolution both in the energy and butterfly pitch angle distribution comparable to the observation, providing a further evidence for the formation of butterfly distribution of relativistic electrons driven by very low frequency （VLF） plasma waves.

关键词： butterfly distribution relativistic electrons radiation belts wave-particle interaction dayside chorus