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Quantum-classical correspondence for the inverted oscillator

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Chinese Physics C 2017年第11期41卷 56-62页

作者： Mustapha Maamache jeong ryeol choi Laboratoire de Physique Quantique et Systèmes Dynamiques Faculté des SciencesUniversité Ferhat Abbas Sétif 1 Sétif 19000 Department of Radiologic Technology Daegu Health College

While quantum-classical correspondence for a system is a very fundamental problem in modern physics,the understanding of its mechanism is often elusive,so the methods used and the results of detailed theoretical analysis have been accompanied by active *** this study,the differences and similarities between quantum and classical behavior for an inverted oscillator have been analyzed based on the description of a complete generalized Airy function-type quantum wave *** inverted oscillator model plays an important role in several branches of cosmology and particle *** quantum wave packet of the system is composed of many sub-packets that are localized at different positions with regular intervals between *** is shown from illustrations of the probability density that,although the quantum trajectory of the wave propagation is somewhat different from the corresponding classical one,the difference becomes relatively small when the classical excitation is sufficiently *** have confirmed that a quantum wave packet moving along a positive or negative direction accelerates over time like a classical *** these main interpretations and others in the text,we conclude that our theory exquisitely illustrates quantum and classical correspondence for the system,which is a crucial concept in quantum mechanics.

关键词： quantum-classical correspondence inverted oscillator quantum wave packet

Nonlinear description of Yang-Mills cosmology： cosmic inflation and the accompanying Hannay's angle

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Chinese Physics C 2017年第6期41卷 115-121页

作者： Yacine Bouguerra Mustapha Maamache jeong ryeol choi Laboratoire de Physique Quantique et Systèmes Dynamiques Faculté des SciencesUniversite Ferhat Abbas Setif 1 Setif 19000 Algeria Département de Physique Facultédes Sciences Université de Jijel BP 98Ouled Aissa Jijel 18000 Algeria Department of Radiologic Technology Daegu Health College Yeongsong-ro 15 Buk-gu Daegu 41453 Republic of Korea

Hannay＇s angle is a classical analogue of the ＂geometrical phase factor＂ found by Berry in his research on the quantum adiabatic theorem. This classical analogue is defined if closed curves of constant action variables return to the same curves in phase space after an adaibatic evolution. Adiabatic evolution of Yang-Mills cosmology, which is described by a time-dependent quartic oscillator, is investigated. Phase properties of the Yang-Mills fields are analyzed and the corresponding Hannay＇s angle is derived from a rigorous evaluation. The obtained Hannay＇s angle shift is represented in terms of several observable parameters associated with such an angle shift. The time evolution of Hannay＇s angle in Yang-Mills cosmology is examined from an illustration plotted on the basis of numerical evaluation,and its physical nature is addressed. Hannay＇s angle, together with its quantum counterpart Berry＇s phase, plays a pivotal role in conceptual understanding of several cosmological problems and indeed can be used as a supplementary probe for cosmic inflation.

关键词： Yang-Mills cosmology Hannay angle time-dependent quartic Hamiltnian inflation

Testing the validity of the Ehrenfest theorem beyond simple static systems: Caldirola–Kanai oscillator driven by a time-dependent force

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Chinese Physics B 2016年第8期25卷 15-20页

作者： Salim Medjber Hacene Bekkar Salah Menouar jeong ryeol choi Department of Material Science Faculty of Science University of M’sila Faculty of Technology University of Ferhat Abbas Setif 1 Laboratory of Optoelectronics and Compounds (LOC) Department of Physics Faculty of Science University of Ferhat Abbas Setif 1 Department of Radiologic Technology Daegu Health College

The relationship between quantum mechanics and classical mechanics is investigated by taking a Gaussian-type wave packet as a solution of the Schr o¨dinger equation for the Caldirola–Kanai oscillator driven by a sinusoidal force. For this time-dependent system, quantum properties are studied by using the invariant theory of Lewis and Riesenfeld. In particular,we analyze time behaviors of quantum expectation values of position and momentum variables and compare them to those of the counterpart classical ones. Based on this, we check whether the Ehrenfest theorem which was originally developed in static quantum systems can be extended to such time-varying systems without problems.

关键词： Ehrenfest theorem time-dependent Hamiltonian system invariant theory

Quantum Systems Connected by a Time-Dependent Canonical Transformation

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Communications in Theoretical Physics 2009年第9期52卷 416-420页

作者： Kyu Hwang Yeon jeong ryeol choi ZHANG Shou BK21 Physics Program and Department of Physics College of Natural Science Chungbuk National University Cheongju Chungbuk 361-763 Korea School of Electrical Engineering and Computer Science Kyungpook National University 1370 Sankyuk-dong Buk-gu Daegu 702-701 Korea Center for the Condensed-Matter Science and Technology Harbin Institute of Technology Harbin 150001 China Department of Physics College of Science Yanbinn University Yanji 133002 China

We study both classical and quantum relation between two Hamiltonian systems which are mutually connected by time-dependent canonical transformation. One is ordinary conservative system and the other is timedependent Hamiltonian system. The quantum unitary operator relevant to classical canonical transformation between the two systems are obtained through rigorous evaluation. With the aid of the unitary operator, we have derived quantum states of the time-dependent Hamiltonian system through transforming the quantum states of the conservative system. The invariant operators of the two systems are presented and the relation between them are addressed. We showed that there exist numerous Hamiltonians, which gives the same classical equation of motion. Though it is impossible to distinguish the systems described by these Hamiltonians within the realm of classical mechanics, they can be distinguishable quantum mechanically.

关键词： canonical transformation innumerable kind of Hamiltonians canonical quantization invariant operator unitary transformation

Nanocrystalline low-silica X zeolite as an efficient ion-exchanger enabling fast radioactive strontium capture

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 15-23页

作者： Hyungmin Jeon Susung Lee jeong-Chul Kim Minkee choi Department of Chemical and Biomolecular Engineering(BK21 Four) Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Center for Nanomaterials and Chemical Reactions Institute for Basic Science(IBS)Daejeon 34141Republic of Korea

NaA zeolite(Si/Al=1.00)has been commercially applied for capturing radioactive 90Sr^(2+)because of its high surface charge density,effectively stabilizing the multivalent ***,owing to its narrow micropore opening(4.0Å),large micron-sized crystallites,and bulkiness of hydrated Sr^(2+),the Sr^(2+)exchange over NaA has been limited by very slow *** this study,we synthesized nanocrystalline low-silica X by minimizing a water content in a synthesis gel and utilizing a methyl cellulose hydrogel as a crystal growth *** resulting zeolite exhibited high crystallinity and Al-rich framework(Si/Al of approximately 1.00)with the sole presence of tetrahedral Al sites,which are capable of high Sr^(2+)uptake and ion ***,the zeolite with a FAU topology has a much larger micropore opening size(7.4Å)and a much smaller crystallite size(~340 nm)than NaA,which enable significantly enhanced ion-exchange *** to conventional NaA,the nanocrystalline low-silica X exhibited remarkably increased Sr^(2+)-exchange kinetics(>18-fold larger rate constant)in batch *** both the nanocrystalline low-silica X and NaA exhibited comparable Sr^(2+)capacities under equilibrated conditions,the former demonstrated a 5.5-fold larger breakthrough volume than NaA under dynamic conditions,attributed to its significantly faster Sr^(2+)-exchange kinetics.

关键词： Sr^(2+)removal low-silica X zeolite nanocrystal hydrogel methyl cellulose

Enhanced performance of solution-processed carbon nanotube transparent electrodes in foldable perovskite solar cells through vertical separation of binders by using eco-friendly parylene substrate

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Carbon Energy 2024年第7期6卷 83-93页

作者： Unsoo Kim jeong-Seok Nam Jungjin Yoon Jiye Han Mansoo choi Il Jeon Department of Mechanical Engineering Seoul National UniversitySeoulRepublic of Korea Global Frontier Center for Multiscale Energy Systems Seoul National UniversitySeoulRepublic of Korea Frontier Energy Solution SeoulRepublic of Korea Department of Nano Engineering Department of Nano Science and TechnologySKKU Advanced Institute of Nanotechnology(SAINT)Sungkyunkwan University(SKKU)SuwonRepublic of Korea Department of Materials Science and Engineering Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA

The successful utilization of an eco-friendly and biocompatible parylene-C substrate for high-performance solution-processed double-walled carbon nanotube(CNT)electrode-based perovskite solar cells(PSCs)was *** the use of a novel inversion transfer technique,vertical separation of the binders from the CNTs was induced,rendering a stronger p-doping effect and thereby a higher conductivity of the *** resulting foldable devices exhibited a power conversion efficiency of 18.11%,which is the highest reported among CNT transparent electrode-based PSCs to date,and withstood more than 10,000 folding cycles at a radius of 0.5 mm,demonstrating unprecedented mechanical ***,solar modules were fabricated using entirely laser scribing processes to assess the potential of the solution-processable nanocarbon ***,this is the only one to be processed entirely by the laser scribing process and to be biocompatible as well as eco-friendly among the previously reported nonindium tin oxide-based perovskite solar modules.

关键词： double-walled carbon nanotubes parylene substrates perovskite modules perovskite solar cells solution-processable electrodes surfactant removal

One dimensional pea-shaped NiSe_(2) nanoparticles encapsulated in N-doped graphitic carbon fibers to boost redox reversibility in sodium-ion batteries

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Journal of Materials Science & Technology 2024年第1期168卷 215-226页

作者： Hyunjeong Gim Achmad Yanuar Maulana Jiwon choi Jungwook Song Boram Yun Yuri jeong Nahyun An Myeongkee Park Cybelle M.Futalan Jongsik Kim Department of Chemical Engineering(BK21 FOUR Graduate Program) Dong-A UniversityBusan 49315Korea(the Republic of) Department of Chemistry Dong-A UniversityBusan 49315Korea(the Republic of) Department of Chemistry Pukyong National UniversityBusan 48513Korea(the Republic of) Institute of Civil Engineering University of the PhilippinesDiliman 1127Philippines

In recent years,sodium-ion batteries(SIBs)have emerged as a promising technology for energy storage systems(ESSs)because of the abundance and affordability of ***,metal selenides have been studied as promising high-performance conversion-type anode materials in *** them,nickel se-lenide(NiSe_(2))has received considerable attention due to its high theoretical capacity of 495 mAh g^(-1)and ***,it still suffers from poor cycling stability because of the low electrochemical reactivity,large volume expansion,and structural instability during *** address these challenges,NiSe_(2)nanoparticles encapsulated in N-doped graphitic carbon fibers(NiSe_(2)@NGCF)were synthesized by using ZIF-8 as a ***_(2)@NGCF showed a high discharge capacity of 558.3 mAh g^(-1)with a fading rate of 0.14%per cycle after 200 cycles at 0.5 A g^(-1)in 0.01-3.0 *** a very high current density of 5 A g^(-1),the capacity still displayed excellent long-term cycle life with a discharge capacity of 406.1 mAh g^(-1)with a fading rate of 0.016%per cycle after 3000 *** mechanism of the excellent electrochem-ical performance of NiSe_(2)@NGCF was thoroughly investigated by ex-situ XRD,TEM,and SEM ***,NiSe_(2)@NGCF//Na_(3)V_(2)(PO_(4))_(3)full-cell also delivered an excellent reversible capacity of 378.7 mAh g^(−1)at 0.1 A g^(−1)after 50 cycles,demonstrating its potential for practical application in SIBs.

关键词： Sodium-ion batteries Anode materials Nickel selenide N-doped graphitic carbon fibers One-dimensional electrode

Tailoring local structures of atomically dispersed copper sites for highly selective CO_(2) electroreduction

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Carbon Energy 2024年第4期6卷 79-90页

作者： Kyung‐Jong Noh Byoung Joon Park Ying Wang Yejung choi Sang‐Hoon You Yong‐Tae Kim Kug‐Seung Lee jeong Woo Han Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Pohang Accelerator Laboratory(PAL) Beamline DivisionPohangGyeongbukRepublic of Korea

Atomically‐dispersed copper sites coordinated with nitrogen‐doped carbon(Cu–N–C)can provide novel possibilities to enable highly selective and active electrochemical CO_(2) reduction ***,the construction of optimal local electronic structures for nitrogen‐coordinated Cu sites(Cu–N_(4))on carbon remains ***,we synthesized the Cu–N–C catalysts with atomically‐dispersed edge‐hosted Cu–N_(4) sites(Cu–N_(4)C_(8))located in a micropore between two graphitic sheets via a facile method to control the concentration of metal ***‐hosted Cu–N_(4)C_(8) catalysts outperformed the previously reported M–N–C catalysts for CO_(2)‐to‐CO conversion,achieving a maximum CO Faradaic efficiency(FECO)of 96%,a CO current density of–8.97 mA cm^(–2) at–0.8 V versus reversible hydrogen electrode(RHE),and over FECO of 90%from–0.6 to–1.0 V versus *** studies revealed that the micropore of the graphitic layer in edge‐hosted Cu–N_(4)C_(8) sites causes the d‐orbital energy level of the Cu atom to shift upward,which in return decreases the occupancy of antibonding states in the*COOH *** research suggests new insights into tailoring the locally coordinated structure of the electrocatalyst at the atomic scale to achieve highly selective electrocatalytic reactions.

关键词： atomic local structure density functional theory electrochemical CO_(2)reduction metal nitrogen‐doped carbon single‐atom catalyst

Adiponectin restores the obesity-induced impaired immunomodulatory function of mesenchymal stromal cells via glycolytic reprogramming

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Acta Pharmaceutica Sinica B 2024年第1期14卷 273-291页

作者： Duc-Vinh Pham Thi-Kem Nguyen Bao-Loc Nguyen Jong-Oh Kim Jee-Heon jeong Inho choi Pil-Hoon Park Department of Pharmacology Hanoi University of PharmacyHanoi 100000Viet Nam College of Pharmacy Yeungnam UniversityGyeongsan 38541Republic of Korea Department of Medical Biotechnology Yeungnam UniversityGyeongsan 38541Republic of Korea Research Institute of Cell Culture Yeungnam UniversityGyeongsan 38541Republic of Korea Department of Precision Medicine School of MedicineSungkyunkwan UniversitySuwon 16419Republic of Korea

Obesity has been known to negatively modulate the life-span and immunosuppressive potential of mesenchymal stromal cells(MSC).However,it remains unclear what drives the compromised potency of obese *** this study,we examined the involvement of adiponectin,an adipose tissuederived hormone,in obesity-induced impaired therapeutic function of ***-induced obesity leads to a decrease in serum adiponectin,accompanied by impairment of survival and immunomodulatory effects of adipose-derived MSC(ADSC).Interestingly,priming with globular adiponectin(gAcrp)improved the immunomodulatory potential of obese *** effects were also observed in lean *** addition,gAcrp potentiated the therapeutic effectiveness of ADSC in a mouse model of DSS-induced ***,while obesity inhibited the glycolytic capacity of MSC,gAcrp treatment induced a metabolic shift toward glycolysis through activation of adiponectin receptor type 1/p38 MAPK/hypoxia inducible factor-1a *** findings suggest that activation of adiponectin signaling is a promising strategy for enhancing the therapeutic efficacy of MSC against immune-mediated disorders.

关键词： Adiponectin Adipose-derived stromal cells Colitis Glycolytic induction HIF1a Immunomodulation Mesenchymal stromal cells Obesity