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Progress in the preparation and physical properties of two-dimensional Cr-based chalcogenide materials and heterojunctions

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Frontiers of physics 2024年第2期19卷 105-130页

作者： Xiulian Fan Ruifeng Xin Li Li Bo Zhang Cheng Li Xilong Zhou Huanzhi Chen Hongyan Zhang Fangping OuYang Yu Zhou School of Physics and Electronics Hunan Key Laboratory of Nanophotonics and DevicesCentral South UniversityChangsha 410083China Jincheng research Institute of Opto-mechatronics Industry Jincheng 048000China Shanxi Key laboratory of Advanced Semiconductor Optoelectronic Devices and Integrated Systems Jincheng 048000China School of physical Science and Technology Xinjiang UniversityUrumqi 830046China State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Two-dimensional transition metal dichalcogenides(TMDs)exhibit promising application prospects in the domains of electronic devices,optoelectronic devices and spintronic devices due to their distinctive energy band structures and spin−orbit coupling properties.Cr-based chalcogenides with narrow or even zero bandgap,covering from semiconductors to metallic materials,have considerable potential for wide-band photodetection and two-dimensional magnetism.Currently,the preparation of 2D CrX_(n)(X=S,Se,Te)nanosheets primarily relies on chemical vapor deposition(CVD)and molecule beam epitaxy(MBE),which enable the production of high-quality large-area materials.This review article focuses on recent progress of 2D Cr-based chalcogenides,including unique crystal structure of the CrX_(n)system,phase-controlled synthesis,and heterojunction construction.Furthermore,a detailed introduction of room-temperature ferromagnetism and electrical/optoelectronic properties of 2D CrXn is presented.Ultimately,this paper summarizes the challenges associated with utilizing 2D Cr-based chalcogenides in preparation strategies,optoelectronics devices,and spintronic devices while providing further insights.

关键词： physical properties two-dimensional materials Cr-based chalcogenide controlled synthesis heterojunction eletronic and optoelectronic devices

Selective synthesis and physical properties of a bismacrocycle:Cycloparaphenylene-pillar[5]arene

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Chinese Chemical Letters 2024年第3期35卷 273-276页

作者： Yu Zhou Guilin Zhuang Pingwu Du Key laboratory of Precision and Intelligent Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleCAS Key Laboratory of Materials for Energy ConversionDepartment of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310032China

Macrocyclic materials have attracted much attention due to their particular chemical and physical properties.Herein we report the precise synthesis and characterization of a new bismacrocycle structure base on cycloparaphenylene(CPP)and pillar[5]arene,named cycloparaphenylene-pillar[5]arenes(CPPn[5]).The bismacrocycle was fully characterized by NMR and HR-MS.The photophysical properties of CPPn[5]were investigated by UV–vis,and the maximum absorption peak was located at 331 nm,which was consistent with density functional theory(DFT)calculations.The fluorescence spectrum was further studied and the emission peak was maximized at 458 nm.The computational results indicate the strain energy of CPPn[5]is 27.80 kcal/mol and the HOMO-LUMO gap is 3.39 eV Notably,CPPn[5]showed interesting supramolecular properties.

关键词： Pillararene Cycloparaphenylene Bismacrocycles Supramolecular chemistry

Holevo bound independent of weight matrices for estimating two parameters of a qubit

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Chinese Physics B 2024年第2期33卷 137-143页

作者：牛畅郁司夏 Department of Modern Physics&Hefei National research Center for physical Sciences at the Microscale and School of physical Sciences University of Science and Technology of ChinaHefei 230026China Hefei National laboratory University of Science and Technology of ChinaHefei 230088China

Holevo bound plays an important role in quantum metrology as it sets the ultimate limit for multi-parameter estimations,which can be asymptotically achieved.Except for some trivial cases,the Holevo bound is implicitly defined and formulated with the help of weight matrices.Here we report the first instance of an intrinsic Holevo bound,namely,without any reference to weight matrices,in a nontrivial case.Specifically,we prove that the Holevo bound for estimating two parameters of a qubit is equivalent to the joint constraint imposed by two quantum Cramér–Rao bounds corresponding to symmetric and right logarithmic derivatives.This weightless form of Holevo bound enables us to determine the precise range of independent entries of the mean-square error matrix,i.e.,two variances and one covariance that quantify the precisions of the estimation,as illustrated by different estimation models.Our result sheds some new light on the relations between the Holevo bound and quantum Cramer–Rao bounds.Possible generalizations are discussed.

关键词： quantum metrology quantum Fisher information Holevo bound quantum multi-parameter estimation

Relationship between physical activity and specific working memory indicators of depressive symptoms in university students

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World Journal of Psychiatry 2024年第1期14卷 148-158页

作者： Qun Zhao Xing Wang Shu-Fan Li Peng Wang Xiang Wang Xin Xin Suo-Wang Yin Zhao-Song Yin Li-Juan Mao School of physical Education Shanghai University of SportShanghai 200438China Department of physical Education Donghua UniversityShanghai 201620China

BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental health.According to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of death.AIM To explore the relationship between different elements and levels of physical activity and college students’depression-symptom-specific working memory indicators.METHODS Of 143 college students were analyzed using the Beck Depression Self-Rating Scale,the physical Activity Rating Scale,and the Working Memory Task.RESULTS There was a significant difference between college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all Pphysical Activity Scale-3 scores were significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all P0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks.

关键词： physical activity Depression symptoms University students Working memory

Recent advances in protein conformation sampling by combining machine learning with molecular simulation

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Chinese Physics B 2024年第3期33卷 80-87页

作者：唐一鸣杨中元姚逸飞周运谈圆王子超潘瞳熊瑞孙俊力韦广红 Department of Physics State Key Laboratory of Surface Physicsand Key Laboratory for Computational Physical Sciences (Ministry of Education)Shanghai 200438China

The rapid advancement and broad application of machine learning(ML)have driven a groundbreaking revolution in computational biology.One of the most cutting-edge and important applications of ML is its integration with molecular simulations to improve the sampling efficiency of the vast conformational space of large biomolecules.This review focuses on recent studies that utilize ML-based techniques in the exploration of protein conformational landscape.We first highlight the recent development of ML-aided enhanced sampling methods,including heuristic algorithms and neural networks that are designed to refine the selection of reaction coordinates for the construction of bias potential,or facilitate the exploration of the unsampled region of the energy landscape.Further,we review the development of autoencoder based methods that combine molecular simulations and deep learning to expand the search for protein conformations.Lastly,we discuss the cutting-edge methodologies for the one-shot generation of protein conformations with precise Boltzmann weights.Collectively,this review demonstrates the promising potential of machine learning in revolutionizing our insight into the complex conformational ensembles of proteins.

关键词： machine learning molecular simulation protein conformational space enhanced sampling

Comparative measurement of CO_(2),CH_(4)and CO at two traffic interjunctions having inflated vehicular flow in Delhi

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Journal of Environmental Sciences 2024年第7期141卷 314-329页

作者： Komal Daya Soni Khem Singh Shankar G.Aggarwal CSIR-National physical laboratory Dr.K.S.Krishnan MargNew Delhi 110012India Academy of Scientific&Innovative research(AcSIR) Ghaziabad 201002India

Vehicular emissions are considered one of the major anthropogenic sources of greenhouse gases and poor air quality in metropolitan cities.This study aims to see the correlation of CO_(2),CH_(4),and CO through monitoring over a period from December 2020 to October 2021 covering three seasons’winter,summer,and monsoon at two different traffic locations of Delhi having different traffic volumes,road patterns,and traffic management.The annual average morning concentration of CO_(2),CH_(4)and CO was found(533±105),(7.3±3.1),(10.7±3.0)ppm at Najafgarh and(480±70),(5.2±1.8),(7.8±2.8)ppm at Rajendra Place,respectively.A relationship between concentration of all three gases and meteorological parameters such as temperature,humidity,wind speed and wind direction has also been investigated using Pearson correlation coefficient and pollution rose diagram.A comparable pattern in concentration was observed for all three gases in spatial(location)and temporal(diurnal)distribution.The concentration trend of CO_(2)in different seasons is winter>summer>monsoon,while in the case of CH_(4)winter=summer>monsoon but not any seasonal trend was noted in CO case.It is observed that CO_(2)has a good relation with CO(a tracer for vehicular emission)in terms of diurnal variation,whereas,CH_(4)does not represent a relation with CO and CO_(2)diurnally,suggesting that vehicles are the source of CO_(2)but not much contributing to other greenhouse gases like CH_(4).

关键词： Vehicular emission Greenhouse gases Harmful pollutants Meteorological parameters

Unveiling a novel metal-to-metal transition in LuH_(2):Critically challenging superconductivity claims in lutetium hydrides

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Matter and Radiation at Extremes 2024年第3期9卷 65-73页

作者： Dong Wang Ningning Wang Caoshun Zhang Chunsheng Xia Weicheng Guo Xia Yin Kejun Bu Takeshi Nakagawa Jianbo Zhang Federico Gorelli Philip Dalladay-Simpson Thomas Meier Xujie Lü Liling Sun Jinguang Cheng Qiaoshi Zeng Yang Ding Ho-kwang Mao Center for High-Pressure Science and Technology Advanced research Beijing 100094China Beijing National laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China Shanghai Key laboratory of Material Frontiers research in Extreme Environments(MFree) Shanghai Advanced Research in Physical Sciences(SHARPS)Shanghai 201203China

Following the recent report by Dasenbrock-Gammon et al.[Nature 615,244–250(2023)]of near-ambient superconductivity in nitrogendoped lutetium trihydride(LuH_(3-δ)N_(ε)),significant debate has emerged surrounding the composition and interpretation of the observed sharp resistance drop.Here,we meticulously revisit these claims through comprehensive characterization and investigations.We definitively identify the reported material as lutetium dihydride(LuH_(2)),resolving the ambiguity surrounding its composition.Under similar conditions(270–295 K and 1–2 GPa),we replicate the reported sharp decrease in electrical resistance with a 30%success rate,aligning with the observations by Dasenbrock-Gammon et al.However,our extensive investigations reveal this phenomenon to be a novel pressure-induced metal-to-metal transition intrinsic to LuH_(2),distinct from superconductivity.Intriguingly,nitrogen doping exerts minimal impact on this transition.Our work not only elucidates the fundamental properties of LuH_(2)andLuH_(3),but also critically challenges the notion of superconductivity in these lutetium hydride systems.These findings pave the way for future research on lutetium hydride systems,while emphasizing the crucial importance of rigorous verification in claims of ambient-temperature superconductivity.

关键词： resistance hydride superconductivity

Regulating atomic Fe-Rh site distance for efficient oxygen reduction reaction

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Science China Chemistry 2024年第4期67卷 1352-1359页

作者： Tong Liu Yudan Chen Airong Xu Xiaokang Liu Dong Liu Sicheng Li Hui Huang Li Xu Shuaiwei Jiang Qiquan Luo Tao Ding Tao Yao National Synchrotron Radiation laboratory University of Science and Technology of ChinaHefei 230029China Key laboratory of Precision and Intelligent Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Institutes of physical Science and Information Technology Anhui UniversityHefei 230601China

Exploring the atomic interaction mechanisms of dense single-atom catalysts(SACs)is of great significance for their application in oxygen reduction reaction(ORR).However,the intrinsic mechanism of the site-distance effect on the catalytic performance has been largely ignored.Here,we demonstrate the site-distance effect of Fe-Rh_(x)@NC catalysts in ORR theoretically and experimentally.Bader charge analysis reveals that the strong interaction between Fe and Rh atoms at a certain atomic distance(dFe-Rh)alters the catalytic electronic structure,facilitating the optimization of catalyst adsorption strength.Motivated by the theoretical calculations,we designed and synthesized the Fe-Rhx@NC catalysts through a spatial confinement strategy.The characterization results prove that the Fe-Rh_(2)@NC has the optimal d_(Fe-Rh),which improves its intrinsic ORR activity,providing a half wave potential of 0.91 V,higher than that of the commercial Pt/C(0.86 V).This study emphasizes the importance of determining the basic mechanism of the site-distance effect in dissimilar metal atoms catalysts,which is conducive to the design of efficient catalyst systems for practical applications.

关键词： Density functional theory single-atom catalyst in-situ encapsulating site-distance effect oxygen reduction reaction

Acetaminophen overdose-induced acute liver injury can be alleviated by static magnetic field

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Zoological research 2024年第3期45卷 478-490页

作者： Han-Xiao Chen Xin-Yu Wang Biao Yu Chuan-Lin Feng Guo-Feng Cheng Lei Zhang Jun-Jun Wang Ying Wang Ruo-Wen Guo Xin-Miao Ji Wen-Jing Xie Wei-Li Chen Chao Song Xin Zhang CAS Key laboratory of High Magnetic Field and Ion Beam physical Biology High Magnetic Field LaboratoryHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhui 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefeiAnhui 230026China Institutes of physical Science and Information Technology Anhui UniversityHefeiAnhui 230601China

Acetaminophen(APAP),the most frequently used mild analgesic and antipyretic drug worldwide,is implicated in causing 46%of all acute liver failures in the USA and between 40%and 70%in Europe.The predominant pharmacological intervention approved for mitigating such overdose is the antioxidant N-acetylcysteine(NAC);however,its efficacy is limited in cases of advanced liver injury or when administered at a late stage.In the current study,we discovered that treatment with a moderate intensity static magnetic field(SMF)notably reduced the mortality rate in mice subjected to high-dose APAP from 40%to 0%,proving effective at both the initial liver injury stage and the subsequent recovery stage.During the early phase of liver injury,SMF markedly reduced APAPinduced oxidative stress,free radicals,and liver damage,resulting in a reduction in multiple oxidative stress markers and an increase in the antioxidant glutathione(GSH).During the later stage of liver recovery,application of vertically downward SMF increased DNA synthesis and hepatocyte proliferation.Moreover,the combination of NAC and SMF significantly mitigated liver damage induced by high-dose APAP and increased liver recovery,even 24 h post overdose,when the effectiveness of NAC alone substantially declines.Overall,this study provides a noninvasive non-pharmaceutical tool that offers dual benefits in the injury and repair stages following APAP overdose.Of note,this tool can work as an alternative to or in combination with NAC to prevent or minimize liver damage induced by APAP,and potentially other toxic overdoses.

关键词： Acetaminophen Acute liver injury Static magnetic fields Oxidative stress DNA synthesis