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Linear instability of hairy black holes in Horndeski theory

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Chinese physics C 2024年第7期48卷 253-258页

作者：张超朱涛 Beijing Key Laboratory of optical Detection Technology for Oil and Gas Basic Research Center for Energy InterdisciplinaryCollege of ScienceChina University of Petroleum-BeijingBeijing 102249China institute for Theoretical physics and Cosmology Zhejiang University of TechnologyHangzhou 310023China United Center for Gravitational Wave physics(UCGWP) Zhejiang University of TechnologyHangzhou 310023China

Horndeski theory constitutes the most general model of scalar-tensor *** has attracted much attention in recent years in relation with black holes,celestial dynamics,stability analysis,*** is important to note that,for certain subclasses of Horndeski models,one can obtain analytic solutions for the background *** facilitates the investigation of the corresponding stability problems in *** particular,we aim to determine the constraints to the model or theory under which the stability conditions can be *** this study,we focused on a subclass of Horndeski theory and a set of analytic background *** addition,the odd-parity gravitational perturbation and 2nd-order Lagrangian were *** careful analysis,the instability was identified within the neighborhood of the event *** allows exclusion of a specific geometry for the *** an instability is implanted in the structure of the corresponding Lagrangian and is not erased by simply adding numerical constraints on the coupling *** a starting point of our research,the current study provides insights for further exploration of the Horndeski theory.

关键词： black holes black hole perturbations scalar-tensor theories Horndeski theory

A comprehensive diagnostic system of ultra-thin liquid sheet targets

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High Power Laser Science and Engineering 2024年第3期12卷 41-50页

作者： Ziyang Peng Zhengxuan Cao Xuan Liu Yinren Shou Jiarui Zhao Shiyou Chen Ying Gao Pengjie Wang Zhusong Mei Zhuo Pan Defeng Kong Shirui Xu Zhipeng Liu Yulan Liang Tianqi Xu Tan Song Xun Chen Qingfan Wu Yujia Zhang Zihao Zhang Xueqin Yan Wenjun Ma State Key Laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijingChina National Key Laboratory of Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyangChina Center for Relativistic Laser Science Institute for Basic ScienceGwangjuRepublic of Korea institute of Radiation physics Helmholtz-Zentrum Dresden RossendorfDresdenGermany Beijing Laser Acceleration Innovation Center BeijingChina institute of Guangdong Laser Plasma Technology GuangzhouChina

To meet the demands of laser-ion acceleration at a high repetition rate,we have developed a comprehensive diagnostic system for real-time and in situ monitoring of liquid sheet targets(LSTs).The spatially resolved rapid characterizations of an LST’s thickness,flatness,tilt angle and position are fulfilled by different subsystems with high *** the help of the diagnostic system,we reveal the dependence of thickness distribution on collision parameters and report the 238-nm liquid sheet generated by the collision of two liquid *** methods for the flatness and tilt angle of LSTs have also been provided,which are essential for applications of laser-driven ion acceleration and others.

关键词： diagnostics laser-ion acceleration liquid sheet targets

Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

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National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan Zhang Zhiyong Zhang Key Laboratory for the physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS

Recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

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Nano Research 2024年第3期17卷 1384-1401页

作者： Huanzhu Lv Xiaoqi Zhu Jun Mei Yuanhua Xia Bin Wang institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200China Key Laboratory of Neutron physics and institute of Nuclear physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 621999China

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of ***_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature ***,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary *** the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and *** this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XRD),fourier transform infrared(FT-IR)spectroscopy,Raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is *** mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are ***,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in ***,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

关键词： lithium metal batteries(LMBs) In-situ characterization LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)

Unbound^(28)O,the heaviest oxygen isotope observed:a cutting-edge probe for testing nuclear models

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Nuclear Science and Techniques 2024年第2期35卷 1-2页

作者： Jian-Guo Li Bai-Shan Hu Shuang Zhang Fu-Rong Xu School of physics and State Key Laboratory of Nuclear Physics and TechnologyPeking UniversityBeijing 100871China institute of Modern physics Chinese Academy of SciencesLanzhou 730000China Southern Center for Nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China

The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting *** unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear *** atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.

关键词： testing quantum system

Even-odd layer-dependent multiferroic in freestanding rare-earth orthorhombic perovskite

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 151-157页

作者： Shaowen Xu Fanhao Jia Ning Dai School of physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Department of physics College of ScienceHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Infrared physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Freestanding oxide perovskites possess strong interlayer coupling between adjacent atomic layers,thus exerting a determinative effect on the magnetism and ferroelectricity of these atomic-scale ***,we propose an effective strategy to manipulate magnetism and ferroelectricity in freestanding rare-earth orthorhombic perovskite via modulation of layer *** performing first-principles calculations,an even-odd oscillation is demonstrated in few-layer GdAlO_(3)perovskite(GAP).Specifically,odd-layer systems with charged atomic layers are ferromagnetic polar metals,while even-layer systems are antiferromagnetic ferroelectric *** thickness-dependent magnetic phase transition originates from carrier doping,as rationalized by the Stoner ***,we demonstrate the promotion of in-plane ferroelectricity via the concurrent application of two distinct antiferrodistortive displacements,each driven by formation and breaking of *** multiferroic phases may emerge in other transition metal oxide perovskites supporting multiple valence states,e.g.,few-layer Gd MO_(3)(M=V,Cr,Mn,and Ni).This work puts forward a strategy for layer thickness engineering of magnetism and ferroelectricity in 2D oxide perovskite multiferroic materials.

关键词： few-layer rare-earth perovskite multiferroicity size effect first principles calculations

Enhanced soft magnetic properties of SiO_(2)-coated FeSiCr magnetic powder cores by particle size effect

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Chinese physics B 2024年第10期33卷 405-412页

作者： Mingyue Ge Likang Xiao Xiaoru Liu Lin Pan Zhangyang Zhou Jianghe Lan Zhengwei Xiong Jichuan Wu Zhipeng Gao Joint Laboratory for Extreme Conditions Matter Properties School of Mathematics and PhysicsSouthwest University of Science and TechnologyMianyang 621010China Southwest institute of Applied Magnetism Mianyang 621010China institute of Fluid physics China Academy of Engineering PhysicsMianyang 621900China Sichuan Civil-military Integration institute Mianyang 621010China

It has been known that metal FeSiCr powders with large average particle sizes have been typically employed to prepare magnetic powder cores(SMCs),with few studies reported on the influence of magnetic properties for original powders with various average particle sizes less than 10*** this work,SiO_(2)-coated FeSiCr SMCs with different small particle sizes were synthesized using the sol-gel *** contribution of SiO_(2)coating amount and voids to the soft magnetic properties was *** mechanism was revealed such that smaller particle sizes with less voids could be beneficial for reducing core loss in the *** optimizing the core structure,permeability and magnetic loss of 26 and 262 kW/cm^(3)at 100 kHz and 50 mT were achieved at a particle size of 4.8m and ethyl orthosilicate addition of 0.1 mL/*** best DC stacking performance,reaching 87%,was observed at an ethyl orthosilicate addition rate of 0.25 mL/g under 100 *** to other soft magnetic composites(SMCs),the FeSiCr/SiO_(2)SMCs exhibit significantly reduced magnetic *** further reduces the magnetic loss of the powder core,providing a new strategy for applications of SMCs at high frequencies.

关键词： FeSiCr SiO_(2) size effect magnetic properties DC superposition

Efficient second and third harmonic generation in dual-layer lithium niobate microdisk resonator

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Science China(physics,Mechanics & Astronomy) 2024年第5期67卷 33-38页

作者： Zhenzhong Hao Xiao Wu Qiang Luo Zhang Li Rui Ma Fang Bo Feng Gao Guoquan Zhang Jingjun Xu MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300457China

Lithium niobate thin film frequency doubler has extensive applications in the preparation of classical and quantum *** this study,we successfully fabricated microdisk resonators with a quality factor of 2.2×10^(5) in reverse-polarization dual-layer x-cut lithium niobate for the first *** on the modal phase matching condition,efficient second harmonic generation with a record normalized conversion efficiency of~56000%W-1 and cascaded third harmonic generation with an efficiency of~6500%W-2 were obtained in the microdisk *** with the periodically poled lithium niobate microcavity,the complex domain structure preparation processes are *** work provides a scheme for achieving highly efficient second-order nonlinear effects in non-periodically poled microcavities.

关键词： harmonic lithium niobate

Peak structure in the interlayer conductance of Moirésuperlattices

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Chinese physics B 2024年第10期33卷 376-380页

作者： Yizhou Tao Chao Liu Mingwen Xiao Henan Fang College of Electronic and optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China Department of physics Nanjing UniversityNanjing 210093China

We investigate the peak structure in the interlayer conductance of Moirésuperlattices using a tunneling theory wedeveloped *** theoretical results predict that,due to the resonance of two different partial waves,the doublepeakstructure can appear in the curve of the interlayer conductance versus twist ***,we study the influencesof the model parameters,i.e.,the chemical potential of electrodes,the thickness of Moirésuperlattice,and the strength ofinterface potential,on the peak structure of the interlayer *** particular,the parameter dependence of the peakstructure is concluded via a phase diagram,and the physical meanings of the phase diagram is ***,thepotential applications of the present work is discussed.

关键词： Moirésuperlattice interlayer conductance electronic transport twistronics