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Room-temperature phonon-coupled single-photon emission in hexagonal boron nitride

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 109-114页

作者： Jia-Min Lai Qing-Hai Tan Feilong Song Haonan Chang Yanpei Lv Xue-Lu Liu Jinghua Teng Weibo Gao Ping-Heng Tan Jun Zhang State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing100083China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education&Research Institute of Materials Science Shanxi Normal UniversityTaiyuan 030000China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China division of Physics and applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Institute of Materials Research and engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Photon-lattice(phonon)coupling is fundamental to light-matter interaction,particularly when it reaches the quantum limit of the phonon-coupled single-photon emission,which holds great potential for quantum manipulation and quantum information ***,we report single defect state-phonon coupling in hexagonal boron nitride(h BN)at room *** ultrabroad spectrum of single-photon emissions can be achieved by selecting the excitation *** photoluminescence excitation spectroscopy,we observe single-phonon-assisted resonance-enhanced single-photon emission,along with multiple phonon replicas that herald the creation of phonon Fock *** also develop a transition model to gain insight into the physical process behind the single defect state-phonon *** work sets the stage for manipulating electron-phonon coupling state with single quantum-level precision at room temperature.

关键词： temperature phonon hexagonal

Accurate estimation of Li/Ni mixing degree of lithium nickel oxide cathode materials

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Chinese Physics B 2024年第5期33卷 631-635页

作者：陈鹏浩徐磊禹习谦李泓 Institute of Physics Chinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Frontier Research Center on Clean Energy Huairou DivisionInstitute of PhysicsChinese Academy of SciencesBeijing 101400China

Li/Ni mixing negatively influences the discharge capacity of lithium nickel oxide and high-nickel ternary cathode ***,accurately measuring the Li/Ni mixing degree is difficult due to the preferred orientation of labbased XRD measurements using Bragg–Brentano ***,we find that employing spherical harmonics in Rietveld refinement to eliminate the preferred orientation can significantly decrease the measurement error of the Li/Ni mixing *** Li/Ni mixing ratio obtained from Rietveld refinement with spherical harmonics shows a strong correlation with discharge capacity,which means the electrochemical capacity of lithium nickel oxide and high-nickel ternary cathode can be estimated by the Li/Ni mixing *** findings provide a simple and accurate method to estimate the Li/Ni mixing degree,which is valuable to the structural analysis and screening of the synthesis conditions of lithium nickel oxide and high-nickel ternary cathode materials.

关键词： lithium nickel oxide high-nickel ternary cathode Li/Ni mixing spherical harmonics function discharge capacity

Assessment of large-scale multiple forest disturbance susceptibilities with AutoML framework: an Izmir Regional Forest Directorate case

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Journal of Forestry Research 2024年第4期35卷 73-88页

作者： Remzi Eker Kamber Can Alkiş Abdurrahim Aydın Department of Forest engineering Faculty of ForestryIzmir KatipÇelebi University35620 IzmirTurkey Graduate School of Natural and applied sciences Izmir KatipÇelebi University35620 IzmirTurkey Department of Forest engineering Faculty of ForestryDüzce University81620 DüzceTurkey

Disturbances such as forest fires,intense winds,and insect damage exert strong impacts on forest ecosystems by shaping their structure and growth dynamics,with contributions from climate ***,there is a need for reliable and operational methods to monitor and map these disturbances for the development of suitable management *** susceptibility assessment using machine learning methods has increased,most studies have focused on a single ***,there has been limited exploration of the use of“Automated Machine Learning(AutoML)”in the *** this study,susceptibility assessment for multiple forest disturbances(fires,insect damage,and wind damage)was conducted using the PyCaret AutoML framework in the Izmir Regional Forest Directorate(RFD)in *** AutoML framework compared 14 machine learning algorithms and ranked the best models based on AUC(area under the curve)*** extra tree classifier(ET)algorithm was selected for modeling the susceptibility of each disturbance due to its good performance(AUC values>0.98).The study evaluated susceptibilities for both individual and multiple disturbances,creating a total of four susceptibility maps using fifteen driving factors in the *** to the results,82.5%of forested areas in the Izmir RFD are susceptible to multiple disturbances at high and very high ***,a potential forest disturbances map was created,revealing that 15.6%of forested areas in the Izmir RFD may experience no damage from the disturbances considered,while 54.2%could face damage from all three *** SHAP(Shapley Additive exPlanations)methodology was applied to evaluate the importance of features on prediction and the nonlinear relationship between explanatory features and susceptibility to disturbance.

关键词： AutoML Forest disturbances Forest fire Insect Susceptibility Wind

Temporally consistent video colorization with deep feature propagation and self-regularization learning

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Computational Visual Media 2024年第2期10卷 375-395页

作者： Yihao Liu Hengyuan Zhao Kelvin CKChan Xintao Wang Chen Change Loy Yu Qiao Chao Dong Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China University of Chinese Academy of sciences Beijing 100049China Department of Electrical&Computer engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798 applied Research Center Tencent PCGShenzhenChina

Video colorization is a challenging and highly ill-posed *** recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and existing methods always suffer from severe flickering artifacts(temporal inconsistency)or unsatisfactory *** address this problem from a new perspective,by jointly considering colorization and temporal consistency in a unified ***,we propose a novel temporally consistent video colorization(TCVC)*** effectively propagates frame-level deep features in a bidirectional way to enhance the temporal consistency of ***,TCVC introduces a self-regularization learning(SRL)scheme to minimize the differences in predictions obtained using different time *** does not require any ground-truth color videos for training and can further improve temporal *** demonstrate that our method can not only provide visually pleasing colorized video,but also with clearly better temporal consistency than state-of-the-art methods.A video demo is provided at https://***/watch?v=c7dczMs-olE,while code is available at https://***/lyh-18/TCVC-Tem porally-Consistent-Video-Colorization.

关键词： video colorization temporal consistency feature propagation self-regularization

Determination of uncertainties of geomechanical parameters of metamorphic rocks using petrographic analyses

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Journal of Rock Mechanics and Geotechnical engineering 2024年第2期16卷 345-364页

作者： Behzad Dastjerdy Ali Saeidi Shahriyar Heidarzadeh Department of applied sciences University of Quebec at ChicoutimiSaguenayQCCanada SNC-Lavalin MontrealCanada

Geomechanical parameters of intact metamorphic rocks determined from laboratory testing remain highly uncertain because of the great intrinsic variability associated with the degrees of *** aim of this paper is to develop a proper methodology to analyze the uncertainties of geomechanical characteristics by focusing on three domains,*** treatment process,schistosity angle,and ***,the variabilities of the geomechanical laboratory data of Westwood Mine(Quebec,Canada)were examined statistically by applying different data treatment techniques,through which the most suitable outlier methods were selected for each parameter using multiple decision-making criteria and engineering *** indicated that some methods exhibited better performance in identifying the possible outliers,although several others were unsuccessful because of their limitation in large sample *** well-known boxplot method might not be the best outlier method for most geomechanical parameters because its calculated confidence range was not acceptable according to engineering ***,several approaches,including adjusted boxplot,2MADe,and 2SD,worked very well in the detection of true ***,the statistical tests indicate that the best-fitting probability distribution function for geomechanical intact parameters might not be the normal distribution,unlike what is assumed in most geomechanical ***,the negative effects of schistosity angle on the uniaxial compressive strength(UCS)variabilities were reduced by excluding the samples within a specific angle range where the UCS data present the highest ***,a petrographic analysis was conducted to assess the associated uncertainties such that a logical link was found between the dispersion and the variabilities of hard and soft minerals.

关键词： Intact rock parameters Natural variabilities Outlier detection methods Uncertainties Westwood mine Mineralogy

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

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Nano Research 2024年第3期17卷 1666-1675页

作者： Cuiping Li Lu Zhang Shuai Zhang Qiqi Yu Dan Li Lei Zhang Chunhong Gong Jingwei Zhang Institute of Functional Polymer Composites College of Chemistry and Molecular SciencesHenan UniversityKaifeng 475004China National&Local Joint engineering Research Center for applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature ***,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about ***,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of ***,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on *** hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated *** from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 *** work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

关键词： flexible titanium nitride nanofibrous membranes local conductive loss dielectric loss electromagnetic microwave absorption wide temperature spectrum

Exceptional reversed yield strength asymmetry in a rare-earth free Mg alloy containing quasicrystal precipitates

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Journal of Magnesium and Alloys 2024年第2期12卷 687-699页

作者： Qiang Yang Shuhui Lv Zixiang Yan Zefeng Xie Xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022PR China School of Materials Science and engineering Changchun University of Science and Technology130022PR China

This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)*** exhibiting traditional basal texture,it owns an exceptional CYS/TYS as high as~*** back-scattered diffraction(EBSD)and transmission electron microscopy(TEM)examinations indicate pyramidal and prismatic dislocations plus tensile twinning being activated after immediate yielding in compression while basal and non-basal dislocations in tension.I-phase particles transferred the concentrated stress by self-twinning to provide the driving force for tensile twin initiating in neighboring grains,thereby significantly increasing the critical resolved shear stress of tensile twinning to possibly the level of pyramidal slip,finally leading to the dominance of pyramidal slip plus tensile twinning in texture *** results in a higher contribution on yield strength by~55 MPa in compression than in tension,which reasonably agrees with the experimental yield strength difference(~38 MPa).It can be concluded that I-phase particles influence deformation modes in tension and in compression,finally result in reversed yield strength asymmetry.

关键词： Magnesium alloy Reversed yield strength asymmetry Transmission electron microscopy(TEM) Twinning Dislocations

Designing hierarchical structures for innovative cooling textile

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Nano Research 2024年第10期17卷 9202-9224页

作者： Xiran Du Jinlei Li Bin Zhu Jia Zhu National Laboratory of Solid State Microstructures College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210023China School of Sustainable Energy and Resources Nanjing UniversitySuzhou 215163China

The potential of personal cooling technologies in reducing air conditioning energy consumption and enhancing human thermal comfort is *** review focuses on recent advancements in hierarchical structure design for innovative cooling *** with insights into fundamental heat transfer processes between the human body,textile,and the surroundings,we uncover key control *** the advanced hierarchical structure designs enabling effective radiation,sweat evaporation,conduction management,and integration of cold energy sources for realizing effective human body cooling are systematically ***,we explore multifunctional designs beyond cooling,including switchable cooling-heating and ***,we engage in discussions on unifying cooling performance tests and additional multiple requirements to make strides toward practical *** review is anticipated to be a valuable resource,providing the scientific and industrial communities with a quick grasp of past advancements,current challenges,and future directions in achieving effective human body cooling.

关键词： thermal comfort personal cooling textile hierarchical structures

High-efficiency PdNi single-atom alloy catalyst toward cross-coupling reaction

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Chinese Chemical Letters 2024年第7期35卷 480-483页

作者： Baokang Geng Xiang Chu Li Liu Lingling Zhang Shuaishuai Zhang Xiao Wang Shuyan Song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of applied Chemistry and engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry Tsinghua UniversityBeijing 100084China

The preparation of Pd-based catalysts with rich electrons and a high atom dispersion rate is of great significance for improving the reactivity of cross-coupling reactions,which is a powerful tool for pharmaceutical and fine chemical ***,we report a PdNi single-atom alloy(SAA)catalyst in which isolated Pd single atoms are anchored onto the surface of Ni nanoparticles(NPs)applied for Suzuki coupling reactions and Heck coupling *** 0.1%PdNi SAA exhibits extraordinary catalytic activity(reaction rate:17,032.25 mmol h^(-1)gPd^(-1))toward the Suzuki cross-coupling reaction between 4-bromoanisole and phenylboronic acid at 80℃for 1 *** excellent activity is supposed to attribute to the 100 percent utilization rate of Pd atoms and the highly stable surface zero-valance Pd atoms,which provides abundant sites and electrons for the adsorption and fracture of the C-X(X=Cl,Br,I)***,our work demonstrates the excellent application prospect of SAAs for cross-coupling reactions.

关键词： Single-atom alloy Cross-coupling reaction Palladium catalysis Heterogeneous catalysis High-efficiency