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Disorder-induced enhancement of nonclassical correlations in programmable integrated quantum walks
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作者 Zhi-Yuan Zhang Yang Chen +7 位作者 Lan-Tian Feng Jin-Hao Zheng Qin-Qin Wang Bo-Yu Xu Yu-Yang Ding Xiao-Ye Xu Guang-Can Guo Xi-Feng Ren 《Advanced Photonics Nexus》 2026年第1期248-256,共9页
Programmable two-particle quantum walks are crucial for advancing quantum simulation,computation,and information processing.Although disorder is traditionally associated with information loss,it can also facilitate em... Programmable two-particle quantum walks are crucial for advancing quantum simulation,computation,and information processing.Although disorder is traditionally associated with information loss,it can also facilitate emergent phenomena such as enhanced energy transport.Here,we experimentally realize a 12-step discrete-time quantum walk in programmable integrated photonic circuits,introducing tunable static and dynamic disorder to explore quantum transport dynamics.In periodic lattices,disorder induces light localization and drives a transition from quantum ballistic to classical diffusive behavior.In particular,quantum walks of correlated photons exhibit a disorder-induced bunching effect,accompanied by enhanced nonclassical correlations.Our platform provides a scalable framework for investigating multiparticle quantum dynamics in engineered environments,promoting the development of quantum optics toward large-scale applications. 展开更多
关键词 integrated quantum photonics disordered quantum walks SUPERDIFFUSION quantum correlations
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The measurement of the energy correlations between two^(252)Cf prompt fission neutrons
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作者 Huai-Yong Bai Hang Li +8 位作者 Hong-Jun Zhang Cheng-Guo Pang Ming Su Zhong-Hua Xiong Ji Wen Fan Gao Chen-Guang Li Xiao-Dong Wang Li-Sheng Yang 《Nuclear Science and Techniques》 2026年第4期202-215,共14页
The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was perf... The energy correlations of prompt fission neutrons have not yet been considered in the related coincidence and multiplication measurement techniques.To measure and verify the energy correlations,an experiment was performed with a total measurement duration of approximately 1200 h.In the experiment,eight CLYC detectors and sixteen EJ309 liquid scintillation detectors were utilized,and the fission moment was tagged with the measured fissionγ-rays.The relative ratios of the energy spectra of the neutrons correlated with different energy neutrons to the^(252)Cf fission neutron energy spectra were obtained.The present results may be helpful for studying fission physics and nuclear technology applications. 展开更多
关键词 Energy correlations Prompt fission neutrons Energy spectrum Fissionγ-rays
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Electronic correlations and topological states at the interface of twisted bilayer graphene and chromium oxychloride
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作者 Minsheng Li Zehao Jia +6 位作者 Xiangyu Cao Qiang Ma Chang Jiang Yuda Zhang Linfeng Ai Pengliang Leng Faxian Xiu 《Chinese Physics B》 2026年第2期185-192,共8页
When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–el... When two layers of graphene are stacked with a twist angle of approximately 1.1°,strong interlayer coupling gives rise to a pair of flat bands in twisted bilayer graphene(TBG),resulting in pronounced electron–electron interactions.At half filling of the flat bands,TBG exhibits correlated insulating states.Here,we investigate the electrical transport properties of heterostructures composed of TBG and the antiferromagnetic insulator chromium oxychloride(CrOCl),and propose a strategy to modulate the correlated insulating states in TBG.During the transition from a conventional phase to a strong interfacial coupling phase,kink-like features are observed in the charge neutrality point(CNP),correlated insulating state,and band insulating state.Under a perpendicular magnetic field,the system exhibits broadened quantum Hall plateaus in the strong interfacial coupling regime.Electrons localized in the CrOCl layer screen the bottom gate,rendering the carrier density in TBG less sensitive to variations in the bottom gate voltage.These phenomena are well captured by a charge-transfer model between TBG and CrOCl.Our results provide insights into the control of electronic correlations and topological states in graphene moirésystems via interfacial charge coupling. 展开更多
关键词 twisted bilayer graphene correlated insulating state CrOCl interfacial coupling charge transfer
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Probability distributions for kinetic roughening in the Kardar-Parisi-Zhang growth with long-range spatiotemporal correlations
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作者 Zhichao Chang Hui Xia 《Communications in Theoretical Physics》 2026年第1期153-165,共13页
We investigate numerically the effects of long-range temporal and spatial correlations based on the rescaled distributions of the squared interface width W^(2)(L, t) and the interface height h(x, t)in the(1+1)-dimensi... We investigate numerically the effects of long-range temporal and spatial correlations based on the rescaled distributions of the squared interface width W^(2)(L, t) and the interface height h(x, t)in the(1+1)-dimensional Kardar-Parisi-Zhang(KPZ) growth system within the early growth regime. Through extensive numerical simulations, we find that long-range temporally correlated noise does not significantly impact the distribution form of the interface width. Generally,W^(2)(L, t) approximately obeys a lognormal distribution when the temporal correlation exponentθ ≥0. On the other hand, the effects of long-range spatially correlated noise are evidently different from the temporally correlated case. Our results show that, when the spatial correlation exponent ρ ≤ 0.20, the distribution forms of W^(2)(L, t) approach the lognormal distribution, and when ρ > 0.20, the distribution becomes more asymmetric, steep, and fat-tailed, and tends to an unknown distribution form. As a comparison, probability distributions of the interface height are also provided in the temporally and spatially correlated KPZ system, exhibiting quite different characteristics from each other within the whole correlated strengths. For the temporal correlation, the height distributions follow Tracy-Widom Gaussian orthogonal ensemble(TW-GOE) when θ → 0, and with increasing θ, the height distributions crossover continuously to an unknown distribution. However, for the spatial correlation, the height distributions gradually transition from the TW-GOE distribution to the standard Gaussian form. 展开更多
关键词 Kardar-Parisi-Zhang equation long-range correlated noise probability distribution universality class
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Ab initio density functional theory approach to warm dense hydrogen:From density response to electronic correlations
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作者 Zhandos A.Moldabekov Xuecheng Shao +5 位作者 Hannah M.Bellenbaum Cheng Ma Wenhui Mi Sebastian Schwalbe Jan Vorberger Tobias Dornheim 《Matter and Radiation at Extremes》 2026年第2期14-20,共7页
Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse ... Understanding the properties of warm dense hydrogen is of key importance for the modeling of compact astrophysical objects and to understand and further optimize inertial confinement fusion applications.The workhorse of warm dense matter theory is thermal density functional theory(DFT),which,however,suffers from two limitations:(i)its accuracy can depend on the utilized exchange-correlation functional,which has to be approximated,and(ii)it is generally limited to single-electron properties such as the density distribution.Here,we present a new ansatz combining time-dependent DFT results for the dynamic structure factor S_(ee)(q,ω)with static DFT results for the density response.This allows us to estimate the electron-electron static structure factor S_(ee)(q)of warm dense hydrogen with high accuracy over a broad range of densities and temperatures.In addition to its value for the study of warm dense matter,our work opens up new avenues for the future study of electronic correlations exclusively within the framework of DFT for a host of applications. 展开更多
关键词 thermal density functional theory dft whichhoweversuffers understanding properties warm dense hydrogen thermal density functional theory understand further optimize inertial confinement fusion applicationsthe warm dense matter theory electronic correlations warm dense hydrogen density functional theory
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Octupole correlations of the K^(π)=5/2^(+)ground-state band in^(229)Th
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作者 Yuan-Yuan Wang Peng-Wei Zhao 《Chinese Physics B》 2026年第2期156-161,共6页
The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice sp... The octupole correlations of the K^(π)=5/2^(+)ground state and the rotational spectrum built on it in^(229)Th are studied using the microscopic relativistic density functional theory on a three-dimensional lattice space and the reflection-asymmetric triaxial particle rotor model.It is found that^(229)Th has a ground state with static axial octupole and quadrupole deformations.The occurrence of octupole correlations,driven by the octupole deformation,is analyzed through the evolution of single-particle levels around the Fermi surface.The experimental energy spectrum and the electromagnetic transition probabilities,including B(E2)and B(M1),are reasonably well reproduced. 展开更多
关键词 octupole correlation relativistic density functional theory reflection-asymmetric triaxial particle rotor model rotational spectrum
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Recent advances in modelling structure-property correlations in high-entropy alloys 被引量:2
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作者 Akash A.Deshmukh Raghavan Ranganathan 《Journal of Materials Science & Technology》 2025年第1期127-151,共25页
Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery... Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery of high-entropy alloys(HEAs)comprising multi-principal elements.Owing to the four“core-effects”,these alloys exhibit exceptional properties including better structural stability,high strength and ductility,improved fatigue/fracture toughness,high corrosion and oxidation resistance,superconductiv-ity,magnetic properties,and good thermal properties.Different synthesis routes have been designed and used to meet the properties of interest for particular applications with varying dimensions.How-ever,HEAs are providing new opportunities and challenges for computational modelling of the complex structure-property correlations and in predictions of phase stability necessary for optimum performance of the alloy.Several attempts have been made to understand these alloys by empirical and computa-tional models,and data-driven approaches to accelerate the materials discovery with a desired set of properties.The present review discusses advances and inferences from simulations and models spanning multiple length and time scales explaining a comprehensive set of structure-properties relations.Addi-tionally,the role of machine learning approaches is also reviewed,underscoring the transformative role of computational modelling in unravelling the multifaceted properties and applications of HEAs,and the scope for future efforts in this direction. 展开更多
关键词 High-entropy alloys DFT Molecular dynamics CALPHAD Machine learning Structure-property correlations
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Utilizing On-the-Go Soil Sensors to Explore Correlations between Electrical Conductivity, Soil Reflectance, Slope, and Elevation of Mississippi Farm Soils 被引量:1
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作者 Reginald S. Fletcher 《Agricultural Sciences》 2025年第1期112-122,共11页
Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the m... Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites. 展开更多
关键词 Mobile Soil Sensors NEAR-INFRARED Correlation Nonlinear
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Correlations of resilience with coping styles and quality of life in patients with malignancies 被引量:1
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作者 Xue-Jin Qin Man-Man Kang +4 位作者 Fei Zhong Jing-Jing Liu Zheng-Chun Zhu Di Zhang Ke Han 《World Journal of Psychiatry》 2025年第4期186-194,共9页
BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine t... BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine the association of resilience with coping styles and quality of life in patients with malignancies.METHODS This study included patients with malignant tumors who were hospitalized at Fuyang Hospital Affiliated to Anhui Medical University from March 2022 to March 2024.The Connor-Davidson Resilience Scale,Medical Coping Modes Questionnaire,Social Support Rating Scale,and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 were utilized to assess patients’resilience,coping styles,social support,and quality of life,respectively.Pearson correlation analysis was conducted to assess the correlations.RESULTS A total of 175 patients with malignant tumors demonstrated no marked difference in terms of age,education level,employment status,monthly household income,and disease staging(P<0.05).Further,patients with malignancies demonstrated scores of 17.49±1.20,17.27±1.46,and 11.19±1.29 points in terms of coping styles in confrontation,avoidance,and resignation dimensions,respectively.Subjective support,objective support,and support utilization scores in terms of social support were 10.67±1.80,11.26±2.08,and 9.24±1.14 points,respectively.The total resilience score and tenacity,self-improvement,and optimism dimension scores were positively correlatedwith the confrontation coping style score,whereas the total resilience score and tenacity and self-improvementscores were negatively associated with avoidance and resignation coping style scores(P<0.05).The total resiliencescore and the tenacity dimension score were positively associated with physical,role,cognitive,emotional,andsocial functions,as well as global health status(P<0.05),and were inversely related to fatigue,insomnia,andeconomic difficulties(P<0.05).CONCLUSIONThe resilience of patients with malignancies is positively associated with the confrontation dimension in the copingstyle,the total and various social support domain scores,and the overall quality of life.Clinical medical staff needto pay attention to the effect of medical coping styles and social support on the resilience level of patients withmalignancies to further improve their quality of life. 展开更多
关键词 Malignant tumor RESILIENCE Coping style Quality of life CORRELATION
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Correlations of the expression of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in colon cancer tissues
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作者 Rong-Gang Luan Ming-Da Liu +9 位作者 Zi-Feng Deng Cong-Lan Lu Mei-Ling Yu Ming-Yu Zhang Rong Liu Ran An You-Liang Yao Dong-Bei Guo Yong-Xing Zhang Lei Zhao 《World Journal of Gastrointestinal Oncology》 SCIE 2025年第1期207-213,共7页
BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression result... BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1. 展开更多
关键词 Colon cancer CX43 SCF^(FBXW7) Phosphorylation of cyclin E1 Sites of cyclin E1 Correlation analysis
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Application of Multiple Correlations Analysis in Portfolio Selection
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作者 Ruili Sun Junpeng Jia Shiguo Huang 《Proceedings of Business and Economic Studies》 2025年第4期305-319,共15页
Portfolio selection based on the global minimum variance(GMV)model remains a significant focus in financial research.The covariance matrix,central to the GMV model,determines portfolio weights,and its accurate estimat... Portfolio selection based on the global minimum variance(GMV)model remains a significant focus in financial research.The covariance matrix,central to the GMV model,determines portfolio weights,and its accurate estimation is key to effective strategies.Based on the decomposition form of the covariance matrix.This paper introduces semi-variance for improved financial asymmetric risk measurement;addresses asymmetry in financial asset correlations using distance,asymmetric,and Chatterjee correlations to refine covariance matrices;and proposes three new covariance matrix models to enhance risk assessment and portfolio selection strategies.Testing with data from 30 stocks across various sectors of the Chinese market confirms the strong performance of the proposed strategies. 展开更多
关键词 Portfolio selection GMV model Semi-variance Asymmetric correlation Chatterjee correlation
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Observable-manifested correlations in many-body quantum chaotic systems
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作者 Xiao Wang Jiaozi Wang Wen-ge Wang 《Communications in Theoretical Physics》 2025年第12期143-151,共9页
In this paper,we investigate the distinctions between dynamical quantum chaotic systems and random models from the perspective of observable properties,particularly focusing on the eigenstate thermalization hypothesis... In this paper,we investigate the distinctions between dynamical quantum chaotic systems and random models from the perspective of observable properties,particularly focusing on the eigenstate thermalization hypothesis(ETH).Through numerical simulations,we find that for dynamical systems,the envelope function of off-diagonal elements of observables exhibits an exponential decay at largeΔE,while for randomized models,it tends to be flat.We demonstrate that the correlations of chaotic eigenstates,originating from the delicate structures of Hamiltonians,play a crucial role in the non-trivial structure of the envelope function.Furthermore,we analyze the numerical results from the perspective of the dynamical group elements in Hamiltonians.Our findings highlight the importance of correlations in physical chaotic systems and provide insights into the deviations from random matrix theory(RMT)predictions.These understandings offer valuable directions for future research. 展开更多
关键词 eigenstate thermalization quantum chaos many body correlations
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Correlations of the net baryon number and electric charge in nuclear matter
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作者 Xin-Ran Yang Guo-Yun Shao +1 位作者 Chong-Long Xie Zhi-Peng Li 《Nuclear Science and Techniques》 2025年第8期154-164,共11页
We investigated the correlations between the net baryon number and electric charge up to the sixth order related to the interactions of nuclear matter at low temperature and explored their relationship with the nuclea... We investigated the correlations between the net baryon number and electric charge up to the sixth order related to the interactions of nuclear matter at low temperature and explored their relationship with the nuclear liquid-gas phase transition(LGPT)within the framework of the nonlinear Walecka model.The calculations showed that strong correlations between the baryon number and electric charge existed near the LGPT,and higher-order correlations were more sensitive than the lower-order correlations near the phase transition.However,in the high-temperature region away from the LGPT,the rescaled lower-order correlations were relatively larger than most of the higher-order correlations.In addition,some of the fifth-and sixth-order correlations possibly changed sign from negative to positive along the chemical freeze-out line with decreasing temperature.In combination with future experimental projects at lower collision energies,the derived results can be used to study the phase structure of strongly interacting matter and analyze the related experimental signals. 展开更多
关键词 correlations of conserved charges Nuclear matter Nuclear liquid–gas phase transition Heavy-ion collision
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Towards understanding the microstructure-mechanical property correlations of multi-level heterogeneous-structured Al matrix composites
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作者 Yuesong Wu Xiaobin Lin +4 位作者 Xudong Rong Xiang Zhang Dongdong Zhao Chunnian He Naiqin Zhao 《Journal of Materials Science & Technology》 2025年第6期117-123,共7页
1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain bounda... 1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain boundaries(GBs),which restricts local plastic flow dur-ing the plastic deformation and leads to stress concentration[3,4].Recently,the development of concepts aimed at achieving hetero-geneous grain has emerged as a promising approach for enhanc-ing comprehensive mechanical properties[5,6]. 展开更多
关键词 reinforcements agglomeration comprehensive mechanical properties agglomeration reinforcements plastic deformation strength ductility trade off multi level heterogeneous structured Al matrix composites microstructure mechanical property correlations al matrix composites amcs
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The impact of tensor force on collective correlations and neutrinoless double-βdecay
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作者 Chang-Feng Jiao Cen-Xi Yuan 《Nuclear Science and Techniques》 2025年第11期233-242,共10页
The tensor force changes the nuclear shell structure and thus may result in underlying influence of the collectivity and decay properties of the nucleus.We carefully examined the impact of the monopole and multipole e... The tensor force changes the nuclear shell structure and thus may result in underlying influence of the collectivity and decay properties of the nucleus.We carefully examined the impact of the monopole and multipole effects originating from the tensor force on both the collectivity and the matrix element for the neutrinoless double-β(0νββ)decay,using the generatorcoordinate method with an effective interaction.To analyze the effect of the tensor force,we employed an effective Hamiltonian associated with the monopole-based universal interaction that explicitly consists of the central,tensor,and spin-orbit coupling terms.The interferences among the shell structure,quadrupole collectivity,nucleon occupancy,and 0νββmatrix elements were analyzed in detail.A better understanding of the tensor force would be of great importance in reducing the theoretical uncertainty in 0νββnuclear matrix element calculations. 展开更多
关键词 Neutrinoless double-beta decay Collective correlations Tensor force
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Canopy structural heterogeneity drives α and β species-genetic diversity correlations in a Chinese subtropical forest
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作者 Zhiliang Yao Xia Pan +6 位作者 Xin Yang Xiaona Shao Bin Wang Yun Deng Zhiming Zhang Qiaoming Li Luxiang Lin 《Plant Diversity》 2025年第1期106-114,共9页
Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies ha... Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs. 展开更多
关键词 Dominant species Forest structure LIDAR Lithocarpus xylocarpus Speciesegenetic diversity correlation Subtropical evergreen broad-leaved forest
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Cross-correlations between signal's components
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作者 Quankun Zhao Sen Li +2 位作者 Changgui Gu Haiying Wang Huijie Yang 《Chinese Physics B》 2025年第2期483-494,共12页
Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with ot... Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with other elements, and the environment. It is subsequently composed of many components, only some of which take part in the couplings. In this paper we present a framework to detect the component correlation pattern. Firstly, the interested trajectories are decomposed into components by using decomposing methods such as the Fourier expansion and the Wavelet transformation. Secondly, the cross-correlations between the components are calculated, resulting into a component cross-correlation matrix(network).Finally, the dominant structure in the network is identified to characterize the coupling pattern in the system. Several deterministic dynamical models turn out to be characterized with rich structures such as the clustering of the components. The pattern of correlation between respiratory(RESP) and ECG signals is composed of five sub-clusters that are mainly formed by the components in ECG signal. Interestingly, only 7 components from RESP(scattered in four sub-clusters) take part in the realization of coupling between the two signals. 展开更多
关键词 coupling structure cross-correlation matrix component correlation network
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Detailed discussion of discrepancy between theoretical and observed spectral lines in Kr-like W^(38+)based on advanced consideration of core electron correlations
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作者 Guo-Qing Peng Kai Wang +1 位作者 Jun Yan Wei Kang 《Chinese Physics B》 2025年第5期328-337,共10页
For the observed line at 799.23°A in tungsten EBIT experiment,which was assigned to be^(3)F_(4)^(o)−^(3)F_(3)^(o)([Ar]4s^(2)4p^(5)4d)of W^(38+)ion,there were noticeable deviations for most calculated wavelengths ... For the observed line at 799.23°A in tungsten EBIT experiment,which was assigned to be^(3)F_(4)^(o)−^(3)F_(3)^(o)([Ar]4s^(2)4p^(5)4d)of W^(38+)ion,there were noticeable deviations for most calculated wavelengths from the measured value.To clarify this issue,we carry out an extensive calculation for energy levels and transition properties of W^(38+)ion using the multi-configuration Dirac–Hartree–Fock and relativistic configuration interaction method,in which more deeper inner core electron correlations are included,and different forms of Breit interaction as well as quantum electrodynamics corrections are investigated.It is found that the inner core electron correlations can affect the total energy of levels,while only slightly modify the excited energy of levels in 4s^(2)4p^(5)4d complex.The present calculated wavelengths agree with the corresponding measured values excellently except the line at 799.23Å.Thus we are strongly suspicious this line should be misidentified,and suggest that new experiment with higher resolution and spectra analysis based on more accurate atomic data should be performed for W^(38+)ion. 展开更多
关键词 Kr-like W^(38+) the multi-configuration Dirac-Hartree-Fock(MCDHF)method electron correlation imbalance Breit interaction quantum electrodynamic(QED)
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上行相关性、下行相关性与收益率预测
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作者 郑振龙 杨玉晓 陈蓉 《数理统计与管理》 北大核心 2026年第1期147-160,共14页
投资者在股票市场进行分散投资时,仍然承担着股票间的相关性风险,研究相关性风险与预期收益率的关系,对投资组合的选择有重要的参考意义。本文首次把相关性风险分解为上行相关性和下行相关性,然后利用日内高频数据,分析了它们对未来不... 投资者在股票市场进行分散投资时,仍然承担着股票间的相关性风险,研究相关性风险与预期收益率的关系,对投资组合的选择有重要的参考意义。本文首次把相关性风险分解为上行相关性和下行相关性,然后利用日内高频数据,分析了它们对未来不同期限中国股票市场收益率的预测能力。实证结果发现:(1)相关性风险对股票市场未来不同期限收益率有负向预测力。(2)相关性对中长期整体市场收益率预测表现更佳,在对未来六个月和一年的沪深300样本内预测R^(2)超过了7%。(3)结合样本内和样本外的预测结果,与总的相关性和上行相关性相比,下行相关性对股票市场收益率的预测能力更稳健,尤其是样本外预测效果更优。为了进一步说明相关性稳健的预测能力,我们还考察了上证50,结果显示相关性对其仍保持着预测能力。相关性风险是投资者不可忽视的风险,特别是下行相关性风险。 展开更多
关键词 上行相关性 下行相关性 收益率预测
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基于湖北省传染病监测预警与应急指挥平台的呼吸道传染病和症候群监测分析
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作者 刘红慧 李诺 +3 位作者 石萌 郑立国 朱可 童叶青 《中华疾病控制杂志》 北大核心 2026年第2期243-248,共6页
目的 对湖北省传染病监测预警与应急指挥信息平台(简称湖北省统筹平台)呼吸系统传染病及症候群病例开展流行病学分析和数据质量评估,为完善传染病防控策略提供科学依据。方法 采用描述性研究分析湖北省统筹平台2023年1月1日―2025年3月1... 目的 对湖北省传染病监测预警与应急指挥信息平台(简称湖北省统筹平台)呼吸系统传染病及症候群病例开展流行病学分析和数据质量评估,为完善传染病防控策略提供科学依据。方法 采用描述性研究分析湖北省统筹平台2023年1月1日―2025年3月13日流行性感冒(简称流感)、呼吸道合胞病毒感染等传染病,以及发热呼吸道症候群、发热伴出疹症候群等五大症候群病例就诊、住院病例流行特征,并基于Pearson相关分析对流感报告卡病例和就诊、住院量在时间、空间分布上的一致性开展评价。结果 湖北省统筹平台可实现对呼吸道合胞病毒等非法定报告传染病、症候群等监测分析。流感报告卡病例与湖北省平台监测病例在时间分布上高度一致,Pearson相关系数为0.86(95%CI:0.85~0.86,P<0.001)。时间相关性方面,超70%的月度相关性为强相关及以上;空间相关性方面,除黄冈市(r=0.26, 95%CI:0.19~0.33,P<0.001)、荆门市(r=0.46, 95%CI:0.40~0.52,P<0.001)外,其他市州均为强相关及以上。结论 湖北省统筹平台在数据质量、监测模式、监测对象上呈现出一定优势,能有效实现对非法定传染病和症候群的常态化实时监测评估。 展开更多
关键词 呼吸道传染病 症候群 监测分析 相关系数
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