期刊文献+
共找到110,439篇文章
< 1 2 250 >
每页显示 20 50 100
Cr-Substitution-Driven Correlation Enhancement and Hund's Metallicity in CsV_(3-x)Cr_(x)Sb_(5)
1
作者 Guiyan Dong Zihao Huo +3 位作者 Wenxuan Chen Tiancheng Ma Jialiang Cai Defang Duan 《Chinese Physics Letters》 2026年第3期283-293,共11页
The Kagome metal CsV3Sb5 transitions from a weakly correlated state to a strongly correlated state upon Cr substitution;however,the mechanism driving this enhancement remains an open question.Here,we employed a combin... The Kagome metal CsV3Sb5 transitions from a weakly correlated state to a strongly correlated state upon Cr substitution;however,the mechanism driving this enhancement remains an open question.Here,we employed a combination of density functional theory and dynamical mean-field theory(DFT+DMFT)to systematically investigate the evolution of electronic correlations in the CsV_(3−x)Cr_(x)Sb_(5)(x=0,1,and 3)series.Our calculations revealed that Cr doping drives the system into a strongly correlated Hund’s metal phase,which is characterized by significant and orbital-dependent enhancements in the quasiparticle effective masses and electronic scattering rates.We trace the origin of this transition to the doping-induced shift from low-to high-spin atomic configurations.This preference for high-spin states,which is promoted by near-half-filling of the Cr-d orbitals,induces a pronounced orbital blocking effect that strengthens the correlations.Our findings establish that Hund’s coupling is the decisive factor governing the rich correlation physics in the CsV_(3−x)Cr_(x)Sb_(5) family,providing a tunable platform for exploring Hund’s metallicity. 展开更多
关键词 hund s metal pha dynamical mean field theory density functional theory electronic correlations evolution electronic correlations hunds metallicity kagome metal csv sb cr substitution
原文传递
Probing QCD confinement with spin-spin correlation in proton-proton collisions
2
作者 Zuo-Tang Liang Qing-Hua Xu Jin-Long Zhang 《Nuclear Science and Techniques》 2026年第5期1-4,共4页
An important feature of quantum chromodynamics(QCD)is that the strong force grows as the distance between partons increases,which confines partons into hadrons,commonly known as QCD confinement.Perturbative QCD(pQCD)d... An important feature of quantum chromodynamics(QCD)is that the strong force grows as the distance between partons increases,which confines partons into hadrons,commonly known as QCD confinement.Perturbative QCD(pQCD)does not work at large distance,such as the length scale of a hadron,which is the regime of non-perturbative QCD.The detailed QCD mechanisms through which confinement occurs from partons to hadrons(usually known as hadronization),and how it manifests itself in partonic structure of hadrons(usually known as parton distribution),remain unresolved puzzles of first-principle QCD calculations. 展开更多
关键词 spin spin correlation quantum chromodynamics qcd PARTONS QCD confinement HADRONS non perturbative QCD strong force proton proton collisions
在线阅读 下载PDF
Ab initio density functional theory approach to warm dense hydrogen:From density response to electronic correlations
3
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
在线阅读 下载PDF
The Pursuit of Fallacy in Density Functional Theory: The Quest for Exchange and Correlation, the Rigorous Treatment of Exchange in the Kohn-Sham Formalism and the Continuing Search for Correlation
4
作者 A. Gonis 《World Journal of Condensed Matter Physics》 2014年第3期200-225,共26页
As pointed out in the paper preceding this one, in the case of functionals whose independent variable must obey conditions of integral normalization, conventional functional differentiation, defined in terms of an arb... As pointed out in the paper preceding this one, in the case of functionals whose independent variable must obey conditions of integral normalization, conventional functional differentiation, defined in terms of an arbitrary test function, is generally inapplicable and functional derivatives with respect to the density must be evaluated through the alternative and widely used limiting procedure based on the Dirac delta function. This leads to the determination of the rate of change of the dependent variable with respect to its independent variable at each isolated pair, , that may not be part of a functional (a set of ordered pairs). This extends the concept of functional derivative to expectation values of operators with respect to wave functions leading to a density even if the wave functions (and expectation values) do not form functionals. This new formulation of functional differentiation forms the basis for the study of the mathematical integrity of a number of concepts in density functional theory (DFT) such as the existence of a universal functional of the density, of orbital-free density functional theory, the derivative discontinuity of the exchange and correlation functional and the extension of DFT to open systems characterized by densities with fractional normalization. It is shown that no universal functional exists but, rather, a universal process based only on the density and independent of the possible existence of a potential, leads to unique functionals of the density determined through the minimization procedure of the constrained search. The mathematical integrity of two methodologies proposed for the treatment of the Coulomb interaction, the self-interaction free method and the optimized effective potential method is examined and the methodologies are compared in terms of numerical calculations. As emerges from this analysis, the optimized effective potential method is found to be numerically approximate but formally invalid, contrary to the rigorously exact results of the self-interaction-free method. 展开更多
关键词 DENSITY FUNCTIONAL THEORY Variational Properties of DENSITY FUNCTIONAL THEORY Self-Interaction Error Optimized Effective Potential FUNCTIONAL DERIVATIVE Parametric DERIVATIVE FUNCTIONAL Rate of Change DERIVATIVE Discontinuity Orbital-Free DENSITY FUNCTIONAL THEORY EXCHANGE and correlation FUNCTIONAL
暂未订购
Spin Supercurrent in Phenomena of Quantum Non-Locality (Quantum Correlations, Magnetic Vector Potential) and in Near-Field Antenna Effect 被引量:1
5
作者 Liudmila B. Boldyreva 《Journal of Modern Physics》 2019年第2期128-144,共17页
It is shown that such phenomena as quantum correlations (interaction of space-separated quantum entities), the action of magnetic vector potential on quantum entities in the absence of magnetic field, and near-field a... It is shown that such phenomena as quantum correlations (interaction of space-separated quantum entities), the action of magnetic vector potential on quantum entities in the absence of magnetic field, and near-field antenna effect (the existence of superluminally propagating electromagnetic fields) may be explained by action of spin supercurrents. In case of quantum correlations between quantum entities, spin supercurrent emerges between virtual particles pairs (virtual photons) created by those quantum entities. The explanation of magnetic vector potential and near-field antenna effect is based on contemporary principle of quantum mechanics: the physical vacuum is not an empty space but the ground state of the field consisting of quantum harmonic oscillators (QHOs) characterized by zero-point energy. Using the properties of the oscillators and spin supercurrent, it is proved that magnetic vector potential is proportional to the moment causing the orientation of spin of QHO along the direction of magnetic field. The near-field antenna effect is supposed to take place as a result of action of spin supercurrent causing secondary electromagnetic oscillations. In this way, the electromagnetic field may spread at the speed of spin supercurrent. As spin supercurrent is an inertia free process, its speed may be greater than that of light, which does not contradict postulates of special relativity that sets limits to the speed of inertial systems only. 展开更多
关键词 SPIN SUPERCURRENT QUANTUM correlations Magnetic Vector Potential NEAR-FIELD Antenna Effect Zero-Point Energy QUANTUM Harmonic Oscillator VIRTUAL Particles Pair VIRTUAL Photon
在线阅读 下载PDF
Semantic Causality Evaluation of Correlation Analysis Utilizing Large Language Models
6
作者 Adam Dudáš 《Computers, Materials & Continua》 2026年第5期2246-2269,共24页
It is known that correlation does not imply causality.Some relationships identified in the analysis of data are coincidental or unknown,and some are produced by real-world causality of the situation,which is problemat... It is known that correlation does not imply causality.Some relationships identified in the analysis of data are coincidental or unknown,and some are produced by real-world causality of the situation,which is problematic,since there is a need to differentiate between these two scenarios.Until recently,the proper−semantic−causality of the relationship could have been determined only by human experts from the area of expertise of the studied data.This has changed with the advance of large language models,which are often utilized as surrogates for such human experts,making the process automated and readily available to all data analysts.This motivates the main objective of this work,which is to introduce the design and implementation of a large language model-based semantic causality evaluator based on correlation analysis,together with its visual analysis model called Causal heatmap.After the implementation itself,the model is evaluated from the point of view of the quality of the visual model,from the point of view of the quality of causal evaluation based on large language models,and from the point of view of comparative analysis,while the results reached in the study highlight the usability of large language models in the task and the potential of the proposed approach in the analysis of unknown datasets.The results of the experimental evaluation demonstrate the usefulness of the Causal heatmap method,supported by the evident highlighting of interesting relationships,while suppressing irrelevant ones. 展开更多
关键词 correlation CAUSALITY correlation analysis large language models VISUALIZATION
在线阅读 下载PDF
Correlation between life satisfaction,pleasure level,and negative emotion in patients with chronic renal failure
7
作者 Lin-Lin Zhang You-Li Zhang +3 位作者 Ting Liu Jian Wang Chen Chen Xiao-Yu Wang 《World Journal of Psychiatry》 2026年第1期291-298,共8页
BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM ... BACKGROUND Anxiety,depression,and other negative emotions are common among patients with chronic renal failure(CRF).Analyzing the factors related to negative emotions is necessary to provide targeted nursing care.AIM To explore the correlations among life satisfaction,pleasure levels,and negative emotions in patients with CRF.METHODS One hundred patients with CRF who received therapy at the First Affiliated Hospital of Jinzhou Medical University between December 2022 and February 2025 were included.The Depression,Anxiety,and Stress Scale(DASS-21),Satisfaction with Life Scale(SWLS),and Temporal Experience of Pleasure Scale(TEPS)were used to evaluate negative emotions,life satisfaction,and pleasure level,respectively.Pearson’s correlation coefficient analyzed the correlation between life satisfaction,pleasure level,and negative emotions.Linear regression analysis identified the factors affecting negative emotions.RESULTS The average DASS-21 score among patients with CRF was 51.90±2.30,with subscale scores of 17.90±1.50 for depression,18.53±1.18 for anxiety,and 15.47±2.36 for stress,all significantly higher than the domestic norm(P<0.05).The average SWLS score was 22.17±4.90.Correlation analysis revealed a negative correlation between the SWLS and total DASS-21 scores(P<0.05),but not with the individual depression,anxiety,or stress dimensions.The average TEPS score was 67.80±8.34.TEPS scores were negatively correlated with the DASS-21 score and the stress dimension(P<0.05),but not with depression or anxiety.Linear regression analysis showed that TEPS scores significantly influenced DASS-21 scores(P<0.05).CONCLUSION Patients with CRF experience high levels of negative emotions,which are negatively correlated with life satisfaction and pleasure.Furthermore,pleasure level had an impact on negative emotions. 展开更多
关键词 Chronic renal failure HEMODIALYSIS Negative emotion Life satisfaction PLEASURE correlation
暂未订购
Experimentally-Induced Inhibition of Growth in Melanoma Cell Cultures Separated by ~2 Kilometers When Both Share Excess Correlation Magnetic Fields: Macroscopic Evidence of Free-Space Quantum Teleportation?
8
作者 Lukasz M. Karbowski Nirosha J. Murugan Michael A. Persinger 《Journal of Signal and Information Processing》 2015年第1期39-48,共10页
In multiple experiments plates of melanoma cells separated by either 3 m or 1.7 km were placed in the centers of toroids. A specific protocol of changing, angular velocity, pulsed magnetic fields that has been shown t... In multiple experiments plates of melanoma cells separated by either 3 m or 1.7 km were placed in the centers of toroids. A specific protocol of changing, angular velocity, pulsed magnetic fields that has been shown to produce excess correlation in photon durations and shift in proton concentrations (pH) in spring water were generated around both plates of cells. Serial injections of 50 μL of standard concentrations of hydrogen peroxide into the “local” plates of cells during the 12 min of field activation produced conspicuous cell death (reduction of viable cells by about 50%) with comparable diminishments of cell numbers in the non-local plates of cells within 24 hr but only if both loci separated by either 3 m or 1.7 km had shared the “excess correlation” magnetic field sequence. The non-local effect did not occur if the magnetic fields had not been present. Higher or lower concentrations of peroxide or concentrations that eliminated all of the cells or very few cells in the local dishes were associated with no significant diminishment of non-local cell growth. The data indicate that there must be a critical number of cells remaining viable following the local chemical reaction for the excess correlation to be manifested in the non-local cells. We suggest that this specific spatial-temporal pattern of fields generated within the paired toroidal geometries promotes transposition of virtual chemical reactions as an information field. Calculations of the energy available per cell and per volume of the quantity of reactants injected into the local space from the intensity of the changing velocity toroidal magnetic field support previous measurements and derivations that the units of information transposition may involve discrete quantities that represent equivalents of photons, electrons and protons. 展开更多
关键词 EXCESS correlation Entanglement Malignant Cell Death MELANOMA Cells Magnetic Fields Changing Angular Velocities BIOPHOTON Emissions 10-20 J
暂未订购
Improved Representation of Biological Information by Using Correlation as Distance Function for Heatmap Cluster Analysis
9
作者 Axel Tiessen Edgar A. Cubedo-Ruiz Robert Winkler 《American Journal of Plant Sciences》 2017年第3期502-516,共15页
Heatmap cluster figures are often used to represent data sets in the?omic sciences. The default option of the frequently used R heatmap function is to cluster data according to Euclidean distance, which groups data ma... Heatmap cluster figures are often used to represent data sets in the?omic sciences. The default option of the frequently used R heatmap function is to cluster data according to Euclidean distance, which groups data mainly to their numerical value and not to its relative behaviour. The disadvantage of using the default clustering?dendrograms of R is demonstrated. Instead, a script is provided that uses correlation as distance function, which better reveals biologically meaningful information. This optimized script was used to detect heterotic groups in Vitamaize hybrids (purple maize with high nutraceutical value). A field trial with different genetic combinations was performed through an agricultural phenomics approach (holistic evaluation of the phenotype). The grain yield data and other phenotypic variables were represented through heatmap figures. In the data set of Mexican tropical maize germplasm, at least three heterotic groups were detected, in contrast to only two heterotic groups reported earlier in temperate yellow maize from USA and Europe. This optimized script for heatmap correlation bicluster can also be used to better represent metabolomic fingerprints and transcriptomic data sets. 展开更多
关键词 Clusters CORN Dendogram Grain Yield HETEROSIS Hybrid VIGOUR Plant Breeding PHENOTYPING Pearson correlation Coefficient ZEA mays
暂未订购
Genetic Diversity and Correlation Studies for Cotton Leaf Curl Disease (CLCuD), Fiber &Yield Related Attributes in Exotic Lines of <i>Gossypium arboreum</i>L.
10
作者 Muhammad Idrees Khan Hafiz Abdul Haq +2 位作者 Kalim Ullah Muhammad Arshad Abdul Majid 《American Journal of Plant Sciences》 2017年第3期615-624,共10页
Genetic diversity provides the foundation for crop improvement. Genetic variation and associations among Cotton Leaf Curl Disease (CLCuD), fiber and yield related traits were investigated in exotic lines of Gossypium ... Genetic diversity provides the foundation for crop improvement. Genetic variation and associations among Cotton Leaf Curl Disease (CLCuD), fiber and yield related traits were investigated in exotic lines of Gossypium arboreum L. in an experimental field at the Central Cotton Research Institute (CCRI), Multan, Pakistan during the crop season 2011-12. One hundred and nineteen (119) accessions imported from USA through the Pakistan and US “Cotton Productivity Enhancement Program” (CPEP), were evaluated in this study. Various statistical approaches including descriptive statistics, correlation and principal component analysis was performed to evaluate and identify desirable genotypes. Results revealed that seed cotton yield was significantly and positively correlated with boll weight and number of bolls plant-1. Similarly, plant height was also significantly correlated with sympodial branches, lint percentage and micronaire value. Lint percentage showed a highly significant and positive correlation with plant height, sympodial branches and micronaire value. With respect to fiber traits, negative and significant relationships were observed between the micronaire value (MIC) and fiber strength. CLCuD showed no relationship with any of the studied traits, as all the G. arboreum L. lines evaluated were scored resistant to CLCuD. Principal component analysis (PCA) showed that the first four out of 11 components contributed about 65.88% of the total variation having an eigen value greater than 1. Based on PCA, the genotypes GS-4, GS-9, GS-8, GS-55 and GS-50 could be utilized successfully in a future breeding program based on having the highest positive loading factor for staple length (0.135) in PC1 and seed cotton yield (0.625), number of bolls plant-1, boll weight, first sympodial nod, staple length and fiber strength in PC2 respectively. 展开更多
关键词 Gossypium arboreum Genetic Diversity CLCuD YIELD LINT % Age FIBER Strength Principle Component Analysis and correlation
暂未订购
RS-based Analysis of the Correlation between Brightness Temperature and Vegetation Cover—A Case Study of Neijiang City,Sichuan Province of China
11
作者 薛万蓉 许辉熙 +2 位作者 但尚铭 何政伟 仇文侠 《Journal of Landscape Research》 2012年第2期35-37,共3页
Landsat TM data(June 23,1988,May 6,2007) and Landsat ETM+data(May 10,2000) of Neijiang City,Sichuan Province was taken as the data source,brightness temperature of the study area was obtained by using TM/ETM+thermal i... Landsat TM data(June 23,1988,May 6,2007) and Landsat ETM+data(May 10,2000) of Neijiang City,Sichuan Province was taken as the data source,brightness temperature of the study area was obtained by using TM/ETM+thermal infrared wave,and also normalized difference vegetation index(NDVI) was calculated.NDVI of the study area on June 23,1988,May 6,2007,and May 10,2000 was respectively obtained by using Band Math,the least square fitting was adopted to simulate the correlation between surface temperature and vegetation cover.Moreover,linear regression analysis of the correlation between vegetation cover and NDVI was carried out in Excel.The results showed that(a) most of the constructed area has a low NDVI value because there are large areas of hard surface such as buildings and roads,but less vegetation cover;(b) the quarters with better vegetation cover have higher NDVI values;the Tuojiang River has a negative NDVI value;rural areas have better vegetation cover and higher NDVI values.Brightness temperature and vegetation cover has distinct negative correlation,specifically,the higher the vegetation cover is,the lower the surface temperature is,and vice versa. 展开更多
关键词 Urban heat ISLAND effects Remote sensing(RS) BRIGHTNESS temperature Normalized difference VEGETATION index(NDVI) correlation ANALYSIS
全文增补中
Correlation Analysis of Anatomical and Pathological Characteristics of the Respiratory- Circulatory System
12
作者 Min Li 《Journal of Clinical and Nursing Research》 2026年第2期155-161,共7页
The respiratory-circulatory system, including organs such as the nose, pharynx, larynx, trachea, bronchi, and heart, is an organic community responsible for ventilation and gas exchange. The integrity of its anatomica... The respiratory-circulatory system, including organs such as the nose, pharynx, larynx, trachea, bronchi, and heart, is an organic community responsible for ventilation and gas exchange. The integrity of its anatomical structure directly affects the evolution of pathological processes, and the analysis of their correlation is a core entry point for clinical disease diagnosis, treatment, and mechanism research. Based on this, this paper mainly explores the correlation between the anatomical and pathological characteristics of the respiratory-circulatory system, aiming to provide anatomical and pathological theoretical support for clinical accurate diagnosis, targeted therapy, and prognosis evaluation. 展开更多
关键词 Respiratory-circulatory system PATHOLOGY ANATOMY CHARACTERISTICS correlation
暂未订购
From Shallow to Deep:A Novel Correlation Network Representation Regression Framework for Modeling and Monitoring MIQ-Driven Blast Furnace Ironmaking Processes
13
作者 Siwei Lou Chunjie Yang +3 位作者 Zhe Liu Hanwen Zhang Chao Liu Ping Wu 《IEEE/CAA Journal of Automatica Sinica》 2026年第2期281-299,共19页
Ironmaking process(IP)is indispensable to modern iron and steel industry,where real-time monitoring is crucial for achieving high molten iron quality(MIQ)with low energy consumption.While neural network-based models s... Ironmaking process(IP)is indispensable to modern iron and steel industry,where real-time monitoring is crucial for achieving high molten iron quality(MIQ)with low energy consumption.While neural network-based models show some promising results,they are generally limited by non-negligible drawbacks such as interpretability issues of feature learning.To address these issues,we propose a novel concept based on the shallow-to-deep correlation network representation regression(Sh-to-De CNRR).Our approach,shallow correlation network representation regression(ShCNRR),combines neural network and canonical correlation analysis thoughts to generate explainable features via shallow correlation network representation(CNR).A twin inverse network is then derived to obtain the explicit model output,leveraging the shallow CNR.To capture deeper nonlinear information,we extend ShCNRR into a hierarchical deep correlation network representation regression(DeCNRR)model that features stacked neural networks,enabling us to learn deeper CNR from process data.The feasibility and advantages of our proposals are validated by theoretical derivations and practical IP cases,which contain one MIQ regression and three MIQ-related fault detection tasks.The results reveal that highly fused statistical and neural network models yield superior monitoring performance compared to current state-of-the-art models,while statistical tests verify the convincing feature mining. 展开更多
关键词 Canonical correlation analysis(CCA) ironmaking process(IP) molten iron quality(MIQ) neural network(NN) process monitoring
在线阅读 下载PDF
Strong Correlation of Abnormal Serum and Urinary Iodine Levels with Papillary Thyroid Cancer:A Case-control Study 被引量:2
14
作者 XIU Cheng HE Qian +10 位作者 ZHAO Hong Jian YUAN Zhen Nan GUO Lun Hua WANG Feng Qian YANG Xian Guang TIAN Qiu Shi SUN Qi Hao MIAO Su Sheng SUN Ji FAN Li Jun JIA Shen Shan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第1期62-67,共6页
Thyroid cancer is the most common malignancy of the endocrine system,and its incidence is increasing worldwide.In China,its incidence has increased from 1.78/104 in 1988 to 10.58/104 in2013.Thyroid cancers are mainly ... Thyroid cancer is the most common malignancy of the endocrine system,and its incidence is increasing worldwide.In China,its incidence has increased from 1.78/104 in 1988 to 10.58/104 in2013.Thyroid cancers are mainly classified into papillary thyroid cancer(PTC),follicular thyroid cancer(FTC),medullary thyroid cancer(MTC). 展开更多
关键词 PTC Strong correlation ABNORMAL SERUM and Urinary Iodine LEVELS PAPILLARY Thyroid Cancer:A CASE-CONTROL Study
暂未订购
Detection of Mechanical Deformation in Old Aged Power Transformer Using Cross Correlation Co-Efficient Analysis Method 被引量:2
15
作者 Asif Islam Shahidul Islam Khan Aminul Hoque 《Energy and Power Engineering》 2011年第4期585-591,共7页
Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an... Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an effective low-voltage, off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the Transformer, due to large electromechanical forces occurring from the fault currents or due to Transformer transportation and relocation. In this method, the frequency response of a transformer is taken both at manufacturing industry and concern site. Then both the response is compared to predict the fault taken place in active part. But in old aged transformers, the primary reference response is unavailable. So Cross Correlation Co-Efficient (CCF) measurement technique can be a vital process for fault detection in these transformers. In this paper, theoretical background of SFRA technique has been elaborated and through several case studies, the effectiveness of CCF parameter for fault detection has been represented. 展开更多
关键词 Core Damage RADIAL DEFORMATION AXIAL DEFORMATION SWEEP Frequency Response Analysis Cross correlation Co-efficient Power Transformer
暂未订购
Analysis of the Correlation between the Geographical Distribution of Populus euphratica Oliv. and the Climatic Environment
16
作者 杨银科 阎正龙 《Agricultural Science & Technology》 CAS 2012年第7期1450-1455,共6页
[Objective] This research was to study the correlation regional climatic characteristics and changing geographic distribution of Populus euphratica Oliv. (Salicaceae), as well as the adaption of Populus euphratica Oli... [Objective] This research was to study the correlation regional climatic characteristics and changing geographic distribution of Populus euphratica Oliv. (Salicaceae), as well as the adaption of Populus euphratica Oliv. to the climatic environment. [Method] The climatic characteristics, water source, groundwater and soil type in the distribution regions of Populus euphratica Oliv. and the effect of long-term human activities were comprehensively analyzed based an overview of Populus euphratica Oliv. and its distribution. [Result] Specific regional climatic characteristics and long term human activities are the principle determinants for the growth of Populus euphratica Oliv. The change of leaf shape is a distinct feature of Populus euphratica Oliv. in adapting to the climatic environment. Populus euphratica Oliv. withstands various environmental stresses by means of in vivo synthesis, transport and conversion of secondary phenolic metabolites. Effective protection and rehabilitation measures, and ecological water transport have obvious effect on the restoration and reconstruction of damaged ecological environment of Populus euphratica oasis. [Conclusion] This study is of great significance for the restoration of ecological environment in the arid inland regions, north-west China. 展开更多
关键词 POPULUS EUPHRATICA Oliv. (Salicaceae) Geographic distribution Climatic and environmental characteristics correlation ANALYSIS
在线阅读 下载PDF
Pricing Multi-Strike Quanto Call Options on Multiple Assets with Stochastic Volatility, Correlation, and Exchange Rates
17
作者 Boris Ter-Avanesov Gunter Meissner 《Applied Mathematics》 2025年第1期113-142,共30页
Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign cur... Quanto options allow the buyer to exchange the foreign currency payoff into the domestic currency at a fixed exchange rate. We investigate quanto options with multiple underlying assets valued in different foreign currencies each with a different strike price in the payoff function. We carry out a comparative performance analysis of different stochastic volatility (SV), stochastic correlation (SC), and stochastic exchange rate (SER) models to determine the best combination of these models for Monte Carlo (MC) simulation pricing. In addition, we test the performance of all model variants with constant correlation as a benchmark. We find that a combination of GARCH-Jump SV, Weibull SC, and Ornstein Uhlenbeck (OU) SER performs best. In addition, we analyze different discretization schemes and their results. In our simulations, the Milstein scheme yields the best balance between execution times and lower standard deviations of price estimates. Furthermore, we find that incorporating mean reversion into stochastic correlation and stochastic FX rate modeling is beneficial for MC simulation pricing. We improve the accuracy of our simulations by implementing antithetic variates variance reduction. Finally, we derive the correlation risk parameters Cora and Gora in our framework so that correlation hedging of quanto options can be performed. 展开更多
关键词 Quanto Option Multi-Strike Option Stochastic Volatility (SV) Stochastic correlation (SC) Stochastic Exchange Rates (SER) CORA GORA correlation Risk
在线阅读 下载PDF
Superconducting Correlations in Small Metallic Grains
18
作者 WANG Jing JI An-Chun TIAN Guang-Shan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2001年第12期705-714,共10页
By applying the path-integral formulation and the Feynman theorem, we calculate the off-diagonal superconducting correlation in an ultrasmall metallic grain. Unlike its behavior in the bulk limit, we find that this co... By applying the path-integral formulation and the Feynman theorem, we calculate the off-diagonal superconducting correlation in an ultrasmall metallic grain. Unlike its behavior in the bulk limit, we find that this correlation function is an intensive quantity in this case. Therefore, superconductivity is indeed completely suppressed by quantum fluctuations as the diameter of the grain shrinks to the nanometer scale. This conclusion confirms the previous results by numerical calculations. Furthermore, it also imposes a strong constraint on the delocalizing amplitude of the pair-mixing function, which was recently proposed to characterize superconductivity in the canonical ensemble.PACS numbers: 74.20.Fg, 73.23.Hk, 74.80. 展开更多
关键词 ultrasmall SUPERCONDUCTING grain the off-diagonal correlation function path INTEGRAL FORMULATION and RESOLVENT expansion method
在线阅读 下载PDF
Diffusion tensor imaging and proton magnetic resonance spectroscopy in brain tumor Correlation between structure and metabolism
19
作者 Zhigang Min Chen Niu +2 位作者 Netra Rana Huanmei Ji Ming Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第10期930-937,共8页
Proton magnetic resonance spectroscopy and diffusion tensor imaging are non-invasive techniques used to detect metabolites and water diffusion in vivo. Previous studies have confirmed a positive correlation of individ... Proton magnetic resonance spectroscopy and diffusion tensor imaging are non-invasive techniques used to detect metabolites and water diffusion in vivo. Previous studies have confirmed a positive correlation of individual fractional anisotropy values with N-acetylaspartate/creatine and N-acetylaspartate/choline ratios in tumors, edema, and normal white matter. This study divided the brain parenchyma into tumor, pedtumoral edema, and normal-appearing white matter according to MRI data, and analyzed the correlation of metabolites with water molecular diffusion. Results demonstrated that in normal-appearing white matter, N-acetylaspartate/creatine ratios were positively correlated with fractional anisotropy values, negatively correlated with radial diffusivities, and positively correlated with maximum eigenvalues. Maximum eigenvalues and radial diffusivities in peritumoral edema showed a negative correlation with choline, N-acetylaspartate, and creatine. Radial diffusivities in tumor demonstrated a negative correlation with choline. These data suggest that the relationship between metabolism and structure is markedly changed from normal white matter to peritumoral edema and tumor. Neural metabolism in the peritumoral edema area decreased with expanding extracellular space. The normal relationship of neural function and microstructure disappeared in the tumor region. 展开更多
关键词 neural regeneration NEUROIMAGING brain neoplasms magnetic resonance spectroscopy diffusiontensor imaging METABOLISM diffusion anisotropy EDEMA nerve fiber extracellular space correlation analysis grants-supported paper NEUROREGENERATION
暂未订购
The radial correlation of atomic electrons in (e,2e) reaction
20
作者 V.A.Knyr V.V.Nasyrov 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第S1期113-115,共3页
We perform a research of the influence of atomic electrons correlation to some characteristics of the (e,2e) process on helium. The Hilleraas type J-matrix approach was used for numerical calculations.
关键词 correlation IONISATION cross section three body ATOMIC system Schr%MUL%idinger equation J-matrix method (E 2E) reaction.
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部