期刊文献+
共找到172,137篇文章
< 1 2 250 >
每页显示 20 50 100
Exploring the influence of mixing energy on strength of sand treated by deep soil mixing
1
作者 Mahdi Safdari Seh Gonbad Mahmood Reza Abdi 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期792-809,共18页
This study investigates the impacts of mixing time,execution procedure,cement dosage(α),and total water-to-cement ratio(W_(Total)/C)on the mixing energy(E)of deep soil mixing(DSM)columns and how E influences the stre... This study investigates the impacts of mixing time,execution procedure,cement dosage(α),and total water-to-cement ratio(W_(Total)/C)on the mixing energy(E)of deep soil mixing(DSM)columns and how E influences the strength of treated sand.Columns with a diameter of 7.5 cm were constructed using three mixing times(130,190,and 250 s),two execution procedures(normal and zigzag),threeαvalues(300,400,and 500 kg/m^(3)),and three W_(Total)/C ratios(2.5,3.0,and 3.5).For comparison,equivalent laboratory samples were also examined.Results revealed that increasing the mixing time andα,adopting the zigzag execution procedure,and reducing the W_(Total)/C ratio increase E.Outcomes indicated that an increase in E from 0.49-0.70 kJ to 0.70-0.90 kJ,0.90-1.10 kJ,and 1.10-1.40 kJ improves the unconfined compressive strength(UCS)of columns on average by 66%,124%,and 179%,respectively,and the secant modulus by 61%,110%,and 152%.Average strain at maximum stress also rises from 0.68%to 0.75%,0.81%,and 0.84%,respectively.The study identified a threshold in the direct relationship between E and the strength ratio(λ),beyond whichλdid not increase significantly with further increases in E.Additionally,at low and high E levels,DSM samples mainly failed by crushing and cracking modes,respectively.In DSM columns withα=500 kg/m^(3)and W_(Total)/C=2.5,increasing average E from 0.77 kJ to 0.95 kJ,1.08 kJ,and 1.28 kJ resulted in a reduction of coefficients of variation of UCS from 30.4%to 27.8%,24.5%,and 21.1%,respectively. 展开更多
关键词 Deep soil mixing(DSM) mixing energy Unconfined compressive strength(UCS) Secant modulus Strain at maximum stress Failure mode Strength variability
在线阅读 下载PDF
A Unified Feature Selection Framework Combining Mutual Information and Regression Optimization for Multi-Label Learning
2
作者 Hyunki Lim 《Computers, Materials & Continua》 2026年第4期1262-1281,共20页
High-dimensional data causes difficulties in machine learning due to high time consumption and large memory requirements.In particular,in amulti-label environment,higher complexity is required asmuch as the number of ... High-dimensional data causes difficulties in machine learning due to high time consumption and large memory requirements.In particular,in amulti-label environment,higher complexity is required asmuch as the number of labels.Moreover,an optimization problem that fully considers all dependencies between features and labels is difficult to solve.In this study,we propose a novel regression-basedmulti-label feature selectionmethod that integrates mutual information to better exploit the underlying data structure.By incorporating mutual information into the regression formulation,the model captures not only linear relationships but also complex non-linear dependencies.The proposed objective function simultaneously considers three types of relationships:(1)feature redundancy,(2)featurelabel relevance,and(3)inter-label dependency.These three quantities are computed usingmutual information,allowing the proposed formulation to capture nonlinear dependencies among variables.These three types of relationships are key factors in multi-label feature selection,and our method expresses them within a unified formulation,enabling efficient optimization while simultaneously accounting for all of them.To efficiently solve the proposed optimization problem under non-negativity constraints,we develop a gradient-based optimization algorithm with fast convergence.Theexperimental results on sevenmulti-label datasets show that the proposed method outperforms existingmulti-label feature selection techniques. 展开更多
关键词 feature selection multi-label learning regression model optimization mutual information
在线阅读 下载PDF
Rydberg six-wave mixing spectrum under ionized environment variation
3
作者 Yinglong Diao Haoliang Hu +4 位作者 Xiaofei Li Zhibo Li Feitong Zeng Yanbin Chen Shuhang You 《Chinese Physics B》 2026年第2期357-362,共6页
This paper presents the high-order nonlinear spectrum of six-wave mixing(SWM)influenced by ionizing Rydberg atom environment in rubidium thermal vapor.The experimentally measured transmitted SWM signals reveal signifi... This paper presents the high-order nonlinear spectrum of six-wave mixing(SWM)influenced by ionizing Rydberg atom environment in rubidium thermal vapor.The experimentally measured transmitted SWM signals reveal significant spectrum shifts and novel regularities,providing nonlinear spectrum insights into the ionization characteristics of Rydberg atoms.The detailed spectrum variations with increasing ion density are presented,paving the way for multi-wave mixing distribution of plasma and demonstrating SWM’s potential as a tool for measuring the electric field induced by the ionization process. 展开更多
关键词 Rydberg atoms six-wave mixing(SWM) electric field measurement
原文传递
How Does Urban Public Transit Accessibility Affect Housing Prices?A Comprehensive Analysis with Geographical Detector Combined and Geographically Weighted Regression
4
作者 TANG Jingjing HAN Huiran +3 位作者 YANG Chengfeng XU Lingyi GENG Hui LI Lei 《Chinese Geographical Science》 2026年第1期127-143,共17页
The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such... The accessibility of urban public transit directly influences residents’quality of life,travel behavior,and social equity.Its correlation with housing prices has garnered significant attention across disciplines such as geography,economics,and urban planning.Although much existing research focuses on the impact of individual transportation facilities on housing prices,there is a notable gap in comprehensive analyses that assess the influence of overall urban transit accessibility on housing market dynamics.This study selected the main urban area of Hefei,China,as a case to investigate the spatial distribution of housing prices and evaluate public transit accessibility in 2022.Employing techniques such as the optimized parameter geographical detector and local spatial regression models,the study aimed to elucidate the effects and underlying mechanisms of urban transit accessibility on housing prices.The findings revealed that:1)housing prices in Hefei exhibited a clustered spatial pattern,with high prices concentrated in the city center and lower prices in peripheral areas,forming three distinct high-price hotspots with a‘belt-like’distribution;2)public transit accessibility showed a‘coreperiphery’structure,with accessibility declining in a‘circumferential’pattern around the city center.Based on the‘housing price-accessibility’dimension,four categories were identified:high price-high accessibility(37.25%),high price-low accessibility(19.07%),low price-high accessibility(21.95%),and low price-low accessibility(21.73%);3)the impact of transit accessibility on housing prices was spatially heterogeneous,with bus travel showing the strongest explanatory power(0.692),followed by automobile,subway,and bicycle travel.The interaction of these transportation modes generated a synergistic effect on housing price differentiation,with most influencing factors contributing more than 25%.These findings offer valuable insights for optimizing the spatial distribution of public transit infrastructure and improving both urban housing quality and residents’living standards. 展开更多
关键词 public transit accessibility housing prices geographically weighted regression geographical detector Hefei City China
在线阅读 下载PDF
Risk factors for paternal perinatal depression in Chinese advanced maternal age couples:A regression mixture model
5
作者 Xing Yin Juan Du +1 位作者 Shao-Lian Cai Xing-Qiang Chen 《World Journal of Psychiatry》 2026年第1期267-277,共11页
BACKGROUND Paternal perinatal depression(PPD)is closely associated with maternal mental health challenges,marital strain,and adverse child developmental outcomes.Despite its significant impact,PPD remains under-recogn... BACKGROUND Paternal perinatal depression(PPD)is closely associated with maternal mental health challenges,marital strain,and adverse child developmental outcomes.Despite its significant impact,PPD remains under-recognized in family-centered clinical practice.Concurrently,against the backdrop of rising rates of delayed marriage and China’s Maternity Incentive Policy,the proportion of women giving birth at an advanced maternal age is increasing.Nevertheless,research specifically examining PPD among spouses of older mothers remains critically scarce,both in China and globally.AIM To investigate PPD and its influencing factors in Chinese advanced maternal age families.METHODS This cross-sectional study included 358 participants;it was conducted among fathers of pregnant women of advanced maternal age at five hospitals in the Pearl River Delta region of China from September 2023 to June 2024.Data were collected via a general information questionnaire,the Social Support Rating Scale,and the Edinburgh Postnatal Depression Scale.Latent profile analysis and regression mixture models(RMMs)were adopted to analyze the latent PPD types and factors that influenced PPD.RESULTS The incidence of PPD was 16.48%,and three profiles were identified:Low-symptomatic(175 cases,48.89%),monophasic(140 cases,39.10%),and high-symptomatic(43 cases,12.01%).The RMM analysis revealed that first pregnancy,low income(<¥3000/month),part-time work,and a history of abnormal pregnancy were positively associated with the high-symptomatic type(P<0.05).Conversely,high subjective support and support utilization were negatively associated with the high-symptomatic type compared with the low-symptomatic type(P<0.05).Good couple relationships,high objective and subjective support,and high support utilization were negatively associated with monophasic disorder(P<0.05).CONCLUSION PPD incidence is high among Chinese fathers with advanced maternal age partners,and the characteristics of depression are varied.Healthcare practitioners should prioritize individuals with low levels of social support. 展开更多
关键词 Advanced maternal age Paternal perinatal depression Fathers’mental health regression mixture model Advanced-age pregnancy Latent profile analysis
暂未订购
A Cross-Band Quantum Light Source Based on Spontaneous Four-Wave Mixing in a Shallow-Ridge Silicon Waveguide
6
作者 Yijia Wang Qirui Ren +2 位作者 Zhanping Jin Yidong Huang Wei Zhang 《Chinese Physics Letters》 2026年第1期64-70,共7页
To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.T... To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks. 展开更多
关键词 photon pair generation shallow ridge silicon waveguide spontaneous four wave mixing optical fiber networks adjusting ridge widthenabling cross band quantum light source broadband photon pair generation waveguide dispersion
原文传递
Convergence Rate of Estimator forNonparametric Regression Model under ρ-mixing Errors
7
作者 ttU Qi HUANG Qian +1 位作者 YANG Wen-zhi LI Xiao-qin 《Chinese Quarterly Journal of Mathematics》 2017年第4期407-414,共8页
In this paper, we investigate the nonparametric regression model based on ρ-mixing errors, which are stochastically dominated by a nonnegative random variable. Weobtain the convergence rate for the weighted estimator... In this paper, we investigate the nonparametric regression model based on ρ-mixing errors, which are stochastically dominated by a nonnegative random variable. Weobtain the convergence rate for the weighted estimator of unknown function g(x) in pth-mean, which yields the convergence rate in probability. Moreover, an example of the nearestneighbor estimator is also illustrated and the convergence rates of estimator are presented. 展开更多
关键词 convergence rate pth-mean Ρ-mixing sequence NONPARAMETRIC regressionmodel
在线阅读 下载PDF
Analyzing the influence of COVID-19 on influenza activity in Fujian Province(2020-2023):A regression discontinuity study 被引量:1
8
作者 Hong-Jin Li Yan-Hua Zhang Yu-Wei Weng 《Infectious Diseases Research》 2025年第3期9-15,共7页
Background:The COVID-1’s impact on influenza activity is of interest to inform future flu prevention and control strategies.Our study aim to examine COVID-19’s effects on influenza in Fujian Province,China,using a r... Background:The COVID-1’s impact on influenza activity is of interest to inform future flu prevention and control strategies.Our study aim to examine COVID-19’s effects on influenza in Fujian Province,China,using a regression discontinuity design.Methods:We utilized influenza-like illness(ILI)percentage as an indicator of influenza activity,with data from all sentinel hospitals between Week 4,2020,and Week 51,2023.The data is divided into two groups:the COVID-19 epidemic period and the post-epidemic period.Statistical analysis was performed with R software using robust RD design methods to account for potential confounders including seasonality,temperature,and influenza vaccination rates.Results:There was a discernible increase in the ILI percentage during the post-epidemic period.The robustness of the findings was confirmed with various RD design bandwidth selection methods and placebo tests,with certwo bandwidth providing the largest estimated effect size:a 14.6-percentage-point increase in the ILI percentage(β=0.146;95%CI:0.096–0.196).Sensitivity analyses and adjustments for confounders consistently pointed to an increased ILI percentage during the post-epidemic period compared to the epidemic period.Conclusion:The 14.6 percentage-point increase in the ILI percentage in Fujian Province,China,after the end of the COVID-19 pandemic suggests that there may be a need to re-evaluate and possibly enhance public health measures to control influenza transmission.Further research is needed to fully understand the factors contributing to this rise and to assess the ongoing impacts of post-pandemic behavioral changes. 展开更多
关键词 COVID-19 influenza-like illness regression discontinuity design INFLUENZA
暂未订购
Mixing Intensification for Advanced Materials Manufacturing 被引量:1
9
作者 Chao Yang Guang-Wen Chu +5 位作者 Xin Feng Yan-Bin Li Jie Chen Dan Wang Xiaoxia Duan Jian-Feng Chen 《Engineering》 2025年第1期135-144,共10页
The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.... The mixing process plays a pivotal role in the design,optimization,and scale-up of chemical reactors.For most chemical reactions,achieving uniform and rapid contact between reactants at the molecular level is crucial.Mixing intensification encompasses innovative methods and tools that address the limitations of inadequate mixing within reactors,enabling efficient reaction scaling and boosting the productivity of industrial processes.This review provides a concise introduction to the fundamentals of multiphase mixing,followed by case studies highlighting the application of mixing intensification in the production of energy-storage materials,advanced optical materials,and nanopesticides.These examples illustrate the significance of theoretical analysis in informing and advancing engineering practices within the chemical industry.We also explore the challenges and opportunities in this field,offering insights based on our current understanding. 展开更多
关键词 mixing intensification Chemical reaction Advanced materials High-end manufacturing
在线阅读 下载PDF
Irreversibility analysis and multiple cubic regression based efficiency evaluation of ternary nanofluids(TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O and TiO_(2)+SiO_(2)+Cu/H_(2)O)via converging/diverging channels 被引量:1
10
作者 Siddhant Taneja Sapna Sharma Bhuvaneshvar Kumar 《Acta Mechanica Sinica》 2025年第6期63-75,共13页
This study numerically examines the heat and mass transfer characteristics of two ternary nanofluids via converging and diverg-ing channels.Furthermore,the study aims to assess two ternary nanofluids combinations to d... This study numerically examines the heat and mass transfer characteristics of two ternary nanofluids via converging and diverg-ing channels.Furthermore,the study aims to assess two ternary nanofluids combinations to determine which configuration can provide better heat and mass transfer and lower entropy production,while ensuring cost efficiency.This work bridges the gap be-tween academic research and industrial feasibility by incorporating cost analysis,entropy generation,and thermal efficiency.To compare the velocity,temperature,and concentration profiles,we examine two ternary nanofluids,i.e.,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O and TiO_(2)+SiO_(2)+Cu/H_(2)O,while considering the shape of nanoparticles.The velocity slip and Soret/Dufour effects are taken into consideration.Furthermore,regression analysis for Nusselt and Sherwood numbers of the model is carried out.The Runge-Kutta fourth-order method with shooting technique is employed to acquire the numerical solution of the governed system of ordinary differential equations.The flow pattern attributes of ternary nanofluids are meticulously examined and simulated with the fluc-tuation of flow-dominating parameters.Additionally,the influence of these parameters is demonstrated in the flow,temperature,and concentration fields.For variation in Eckert and Dufour numbers,TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher temperature than TiO_(2)+SiO_(2)+Cu/H_(2)O.The results obtained indicate that the ternary nanofluid TiO_(2)+SiO_(2)+Al_(2)O_(3)/H_(2)O has a higher heat transfer rate,lesser entropy generation,greater mass transfer rate,and lower cost than that of TiO_(2)+SiO_(2)+Cu/H_(2)O ternary nanofluid. 展开更多
关键词 Converging/Diverging channels Ternary nanofluids Multiple cubic regression Entropy generation
原文传递
Impact of Dataset Size on Machine Learning Regression Accuracy in Solar Power Prediction 被引量:1
11
作者 S.M.Rezaul Karim Md.Shouquat Hossain +3 位作者 Khadiza Akter Debasish Sarker Md.Moniul Kabir Mamdouh Assad 《Energy Engineering》 2025年第8期3041-3054,共14页
Knowing the influence of the size of datasets for regression models can help in improving the accuracy of a solar power forecast and make the most out of renewable energy systems.This research explores the influence o... Knowing the influence of the size of datasets for regression models can help in improving the accuracy of a solar power forecast and make the most out of renewable energy systems.This research explores the influence of dataset size on the accuracy and reliability of regression models for solar power prediction,contributing to better forecasting methods.The study analyzes data from two solar panels,aSiMicro03036 and aSiTandem72-46,over 7,14,17,21,28,and 38 days,with each dataset comprising five independent and one dependent parameter,and split 80–20 for training and testing.Results indicate that Random Forest consistently outperforms other models,achieving the highest correlation coefficient of 0.9822 and the lowest Mean Absolute Error(MAE)of 2.0544 on the aSiTandem72-46 panel with 21 days of data.For the aSiMicro03036 panel,the best MAE of 4.2978 was reached using the k-Nearest Neighbor(k-NN)algorithm,which was set up as instance-based k-Nearest neighbors(IBk)in Weka after being trained on 17 days of data.Regression performance for most models(excluding IBk)stabilizes at 14 days or more.Compared to the 7-day dataset,increasing to 21 days reduced the MAE by around 20%and improved correlation coefficients by around 2.1%,highlighting the value of moderate dataset expansion.These findings suggest that datasets spanning 17 to 21 days,with 80%used for training,can significantly enhance the predictive accuracy of solar power generation models. 展开更多
关键词 Correlation coefficients dataset size machine learning mean absolute error regression solar power prediction
在线阅读 下载PDF
Investigation of mixing performance and safety characteristics of polymer-based energetic materials simulant via screw-pressing blending extrusion charges 被引量:1
12
作者 Gaoming Lin Huzeng Zong +6 位作者 Suwei Wang Huang Chen Siyu Yu Xiaojie Hao Kang Wang Yuanyuan Li Guohui Zhang 《Defence Technology(防务技术)》 2025年第2期287-305,共19页
The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experim... The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experiments,this study used inert materials with similar physical properties to partially substitute for the actual energetic components in the preparation of simulant materials.By thoroughly analyzing slurry physical properties,a simulation framework and an extensive performance evaluation method were developed.Such tools guide the design of the structure and configuration of process parameters.Results demonstrate that employing the Pin element significantly enhances radial mixing within the screw,minimizes temperature variations in the slurry,and improves both efficiency and safety in the mixing process.Further,adjustments such as widening the cone angle of the barrel,modifying the solid content of the slurry,and varying the speed of the screw can optimize the mechanical and thermal coupling in the flow field.These adjustments promote higher-quality slurry and create a safer production environment for the extrusion process. 展开更多
关键词 Polymer-based energetic materials Screw-pressing charging process Structural design Process safety mixing performance
在线阅读 下载PDF
Temperature error compensation method for fiber optic gyroscope based on a composite model of k-means,support vector regression and particle swarm optimization 被引量:1
13
作者 CAO Yin LI Lijing LIANG Sheng 《Journal of Systems Engineering and Electronics》 2025年第2期510-522,共13页
As the core component of inertial navigation systems, fiber optic gyroscope (FOG), with technical advantages such as low power consumption, long lifespan, fast startup speed, and flexible structural design, are widely... As the core component of inertial navigation systems, fiber optic gyroscope (FOG), with technical advantages such as low power consumption, long lifespan, fast startup speed, and flexible structural design, are widely used in aerospace, unmanned driving, and other fields. However, due to the temper-ature sensitivity of optical devices, the influence of environmen-tal temperature causes errors in FOG, thereby greatly limiting their output accuracy. This work researches on machine-learn-ing based temperature error compensation techniques for FOG. Specifically, it focuses on compensating for the bias errors gen-erated in the fiber ring due to the Shupe effect. This work pro-poses a composite model based on k-means clustering, sup-port vector regression, and particle swarm optimization algo-rithms. And it significantly reduced redundancy within the sam-ples by adopting the interval sequence sample. Moreover, met-rics such as root mean square error (RMSE), mean absolute error (MAE), bias stability, and Allan variance, are selected to evaluate the model’s performance and compensation effective-ness. This work effectively enhances the consistency between data and models across different temperature ranges and tem-perature gradients, improving the bias stability of the FOG from 0.022 °/h to 0.006 °/h. Compared to the existing methods utiliz-ing a single machine learning model, the proposed method increases the bias stability of the compensated FOG from 57.11% to 71.98%, and enhances the suppression of rate ramp noise coefficient from 2.29% to 14.83%. This work improves the accuracy of FOG after compensation, providing theoretical guid-ance and technical references for sensors error compensation work in other fields. 展开更多
关键词 fiber optic gyroscope(FOG) temperature error com-pensation composite model machine learning CLUSTERING regression.
在线阅读 下载PDF
Synergistic surface restructuring and cation mixing via ultrafast Joule heating enhancing ultrahigh-nickel cathodes for advanced lithium-ion batteries 被引量:1
14
作者 Haoyu Wang Jinyang Dong +10 位作者 Meng Wang Yun Lu Hongyun Zhang Jinzhong Liu Yun Liu Na Liu Ning Li Qing Huang Feng Wu Yuefeng Su Lai Chen 《Journal of Energy Chemistry》 2025年第4期371-382,共12页
The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during cycling.In this study,doping-induced surface restructur... The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during cycling.In this study,doping-induced surface restructuring in ultrahigh-nickel cathode materials is rapidly facilitated through an ultrafast Joule heating method.Density functional theory(DFT)calculations,synchrotron X-ray absorption spectroscopy(XAS),and single-particle force test confirmed the establishment of a stable crystal framework and lattice oxygen,which mitigated H2-H3 phase transitions and improved structural reversibility.Additionally,the Sc doping process exhibits a pinning effect on the grain boundaries,as shown by scanning transmission electron microscopy(STEM),enhancing Li~+diffusion kinetics and decreasing mechanical strain during cycling.The in situ development of a cation-mixing layer at grain boundaries also creates a robust cathode/electrolyte interphase,effectively reducing interfacial parasitic reactions and transition metal dissolution,as validated by STEM and time-of-flight secondary ion mass spectrometry(TOF-SIMS).These synergistic modifications reduce particle cracking and surface/interface degradation,leading to enhanced rate capability,structural integrity,and thermal stability.Consequently,the optimized Sc-modified ultrahigh-Ni cathode(Sc-1)exhibits 93.99%capacity retention after 100 cycles at 1 C(25℃)and87.06%capacity retention after 100 cycles at 1 C(50℃),indicating excellent cycling and thermal stability.By presenting a one-step multifunctional modification approach,this research delivers an extensive analysis of the mechanisms governing the structure,microstructure,and interface properties of nickel-rich layered cathode materials(NCMs).These results underscore the potential of ultrahigh-Ni cathodes as viable candidates for advanced lithium-ion batteries(LIBs)in next-generation electric vehicles(EVs). 展开更多
关键词 Lithium-ion batteries Ultrahigh-nickel layered cathodes In situ surface doping Cation mixing layer Structure and thermal stability
在线阅读 下载PDF
A splicing algorithm for best subset selection in sliced inverse regression
15
作者 Borui Tang Jin Zhu +1 位作者 Tingyin Wang Junxian Zhu 《中国科学技术大学学报》 北大核心 2025年第5期22-34,21,I0001,共15页
In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by re... In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors. 展开更多
关键词 splicing technique best subset selection sliced inverse regression nonconvex optimization sparsity constraint optimal conditions
在线阅读 下载PDF
Model’s parameter sensitivity assessment and their impact on Urban Densification using regression analysis
16
作者 Anasua Chakraborty Mitali Yeshwant Joshi +2 位作者 Ahmed Mustafa Mario Cools Jacques Teller 《Geography and Sustainability》 2025年第2期143-156,共14页
The impact of different global and local variables in urban development processes requires a systematic study to fully comprehend the underlying complexities in them.The interplay between such variables is crucial for... The impact of different global and local variables in urban development processes requires a systematic study to fully comprehend the underlying complexities in them.The interplay between such variables is crucial for modelling urban growth to closely reflects reality.Despite extensive research,ambiguity remains about how variations in these input variables influence urban densification.In this study,we conduct a global sensitivity analysis(SA)using a multinomial logistic regression(MNL)model to assess the model’s explanatory and predictive power.We examine the influence of global variables,including spatial resolution,neighborhood size,and density classes,under different input combinations at a provincial scale to understand their impact on densification.Additionally,we perform a stepwise regression to identify the significant explanatory variables that are important for understanding densification in the Brussels Metropolitan Area(BMA).Our results indicate that a finer spatial resolution of 50 m and 100 m,smaller neighborhood size of 5×5 and 3×3,and specific density classes—namely 3(non-built-up,low and high built-up)and 4(non-built-up,low,medium and high built-up)—optimally explain and predict urban densification.In line with the same,the stepwise regression reveals that models with a coarser resolution of 300 m lack significant variables,reflecting a lower explanatory power for densification.This approach aids in identifying optimal and significant global variables with higher explanatory power for understanding and predicting urban densification.Furthermore,these findings are reproducible in a global urban context,offering valuable insights for planners,modelers and geographers in managing future urban growth and minimizing modelling. 展开更多
关键词 Urban densification Sensitivity analysis Multinomial logistic regression Stepwise regression
在线阅读 下载PDF
Estimating rock strength parameters across varied failure criteria:Application of spreadsheet and R-based orthogonal regression to triaxial test data
17
作者 RobertoÚcar Luis Arlegui +1 位作者 Norly Belandria Francisco Torrijo 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4685-4699,共15页
Triaxial tests,a staple in rock engineering,are labor-intensive,sample-demanding,and costly,making their optimization highly advantageous.These tests are essential for characterizing rock strength,and by adopting a fa... Triaxial tests,a staple in rock engineering,are labor-intensive,sample-demanding,and costly,making their optimization highly advantageous.These tests are essential for characterizing rock strength,and by adopting a failure criterion,they allow for the derivation of criterion parameters through regression,facilitating their integration into modeling programs.In this study,we introduce the application of an underutilized statistical technique—orthogonal regression—well-suited for analyzing triaxial test data.Additionally,we present an innovation in this technique by minimizing the Euclidean distance while incorporating orthogonality between vectors as a constraint,for the case of orthogonal linear regression.Also,we consider the Modified Least Squares method.We exemplify this approach by developing the necessary equations to apply the Mohr-Coulomb,Murrell,Hoek-Brown,andÚcar criteria,and implement these equations in both spreadsheet calculations and R scripts.Finally,we demonstrate the technique's application using five datasets of varied lithologies from specialized literature,showcasing its versatility and effectiveness. 展开更多
关键词 Rock failure criteria Nonlinear regression Orthogonal regression Triaxial testing Dot product
在线阅读 下载PDF
Quantile Regression Estimation for Self-Exciting Threshold Integer-Valued Autoregressive Process
18
作者 LIU Chang WANG Zheqi WANG Dehui 《应用概率统计》 北大核心 2025年第6期837-863,共27页
To better capture the characteristics of asymmetry and structural fluctuations observed in count time series,this study delves into the application of the quantile regression(QR)method for analyzing and forecasting no... To better capture the characteristics of asymmetry and structural fluctuations observed in count time series,this study delves into the application of the quantile regression(QR)method for analyzing and forecasting nonlinear integer-valued time series exhibiting a piecewise phenomenon.Specifically,we focus on the parameter estimation in the first-order Self-Exciting Threshold Integer-valued Autoregressive(SETINAR(2,1))process with symmetry,asymmetry,and contaminated innovations.We establish the asymptotic properties of the estimator under certain regularity conditions.Monte Carlo simulations demonstrate the superior performance of the QR method compared to the conditional least squares(CLS)approach.Furthermore,we validate the robustness of the proposed method through empirical quantile regression estimation and forecasting for larceny incidents and CAD drug call counts in Pittsburgh,showcasing its effectiveness across diverse levels of data heterogeneity. 展开更多
关键词 nonlinear time series of counts jittering smoothing technique quantile regression estimation threshold integer-valued autoregressive process
在线阅读 下载PDF
Asymmetric mixing in unbaffled stirred tank reactors:A mini-review
19
作者 Anqi Li Yuan Yao +3 位作者 Xin Zhang Yundong Wang Changyuan Tao Zuohua Liu 《Chinese Journal of Chemical Engineering》 2025年第11期273-287,共15页
The formation,evolution and modelling of organized flow structures(e.g.,segregated regions and centre-surface vortices) and their destruction in unbaffled stirred tank reactors(UBSTRs) have been a hot research topic i... The formation,evolution and modelling of organized flow structures(e.g.,segregated regions and centre-surface vortices) and their destruction in unbaffled stirred tank reactors(UBSTRs) have been a hot research topic in the field of fluid mixing.In this paper,the relevant researches in the past 30 years were reviewed,focusing on the application of asymmetric mixing.In particular,by drawing on chaotic phenomena in nature and human society(e.g.,kneading-dough,traffic flow,frightened school of fish),we propose a fluid mixing mechanism:squeezing-induced chaotic mixing,and further propose a bionics-imitation-simulation design concept for UBSTRs.This concept is also an important inspiration for the design of other chemical reactors. 展开更多
关键词 Unbaffled stirred tank reactor Organized flow structure Asymmetric mixing Squeezing-induced chaotic mixing Process-intensification
在线阅读 下载PDF
Is there an Association between Per-and Poly-Fluoroalkyl Substances and Serum Pepsinogens?Evidence from Linear Regression and Bayesian Kernel Machine Regression Analyses
20
作者 Jing Wu Shenglan Yang +2 位作者 Yiyan Wang Yuzhong Yan Ming Li 《Biomedical and Environmental Sciences》 2025年第6期763-767,共5页
Gastric cancer is the third leading cause of cancer-related mortality and remains a major global health issue^([1]).Annually,approximately 479,000individuals in China are diagnosed with gastric cancer,accounting for a... Gastric cancer is the third leading cause of cancer-related mortality and remains a major global health issue^([1]).Annually,approximately 479,000individuals in China are diagnosed with gastric cancer,accounting for almost 45%of all new cases worldwide^([2]). 展开更多
关键词 Bayesian kernel machine regression gastric canceraccounting gastric cancer per poly fluoroalkyl substances serum pepsinogens linear regression
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部