期刊文献+
共找到9,082篇文章
< 1 2 250 >
每页显示 20 50 100
Method for Behavior Recognition of Hu Sheep in Intensive Farming Based on HLNC-YOLO
1
作者 JI Ronghua CHANG Hongrui +2 位作者 ZHANG Suoxiang LIU Zhongying WU Zhonghong 《农业机械学报》 北大核心 2026年第2期265-275,共11页
Behavior recognition of Hu sheep contributes to their intensive and intelligent farming.Due to the generally high density of Hu sheep farming,severe occlusion occurs among different behaviors and even among sheep perf... Behavior recognition of Hu sheep contributes to their intensive and intelligent farming.Due to the generally high density of Hu sheep farming,severe occlusion occurs among different behaviors and even among sheep performing the same behavior,leading to missing and false detection issues in existing behavior recognition methods.A high-low frequency aggregated attention and negative sample comprehensive score loss and comprehensive score soft non-maximum suppression-YOLO(HLNC-YOLO)was proposed for identifying the behavior of Hu sheep,addressing the issues of missed and erroneous detections caused by occlusion between Hu sheep in intensive farming.Firstly,images of four typical behaviors-standing,lying,eating,and drinking-were collected from the sheep farm to construct the Hu sheep behavior dataset(HSBD).Next,to solve the occlusion issues,during the training phase,the C2F-HLAtt module was integrated,which combined high-low frequency aggregation attention,into the YOLO v8 Backbone to perceive occluded objects and introduce an auxiliary reversible branch to retain more effective features.Using comprehensive score regression loss(CSLoss)to reduce the scores of suboptimal boxes and enhance the comprehensive scores of occluded object boxes.Finally,the soft comprehensive score non-maximal suppression(Soft-CS-NMS)algorithm filtered prediction boxes during the inferencing.Testing on the HSBD,HLNC-YOLO achieved a mean average precision(mAP@50)of 87.8%,with a memory footprint of 17.4 MB.This represented an improvement of 7.1,2.2,4.6,and 11 percentage points over YOLO v8,YOLO v9,YOLO v10,and Faster R-CNN,respectively.Research indicated that the HLNC-YOLO accurately identified the behavior of Hu sheep in intensive farming and possessed generalization capabilities,providing technical support for smart farming. 展开更多
关键词 behavior recognition YOLO loss function attention mechanism
在线阅读 下载PDF
Effect of Initial Microstructure States on Flow Behavior of Al-Zn-Mg-Cu Alloy During Hot Tensile Deformation
2
作者 Wang Shuyan Zhou Yuting +3 位作者 Du Ruibo Long Shuai Lin Haitao Wang Shaoyang 《稀有金属材料与工程》 北大核心 2026年第2期302-314,共13页
To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator a... To investigate the influence of Al-Zn-Mg-Cu alloy with as-homogenized and as-rolled initial microstructures on the tensile flow behavior,isothermal tensile tests were conducted on a GLEEBLE-3500 isothermal simulator at temperatures of 380-440℃and strain rates of 0.05-1 s^(−1).The Johnson-Cook model,Hensel-Spittel model,strain-compensated Arrhenius model,and critical fracture strain model were established.Results show that through the evaluation of the models using the correlation coefficient(R)and the average absolute relative error,the strain-compensated Arrhenius model can represent the flow behavior of the alloy more accurately.Shear bands are more pronounced in the as-homogenized specimens,whereas dynamic recrystallization is predominantly observed in as-rolled specimens.Fracture morphology analysis reveals that a mixed fracture mechanism is prevalent in the as-homogenized specimen,whereas a ductile fracture mechanism is predominant in the as-rolled specimen.The processing maps indicate that the unstable region is reduced in the as-rolled specimens compared with that in the as-homogenized specimens.The optimal hot working windows for the as-homogenized and as-rolled specimens are determined as 410-440℃/0.14-1 s^(−1)and 380-400℃/0.05-0.29 s^(−1),respectively. 展开更多
关键词 Al-Zn-Mg-Cu alloy tensile flow behavior MICROSTRUCTURE constitutive modelling processing map
原文传递
Global Existence and Blow-up of Solutions for Fourth-order Parabolic Equation with p(x)-Laplacian and Variable Exponents
3
作者 YANG Chunxiao YU Lifei DUAN Chenyan 《数学进展》 北大核心 2026年第1期221-239,共19页
In this paper,we consider the fourth-order parabolic equation with p(x)Laplacian and variable exponent source ut+∆^(2)u−div(|■u|^(p(x)−2■u))=|u|^(q(x))−1u.By applying potential well method,we obtain global existence... In this paper,we consider the fourth-order parabolic equation with p(x)Laplacian and variable exponent source ut+∆^(2)u−div(|■u|^(p(x)−2■u))=|u|^(q(x))−1u.By applying potential well method,we obtain global existence,asymptotic behavior and blow-up of solutions with initial energy J(u_(0))≤d.Moreover,we estimate the upper bound of the blow-up time for J(u_(0))≤0. 展开更多
关键词 fourth-order parabolic equation variable exponent source global existence asymptotic behavior BLOW-UP
原文传递
Thermodynamics of Reduction of Titania by CH_(4)-H_(2) Gas Mixture
4
作者 Tian Zhenyun Chen Jiawen +2 位作者 Zhang Run Fan Gangqiang Qiu Guibao 《稀有金属材料与工程》 北大核心 2026年第3期615-626,共12页
Given the considerable global interest in the preparation of Ti and TiC,a novel reduction method for TiO_(2) in a CH_(4)-H_(2) atmosphere was proposed,and the reduction thermodynamic behavior,phase equilibrium,and ene... Given the considerable global interest in the preparation of Ti and TiC,a novel reduction method for TiO_(2) in a CH_(4)-H_(2) atmosphere was proposed,and the reduction thermodynamic behavior,phase equilibrium,and energy consumption of TiO_(2) during its reaction with a CH_(4)-H_(2) gas mixture were investigated.The results indicate that the reaction proceeds via a stepwise reduction pathway from TiO_(2) to Ti(C,O),with the Magnéli phase(TinO_(2n-1))and Ti_(3)O_(5) serving as intermediate phases.Notably,the reduction of TiO_(2) by H_(2) is more challenging than that by CH_(4),which may be attributed to the inhibitory effect of H_(2) on the surface carbon precipitation.For the complete carbonization of 1 mol TiO_(2),the total energy required at 1000,1100,and 1200℃is 1159,925,and 977 kJ/mol,respectively,which may be related to the shift of gas-phase equilibrium and the increase in side reactions at high temperatures. 展开更多
关键词 TiO_(2) TiC_(x)O_(y) reduction-carbonization thermodynamic behavior energy consumption
原文传递
Dynamic Behaviors of Localized Waves of the(2+1)-Dimensional Yu-Toda-Sasa-Fukuyama Equation
5
作者 SUN Xiaoqing XIA Yarong +1 位作者 YAO Ruoxia WANG Weiqing 《应用数学》 北大核心 2026年第2期624-638,共15页
In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equ... In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations. 展开更多
关键词 (2+1)-dimensional Yu-Toda-Sasa-Fukuyama equation Hirota bilinear approach Lump solutions Dynamic behaviors
在线阅读 下载PDF
Adherence to the 24-Hour Movement Guidelines is related to a lower risk of all-cause mortality:A prospective cohort study of 14,288 participants from the SUN Project
6
作者 JoséFrancisco López-Gil Mark S.Tremblay +4 位作者 Maira Bes-Rastrollo Laura Moreno-Galarraga Stefanos N.Kales MiguelÁngel Martínez-González Alejandro Fernandez-Montero 《Journal of Sport and Health Science》 2026年第3期74-83,共10页
Purpose:The purpose of this study was to examine the associations between adherence to the 24-Hour Movement Guidelines and all-cause and cause-specific mortality in a large Spanish prospective cohort.Methods:We analyz... Purpose:The purpose of this study was to examine the associations between adherence to the 24-Hour Movement Guidelines and all-cause and cause-specific mortality in a large Spanish prospective cohort.Methods:We analyzed data from 14,288 participants of the Seguimiento Universidad de Navarra(SUN)Project,followed for a mean of 12.8 years(mean baseline age=38.3 years;60.1%women).Data were collected at baseline and through biennial follow-up questionnaires(up to 10 waves,depending on year of entry).The participants self-reported 24-h movement behaviors at baseline and were categorized based on the number of guidelines met(0-3).Behaviors were assessed at baseline only;changes in adherence during follow-up were not accounted for.Cox proportional hazards models were used to estimate hazard ratios(HRs)for all-cause and cause-specific mortality,adjusting for sociodemographic,lifestyle,and clinical covariates.Results:Meeting a greater number of 24-Hour Movement Guidelines at baseline was associated with a progressively lower risk of all-cause mortality.Compared with those meeting none,the multivariable-adjusted HRs were 0.52(95%confidence interval(95%CI):0.33-0.82)for meeting 1 guideline,0.47(95%CI:0.30-0.73)for meeting 2 guidelines,and 0.44(95%CI:0.28-0.71)for meeting all 3 guidelines.Only adherence to the physical activity guidelines was independently associated with a significantly lower mortality risk(HR=0.70;95%CI:0.55-0.89).A reduced risk was also observed for cancer and other-cause mortality among those meeting 2 or more guidelines.Conclusion:Adherence to the 24-Hour Movement Guidelines at baseline,particularly physical activity,was associated with a lower risk of mortality.Promoting an integrated approach to movement behaviors may be an effective strategy for improving population health and longevity. 展开更多
关键词 Physical activity Sedentary behavior Sleep duration LIFESTYLE Movement behaviors
在线阅读 下载PDF
Rheology of Paste in Mine Backfilling:Mechanisms,Models,and Key Influencing Factors
7
作者 Mingzhi Zhang Qian Zhang +7 位作者 Haonan Zhang Xuecheng Shang Xionghuan Tan Zheyuan Jiang Yun Lin Junwei Shu Tianxing Ma Liangxu Shen 《Fluid Dynamics & Materials Processing》 2026年第3期48-69,共22页
The rheological behavior of paste in mine backfilling systems is governed by multiple coupled mechanisms,including particulate structure evolution,time-dependent effects,spatially heterogeneous flow,and scale dependen... The rheological behavior of paste in mine backfilling systems is governed by multiple coupled mechanisms,including particulate structure evolution,time-dependent effects,spatially heterogeneous flow,and scale dependence.As a result,its macroscopic response cannot be adequately described by a single material parameter or purely local constitutive relations.Although significant progress has been made in experimental characterization and empirical modeling,rheological parameters reported under different conditions remain difficult to reconcile,highlighting the limitations of existing models in capturing structural evolution and nonlocal effects.This review provides a concise synthesis of current advances in paste rheology for mine backfilling applications,with emphasis on yield behavior,shear-rate-dependent nonlinear flow response,thixotropy,and shear history effects.The applicability and limitations of commonly used rheological models,including the Bingham and Herschel-Bulkley models,are critically examined.Key factors influencing paste rheology—such as particle gradation,temperature,and chemical additives—are discussed from a structure-controlled perspective.Finally,physics-constrained data-driven approaches are highlighted as a promising direction for improving the description and prediction of complex rheological behavior.Overall,this review emphasizes the need to balance experimental observability,model simplicity,and physical consistency,and highlights the importance of linking microstructural mechanisms,scale effects,and macroscopic rheological response to establish more unified and engineering-relevant frameworks for paste rheology in mine backfilling systems. 展开更多
关键词 Cemented paste backfill rheological behavior paste rheology rheological modeling yield behavior
在线阅读 下载PDF
Urban-rural differences in residential energy-use behavior and energy-saving awareness:Evidence from a Chinese megacity
8
《建筑节能(中英文)》 2026年第2期150-150,共1页
Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing s... Residential energy-use behavior and energy-saving awareness play a crucial role in sustainable urban energy planning and building energy efficiency,particularly under the pressures of climate change.However,existing studies often lack comparative analysis of urban-rural differences and tend to focus excessively on behavior patterns while neglecting the dimension of energysaving awareness.With China’s urbanization rate reaching 66.16%,understanding such regional disparities has become increasingly important.To address these research gaps,this study conducts a large-scale survey on space cooling behaviors among residents in Beijing,a representative Chinese megacity.It should be noted that living standards in such megacities are generally higher than the national average,which may shape distinctive energy-use profiles.Analyzing 1573valid samples(1064 urban/442 rural)in 2024,this study employed K-Prototypes and K-Modes clustering to identify typical cooling behavior and energy-saving awareness pattems,followed by Kendall/Chi-square correlation tests and XGBoost importance analysis to determine key influencing factors,with subsequent urban-rural comparative analysis.Results indicate that urban residents are primarily heat-sensitive or heat-tolerant,with a secondary patten of mid-low temperature preference,and generally exhibit long cooling durations;rural behavior is dominated by heat-tolerant type,followed by heat-sensitive,mid-low temperature preference,and never-on types as secondary patterns;both urban and rural areas exhibit energy-savingawareness characterized by low consumption-lowwillingness,though urban areas show marginally higher motivation;energy-saving awareness correlates with cooling behavior in rural areas,but this relationship weakens significantly in urban contexts. 展开更多
关键词 behavior patterns such regional disparities energy saving awareness residential energy use behavior climate change urban rural differences China Beijing
在线阅读 下载PDF
Associations of Suicidal Behaviors with Physical Activity Types and Psychosocial Factors among Korean Adolescents:A Secondary Data Analysis
9
作者 Chae-Young Lee Yun-Jung Choi 《International Journal of Mental Health Promotion》 2026年第3期82-98,共17页
Background:Adolescent suicide remains a pressing public health concern in South Korea and worldwide,ranking as one of the leading causes of death among youth.Identifying modifiable risk and protective factors is criti... Background:Adolescent suicide remains a pressing public health concern in South Korea and worldwide,ranking as one of the leading causes of death among youth.Identifying modifiable risk and protective factors is critical for prevention strategies.Physical activity has been suggested as one such factor due to its potential mental health benefits.This study aimed to examine whether associations between physical activity and suicidality differ by activity type and by stage of suicidal behavior,distinguishing suicidal ideation,planning,and attempts among Korean adolescents.Methods:This cross-sectional secondary analysis used data from the 20th Korea Youth Risk Behavior Web-based Survey(KYRBS)conducted in 2024,a nationally representative survey of Korean adolescents.The study included 54,653 middle and high school students with complete data on physical activity,suicidal ideation,planning,and attempts.Three types of physical activity(vigorous activity,muscle-strengthening activity,and≥60 min of daily physical activity)were examined.Associations with suicidal behaviors were analyzed using multivariable logistic regression models,adjusting for psychological,behavioral,and sociodemographic covariates.Results:In this nationally representative sample of Korean adolescents,engaging in at least 60 min of daily physical activity was significantly associated with lower odds of suicide planning,but not ideation or attempts.In contrast,muscle-strengthening activity was linked to increased odds of both suicide planning and attempts,whereas vigorous activity showed no significant associations.Psychological factors,including generalized anxiety,sadness,stress,and loneliness,showed strong associations with suicidal behaviors and were included as covariates in the adjusted models.Female students,low academic performance,and unstable residential status were also associated with higher odds of suicidal behaviors.Conclusion:The associations between physical activity and suicidality differed by activity type and suicidal outcome;muscle-strengthening activity was positively associated with suicide planning and attempts in adjusted models. 展开更多
关键词 Adolescent suicide physical activity mental health Korea Youth Risk Behavior Survey musclestrengthening exercise suicide behavior
在线阅读 下载PDF
A Hybrid Deep Learning Approach for Real-Time Cheating Behaviour Detection in Online Exams Using Video Captured Analysis
10
作者 Dao Phuc Minh Huy Gia Nhu Nguyen Dac-Nhuong Le 《Computers, Materials & Continua》 2026年第3期1179-1198,共20页
Online examinations have become a dominant assessment mode,increasing concerns over academic integrity.To address the critical challenge of detecting cheating behaviours,this study proposes a hybrid deep learning appr... Online examinations have become a dominant assessment mode,increasing concerns over academic integrity.To address the critical challenge of detecting cheating behaviours,this study proposes a hybrid deep learning approach that combines visual detection and temporal behaviour classification.The methodology utilises object detection models—You Only Look Once(YOLOv12),Faster Region-based Convolutional Neural Network(RCNN),and Single Shot Detector(SSD)MobileNet—integrated with classification models such as Convolutional Neural Networks(CNN),Bidirectional Gated Recurrent Unit(Bi-GRU),and CNN-LSTM(Long Short-Term Memory).Two distinct datasets were used:the Online Exam Proctoring(EOP)dataset from Michigan State University and the School of Computer Science,Duy Tan Unievrsity(SCS-DTU)dataset collected in a controlled classroom setting.A diverse set of cheating behaviours,including book usage,unauthorised interaction,internet access,and mobile phone use,was categorised.Comprehensive experiments evaluated the models based on accuracy,precision,recall,training time,inference speed,and memory usage.We evaluate nine detector-classifier pairings under a unified budget and score them via a calibrated harmonic mean of detection and classification accuracies,enabling deployment-oriented selection under latency and memory constraints.Macro-Precision/Recall/F1 and Receiver Operating Characteristic-Area Under the Curve(ROC-AUC)are reported for the top configurations,revealing consistent advantages of object-centric pipelines for fine-grained cheating cues.The highest overall score is achieved by YOLOv12+CNN(97.15%accuracy),while SSD-MobileNet+CNN provides the best speed-efficiency trade-off for edge devices.This research provides valuable insights into selecting and deploying appropriate deep learning models for maintaining exam integrity under varying resource constraints. 展开更多
关键词 Online exam proctoring cheating behavior detection deep learning real-time monitoring object detection human behavior recognition
在线阅读 下载PDF
Experimental Research on Prefabricated Steel Reinforced Concrete(SRC)Column-Reinforced Concrete(RC)Beam Connection
11
作者 CHEN Wentao LIU Yuanchang +1 位作者 LI Xiang FANG Xin 《International Journal of Plant Engineering and Management》 2026年第1期20-34,共15页
To achieve efficient connection and integrity in prefabricated frame structures,a novel beam-column connection between prefabricated steel-reinforced concrete(SRC)columns and cast-in-situ reinforced concrete(RC)beams ... To achieve efficient connection and integrity in prefabricated frame structures,a novel beam-column connection between prefabricated steel-reinforced concrete(SRC)columns and cast-in-situ reinforced concrete(RC)beams is proposed.Four connection specimens with varying thicknesses of connecting cover plates were designed and fabricated.Low-cycle reversed loading tests were conducted to obtain mechanical performance data,allowing for analysis of behavioral patterns,including load-displacement hysteresis curves,skeleton curves,load-carrying capacity,deformation performance,energy dissipation capacity,and stiffness degradation.Test results indicate that properly designed prefabricated connections exhibit mechanical properties comparable to those of cast-in-situ concrete connections.The hysteresis curves of the prefabricated connections are well-shaped,with nearly no reduction in load-carrying capacity and deformation performance,demonstrating excellent seismic behavior.The findings provide a theoretical basis and reference for the design of prefabricated concrete frame structures. 展开更多
关键词 prefabricated connection connecting cover plate low-cycle reversed loading test hysteretic behavior mechanical behavior
在线阅读 下载PDF
Correction: Optimizing Exciton and Charge-Carrier Behavior in Thick-Film Organic Photovoltaics: A Comprehensive Review
12
作者 Lu Wei Yaxin Yang +2 位作者 Lingling Zhan Shouchun Yin Hongzheng Chen 《Nano-Micro Letters》 2026年第1期608-608,共1页
Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.Th... Correction to:Nano-Micro Letters(2026)18:10.https://doi.org/10.1007/s40820-025-01852-8 Following publication of the original article[1],the authors reported that the last author’s name was inadvertently misspelled.The published version showed“Hongzhen Chen”,whereas the correct spelling should be“Hongzheng Chen”.The correct author name has been provided in this Correction,and the original article[1]has been corrected. 展开更多
关键词 charge carrier behavior exciton behavior comprehensive review thick film organic photovoltaics nano micro letters
在线阅读 下载PDF
ADCP-YOLO:A High-Precision and Lightweight Model for Violation Behavior Detection in Smart Factory Workshops
13
作者 Changjun Zhou Dongfang Chen +1 位作者 Chenyang Shi Taiyong Li 《Computers, Materials & Continua》 2026年第3期1895-1919,共25页
With the rapid development of smart manufacturing,intelligent safety monitoring in industrial workshops has become increasingly important.To address the challenges of complex backgrounds,target scale variation,and exc... With the rapid development of smart manufacturing,intelligent safety monitoring in industrial workshops has become increasingly important.To address the challenges of complex backgrounds,target scale variation,and excessive model parameters in worker violation detection,this study proposes ADCP-YOLO,an enhanced lightweight model based on YOLOv8.Here,“ADCP”represents four key improvements:Alterable Kernel Convolution(AKConv),Dilated-Wise Residual(DWR)module,Channel Reconstruction Global Attention Mechanism(CRGAM),and Powerful-IoU loss.These components collaboratively enhance feature extraction,multi-scale perception,and localization accuracy while effectively reducing model complexity and computational cost.Experimental results show that ADCP-YOLO achieves a mAP of 90.6%,surpassing YOLOv8 by 3.0%with a 6.6%reduction in parameters.These findings demonstrate that ADCP-YOLO successfully balances accuracy and efficiency,offering a practical solution for intelligent safety monitoring in smart factory workshops. 展开更多
关键词 YOLO violation behavior detection AKConv CRGAM DWR Powerful-IoU
在线阅读 下载PDF
Elucidating the thermal decomposition mechanism of advanced energetic composites based on nitrated cellulose carbamate/ diethylene glycol dinitrate supplemented with organic stabilizers
14
作者 Lokmene Boumaza Ahmed Fouzi Tarchoun +5 位作者 Djalal Trache Amir Abdelaziz Yacine Yahi Nabil Slimani Chemseddine Boustila Thomas M.Klapötke 《Defence Technology(防务技术)》 2026年第3期16-26,共11页
This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared... This study evaluates the stabilizing effect of lignin, extracted from Eucalyptus globulus, on an energetic composite of nitrated cellulose carbamate (NCC) plasticized with diethylene glycol dinitrate (DEGDN), compared to conventional stabilizers 2-nitrodiphenylamine (2-NDPA) and 1,3-dimethyl-1,3-diphenylurea (C-II). FTIR analysis confirms lignin's capacity to scavenge nitroxyl radicals formed during thermolysis of nitrocarbamate and nitrate ester bonds, thereby inhibiting decomposition. Moreover, the incorporation of C-II, 2-NDPA, and lignin significantly raised the peak temperature of the main thermolysis, as confirmed by DSC and TGA, indicating a progressive stability enhancement in the order: NCC/DEGDN < NCC/DEGDN/C-II < NCC/DEGDN/lignin < NCC/DEGDN/2-NDPA. Additionally, the effect of each stabilizer on the decomposition pathway was characterized by TGA-FTIR. The findings show that stabilizer type significantly affects the intensity of gaseous products released during decomposition without altering their nature. Notably, NH2 groups formed during NCC degradation play a key role in nitrogen conversion, particularly by reducing toxic NO emissions. 展开更多
关键词 Energetic composite Kraft lignin STABILIZERS Thermal behavior PYROLYSIS
在线阅读 下载PDF
Shear behavior and microstructural evolution of Malan loess under climate-induced wetting and drying cycles
15
作者 Pengju Qin Hongrui Guo +3 位作者 Yanrong Li Jun Zhang Yu Lu Yifei Sun 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第3期2122-2141,共20页
Loess landslides are major hazards in the Chinese Loess Plateau(CLP).The loess in this region is frequently subjected to repeated wetting–drying(W-D)cycles due to climatic factors,which significantly increases the li... Loess landslides are major hazards in the Chinese Loess Plateau(CLP).The loess in this region is frequently subjected to repeated wetting–drying(W-D)cycles due to climatic factors,which significantly increases the likelihood of landslides.Therefore,investigating the shear behavior and microstructural evolution of loess under climate-induced W-D cycles is crucial to understanding the mechanisms of loess landslides.In this study,Malan loess is analyzed using unsaturated triaxial tests,resistivity tests,scanning electron microscopy,and mercury intrusion porosimetry.The test results show that shear strength decreases with increased W-D cycles,and the degradation effect is more pronounced under lower confining pressure.The variations in conductive pathways indicate that electrical resistivity can effectively reflect the structural damage of loess during W-D cycles,which is associated with increased direct point contacts and spaced pores.Aggregation of clay particles and growth of cracks during the W-D cycles can further destabilize the loess microstructure.As the confining pressure increases,crushed particles rearrange and convert spaced pores into intergranular pores.The number and peak intensity of dominant spaced pores decrease,resulting in a more stable structure.This study clarifies the mechanisms of loess landslides under W-D cycles and provides theoretical support for landslide prevention and control in the CLP. 展开更多
关键词 LOESS Wetting-drying cycles Electrical resistivity Shear behavior Microstructure
在线阅读 下载PDF
Effects of minimally coupled modified gravity on the gravitational collapse of compact matter structures
16
作者 M Yousaf A Rehman +2 位作者 M M M Nasir S Hanif H Asad 《Communications in Theoretical Physics》 2026年第2期134-162,共29页
Our analysis is particularly motivated by its relevance to understanding compact object instabilities,gravitational collapse thresholds,and the formation of dense structures under the influence of modified gravity the... Our analysis is particularly motivated by its relevance to understanding compact object instabilities,gravitational collapse thresholds,and the formation of dense structures under the influence of modified gravity theories.The interplay of anisotropic pressures,perturbative dynamics,and modified gravity contributions offers insight into both the stable configuration of dense fluids and the mechanisms leading to dynamical instability.Such considerations directly contribute to the aims of high energy density profiles,particularly in modeling physical systems where extreme pressure,curvature,and matter interactions co-exist.We consider an axially symmetric,dense structure with anisotropic matter content and employ a specific equation of state(EoS)to examine the interplay between static and dynamic quantities via the adiabatic index.To address the complex dynamics of the collapse process,a perturbative scheme is utilized under Newtonian and post-Newtonian approximations,enabling a detailed examination of the stability and structural evolution of the system under the influence of the considered minimally coupled gravity.Our results demonstrate that hydrostatic equilibrium is maintained when effective pressure,gravitational,and anti-gravitational forces are balanced,while deviations from this balance initiate dynamical instability.Graphical representations of stable and unstable regimes are presented,revealing how the choice of gravity functions significantly affects the outcome.This work provides insight into the behavior of dense,self-gravitating configurations under modified gravity,offering broader implications for the modeling of compact astrophysical objects and contributing to the understanding of gravitational collapse in energy density regimes. 展开更多
关键词 modified theory gravitational collapse dynamical behavior NEWTONIAN post-Newtonian
原文传递
Energy economic analysis of vehicle driving decisions: Eco-driving behavior assessment
17
作者 ZHOU Shi-jie TIAN Feng 《Ecological Economy》 2026年第1期67-82,共16页
Eco-driving behaviors have been recommended around the world because the transport is a key factor of energy use and pollution emissions.Therefore,based on the driving decision model,this paper introduces three aspect... Eco-driving behaviors have been recommended around the world because the transport is a key factor of energy use and pollution emissions.Therefore,based on the driving decision model,this paper introduces three aspects of the driving decisions(strategic decision,tactical decision and operation decision)to analyze the economy of vehicle energy.The analytic hierarchy process(AHP)is used to assign the weight of the internal evaluation indexes,so as to form a complete assessment for drivers'eco-driving behaviors.The research result can not only quantitatively describe the energy-saving effect of drivers'decisions,but also put forward targeted driving suggestions to optimize drivers'eco-driving behaviors.This assessment model helps to clarify the potential of eco-driving on energy economy of transportation in a hierarchical way,and provides a valuable theoretical basis for the further promotion and application of eco-driving education. 展开更多
关键词 eco-driving energy economy driving decision behavior assessment
原文传递
Simultaneously improving mechanical and corrosion properties of Mg-Y-Nd-Zr alloy via Sm addition
18
作者 Zheng Wu Xiaoya Chen +5 位作者 Dongzhen Wang Quanan Li Yunwei Gui Baosheng Liu Zeyu Zheng Lingxiao Wang 《Journal of Magnesium and Alloys》 2026年第1期306-323,共18页
The strength-ductility trade-off in magnesium alloys remains a critical challenge urgently requiring resolution in their engineering applications.In this study,both mechanical and corrosion properties are enhanced in ... The strength-ductility trade-off in magnesium alloys remains a critical challenge urgently requiring resolution in their engineering applications.In this study,both mechanical and corrosion properties are enhanced in extruded Mg-Y-Nd-Zr alloys by Sm addition.Sm promotes dynamic recrystallization,activates non-basal slip systems and weakens basal texture intensity,leading to the sub-grain lamellar structure and rare earth texture.The EWS2 alloy exhibits an outstanding combination of high yield strength(328 MPa)and ductility(15.1%).Furthermore,the fragmented second phases in the Sm-containing alloy are uniformly distributed,reducing the subsequent corrosion driving force after micro-galvanic corrosion and facilitating the growth of a more passivating and compact corrosion film.These combined effects contribute to the lowest degradation rate in the EWS2 alloy.This study demonstrates the correlation between microstructure and properties in Sm-containing WE series alloys,providing insights for the design of other high performance magnesium alloys. 展开更多
关键词 Mg-Y-Nd-Zr alloy Sm addition Microstructure Mechanical properties Corrosion behavior
在线阅读 下载PDF
Amelioration of behavioral and neural deficits in animal models of neurodegenerative disease by nanoformulations of curcumin and quercetin
19
作者 Bridget Martinez Philip V.Peplow 《Neural Regeneration Research》 2026年第8期3311-3322,共12页
Neurodegenerative diseases are increasing in prevalence due largely to aging populations worldwide and improved medical care for the elderly.Currently approved drugs can reduce some of the symptoms of neurodegenerativ... Neurodegenerative diseases are increasing in prevalence due largely to aging populations worldwide and improved medical care for the elderly.Currently approved drugs can reduce some of the symptoms of neurodegenerative diseases but cannot cure them.Inflammation is involved in the development and progression of neurodegenerative diseases,and oxidative stress is implicated in neurodegeneration associated with cognitive decline and age-related cognitive impairment.Polyphenols such as curcumin,quercetin,and resveratrol possess potent anti-inflammatory and antioxidant properties.Nanoformulations of curcumin and quercetin can optimize their pharmacological effects in the treatment of neurodegenerative diseases.Nanocarriers play a crucial role in delivering drugs across the blood-brain barrier,thereby lowering the risk of peripheral side effects.Various nanoforms have been developed to induce bioavailability and solubility of curcumin and quercetin,including nanoparticles and nanoemulsions.The studies reviewed included 17 using curcumin nanoformulations and seven with quercetin nanoformulations and were tested in widely used animal models of Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and multiple sclerosis.Many of the curcumin and quercetin nanoformulations brought about improvements in learning and memory in behavioral tests of Alzheimer’s disease models and were effective in reducing oxidative stress in the brain.Both nanocurcumin and nanoquercetin decreased the levels of inflammatory markers in the brain.Nanocurcumin formulations improved motor behavior,gait,and memory in Parkinson’s disease models and increased dopaminergic neurons in the striatum and substantia nigra.Furthermore,nanocurcumin improved locomotor activity,memory,and learning,and the number of dendrites of medium spiny neurons in Huntington’s disease models.Nanocurcumin formulations decreased oxidative stress and inflammation in a model of demyelination.Several important limitations were identified in the studies reviewed and these need to be considered in future studies.Also,clinical trials could be performed using the currently available nanoforms of curcumin and quercetin. 展开更多
关键词 animal models behavioral deficits CURCUMIN inflammation nanoformulations neural deficits neurodegeneration oxidative stress QUERCETIN
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部