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2025

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Articles 151 - 180 of 11876

Full-Text Articles in Physical Sciences and Mathematics

Variation Characteristics Of Co2 Adsorption Phase Density In Coal Seam And Its Controlling Mechanism: A Case Study Of Huainan-Huaibei Coalfield, Liu Huihu, Fan Zhengpu, Yang Jinghao, Liu Junlin, Ding Hai, Xu Hongjie, Gao Deyi, Fang Huihuang, Zhao Yuqing Dec 2025

Variation Characteristics Of Co2 Adsorption Phase Density In Coal Seam And Its Controlling Mechanism: A Case Study Of Huainan-Huaibei Coalfield, Liu Huihu, Fan Zhengpu, Yang Jinghao, Liu Junlin, Ding Hai, Xu Hongjie, Gao Deyi, Fang Huihuang, Zhao Yuqing

Coal Geology & Exploration

Objectives and Methods The CO2 adsorption phase density is a key factor determining the CO2 adsorption sequestration capacity in coal seams. To deeply understand the characteristics of CO2 density distribution in pores of the coal seam, taking the No.13 coal from Liuzhuang Mine of Huainan mining area and the No.7 coal in Huaibei mining area as the research objects, the CO2 adsorption phase density of at different pressures and temperatures with different dominant pore diameters was simulated through the simplified local density theory (SLD). The CO2 adsorption phase densities were obtained by different methods, the …

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Mechanisms Underlying Sodium Enrichment In Coals In The Dananhu Mining Area, Turpan-Hami Basin, Qi Zhenghui, Sun Fanxing, Wang Wenlong, Huang Chunhui, Liang Kaihua, Huang Yangyang, Shao Longyi Dec 2025

Mechanisms Underlying Sodium Enrichment In Coals In The Dananhu Mining Area, Turpan-Hami Basin, Qi Zhenghui, Sun Fanxing, Wang Wenlong, Huang Chunhui, Liang Kaihua, Huang Yangyang, Shao Longyi

Coal Geology & Exploration

Background The Dananhu mining area boasts abundant coal resources, serving as a significant coal-fired power generation base in Xinjiang, China. However, the high sodium (Na) content in coals within the mining area tends to cause fouling and slagging during coal combustion, severely affecting the clean and efficient utilization of coal resources in the area. Methods and Results epresentative samples collected from the major mineable coal seams were subjected to proximate and ash-composition analyses. The analytical results show that the coal samples had low ash and sulfur contents and high volatile content. SiO2 predominated in the ash components, followed by …

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Water Quality Characteristics And Reutilization Of Goaf Water From Shallow Coal Seams Within The Datong Mining Area, Shanxi Province, China, Li Jun, Gui Herong, Ding Pengfei, Chen Yongqing, Wan Heyong, Li Weiqi, Huang Dawei, Peng Weihua, Hu Yang, Guo Yan Dec 2025

Water Quality Characteristics And Reutilization Of Goaf Water From Shallow Coal Seams Within The Datong Mining Area, Shanxi Province, China, Li Jun, Gui Herong, Ding Pengfei, Chen Yongqing, Wan Heyong, Li Weiqi, Huang Dawei, Peng Weihua, Hu Yang, Guo Yan

Coal Geology & Exploration

Objective The Datong mining area in Shanxi Province of China faces serious threats from goaf water hazards, while the goaf water drainage is constrained by environmental protection policies. Therefore, the reutilization of goaf water serves as an effective approach to eliminating mine water hazards, protecting water environments, and mitigating water scarcity in the mining area. Methods This study investigated goaf water from shallow coal seams in the Datong mining area. Based on water quality assessment theories and a range of hydrogeochemical indices, including saturation index (SI), chloro-alkaline index (CAI), and sodium adsorption ratio (SAR), this study conducted a joint determination …

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Application Of Seismic-While-Tunnelling Detection In The Identification Of Densely Distributed Sub-Seismic Faults, Li Haodang, Li Kang, Chen Jian, Song Xiaozhong, Jin Dan, Wang Baoli Dec 2025

Application Of Seismic-While-Tunnelling Detection In The Identification Of Densely Distributed Sub-Seismic Faults, Li Haodang, Li Kang, Chen Jian, Song Xiaozhong, Jin Dan, Wang Baoli

Coal Geology & Exploration

Objective and Method Densely distributed sub-seismic faults have emerged as a major hidden disaster-causing geological factor, heavily influencing both the production efficiency and operational safety of coal mines. To achieve precise advance detection of underground sub-seismic faults in coal mines, this study designed a geological model. Using seismic-while-tunneling (SWT) advance detection technology for roadways of coal mines, this study investigated the geological situation of sub-seismic faults through forward modeling. Furthermore, it explored the seismic image characteristics of these faults obtained using the SWT observation system under varying survey line lengths and geophone spacing values. Results and Conclusions The forward modeling …

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2025 December 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Dec 2025

2025 December 25 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

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Shaking Table Test And Numerical Simulation Of Seismic Response Characteristics Of Rock Slope With Muddy Interlayer, Duan Chenggang, Fang Yanlin, Tian Yeqing, Zhou Zhijun Dec 2025

Shaking Table Test And Numerical Simulation Of Seismic Response Characteristics Of Rock Slope With Muddy Interlayer, Duan Chenggang, Fang Yanlin, Tian Yeqing, Zhou Zhijun

Journal of China & Foreign Highway

In order to study the seismic macroscopic failure process and dynamic response characteristics of rock slope with muddy interlayer and reveal the influence of muddy interlayer on slope stability,a similar slope model with concave and convex slope types was designed,and shaking table test was carried out;finite element analysis was used for numerical modeling analysis,and the results obtained by the two models were compared.The results show that:① The macroscopic deformation and failure process of the model slope is divided into three stages.Muddy interlayer dislocates,and cracks occur;mud interlayer slips,and cracks expand;slope collapses;② The seismic load has a decisive influence on the stability …

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Effect Of Lithium Slag Dosage On Strength And Dry Shrinkage Properties Of Cement Stabilized Recycled Macadam, Zhao Ziyu, Gan Xianyong Dec 2025

Effect Of Lithium Slag Dosage On Strength And Dry Shrinkage Properties Of Cement Stabilized Recycled Macadam, Zhao Ziyu, Gan Xianyong

Journal of China & Foreign Highway

To improve the mechanical properties and dry shrinkage properties of cement stabilized bases formed by cold in-place recycling of cement concrete pavements,lithium slag was mixed into the recycled mixture in mass ratios of 0%,6%,9%,and 12%.The effects of lithium slag dosage on the mechanical,dry shrinkage,and water stability properties of the recycled base were analyzed through the unconfined compressive strength,splitting,dry shrinkage,and water stability tests,and the mechanism underlying the improving effect of lithium slag on the cement stabilized base formed by cold in-place recycling of the cement concrete pavement was analyzed by X-ray diffraction (XRD ) and scanning electron microscopy (SEM ).The results …

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Optimization Of Infill Concrete Dimension In Composite Girder Box Based On Igrnn, Wang Yafeng, Liu Jian, Ke Hongjun Dec 2025

Optimization Of Infill Concrete Dimension In Composite Girder Box Based On Igrnn, Wang Yafeng, Liu Jian, Ke Hongjun

Journal of China & Foreign Highway

The mechanical performance of the negative bending moment zone of steel-concrete composite continuous girders has always been a focus of attention in bridge engineering.Existing research mainly proposes improvement measures for the tension of concrete bridge decks,while paying little attention to the common phenomenon of steel girders bearing pressure.The steel girders in steel-concrete composite girders,especially the steel bottom plate in the negative bending moment area of the pier top,bear the highest compressive stress of the entire bridge.Therefore,by taking a steel-concrete composite girder bridge in Zhejiang Province as the engineering background,it is proposed to partially fill the interior of the box girder …

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Research On Cable Force Optimization Of Long-Span Cable-Stayed Bridges Based On Rbfnn+Improved Parti Cle Swarm Optimization Algorithm, Deng Da, He Bowen, Liu Guokun Dec 2025

Research On Cable Force Optimization Of Long-Span Cable-Stayed Bridges Based On Rbfnn+Improved Parti Cle Swarm Optimization Algorithm, Deng Da, He Bowen, Liu Guokun

Journal of China & Foreign Highway

In view of the cable force optimization problem of long-span cable-stayed bridges,a cable force optimization method considering the reliability index of stay cables was proposed based on the response surface fitted by the radial basis function neural network (RBFNN ).The RBFNN-based response surface model for solving the reliability index was established by fitting the structural implicit function through RBFNN training.The improved particle swarm optimization algorithm was used to search for the optimal solution of the cable force optimization model considering the reliability index.The research results show that RBFNN can accurately predict the structural responses and fit the structural implicit performance …

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Design Optimization And Experimental Study Of Cfrp Plate Anchorage With Clip-Extension Type, Qi Yijia, Xiao Dan, Wang Zhongqiang Dec 2025

Design Optimization And Experimental Study Of Cfrp Plate Anchorage With Clip-Extension Type, Qi Yijia, Xiao Dan, Wang Zhongqiang

Journal of China & Foreign Highway

Existing anchorage is prone to damaging the carbon-fiber reinforced polymer (CFRP ) plate due to the “notch effect ” and uneven distribution of clamping stress.This study proposed a new clip-extension type anchorage for the CFRP plate.This design utilized the ductility of steel for stress diffusion and guided the compressive stress zone in the CFRP plate away from the notched end,realizing a smooth transition of the clamping force of the CFRP plate at the clip port and effectively reducing the “notch effect ”.The design also reduced the strain difference between the carbon fibers,resulting in a more synchronized lateral deformation of the …

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Research And Applicat Ion Of Ultra Large-Scale Consolidated Under-Reamed Drilled Shaft Technology Under Special Environmental And Geological Conditions, Ding Yi, Yu Kun, Shi Haiyang, Pei Xiaofeng, Zhu Bo Dec 2025

Research And Applicat Ion Of Ultra Large-Scale Consolidated Under-Reamed Drilled Shaft Technology Under Special Environmental And Geological Conditions, Ding Yi, Yu Kun, Shi Haiyang, Pei Xiaofeng, Zhu Bo

Journal of China & Foreign Highway

This article aims to add ress the poor economic efficiency of large-diameter and ultra-long piles,the high risk of hole collapse in thick sandy soil,and the limited space across the canal faced by the Bridge over Yellow River Diversion to Qindao Canal on Zhanhua ‒ Linyi Expressway.According to the comparison of conventional drilled cast-in-place piles with combined pile-end and pile-side post-grouting,the industry ’s under-reamed drilled shaft foundation with the largest disc diameter (4.5 m) and the largest single-pile volume (456 m3) was proposed and designed.At the same time,supporting devices such as three-arm rotary cutting drill bits and long arm borehole diameter …

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Analysis Of Influence Of Internal Erosion On Deformation Of Subway Station Structure, Qin Tianxin, Wang Chen, Tan Xuyan, Wei Shengming, Liang Fayun Dec 2025

Analysis Of Influence Of Internal Erosion On Deformation Of Subway Station Structure, Qin Tianxin, Wang Chen, Tan Xuyan, Wei Shengming, Liang Fayun

Journal of China & Foreign Highway

Under the long-term effects of disasters such as rainstorms and floods,the soil layer around subway stations may be affected by internal erosion,threatening the structural safety of urban subway stations.To explore the influence of internal erosion on subway station structures,this study conducted isotropic consolidation and triaxial compression tests on gap-graded sand soil.Eroded soil specimens were simulated by adjusting the fine particle content to explore the pattern of variations in physical and mechanical properties caused by internal erosion.Results indicate that internal erosion alters the stress-strain relationship of gap-graded sand soil,increasing compressibility,decreasing shear strength,and weakening dilatancy.Drucker-Prager (DP) cap model parameters for eroded sand …

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Real-Time Production Of High-Resolution, Gap-Free, 3-Hourly Aod Over South Korea: A Machine Learning Approach Using Model Forecasts, Satellite Products, And Air Quality Data, Seoyeon Kim, Youjeong Youn, Menas Kafatos, Jaejin Kim, Wonsik Choi, Seung Hee Kim, Yangwon Lee Dec 2025

Real-Time Production Of High-Resolution, Gap-Free, 3-Hourly Aod Over South Korea: A Machine Learning Approach Using Model Forecasts, Satellite Products, And Air Quality Data, Seoyeon Kim, Youjeong Youn, Menas Kafatos, Jaejin Kim, Wonsik Choi, Seung Hee Kim, Yangwon Lee

Institute for ECHO Articles and Research

Aerosol optical depth (AOD) is essential for air quality monitoring and climate research. However, satellite-based retrievals suffer from cloud-related data gaps, and reanalysis products are limited by coarse spatial resolution and substantial production latency. This study develops a real-time, gap-free, high-resolution (1.5 km) AOD retrieval system for South Korea. The system integrates Copernicus Atmosphere Monitoring Service (CAMS) forecasts, high-resolution meteorological fields, and ground-based air quality observations within a machine learning framework. Three models with varying training periods were systematically evaluated using cross-validation and independent validation with 2024 Aerosol Robotic Network (AERONET) data. The optimal model, trained on 2015–2023 data, achieved …

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Evaluation Method For Nighttime Visual Space Improvement On Mountain Roads, Zhao Yan, Chen Yanli, Chen Jiale Dec 2025

Evaluation Method For Nighttime Visual Space Improvement On Mountain Roads, Zhao Yan, Chen Yanli, Chen Jiale

Journal of China & Foreign Highway

To address issues such as poor visual guidance,narrow field of view,and short sight distance during nighttime driving on mountain roads,this study proposed a visual space enhancement evaluation method applicable to mountainous roads at night.By integrating active and passive traffic safety facilities,a visual space enhancement strategy adapted to the nighttime environment of mountain roads was proposed.A multidimensional evaluation indicator for visual space was established based on co-simulation.The effectiveness of the strategy was verified from the perspectives of visual space expansion and driving safety improvement by taking a trunk highway in the Qinling mountainous region as a case study.The results show that …

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Utilization Technology And Compaction Quality Control Of Hardened Layer In Beam Yard Of Rock-Filled Roadbed, Cheng Xiaoliang, Tian Wendi, Gao Mengke, Zhou Xujia Dec 2025

Utilization Technology And Compaction Quality Control Of Hardened Layer In Beam Yard Of Rock-Filled Roadbed, Cheng Xiaoliang, Tian Wendi, Gao Mengke, Zhou Xujia

Journal of China & Foreign Highway

To investigate the utilization technology and compaction quality control of hardened layers in the beam yard of rock-filled roadbed,the optimization design and construction control methods for rock-filled roadbed under different conditions were proposed based on a highway project in Guangdong Province.When the elevation of the hardened layer was lower than the top surface elevation of the roadbed and the top surface bending and settlement value of the hardened layer was less than that of the rock-filled roadbed,the gravel material could be filled directly on the hardened layer to the top surface elevation of the roadbed,and acceptance and pavement design could …

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Reflection Cracking Resistance And Fatigue Performance Of Super-Flexible Fma Mixture, Lan Yong, Deng Xinghe, Zhang Zida, Wu Kuanghuai, Ding Weizhe, Guan Xuebing, Peng Tiekun Dec 2025

Reflection Cracking Resistance And Fatigue Performance Of Super-Flexible Fma Mixture, Lan Yong, Deng Xinghe, Zhang Zida, Wu Kuanghuai, Ding Weizhe, Guan Xuebing, Peng Tiekun

Journal of China & Foreign Highway

To investigate the fatigue performance and reflection cracking resistance of super-flexible fluid mastic asphalt (FMA ) mixtures,this study designed a super-flexible FMA- 13 mixture by the mastic flow for filling (MaFF ) method.The effects of temperature and maximum horizontal tensile displacement on the cracking resistance of both FMA- 13 and GAC- 13 (as the control ) mixtures were explored via the Overlay Tester.Additionally,small-scale accelerated pavement loading tests were conducted to analyze the effect of load cycles on the rebound modulus of the FMA- 13 mixture.A nonlinear fatigue damage model was employed to predict the fatigue life of both mixtures.The results …

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Research On Pavement Roughness Evaluation Method Based On Smartphones, Siriguleng Bai, Yili Guoqi, A Rong, Guo Guoying, Wang Jing Dec 2025

Research On Pavement Roughness Evaluation Method Based On Smartphones, Siriguleng Bai, Yili Guoqi, A Rong, Guo Guoying, Wang Jing

Journal of China & Foreign Highway

To address the low efficiency and high cost of current detection methods,as well as the insufficient accumulation of pavement damage data on rural low-grade roads,this study developed a vehicle vibration data acquisition application based on smartphones and proposed a conversion method for calculating an index equivalent to the international roughness index (IIRI).Vertical acceleration signals collected during vehicle travel were proposed through high-pass filtering and denoising to calculate the vertical displacement,from which a converted I'IRI was derived.Experimental results show that although the data collected by smartphones has slightly lower accuracy than that collected by professional detection equipment,the proposed I'IRI exhibits a …

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Sound Attenuation Characteristics In Relation To Compaction Degree In Sandy Soil, Liu Junbin, Long Shiguo Dec 2025

Sound Attenuation Characteristics In Relation To Compaction Degree In Sandy Soil, Liu Junbin, Long Shiguo

Journal of China & Foreign Highway

In order to investigate the effect of water content and compaction degree on the attenuation characteristics of sound waves in sandy soil,this paper first determined the particle gradation of the soil through a sieving test and identified its optimal water content through a compaction test.Then,six sets of ring knife specimens of sandy soil with different water contents and nine sets with varying compaction degrees were prepared.Ultrasonic testing was carried out using the acoustic transmission method,and the received acoustic signals were subjected to time-frequency analysis to extract acoustic characteristic parameters indicative of the compaction degree.Finite element simulation was employed to explore …

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Road Performance And Water-Softening Characteristics Of Stabilized Soil Under Cyclic Loading, Hu Hong, Li Zongheng, Feng Yong, Cao Zhigang, Liu Yaoxing Dec 2025

Road Performance And Water-Softening Characteristics Of Stabilized Soil Under Cyclic Loading, Hu Hong, Li Zongheng, Feng Yong, Cao Zhigang, Liu Yaoxing

Journal of China & Foreign Highway

To effectively deal with waste soil and reduce environmental pollution,this paper took a road engineering project in Shaoxing as the research object and conducted a cyclic triaxial incremental loading test on the undisturbed lime soil under undrained conditions to study the effects of confining pressure,cyclic stress ratio,and water immersion on its performance.The results show that when the cyclic stress ratio increases from 1 to 4,the cumulative strain and resilient strain increase rapidly in the initial loading stage,showing a trend of “stepwise” increase.The cumulative strain produced at a cyclic stress ratio of 2 is about twice that at the cyclic stress …

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Study On Mechanical Properties Of Improved High Liquid Limit Soil Based On Solid Waste, Zhang Yafei, Qin Yalan, Wu Jiacheng, Zhang Rui, Gao Yingli, Zhu Zhanghuang, Li Lu Dec 2025

Study On Mechanical Properties Of Improved High Liquid Limit Soil Based On Solid Waste, Zhang Yafei, Qin Yalan, Wu Jiacheng, Zhang Rui, Gao Yingli, Zhu Zhanghuang, Li Lu

Journal of China & Foreign Highway

To improve the application of the solid waste polymer-modified high liquid limit soil as filler in the upper embankment or road bed work area,this study prepared colloidal polymer and improved materials of traditional cement by using industrial solid waste (fly ash,steel slag,etc.) and compared them with the improved high liquid limit soil to investigate its mechanical properties and economic benefits.The mechanical properties of high liquid limit soil improved by the colloidal polymer of solid waste,as well as its stability and durability when immersed in water were studied through a liquid-plastic limit test,a laboratory compaction test,a shrinkage test,a California bearing ratio …

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Comparison Of Calculation Methods For Local Scour In Bridge Pier Foundation Of Piles-Cushion Cap, Liu Hui, Jiang Yanhua, Yan Jiechao Dec 2025

Comparison Of Calculation Methods For Local Scour In Bridge Pier Foundation Of Piles-Cushion Cap, Liu Hui, Jiang Yanhua, Yan Jiechao

Journal of China & Foreign Highway

In order to analyze the calculation methods for local scour in bridge pier foundation of piles-cushion cap,this paper listed the six common Chinese and foreign calculation methods,described their calculation process and selection of calculation parameters,and analyzed the difference of the calculation methods according to typical engineering examples.The results show that there are differences in the selection of parameters in the calculation methods for local scour in bridge pier foundation of piles-cushion cap in Code for Survey and Design on Hydrology of Railway Engineering (TB 10017—2021 ) and Hydrological Specifications for Survey and Design of Highway Engineering (JTG C 30—2015 ),and …

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A Method For Determining Integrity Degree Of Tunnel Surrounding Rock Based On Mobilenet, Liu Houxiang, Yang Caixia Dec 2025

A Method For Determining Integrity Degree Of Tunnel Surrounding Rock Based On Mobilenet, Liu Houxiang, Yang Caixia

Journal of China & Foreign Highway

To determine the integrity degree of tunnel surrounding rock more efficiently,a precise determination method for the integrity degree of tunnel surrounding rock based on the lightweight neural network MobileNet-v 2 was proposed.Firstly,the image was grayscaled and denoised,and the edges of cracks were detected.Then,the lightweight neural network MobileNet-v 2 model was pre-trained on the ImageNet dataset,and combined with transfer learning to complete data detection on the training,validation,and testing sets.Finally,a comparative experiment was conducted with traditional neural networks RestNet- 50 and VGG 16.By identifying the area,width,and length of cracks,the crack ratio Ks was introduced as an indicator to evaluate the integrity of …

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Study On Thermal Corrosion Resistance Of Asphalt Modified By Phase Change Materials, Li Ping, Wang Zhijian, Zheng Zhipeng, Yi Chengxi, Zhou Dexiang Dec 2025

Study On Thermal Corrosion Resistance Of Asphalt Modified By Phase Change Materials, Li Ping, Wang Zhijian, Zheng Zhipeng, Yi Chengxi, Zhou Dexiang

Journal of China & Foreign Highway

In order to address the degradation issues faced by asphalt mixtures in airport runways and highway pavement,particularly focusing on thermal stability and thermal corrosion under high-temperature conditions,this paper investigated the impact of phase change materials (PCMs ) on the thermal corrosion resistance of asphalt.Three types of PCMs were utilized to jointly modify SBS-modified asphalt,and a series of tests were conducted to systematically analyze the performance of the modified asphalt,including thermogravimetric-differential scanning calorimetry (TG-DSC ) analysis,heat storage and release performance evaluation,laboratory thermal corrosion simulation of asphalt,three-index testing,and dynamic shear rheometer (DSR ) testing.The results indicate that PCMs can effectively regulate asphalt …

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Construction And Application Of Knowledge Graph For Quality Management In Bridge Pile Engineering, Fang Xiaofeng, Dong Runhao, Gu Yanke, Pan Yanran Dec 2025

Construction And Application Of Knowledge Graph For Quality Management In Bridge Pile Engineering, Fang Xiaofeng, Dong Runhao, Gu Yanke, Pan Yanran

Journal of China & Foreign Highway

To enhance the efficiency of quality management in bridge pile foundation construction,this study constructed a knowledge graph applicable to the construction field of bridge pile foundation engineering to enable systematic representation and intelligent organization of knowledge.A methodology combining top-down design and bottom-up design was adopted to develop a framework for constructing a knowledge graph for the quality management of bridge pile foundation construction that encompasses both the schema layer and the data layer.The schema layer was established through ontology modeling,clarifying the concept categories,hierarchical structure,and their attribute relationships.The data layer employed a bidirectional long short-term memory (BiLSTM ) network integrated with …

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The Aurora Survey: Robust Helium Abundances At High Redshift Reveal A Subpopulation Of Helium-Enhanced Galaxies In The Early Universe, Danielle A. Berg, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Evan D. Skillman, Erik Aver, Fergus Cullen, Callum T. Donnan, James S. Dunlop, Tucker Jones, Ali Ahmad Khostovan, Derek J. Mcleod, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, N. M. Förster Schreiber, Daniel P. Stark Dec 2025

The Aurora Survey: Robust Helium Abundances At High Redshift Reveal A Subpopulation Of Helium-Enhanced Galaxies In The Early Universe, Danielle A. Berg, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Evan D. Skillman, Erik Aver, Fergus Cullen, Callum T. Donnan, James S. Dunlop, Tucker Jones, Ali Ahmad Khostovan, Derek J. Mcleod, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, N. M. Förster Schreiber, Daniel P. Stark

Physics Faculty Scholarship

We present the first robust helium (He) abundance measurements in star-forming galaxies at redshifts 1.6 ≲ z ≲ 3.3 using deep, moderate-resolution JWST/NIRSpec spectroscopy from the AURORA survey. We establish a high-z He sample consisting of 20 galaxies with multiple high-signal-to-noise-ratio (>5σ) He i emission-line detections, including the critical near-infrared λ10833 line. This is the first study at high redshift leveraging λ10833 to break degeneracies between temperature, electron density, optical depth, and He+/H+, enabling reliable He abundance determinations in the early Universe. We use a custom Markov Chain Monte Carlo framework incorporating direct-method electron …

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Twas-Ctl: A Robust And Efficient Method For Multi-Tissue Transcriptome-Wide Association Studies Using Cross-Tissue Learners, Md Mutasim Billah, Hairong Wei, Fengzhu Sun, Kui Zhang Dec 2025

Twas-Ctl: A Robust And Efficient Method For Multi-Tissue Transcriptome-Wide Association Studies Using Cross-Tissue Learners, Md Mutasim Billah, Hairong Wei, Fengzhu Sun, Kui Zhang

Michigan Tech Publications

The advent of transcriptome-wide association studies (TWAS) has expanded the classical genome-wide association study (GWAS) framework by integrating gene expression with genetic variation to identify trait-associated variants. While multi-tissue TWAS approaches improve statistical power over single-tissue models, existing methods often lose information during result aggregation and require intensive computation. Here, we present TWAS-CTL (Cross-Tissue Learner), a novel framework that leverages heterogeneous gene expression across tissues by adaptively reweighting and optimizing multiple single-tissue learners. Simulations demonstrate that TWAS-CTL achieves higher statistical power than the leading method, UTMOST, while maintaining proper type I error control and reducing computational time by over half. …

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Effects Of Π-Rich Solvents And Nickel And Cobalt Dopants On The Synthesis And Properties Of Cesium Lead Halide Nanocrystals, Tsung-Hsing Chiang Dec 2025

Effects Of Π-Rich Solvents And Nickel And Cobalt Dopants On The Synthesis And Properties Of Cesium Lead Halide Nanocrystals, Tsung-Hsing Chiang

Dissertations - ALL

Colloidal semiconductor nanocrystals feature unique properties like quantum confinement, tunable band gaps, and high surface-to-volume ratio; and have been proven as prominent materials in applications such as light-emitting diodes, sensors, lasers, solar cells, etc. Optoelectronic properties of semiconductor nanocrystals are highly associated with their sizes, morphologies, and compositions. Understanding the growth mechanism can lead to the ability to control the size, morphology, and composition of nanocrystals. In this thesis, growth and b-site doping of perovskite, cesium lead halide (CsPbX3), nanocrystals are discussed. Solvent effects in the growth of cesium lead bromide were first investigated from the aspect of plumbates in …

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Robust Security Assurance In Cyber-Physical Systems: From Attack Diagnosis To Attack Resilience, Zifan Wang Dec 2025

Robust Security Assurance In Cyber-Physical Systems: From Attack Diagnosis To Attack Resilience, Zifan Wang

Dissertations - ALL

Cyber-Physical Systems (CPS) have become integral to critical infrastructure, from autonomous vehicles to industrial control systems. However, their increased connectivity and sophistication introduce new vulnerabilities, making security a paramount concern. This dissertation presents a comprehensive pipeline for enhancing CPS security, focusing on accurate diagnosis of trustworthy time frames and subsystems, followed by system resilience measures to restore safe states. The foundation of system resilience lies in an advanced checkpointing protocol for real-time multi-process systems. A novel three-step approach uniquely addresses both logical and timing correctness, which are crucial for modern CPS applications. By partitioning processes into directed acyclic graphs, implementing …

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Model Inference And Sparse Network Analysis: Machine Learning In The Gene Regulatory Network Framework, Youchuan Wang Dec 2025

Model Inference And Sparse Network Analysis: Machine Learning In The Gene Regulatory Network Framework, Youchuan Wang

Dissertations - ALL

This thesis explores sparse network inference from high-dimensional, noisy, and underdetermined data—a fundamental challenge in many scientific domains. We focus on the development of evolutionary computation methods for discovering underlying network structures that are both interpretable and biologically plausible. Our methods are applied to the domain of Gene Regulatory Network (GRN) inference, where sparsity, indirect interactions, and limited observations pose significant hurdles. The framework models both steady-state and time-series gene expression data, with particular emphasis on biological sparsity and regulatory dynamics. We approach the problem from three perspectives: (1) edge-level analysis using transitive reduction to distinguish direct from indirect regulation; …

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Enzyme Active Bath Affects Protein Condensation, Kevin Ching Dec 2025

Enzyme Active Bath Affects Protein Condensation, Kevin Ching

Dissertations - ALL

The idea that the activity of an active bath can act as an effective temperature and alter system behavior has been theorized and demonstrated for micron-scale systems, but it has not yet been shown for nanoscale systems. Previous studies have suggested that, although passive and active systems can be combined at the nanoscale, activity from the active system typically disrupts and destroys the passive system. In this work, I attempt to create an enzyme-driven active bath to control the liquid–liquid phase separation (LLPS) and condensation of a protein. I find that enzymatic activity enhances phase separation, effectively driving the LLPS …

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