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Optimizing differential travel-time measurements with dynamic time warping 认领 引用
1
作者 LIU Jian-xin NIE Zi-ting +1 位作者 HOU Xin-rong GAO Da-wei 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第2期834-846,共13页
Precise differential travel-time measurement is essential for earthquake relative locating.The waveform cross correlation(WCC)technique is widely regarded as the most effective method for calculating the differential ... Precise differential travel-time measurement is essential for earthquake relative locating.The waveform cross correlation(WCC)technique is widely regarded as the most effective method for calculating the differential travel-time of seismic phases.However,for earthquake pairs with large magnitude differences,substantial biases can arise due to disparities in the duration of the initial pulse,potentially leading to significant mislocations,particularly for mainshocks.To overcome this limitation,we propose to use the dynamic time warping(DTW)algorithm to optimize differential travel-time calculation.Using high-quality earthquake waveform data from the San Andreas Fault(2012−2019),we systematically compared the performance of DTW and WCC,respectively.Our results demonstrate that DTW substantially improves differential travel-time measurements,especially in cases involving large magnitude differences.In addition,we tested the robustness of DTW using noisy seismic data,demonstrating its superior resilience to noise. 展开更多
关键词 dynamic time warping waveform cross-correlation differential travel-time measurement magnitude difference
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Comparison of data driven and data-mechanism hybrid driven methods for key variables prediction based on data sets with different sample sizes and noises 认领 引用
2
作者 Qihang Tan Chao Wang +2 位作者 Wange Li Jinghao Sun Jun Zhao 《ENGINEERING Chemical Engineering》 SCIE EI CAS CSCD 2026年第2期57-68,共12页
Soft measurement based on data-driven models is an important method to predict key variables in process industry due to low latency demand and economics costs.However,data-driven models cannot provide accurate predict... Soft measurement based on data-driven models is an important method to predict key variables in process industry due to low latency demand and economics costs.However,data-driven models cannot provide accurate prediction on a noisy data set with a small number of samples.In response to the challenge of noisy data and lack of samples,several data-mechanism hybrid driven methods are proposed to improve key variables prediction performances on the basis of three data-driven models including random forest,extreme gradient boosting,and artificial neural network.Simultaneously,the effectiveness of hybrid driven methods proposed is validated via two cases including benzene-toluene-xylene distillation and steam methane reforming process,where data sets feature different sample sizes and noise intensity.The comparison results show that the hybrid driven methods can improve the prediction accuracy to a certain extent.The degree of improvement depends on the noise intensity,sample size,and data-driven model selected.Under conditions of noise intensity at 10%–20%and sample size ranging from 100 to 400 in this work,after adopting the hybrid driven methods,the coefficient of determination for random forest,extreme gradient boosting,and artificial neural network can be improved by 0.3%–5.2%,0.6%–17.7%,and 0.1%–36.2%compared to corresponding data driven models. 展开更多
关键词 data-mechanism hybrid driven methods different sample sizes noise dataset machine learning process industry
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A GATED SERVICE SINGLE VACATION M/G/1 QUEUE SYSTEM WITH SETUP AND CLOSEDOWN TIMES AND DIFFERENT CUSTOMER ARRIVAL RATES 认领 引用
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作者 Ying SUN Zhanyou MA Tongyu XU 《Acta Mathematica Scientia》 SCIE CSCD 2026年第1期407-426,共20页
A gated service single vacation M/G/1 queue with setup and closedown periods,and different customer arrival rates,is studied in this paper.The probability generating function of the number of systems for customers who... A gated service single vacation M/G/1 queue with setup and closedown periods,and different customer arrival rates,is studied in this paper.The probability generating function of the number of systems for customers who are at the initial moment of service period is analyzed by using a total probability theorem,and the stability condition of the system is obtained.The stationary distribution of the queue length is solved by the regeneration cycle method.The stochastic decomposition of queue length in the steady state is calculated,and the service cycle is obtained.Moreover,classified discussions are established in order to solve the steady-state distribution for the waiting time.The variation of system performance indicators with parameters is analyzed by performing numerical experiments. 展开更多
关键词 different arrival rates regeneration cycle method stochastic decomposition theorem stationary queue length
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Seepage and blockage characteristics of methane hydrate-bearing porous media under different hydrate distribution conditions 认领 引用
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作者 Guo-Jun Zhao Jia-Nan Zheng +1 位作者 Ming-Jun Yang Yong-Chen Song 《Petroleum Science》 SCIE EI CAS CSCD 2026年第4期2263-2274,共12页
Blockage commonly occurs in and severally affects natural gas(mainly methane)reservoir exploitation,combustion ice(methane hydrate)exploitation and oil and gas pipeline transportation.The formation of methane hydrates... Blockage commonly occurs in and severally affects natural gas(mainly methane)reservoir exploitation,combustion ice(methane hydrate)exploitation and oil and gas pipeline transportation.The formation of methane hydrates is known as one important cause of blockage,but the effects of hydrate distribution on seepage and blockage are rarely studied in experiments.This study employed different proportions of dry and wet sands to simulate three thickness of hydrate-bearing porous media and obtained a uniform kinetic relationship of hydrate formation(N=K(■)).Quantitative results indicate that both water and methane seepage can induce hydrate saturation increase in both hydrate-bearing and hydrate-free zones,which gradually causes the blockage of up to 12.5 MPa(at 6.0 MPa backpressure).The hydratebearing porous media with a uniform saturation is not easy to cause blockage unless the hydrate saturation is high enough.In addition,based on the hydrate-bearing porous media with different thicknesses,this study successively measured the water phase permeability.In addition,the calculation method for blockage location based on pressure evolution was proposed with an error of less than 8%.These findings can help understand and mitigate issues related to flow blockages during oil and gas exploitation and transportation. 展开更多
关键词 Methane hydrate Distribution difference Formation kinetic Porous media permeability Seepage and blockage
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Tribological Properties and Wear Mechanisms of SiCp/6092Al Composites with Different Volume Fractions 认领 引用
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作者 WANG Dongliang DOU Jianming +2 位作者 ZHANG Jilin YI Xiangbin MA Furong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2026年第2期323-332,共10页
SiCp-reinforced 6092Al composites with volume fractions of 25%and 60%were prepared using a powder metallurgy method.Their friction and wear characteristics were analyzed using a reciprocating friction and wear testing... SiCp-reinforced 6092Al composites with volume fractions of 25%and 60%were prepared using a powder metallurgy method.Their friction and wear characteristics were analyzed using a reciprocating friction and wear testing machine under loads of 20 to 50 N against YG6 cemented carbide.The experimental results show that the friction coefficients of all samples increase with increasing load.The 25vol%composite exhibits the lowest friction coefficient(0.1669-0.2716),while the 60vol%composite exhibits the highest(0.3237-0.3990),with the 6092 aluminum alloy falling between the two.The wear volume and specific wear rate also increase with load,but the composites with a higher Si C content demonstrate smaller increments,with the 60vol%composite exhibiting superior wear resistance.Under a 30 N load,the wear scars of the 60vol%composite show a significant increase in the contents of elements such as C,Co,W,and O,indicating more severe wear of the counterpart material.Scanning electron microscopy(SEM)reveals wear mechanisms including adhesive wear,two-body sliding and three-body rolling wear of particles,and delamination. 展开更多
关键词 SiCp/6092Al composites wear mechanisms different volume fractions tribological properties
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Frequency measurement and analysis via different frequency phase synchronization fuzzy region 认领 引用
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作者 DU Baoqiang WANG Xiang YAO Dunzhi 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2026年第2期219-231,共13页
A precise frequency measurement and analysis method utilizing the concept of the different frequency phase synchronization fuzzy region is presented based on the principle of phase synchronization detection.Initially,... A precise frequency measurement and analysis method utilizing the concept of the different frequency phase synchronization fuzzy region is presented based on the principle of phase synchronization detection.Initially,the frequency of the measured signal was roughly estimated by using the traditional high-precision time and frequency detection technology.Subsequently,the frequency estimated was fed into a direct digital synthesizer(DDS)to generate a real-time frequency standard signal that exhibited a slight frequency deviation relative to the measured signal.The edge pulses of the different frequency phase synchronization fuzzy region served as counter switch signals,enabling the counting of both the detected signal and the real-time frequency standard signal within a specified gate time.Through subsequent data processing of the obtained values,the frequency,frequency difference,and frequency accuracy of the detected signal could be determined.Experimental results demonstrate that the system based on this method achieves a frequency stability of 10−13 at 1 s,with a frequency deviation of less than 3 Hz.Compared with traditional frequency measurement and analysis methods,this approach has many advantages,especially its fast response time of less than 1 ms,high measurement accuracy of more than 10−11 at 1 s,high integration with only one FPGA chip,and cost of less than 1000 yuan.It is widely applied in the fields of time and frequency services and security technology of the Beidou satellite(BDS)navigation system,such as BDS pseudo-range measurement,Beidou positioning,navigation and time services,as well as precise time and frequency measurement and control,etc. 展开更多
关键词 different frequency phase synchronization frequency analysis and measurement frequency accuracy phase synchronization fuzzy region frequency stability group period
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Detection and Risk Assessment of Heavy Metal Residues in Agricultural Products Under Different Environmental Conditions 认领 引用
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作者 SUN Bo ZHAN Ao 《外文科技期刊数据库（文摘版）自然科学》 2026年第1期131-135,共5页
Heavy metal contamination in agricultural products is a global food safety and environmental problem that is easily affected by soil, atmospheric environment, water, and anthropogenic environments. Heavy metal residue... Heavy metal contamination in agricultural products is a global food safety and environmental problem that is easily affected by soil, atmospheric environment, water, and anthropogenic environments. Heavy metal residues such as cadmium, lead, chromium, mercury, and arsenic have the characteristics of non-degradability, strong bioaccumulation, and high toxicity. They can migrate and accumulate in soil-crop systems, and ultimately enter the human body through dietary intake, causing potential chronic toxicity and genetic damage. Different environmental conditions produce significant differentiation effects on heavy metal enrichment, residual characteristics, and existing forms in agricultural products, which further affects the accuracy of residue detection and the rationality of risk assessment. This paper systematically analyzes the enrichment rules of heavy metal residues in typical agricultural products under an industrial polluted environment, an agricultural intensive planting environment, an urban fringe environment, and a remote clean ecological environment. It discusses the interference mechanism of different environmental factors on conventional heavy metal detection technologies, summarizes the technical difficulties of qualitative and quantitative detection in complex environmental backgrounds, and constructs a standardized food safety risk assessment system covering dietary exposure risk and potential ecological risk. The study clarifies the correlation between environmental heterogeneity, heavy metal residual levels, and human health risks and proposes targeted detection optimization schemes and risk prevention strategies to provide scientific technical support for agricultural product safety supervision, environmental pollution control, and human health protection. 展开更多
关键词 Different Environmental Conditions Agricultural Products Heavy Metal Residues Detection Technology Bioaccumulation Health Risk Assessment Food Safety
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Genetic susceptibility,environmental risk factors,and incident gastric cancer risk among individuals with different Helicobacter pylori infection status:a population-based study 认领 引用
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作者 Hengmin Xu Hui Ma +9 位作者 Yuxin Wang Xinling Wang Xuan Han Wenjing Zhao Yang Zhang Tong Zhou Jingying Zhang Weicheng You Wenqing Li Kaifeng Pan 《Cancer Biology & Medicine》 SCIE CAS CSCD 2026年第7期1038-1043,共6页
Gastric cancer(GC)remains a leading cause of cancer mortality worldwide1.Helicobacter pylori(H.pylori)infection is the dominant etiologic factor2,yet GC also arises in individuals without infection or after eradicatio... Gastric cancer(GC)remains a leading cause of cancer mortality worldwide1.Helicobacter pylori(H.pylori)infection is the dominant etiologic factor2,yet GC also arises in individuals without infection or after eradication,suggesting alternative carcinogenic pathways3.Accordingly,increasing attention has been paid to potential differences between H.pylori-negative and-positive GC.Clinicopathologic differences by H.pylori infection status have been reported but most evidence derives from case-control studies in which infection status assessed at diagnosis is prone to misclassification due to prior eradication,spontaneous clearance,or tumor-related changes.As a result,prospective data defining the long-term clinical and biological imprint of baseline H.pylori status are limited. 展开更多
关键词 carcinogenic pathways accordinglyincreasing prospective data clinicopathologic differences gastric cancer gc remains Helicobacter pylori infection population based study environmental risk factors genetic susceptibility
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Comprehensive Index Evaluation of the Cooling System with the Level Loop Thermosyphon System in Different Computing Hub Nodes in China 认领 引用
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作者 Li Ling Danhao Song +2 位作者 Qianlong Hu Zihao Xiang Zeyu Zhang 《Energy Engineering》 EI 2025年第8期3309-3328,共20页
Rack-level loop thermosyphons have been widely adopted as a solution to data centers’growing energy demands.While numerous studies have highlighted the heat transfer performance and energy-saving benefits of this sys... Rack-level loop thermosyphons have been widely adopted as a solution to data centers’growing energy demands.While numerous studies have highlighted the heat transfer performance and energy-saving benefits of this system,its economic feasibility,water usage effectiveness(WUE),and carbon usage effectiveness(CUE)remain underexplored.This study introduces a comprehensive evaluation index designed to assess the applicability of the rack-level loop thermosyphon system across various computing hub nodes.The air wet bulb temperature Ta,w was identified as the most significant factor influencing the variability in the combination of PUE,CUE,and WUE values.The results indicate that the rack-level loop thermosyphon system achieves the highest score in Lanzhou(94.485)and the lowest in Beijing(89.261)based on the comprehensive evaluation index.The overall ranking of cities according to the comprehensive evaluation score is as follows:Gansu hub(Lanzhou)>Inner Mongolia hub(Hohhot)>Ningxia hub(Yinchuan)>Yangtze River Delta hub(Shanghai)>Chengdu Chongqing hub(Chongqing)>Guangdong-Hong Kong-Macao Greater Bay Area hub(Guangzhou)>Guizhou hub(Guiyang)>Beijing-Tianjin-Hebei hub(Beijing).Furthermore,Hohhot,Lanzhou,and Yinchuan consistently rank among the top three cities for comprehensive scores across all load rates,while Guiyang(at a 25%load rate),Guangzhou(at a 50%load rate),and Beijing(at 75%and 100%load rates)exhibited the lowest comprehensive scores. 展开更多
关键词 Data center rack level loop thermosyphon different Computing hub node different load rates comprehensive indicator analysis
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Combining different climate datasets better reflects the response of warm-temperate forests to climate:a case study from Mt.Dongling,Beijing 认领 引用
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作者 Shengjie Wang Haiyang Liu +1 位作者 Shuai Yuan Chenxi Xu 《Journal of Forestry Research》 SCIE EI CAS CSCD 2026年第2期131-143,共13页
Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and... Accurately assessing the relationship between tree growth and climatic factors is of great importance in dendrochronology.This study evaluated the consistency between alternative climate datasets(including station and gridded data)and actual climate data(fixed-point observations near the sampling sites),in northeastern China’s warm temperate zone and analyzed differences in their correlations with tree-ring width index.The results were:(1)Gridded temperature data,as well as precipitation and relative humidity data from the Huailai meteorological station,was more consistent with the actual climate data;in contrast,gridded soil moisture content data showed significant discrepancies.(2)Horizontal distance had a greater impact on the representativeness of actual climate conditions than vertical elevation differences.(3)Differences in consistency between alternative and actual climate data also affected their correlations with tree-ring width indices.In some growing season months,correlation coefficients,both in magnitude and sign,differed significantly from those based on actual data.The selection of different alternative climate datasets can lead to biased results in assessing forest responses to climate change,which is detrimental to the management of forest ecosystems in harsh environments.Therefore,the scientific and rational selection of alternative climate data is essential for dendroecological and climatological research. 展开更多
关键词 Climate data representativeness Alternative climate data selection Response differences Deciduous broad-leaf forest Warm temperate zone
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Different fluorinated monomers formed poly(phenanthrene-co-pterphenyl piperidinium)anion exchange membranes for fuel cells 认领 引用 被引量：1
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作者 Yingjie Liu Xibin Yue +5 位作者 Yongqi Hu Hui Peng Guoliang Zhang Aimei Zhu Qiugen Zhang Qinglin Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2025年第6期395-406,I0009,共12页
Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene... Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene-co-p-terphenyl piperidinium)(PPTP3Fx-DIL)AEMs with different fluorinated monomers for high performance AEMFCs.The polymerization of fluorinated monomers with other aryl monomers can effectively promote the separation of microphase in the membrane.It also has a high OH-conductivity at a low swelling.The membrane(PPTP3F4-DIL)prepared by polycondensation of 2,2,2-trifluoro-1-(p-tolyl)ethan 1-one monomer achieves a high conductivity of 168.5 mS cm-1at 80℃.At the same time,the water uptake is 40.0%and the swelling ratio is 12.1%.In addition,these membranes also have good mechanical properties and alkaline stability.After 1440 h of treatment in a NaOH(2 M)solution at 80℃,PPTP3Fx-DIL still maintains excellent tensile strength(>30.3 MPa)and elongation at break(>43.4%),and the conductivity retention of the PPTP3F1-DIL membrane is 90.3%.The PPTP3F4-DIL-based single cell exhibits a high peak power density(918.1 mW cm-2)and excellent durability(100 h)at 80℃.Therefore,these PPTP3Fx-DIL membranes have a wide range of applications in AEMFCs. 展开更多
关键词 Poly(phenanthrene-co-p-terphenyl piperidinium)AEMs Different fluorinated monomers Separation of microphase Swelling
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Wind-sand flow response law of concave surface upwind plane curve embankment under different wind directions 认领 引用 被引量：1
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作者 LI Liangying JI Shuai +2 位作者 XIN Guowei WANG Xu LI Qi 《Journal of Mountain Science》 SCIE CSCD 2025年第12期4379-4391,共13页
Understanding the characteristics of windsand flow field in the curve section of desert highway under different wind directions is helpful for reducing the wind-sand damage in the curve section.Therefore,taking the de... Understanding the characteristics of windsand flow field in the curve section of desert highway under different wind directions is helpful for reducing the wind-sand damage in the curve section.Therefore,taking the desert section of Wuma Expressway in Zhongwei city,Ningxia,China as the research background,the wind-sand flow field and sand accumulation phenomenon of concave surface plane curve embankment under different wind directions is calculated and analyzed by computational fluid dynamics(CFD)numerical simulation method.The results show that:(1)Under different wind directions,along the direction of the route,at the starting point of the route,the windward slope of the embankment is a circular arc section,which reduces the resistance of wind-sand flow and promotes the acceleration of sand particles.In the middle of the route,the low-speed area of the windward slope toe and the leeward slope toe is small;at the end of the route,the high-speed area on the shoulder side of the leeward road rises upward.(2)Under different wind directions,the smaller the angle between the wind direction and the route,the stronger the lateral transport effect on the wind-blown sand flow,and the more sand particles transported along the route direction.(3)Under different wind directions,in the concave windward horizontal curve,with the increase of the angle,the sand area on the top of the embankment shows an increasing trend.Whenα=30°,45°,60°,75°,the percentage of the sand area on the top of the embankment to the total embankment area is 0%,33.3%,64.4%,71.0%,respectively.(4)Under different wind directions,along the route direction,the sand transport efficiency of the concave surface upwind plane curve embankment shows a decreasing trend.In the case of a certain radius of the horizontal curve,the angle range between the wind direction and the concave horizontal curve route is recommended to be 30°-45°. 展开更多
关键词 Desert highway Wind-sand flow Flat curve Numerical simulation Different wind directions
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Beamforming Design for Transmissive RISs-Aided Indoor Communications Under Different Service Requirements 认领 引用
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作者 Pang Lihua Wang Yue +3 位作者 Zhang Yang Zhang Yiteng Chen Yijian Wang Anyi 《China Communications》 SCIE EI CSCD 2025年第8期58-75,共18页
As emerging services continue to be explored,indoor communications geared towards different user requirements will face severe challenges such as larger penetration losses and more critical multipath issues,leading to... As emerging services continue to be explored,indoor communications geared towards different user requirements will face severe challenges such as larger penetration losses and more critical multipath issues,leading to difficulties in achieving flexible coverage.In this paper,we introduce transmissive reconfigurable intelligent surfaces(RISs)as intelligent passive auxiliary devices into indoor scenes,replacing conventional ultra-dense small cell and relay forwarding approaches to address these issues at low deployment and operation costs.Specifically,we study the optimization design of active and passive beamforming for the transmissive RISs-aided indoor multiuser downlink communication systems.This involves considering more realistic indoor congestion modeling and near-field propagation characteristics.The goal of our optimization is to minimize the total transmit power at the access point(AP)for different user service requirements,including quality-of-service(QoS)and wireless power transfer(WPT).Due to the nonconvex nature of the optimization problem,adaptive penalty coefficients are imported to solve it alternatively with closed-form solutions for both active and passive beamforming.Simulation results demonstrate that the use of transmissive RISs is indeed an efficient way to achieve flexible coverage in indoor scenarios.Furthermore,the proposed optimization algorithm has been proven to be effective and robust in achieving energy-saving transmission. 展开更多
关键词 active and passive beamforming different user requirements indoor communications near-field transmissive reconfigurable intelligent surface(RIS)
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New three-dimensional shear strength criterion of discontinuities with different joint wall compressive strengths 认领 引用
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作者 REN Shu-lin CHEN Xi +3 位作者 HE Man-chao YIN Qian YUAN Yong TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2025年第11期4553-4573,共21页
The determination of discontinuity shear strength is an important concern in rock engineering.Previous research mainly focused on the shear behavior of discontinuities with identical joint wall compressive strengths(D... The determination of discontinuity shear strength is an important concern in rock engineering.Previous research mainly focused on the shear behavior of discontinuities with identical joint wall compressive strengths(DIJCS).However,the shear behavior of discontinuities with different joint wall compressive strengths(DDJCS)and 3D surface morphology had been rarely reported.In this study,matched mortar DDJCSs were prepared using 3D printed photosensitive resin molds.Direct shear tests were carried out under three kinds of normal stress(ranging from 0.5 to 3.0 MPa)to analyze the shear strength and contact zones of DDJCS during shearing.The results show that the contact zones of DDJCS during shearing are scattered in the steep zones facing the shear direction.It is verified that Grasselli and Develi’s directional surface roughness characterization method can be used to predict the shear-induced potential contact zones of DDJCS.When the critical apparent dip angle is equal to the peak dilation angle,the predicted contact area agrees well with the actual contact area.A 3D directional roughness parameter with clear physical meaning was introduced to characterize discontinuity surface roughness.A 3D modified joint roughness coefficient-joint wall compressive strength(JRC-JCS)criterion that can both predict the shear strength of DDJCS and DIJCS was proposed based on the newly defined roughness parameter.The proposed criterion was validated by 77 direct shear tests presented by this study and 163 direct shear tests presented by other investigators.The results show that the proposed criterion was generally reliable for the peak shear strength prediction of DDJCS and DIJCS(within 16%).It is also found that the new criterion can capture the anisotropy of the peak shear strength of DDJCS.The anisotropy of DDJCS decreases with increasing normal stress.It should be noted that the anisotropy of the shear strength of DDJCS was not investigated experimentally,and further experiments should be conducted to verify it. 展开更多
关键词 discontinuities with different joint wall compressive strengths(DDJCS) 3D printing directional roughness characterization method shear-induced potential contact zones peak shear strength JRC-JCS criterion anisotropy
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Mechanical properties and energy characteristics of single-fractured composite rock mass with different dip angles under impact load 认领 引用
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作者 XIA Zhiguo MA Chenglong +3 位作者 LUAN Lihua WU Quansen WANG Changxiang CHEN Bing 《Journal of Mountain Science》 SCIE CSCD 2025年第8期3109-3122,共14页
In rock mass and mining engineering,shock waves induced by engineering disturbances significantly affect rock mass stability.To explore the dynamic mechanical behavior and energy dissipation mechanisms of single-fract... In rock mass and mining engineering,shock waves induced by engineering disturbances significantly affect rock mass stability.To explore the dynamic mechanical behavior and energy dissipation mechanisms of single-fractured composite rock masses under impact loading,a series of tests were conducted using a split Hopkinson pressure bar(SHPB)system with a 50 mm rod diameter.Specimens containing a single inclined fracture with seven different dip angles and located in different lithological layers were tested.The results show that both peak stress and peak strain exhibit a non-monotonic trend with increasing dip angleα-first decreasing,then increasing,reaching a minimum atα=45°.This behavior is attributed to enhanced energy concentration and dissipation in the fracture zone,where shear-dominated failure leads to more effective crack propagation and stress redistribution.Moreover,the proportion of crushing energy dissipation is significantly affected by the fracture dip angle,reaching a minimum atα=45°and a maximum atα=90°,indicating a transition from shear to tensile failure modes with increasing angle.Lithology also plays a crucial role:grey sandstone specimens absorbed more energy compared to yellow sandstone,implying higher impact resistance due to differences in microstructural cohesion.The evolution of fragment fractal dimension with increasing dip angle follows an"M-shaped"trend,reflecting changes in fragmentation intensity and failure mode.Notably,yellow sandstone tends to produce higher fractal dimensions,with larger mass but smaller volume of powdered debris,indicating more intense fragmentation.This study reveals the coupling effect of fracture dip angle and lithology on dynamic mechanical response and energy evolution,providing new insights into the failure mechanisms of layered composite rock masses under impact loading. 展开更多
关键词 SHBP Composite rock mass Fractures with different dip angles Energy dissipation Fractal dimension
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All entire solutions of Fermat type difference-differential equations of one variable 认领 引用
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作者 XU Ling LUO Run-zi CAO Ting-bin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2025年第3期509-522,共14页
The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]2+[p2(z)f(z)+p3(z)f′(z)]2=p(z);or[p1(z)f(z)]2+[p2(z)f′(z)+p3(z)f(z+c)]^(... The main purpose of this paper is to try to find all entire solutions of the Fermat type difference-differential equation[p1(z)f(z+c)]2+[p2(z)f(z)+p3(z)f′(z)]2=p(z);or[p1(z)f(z)]2+[p2(z)f′(z)+p3(z)f(z+c)]2=p(z)or[p1(z)f′(z)]2+[p2(z)f(z+c)+p3(z)f(z)]2=p(z);where c is a nonzero complex number,p1;p2 and p3 are polynomials in C satisfying p1p3■0;and p is a nonzero irreducible polynomial in C. 展开更多
关键词 difference equations difference-differential equation Fermat type equation entire solutions
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Role and mechanisms of histone methylation in osteogenic/odontogenic differentiation of dental mesenchymal stem cells 认领 引用 被引量：3
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作者 Meijun Hu Zhipeng Fan 《International Journal of Oral Science》 SCIE CAS CSCD 2025年第3期341-360,共20页
Dental mesenchymal stem cells(DMSCs)are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differen... Dental mesenchymal stem cells(DMSCs)are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differentiation potential and self-renewal ability.The cellular microenvironment regulates the fate of stem cells and can be modified using various optimization techniques.These methods can influence the cellular microenvironment,activate disparate signaling pathways,and induce different biological effects.“Epigenetic regulation”refers to the process of influencing gene expression and regulating cell fate without altering DNA sequences,such as histone methylation.Histone methylation modifications regulate pivotal transcription factors governing DMSCs differentiation into osteo-/odontogenic lineages.The most important sites of histone methylation in tooth organization were found to be H3K4,H3K9,and H3K27.Histone methylation affects gene expression and regulates stem cell differentiation by maintaining a delicate balance between major trimethylation sites,generating distinct chromatin structures associated with specific downstream transcriptional states.Several crucial signaling pathways associated with osteogenic differentiation are susceptible to modulation via histone methylation modifications.A deeper understanding of the regulatory mechanisms governing histone methylation modifications in osteo-/odontogenic differentiation and immune-inflammatory responses of DMSCs will facilitate further investigation of the epigenetic regulation of histone methylation in DMSC-mediated tissue regeneration and inflammation.Here is a concise overview of the pivotal functions of epigenetic histone methylation at H3K4,H3K9,and H3K27 in the regulation of osteo-/odontogenic differentiation and renewal of DMSCs in both non-inflammatory and inflammatory microenvironments.This review summarizes the current research on these processes in the context of tissue regeneration and therapeutic interventions. 展开更多
关键词 tooth development stem cells tissue engineering influence cellular microenvironmentactivate disparate signaling pathwaysand induce different biological effec regenerative medicine cellular microenvironment dental mesenchymal stem cells dmscs
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Different Greening Schemes for Numerical Simulation Research on Summer Thermal Environment in Guangzhou Campus 认领 引用
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作者 LI Hai-yan LI Jiang-bo +3 位作者 WU Xiao-xuan PAN Wei-juan CAI Ming-fu SUN Jia-ren 《Journal of Tropical Meteorology》 SCIE CSCD 2025年第4期406-421,共16页
Reasonable greening design can effectively alleviate campus heat environment issues.This study uses the ENVI-met numerical model,along with in-situ observations and simulations,to analyze the thermal environment under... Reasonable greening design can effectively alleviate campus heat environment issues.This study uses the ENVI-met numerical model,along with in-situ observations and simulations,to analyze the thermal environment under three different greening schemes in typical areas of the Guangzhou University campus.The results indicate that the outdoor thermal environment is significantly influenced by the underlying surface materials and vegetation.The temperature of brick-paved surface is 0.9℃higher than that of natural soil surfaces under tree shade.Numerical simulations further confirm that increasing vegetation coverage effectively reduces outdoor air temperature.When the greening rate increases to 40%,the outdoor average temperature decreases by 0.7℃and relative humidity increases by approximately 4%,while wind speed remains minimal change.The cooling effect of vegetation is found to extend vertically to an altitude of 13 m.As the greening rate increases from 15%to 40%,the Mean Radiant Temperature(MRT)decreases from 50.6℃to 28.9℃,which is lower than the average ambient temperature,indicating improved thermal conditions.The Physiological Equivalent Temperature(PET)decreases from 40.2℃to 30.0℃,with the proportion of the areas classified as″very hot″reducing by 36.8%,significantly improving thermal comfort across most areas.Therefore,changing the ground material and greening landscape design can effectively alter the outdoor wind and thermal environment of the campus,thereby enhancing the thermal comfort for the campus community. 展开更多
关键词 Microclimate thermal environment ENVI-met different greening schemes
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Sexually differentiated decision-making involves faster recruitment in the early stages for the Tibetan antelopes Pantholops hodgsonii 认领 引用 被引量：1
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作者 Qin Zhu Jian Guan +6 位作者 Tianya Lei Kun Xuan Sile Guo Yumeng Zhao Changjian Fu Le Yang Zhongqiu Li 《Current Zoology》 SCIE CAS CSCD 2025年第1期124-135,共12页
Group living is widespread across diverse taxa,and the mechanisms underlying collective decision-making in contexts of variable role division are critical for understanding the dynamics of group stability.While studie... Group living is widespread across diverse taxa,and the mechanisms underlying collective decision-making in contexts of variable role division are critical for understanding the dynamics of group stability.While studies on collective behavior in small animals such as fish and insects are well-established,similar research on large wild animals remains challenging due to the limited availability of sufficient and systematic field data.Here,we aimed to explore the collective decision-making pattern and its sexual difference for the dimorphic Tibetan antelopes Pantholops hodgsonii(chiru)in Xizang Autonomous Region,China,by analyzing individual leadership distribution,as well as the joining process,considering factors such as calving stages and joining ranks.The distinct correlations of decision participants’ratio with group size and decision duration underscore the trade-off between accuracy and speed in decision-making.Male antelopes display a more democratic decision-making pattern,while females exhibit more prompt responses after calving at an early stage.This study uncovers a partially shared decision-making strategy among Tibetan antelopes,suggesting flexible self-organization in group decision processes aligned with animal life cycle progression. 展开更多
关键词 calving stage decision-making leadership sexual differences Tibetan antelopes
Enhancing Hydrothermal Performance of Dimpled Tubes:Investigating the Impact of Different Dimple Sizes and Distribution along the Tube 认领 引用
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作者 Basima Salman Khalaf Abeer H.Falih Basim Freegah 《Frontiers in Heat and Mass Transfer》 EI CAS 2025年第3期943-956,共14页
The main purpose of this research is to optimize the hydrothermal performance of a dimpled tube by augmenting the surface area for heat transmission and thermal layer cracking.To achieve that,the impact of different d... The main purpose of this research is to optimize the hydrothermal performance of a dimpled tube by augmenting the surface area for heat transmission and thermal layer cracking.To achieve that,the impact of different dimple diameters and their distribution along the dimpled tube was investigated numerically using the ANSYS Fluent 2022 R1 software by considering two models,A and B.Both models consist of three regions;the first,second,and third have dimple diameters of 3,2,&1 mm,respectively.Model A included an in-line dimple arrangement,while model B involved a staggered dimple arrangement.The finite volume method(FVM)was used in the modeling techniques to address the turbulent flow problem,which ranged in this investigation from Re of 3000 to 8000.The cooling fluid used in this investigation is water,which concentrated primarily on single-phase flow conditions.The investigation results revealed that as the Re increased,all analyzed models showcased higher.A reduction in pressure drops,thermal resistance,Nu,and overall performance standards.Crucially,compared to the traditionalmodel,both suggested models demonstrated improved heat transmission capacities.Within all the models examined,the tube with dimples in(model B)as staggered showed the greatest enhancement in the Nu,which was almost double that of the conventional type.Model A and Model B have respective average total performance criteria of 1.23 and 1.34. 展开更多
关键词 Dimpled tube different arrangements of dimple overall performance criterion computational fluid dynamics(CFD)
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