In seasonally frozen soil regions,freezing-thawing action and hydrothermal effect have strong influence on physical and mechanical behavior of shallow soil.A field experiment on the Loess Plateau in Northwest China wa...In seasonally frozen soil regions,freezing-thawing action and hydrothermal effect have strong influence on physical and mechanical behavior of shallow soil.A field experiment on the Loess Plateau in Northwest China was carried out to analyze the freezing-thawing process and hydrothermal characteristics of shallow soil considering the climate influence.The results show that the maximum seasonal freezing depth under bare ground surface in this area is from 20 cm to 50 cm.The ground temperature shows a similar changing trend with air temperature,but it has lagged behind the air temperature,and the ground temperature amplitude exponentially decreases with the increase of soil depth.The seasonally frozen soil has experienced four typical stages:unfrozen period,alternate freezing period,freezing period and alternate thawing period.The freezing-thawing process is characterized by unidirectional freezing and bidirectional thawing.The water content of shallow soil is significantly affected by air temperature,evaporation and precipitation,and the soil water content shows a"low-high-low"changing trend with the increase of depth.The soil temperature and water content interact with each other,and are often coupled.The variation trend of soil moisture with time is consistent with the change trend of the ground temperature with time in each soil layer,andthe degree of consistency is higher in the near surface soil than that in the lower layer.Also,the spatial-temporal characteristics of soil moisture and temperature is that the volumetric water content and ground temperatureof near surface soil have strong variability,and the range valueKa and coefficient of variation Cvof soil water content and ground temperaturein different seasons show a decreasing trend with the increase of depth.展开更多
A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800...A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800 mg L-1） on N2O emission from the fluvo-aquic soil subjected to a freezing-thawing cycling. N2O emission sharply decreased at the start of soil freezing, and then showed a smooth line with soil freezing. In subject to soil thawing, N2O emission increased and reached a peak at the initial thawing stage. The average N2O emissions with addition of NH4＋-N, NO3 -N and NH2-N are 119.01, 611.61 and 148. 22 ug m-2 h-1, respectively, at the concentration of 40 mg L-1; 205.28, 1 084.40 and 106.13 ug m2 h-1 at the concentration of 200 mg L-1; and 693.95, 1 820.02 and 49.74 ug m-2 h4 at the concentration of 800 mg L-1. The control is only 100.35 ug m-2 h-1. N2O emissions with addition of NH4＋-N and NO3--N increased with increasing concentration, by ranging from 17.49 to 425.67% for NH4＋-N, and from 563.38 to 1458.6% for NO3--N compared with control. There was a timelag for N2O emission to reach a steady state with an increase of concentration. In contrast, by adding NH2-N to soil, N2O emission decreased with increasing concentration. In sum, NH4＋-N or NO3--N fertilizer incorporated in soil enhanced the cumulative N2O emission from the fluvo-aquic soil relative to amide-N. This study suggested that ammonium and nitrate concentration in overwintering water should be less than 200 and 40 mg L-1 in order to reduce N2O emissions from soil, regardless of amide-N.展开更多
A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameteriza...A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.展开更多
Objective: In this study, the influence and response relationship between the seasonal freezing-thawing process of soil and the spatial factor changes in the management and utilization of water resource processes were...Objective: In this study, the influence and response relationship between the seasonal freezing-thawing process of soil and the spatial factor changes in the management and utilization of water resource processes were explored. Methods: The monitoring equipment in this study was arranged at different altitudes, gradients, and slope directions, such as the typical forest sample area in the Dayekou Basin of the Qilian Mountains. The spatial variation characteristics of the seasonal freezing-thawing process of the soil were analyzed, and a regression model was established. Results: 1) The results of this study determined that the rate of the soil’s freezing increased with the altitude in a trend of volatility. However, the rate of the thawing of the frozen soil was found to have an opposite trend. The variation degree of the freezing-thawing process increased with the altitude in a trend of volatility. The end time of the approximate soil freezing with altitude increased in a volatility trend ahead of schedule. However, the opposite was observed in the thawing rate of the frozen soil;2) The rate of the soil’s freezing under the mosses of the spruce forest at an altitude of 3028 m was found to be the lowest. However, in the sub-alpine scrub forest at an altitude of 3300 m, a maximum in the spatial ordering was observed, with an average of 1.9 cm·d-1. The thawing rate of the frozen soil in scrub-spruce forest at an altitude of 3300 m was found to be minimal. However, in the sunny slope grassland at an altitude of 2946 m, a maximum in the spatial ordering was observed, with an average of 1.5 cm·d-1. In the spatial ordering of the variation degree of the process of freezing-thawing with an average of 1.2, the scrub-grassland at an altitude of 2518 m was found to be the lowest, and the scrub-spruce forest at an altitude of 3195 m was also low;3) The soil freezing began on approximately October 20th, and the rate of soil freezing gradually became reduced. The arrival time of the frozen soil of up to 150 cm in depth in sub-alpine scrub forest was first observed at an altitude of 3028 m. However, the scrub-spruce forest at an altitude of 3100 m did not become frozen until approximately January 12th on average. Then, the thawing rate of the frozen soil increased gradually. The end time of the thawing was earliest observed in the sunny slope grassland at an altitude of 2946 m. However, the scrub-spruce forest at an altitude of 3100 m was found to be the last to thaw, and averaged approximately July 27th. The average durations of the freezing and thawing of the soil were 77 and 121 days, respectively, and the average duration of the entire process of freezing-thawing was 199 days;4) This study’s established regression models of the duration time of frozen soil’s thaw, and the rate of frozen soil’s thaw, all passed the R test of goodness of fit, F test of variance, and t test. Conclusions: The characteristics of the seasonal freezing-thawing process of the soil with the spatial changes were seasonal. However, the characteristics under the different spatial factor influences were not the same.展开更多
The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ),Calamagrostis angustifolia wet meadow(Ⅱ),dry land(Ⅲ)and paddy fie...The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ),Calamagrostis angustifolia wet meadow(Ⅱ),dry land(Ⅲ)and paddy field(Ⅳ),of Sanjiang Plain Wetland,Northeast China.Each sample was collected from three sites of one microhabitat,mixed together,filtrated with 0.45μm membrane,and tested using atomic absorption spectrometry(AAS)for iron measurement.The iron concentrations of soil solutions were investigated as well.Each soil solution was in-situ extracted by negative pressure,filtrated with 0.45μm membrane,and tested using AAS,too.The results showed that the wet precipitation of iron from snow were little to detect.The loss of iron was attributed to the interaction of water and soil surface.展开更多
一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家...一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家赫拉克利特所说的“万物流转”,又说“你不能两次踏进同一条河流,因为新的水不断地流过你的身旁”,他所表达的意思是“世界上唯一不变的就是变化”。展开更多
The construction of water conservancy projects in cold regions experiences freezing-thawing cycles,which can greatly change the engineering properties of soil and have a significant impact on the construction of proje...The construction of water conservancy projects in cold regions experiences freezing-thawing cycles,which can greatly change the engineering properties of soil and have a significant impact on the construction of projects.Lianghekou Hydropower Station(LHS),is a controlling station with the largest installed capacity among the 7 middle reach projects in the Yalong River,the secondary tributary of the Yangtze River.LHS is located in a seasonally frozen soil area.Based on the measured data of air and ground temperature in winter in the dam core wall,the freezing-thawing variation of gravelly soil and contact clay during the filling process of the core wall are compared and analyzed,then the main impact factors of the freezing-thawing variation of soils are discussed.The results show that under the influence of air temperature,soil freezes unidirectionally from ground surface downward and deepens gradually,and the thawing processes are different at the aspects of thawing direction and rate.Air temperature and physical properties of soil including soil type,moisture content and dry density affect the freezingthawing processes of soils.And the impact of engineering construction is more remarkable than natural factors.The engineering construction affects soil temperature and freezing-thawing process by controlling the initial temperature of soil,the speed and duration of the technological conversion of paving,compaction,and the length of placed duration at night.Due to the long placed duration of soil with the slow construction method,the initial temperature of soil gradually reduces,the heat transfer process inside soil is fast.Then the internal heat of soil releases,the decreasing rate of ground temperature of soil at different depths is fast and the frozen depth deepens.While due to the short placed duration of soil with the rapid construction process,the initial temperature of soil is high,high internal heat of soil is supplied every day,and the heat transfer process inside soil is slow.Then the decreasing rate of temperature of soil at different depths is slow,and the variation amplitude of frozen depth is small.This study provides useful guidance for the freezingthawing prevention during the construction process of core wall dams located at high altitude region in winter.展开更多
The corrosion behavior of Q420 steel under constant temperature and freezing-thawing conditions is investigated.The steel exhibits the highest corrosion rate at 25℃ and the lowest corrosion rate at−30℃,while the ste...The corrosion behavior of Q420 steel under constant temperature and freezing-thawing conditions is investigated.The steel exhibits the highest corrosion rate at 25℃ and the lowest corrosion rate at−30℃,while the steel that undergoes freezing-thawing cycling shows lower corrosion rate than that at 0℃.The localized corrosion is significantly affected by the temperature variations,with the samples corroded under freezing-thawing conditions showing the highest pit number density and the highest possibility of the pit initiation.The samples immersed at 0 and 25℃ show comparable pit size with higher pit depth,diameter,and volume,attributed to the higher rate of pit propagation along the vertical and horizontal directions.Galvanic corrosion results demonstrate that there are areas of activated metal under the ice,which form microcells with surrounding unaffected areas,attributed to the local ion concentration and the water crystallization.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental con...Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental concept drift,gradually alter the behavior or structure of processes,making their detection and localization a challenging task.Traditional process mining techniques frequently assume process stationarity and are limited in their ability to detect such drift,particularly from a control-flow perspective.The objective of this research is to develop an interpretable and robust framework capable of detecting and localizing incremental concept drift in event logs,with a specific emphasis on the structural evolution of control-flow semantics in processes.We propose DriftXMiner,a control-flow-aware hybrid framework that combines statistical,machine learning,and process model analysis techniques.The approach comprises three key components:(1)Cumulative Drift Scanner that tracks directional statistical deviations to detect early drift signals;(2)a Temporal Clustering and Drift-Aware Forest Ensemble(DAFE)to capture distributional and classification-level changes in process behavior;and(3)Petri net-based process model reconstruction,which enables the precise localization of structural drift using transition deviation metrics and replay fitness scores.Experimental validation on the BPI Challenge 2017 event log demonstrates that DriftXMiner effectively identifies and localizes gradual and incremental process drift over time.The framework achieves a detection accuracy of 92.5%,a localization precision of 90.3%,and an F1-score of 0.91,outperforming competitive baselines such as CUSUM+Histograms and ADWIN+Alpha Miner.Visual analyses further confirm that identified drift points align with transitions in control-flow models and behavioral cluster structures.DriftXMiner offers a novel and interpretable solution for incremental concept drift detection and localization in dynamic,process-aware systems.By integrating statistical signal accumulation,temporal behavior profiling,and structural process mining,the framework enables finegrained drift explanation and supports adaptive process intelligence in evolving environments.Its modular architecture supports extension to streaming data and real-time monitoring contexts.展开更多
This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)sum...This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)summary writing,or(3)reading comprehension.Eye-tracking data were collected during reading,measuring early(first fixation duration,first pass duration)and late(go-past time,total fixation duration)eye movements.During writing,source-text rereading was tracked via fixation counts and durations.Results showed that task type did not affect initial lexical access,as first fixation duration showed no group differences.However,both production groups exhibited significantly longer first pass durations than the reading comprehension group.Late measures revealed a gradient pattern:the continuation writing group spent significantly longer gopast time and total fixation duration than the summary writing group,which exceeded the reading comprehension group.This indicates that continuation tasks promoted deeper cognitive engagement during reading.During writing,the continuation writing group spent more time rereading the source text with higher fixation counts than the summary writing group.These findings suggest that continuation writing triggers more intensive reader-text interaction during pre-writing and enhances comprehension-production coupling through sustained attention to input during writing.This study sheds light on the cognitive mechanisms underlying the theoretical and pedagogical value of xu-argument.展开更多
The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurode...The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function.展开更多
Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD...Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.展开更多
The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer r...The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer rise earthquakes have been observed along the Sunda arc,following the estimated rupture area of the 2005 M_(W)8.6 Nias earthquakes.Here,we used kinematic waveform inversion(KIWI)to obtain the source parameters of the 14 May 2021 M_(W)6.6 event off the west coast of northern Sumatra and to define the fault plane that triggered this outer rise event.The KIWI algorithm allows two types of seismic source to be configured:the moment tensor model to describe the type of shear with six moment tensor components and the Eikonal model for the rupture of pure double-couple sources.This method was chosen for its flexibility to be applied for different sources of seismicity and also for the automated full-moment tensor solution with real-time monitoring.We used full waveform traces from 8 broadband seismic stations within 1000 km epicentral distances sourced from the Incorporated Research Institutions for Seismology(IRIS-IDA)and Geofon GFZ seismic record databases.The initial origin time and hypocenter values are obtained from the IRIS-IDA.The synthetic seismograms used in the inversion process are based on the existing regional green function database model and were accessed from the KIWI Tools Green's Function Database.The obtained scalar seismic moment value is 1.18×10^(19)N·m,equivalent to a moment magnitude M_(W)6.6.The source parameters are 140°,44°,and−99°for the strike,dip,and rake values at a centroid depth of 10.2 km,indicating that this event is a normal fault earthquake that occurred in the outer rise area.The outer rise events with normal faults typically occur at the shallow part of the plate,with nodal-plane dips predominantly in the range of 30°-60°on the weak oceanic lithosphere due to hydrothermal alteration.The stress regime around the plate subduction zone varies both temporally and spatially due to the cyclic influences of megathrust earthquakes.Tensional outer rise earthquakes tend to occur after the megathrust events.The relative timing of these events is not known due to the viscous relaxation of the down going slab and poroelastic response in the trench slope region.The occurrence of the 14 May 2021 earthquake shows the seismicity in the outer rise region in the strongly coupled Sunda arc subduction zone due to elastic bending stress within the duration of the seismic cycle.展开更多
To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt b...To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.展开更多
In this paper,we propose a novel graph signal processing convolution recurrent network(GSP CRN)for signal enhancement against high suppressive interference(HSI)in wireless communications.GSPCRN consists of the short-t...In this paper,we propose a novel graph signal processing convolution recurrent network(GSP CRN)for signal enhancement against high suppressive interference(HSI)in wireless communications.GSPCRN consists of the short-time graph signal processing(SGSP)approach and a modified convolution recurrent network.Similar to the traditional shorttime time-frequency transformation,SGSP frames the complex-valued communication signal and transforms it to the graph-domain representations,where the connection and weight flexibility of each vertex are fully taken into account.In the presence of HSI,SGSP can extract signal features from new graph-domain dimensions and empower neural networks for weak signal enhancement.Two SGSP methods,adjacency singular value decomposition and implicit graph transformation,are designed to capture relationships among the sampling points in the segmented signals.Simulation results demonstrate that our proposed GSPCRN outperforms existing classic methods in extracting weak signals from the HSI environment.When the interference-to-signal ratio exceeds 27dB,only our proposed GSPCRN can achieve the interference mitigation.展开更多
High entropy alloys(HEAs)have recently attracted significant attention due to their exceptional mechanical properties and potential applications across various fields.Friction stir welding and processing(FSW/P),as not...High entropy alloys(HEAs)have recently attracted significant attention due to their exceptional mechanical properties and potential applications across various fields.Friction stir welding and processing(FSW/P),as notable solid-state welding and processing techniques,have been proved effectiveness in enhancing microstructures and mechanical properties of HEAs.This review article summarizes the current status of FSW/P of HEAs.The welding materials and conditions used for FSW/P in HEAs are reviewed and discussed.The effects of FSW/P on the evolutions of grain structure,texture,dislocation,and secondary phase for different HEAs are highlighted.Furthermore,the influences of FSW/P on the mechanical properties of various HEAs are analyzed.Finally,potential applications,challenges,and future directions of FSW/P in HEAs are forecasted.Overall,FSW/P enable to refine grains of HEAs through dynamic recrystallization and to activate diverse deformation mechanisms of HEAs through tailoring phase structures,thereby significantly improving the strength,hardness,and ductility of both single-and dual-phase HEAs.Future progress in this field will rely on comprehensive optimization of processing parameters and alloy composition,integration of multi-scale modeling with advanced characterization for in-depth exploration of microstructural mechanisms,systematic evaluation of functional properties,and effective bridging of the gap between laboratory research and industrial application.The review aims to provide an overview of recent advancements in the FSW/P of HEAs and encourage further research in this area.展开更多
While the Ordos Basin is recognized for its substantial hydrocarbon exploration prospects,its rugged loess tableland terrain has rendered seismic exploration exceptionally challenging[1-3].Persistent obstacles such as...While the Ordos Basin is recognized for its substantial hydrocarbon exploration prospects,its rugged loess tableland terrain has rendered seismic exploration exceptionally challenging[1-3].Persistent obstacles such as complex 3D survey planning,low signal-tonoise ratio raw data,inadequate near-surface velocity modeling,and imaging inaccuracy have long hindered the advancement of seismic exploration across this region.Through a problem-solving approach rooted in geological target analysis,this research systematically investigates the behavioral patterns of nodal seismometer-based high-density seismic acquisition in loess plateau.Tailored advancements in waveform enhancement and depth velocity modelling methodologies have been engineered.Field validations confirm that the optimized workflow demonstrates marked improvements in amplitude preservation and imaging resolution,offering novel insights for future reservoir characterization endeavors.展开更多
Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening pa...Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening particles also deteriorates the processability and it is of great importance to establish accurate processing maps to guide the thermomechanical processes to enhance the formability.In this study,we performed particle swarm optimization-based back propagation artificial neural network model to predict the high temperature flow behavior of 0.25wt%Al2O3 particle-reinforced Cu alloys,and compared the accuracy with that of derived by Arrhenius-type constitutive model and back propagation artificial neural network model.To train these models,we obtained the raw data by fabricating ODS Cu alloys using the internal oxidation and reduction method,and conducting systematic hot compression tests between 400 and800℃with strain rates of 10^(-2)-10 S^(-1).At last,processing maps for ODS Cu alloys were proposed by combining processing parameters,mechanical behavior,microstructure characterization,and the modeling results achieved a coefficient of determination higher than>99%.展开更多
基金This study was funded by the National Natural Science Foundation of China(grant number 51769013)the Basic Research Innovation Group of Gansu Province(20JR5RA478).
文摘In seasonally frozen soil regions,freezing-thawing action and hydrothermal effect have strong influence on physical and mechanical behavior of shallow soil.A field experiment on the Loess Plateau in Northwest China was carried out to analyze the freezing-thawing process and hydrothermal characteristics of shallow soil considering the climate influence.The results show that the maximum seasonal freezing depth under bare ground surface in this area is from 20 cm to 50 cm.The ground temperature shows a similar changing trend with air temperature,but it has lagged behind the air temperature,and the ground temperature amplitude exponentially decreases with the increase of soil depth.The seasonally frozen soil has experienced four typical stages:unfrozen period,alternate freezing period,freezing period and alternate thawing period.The freezing-thawing process is characterized by unidirectional freezing and bidirectional thawing.The water content of shallow soil is significantly affected by air temperature,evaporation and precipitation,and the soil water content shows a"low-high-low"changing trend with the increase of depth.The soil temperature and water content interact with each other,and are often coupled.The variation trend of soil moisture with time is consistent with the change trend of the ground temperature with time in each soil layer,andthe degree of consistency is higher in the near surface soil than that in the lower layer.Also,the spatial-temporal characteristics of soil moisture and temperature is that the volumetric water content and ground temperatureof near surface soil have strong variability,and the range valueKa and coefficient of variation Cvof soil water content and ground temperaturein different seasons show a decreasing trend with the increase of depth.
基金supported by the Key Tech-nologies R&D Program of China during the 11th Five-Year Plan period (2006BAD17B02)Central Public Research Institutes Basic Funds for Research and Development (Institute of Agro-Environmental Protection,Ministry of Agriculture), China
文摘A lab-incubation experiment was conducted to investigate the effects of different forms of nitrogen application （ammonium, NH4＋-N; nitrate, NO3--N; and amide-N, NH2-N） and different concentrations （40, 200 and 800 mg L-1） on N2O emission from the fluvo-aquic soil subjected to a freezing-thawing cycling. N2O emission sharply decreased at the start of soil freezing, and then showed a smooth line with soil freezing. In subject to soil thawing, N2O emission increased and reached a peak at the initial thawing stage. The average N2O emissions with addition of NH4＋-N, NO3 -N and NH2-N are 119.01, 611.61 and 148. 22 ug m-2 h-1, respectively, at the concentration of 40 mg L-1; 205.28, 1 084.40 and 106.13 ug m2 h-1 at the concentration of 200 mg L-1; and 693.95, 1 820.02 and 49.74 ug m-2 h4 at the concentration of 800 mg L-1. The control is only 100.35 ug m-2 h-1. N2O emissions with addition of NH4＋-N and NO3--N increased with increasing concentration, by ranging from 17.49 to 425.67% for NH4＋-N, and from 563.38 to 1458.6% for NO3--N compared with control. There was a timelag for N2O emission to reach a steady state with an increase of concentration. In contrast, by adding NH2-N to soil, N2O emission decreased with increasing concentration. In sum, NH4＋-N or NO3--N fertilizer incorporated in soil enhanced the cumulative N2O emission from the fluvo-aquic soil relative to amide-N. This study suggested that ammonium and nitrate concentration in overwintering water should be less than 200 and 40 mg L-1 in order to reduce N2O emissions from soil, regardless of amide-N.
基金supported by Chinese National Science Foundation (NSFC) (No.40875050, 40575037, 40175020)National Key Basic Science Studies Developing Program of "973" (2007CB411506)
文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.
文摘Objective: In this study, the influence and response relationship between the seasonal freezing-thawing process of soil and the spatial factor changes in the management and utilization of water resource processes were explored. Methods: The monitoring equipment in this study was arranged at different altitudes, gradients, and slope directions, such as the typical forest sample area in the Dayekou Basin of the Qilian Mountains. The spatial variation characteristics of the seasonal freezing-thawing process of the soil were analyzed, and a regression model was established. Results: 1) The results of this study determined that the rate of the soil’s freezing increased with the altitude in a trend of volatility. However, the rate of the thawing of the frozen soil was found to have an opposite trend. The variation degree of the freezing-thawing process increased with the altitude in a trend of volatility. The end time of the approximate soil freezing with altitude increased in a volatility trend ahead of schedule. However, the opposite was observed in the thawing rate of the frozen soil;2) The rate of the soil’s freezing under the mosses of the spruce forest at an altitude of 3028 m was found to be the lowest. However, in the sub-alpine scrub forest at an altitude of 3300 m, a maximum in the spatial ordering was observed, with an average of 1.9 cm·d-1. The thawing rate of the frozen soil in scrub-spruce forest at an altitude of 3300 m was found to be minimal. However, in the sunny slope grassland at an altitude of 2946 m, a maximum in the spatial ordering was observed, with an average of 1.5 cm·d-1. In the spatial ordering of the variation degree of the process of freezing-thawing with an average of 1.2, the scrub-grassland at an altitude of 2518 m was found to be the lowest, and the scrub-spruce forest at an altitude of 3195 m was also low;3) The soil freezing began on approximately October 20th, and the rate of soil freezing gradually became reduced. The arrival time of the frozen soil of up to 150 cm in depth in sub-alpine scrub forest was first observed at an altitude of 3028 m. However, the scrub-spruce forest at an altitude of 3100 m did not become frozen until approximately January 12th on average. Then, the thawing rate of the frozen soil increased gradually. The end time of the thawing was earliest observed in the sunny slope grassland at an altitude of 2946 m. However, the scrub-spruce forest at an altitude of 3100 m was found to be the last to thaw, and averaged approximately July 27th. The average durations of the freezing and thawing of the soil were 77 and 121 days, respectively, and the average duration of the entire process of freezing-thawing was 199 days;4) This study’s established regression models of the duration time of frozen soil’s thaw, and the rate of frozen soil’s thaw, all passed the R test of goodness of fit, F test of variance, and t test. Conclusions: The characteristics of the seasonal freezing-thawing process of the soil with the spatial changes were seasonal. However, the characteristics under the different spatial factor influences were not the same.
文摘The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ),Calamagrostis angustifolia wet meadow(Ⅱ),dry land(Ⅲ)and paddy field(Ⅳ),of Sanjiang Plain Wetland,Northeast China.Each sample was collected from three sites of one microhabitat,mixed together,filtrated with 0.45μm membrane,and tested using atomic absorption spectrometry(AAS)for iron measurement.The iron concentrations of soil solutions were investigated as well.Each soil solution was in-situ extracted by negative pressure,filtrated with 0.45μm membrane,and tested using AAS,too.The results showed that the wet precipitation of iron from snow were little to detect.The loss of iron was attributed to the interaction of water and soil surface.
文摘一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家赫拉克利特所说的“万物流转”,又说“你不能两次踏进同一条河流,因为新的水不断地流过你的身旁”,他所表达的意思是“世界上唯一不变的就是变化”。
基金supported by National Natural Science Funds of China(Nos.41771066,41825015)the Science and Technology Project of Yalong River Hydropower Development Company(No.LHKA-G201906)。
文摘The construction of water conservancy projects in cold regions experiences freezing-thawing cycles,which can greatly change the engineering properties of soil and have a significant impact on the construction of projects.Lianghekou Hydropower Station(LHS),is a controlling station with the largest installed capacity among the 7 middle reach projects in the Yalong River,the secondary tributary of the Yangtze River.LHS is located in a seasonally frozen soil area.Based on the measured data of air and ground temperature in winter in the dam core wall,the freezing-thawing variation of gravelly soil and contact clay during the filling process of the core wall are compared and analyzed,then the main impact factors of the freezing-thawing variation of soils are discussed.The results show that under the influence of air temperature,soil freezes unidirectionally from ground surface downward and deepens gradually,and the thawing processes are different at the aspects of thawing direction and rate.Air temperature and physical properties of soil including soil type,moisture content and dry density affect the freezingthawing processes of soils.And the impact of engineering construction is more remarkable than natural factors.The engineering construction affects soil temperature and freezing-thawing process by controlling the initial temperature of soil,the speed and duration of the technological conversion of paving,compaction,and the length of placed duration at night.Due to the long placed duration of soil with the slow construction method,the initial temperature of soil gradually reduces,the heat transfer process inside soil is fast.Then the internal heat of soil releases,the decreasing rate of ground temperature of soil at different depths is fast and the frozen depth deepens.While due to the short placed duration of soil with the rapid construction process,the initial temperature of soil is high,high internal heat of soil is supplied every day,and the heat transfer process inside soil is slow.Then the decreasing rate of temperature of soil at different depths is slow,and the variation amplitude of frozen depth is small.This study provides useful guidance for the freezingthawing prevention during the construction process of core wall dams located at high altitude region in winter.
基金National Key Research and Development Program of China(No.2023YFB3710300)the Key R&D Program of Shandong Province(No.2023CXGC010406)+2 种基金the National Natural Science Foundation of China(No.52371080)the Natural Science Foundation of Shandong Province(ZR2024JQ028)the Project of Taishan Scholars(tsqn202312107).
文摘The corrosion behavior of Q420 steel under constant temperature and freezing-thawing conditions is investigated.The steel exhibits the highest corrosion rate at 25℃ and the lowest corrosion rate at−30℃,while the steel that undergoes freezing-thawing cycling shows lower corrosion rate than that at 0℃.The localized corrosion is significantly affected by the temperature variations,with the samples corroded under freezing-thawing conditions showing the highest pit number density and the highest possibility of the pit initiation.The samples immersed at 0 and 25℃ show comparable pit size with higher pit depth,diameter,and volume,attributed to the higher rate of pit propagation along the vertical and horizontal directions.Galvanic corrosion results demonstrate that there are areas of activated metal under the ice,which form microcells with surrounding unaffected areas,attributed to the local ion concentration and the water crystallization.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
文摘Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental concept drift,gradually alter the behavior or structure of processes,making their detection and localization a challenging task.Traditional process mining techniques frequently assume process stationarity and are limited in their ability to detect such drift,particularly from a control-flow perspective.The objective of this research is to develop an interpretable and robust framework capable of detecting and localizing incremental concept drift in event logs,with a specific emphasis on the structural evolution of control-flow semantics in processes.We propose DriftXMiner,a control-flow-aware hybrid framework that combines statistical,machine learning,and process model analysis techniques.The approach comprises three key components:(1)Cumulative Drift Scanner that tracks directional statistical deviations to detect early drift signals;(2)a Temporal Clustering and Drift-Aware Forest Ensemble(DAFE)to capture distributional and classification-level changes in process behavior;and(3)Petri net-based process model reconstruction,which enables the precise localization of structural drift using transition deviation metrics and replay fitness scores.Experimental validation on the BPI Challenge 2017 event log demonstrates that DriftXMiner effectively identifies and localizes gradual and incremental process drift over time.The framework achieves a detection accuracy of 92.5%,a localization precision of 90.3%,and an F1-score of 0.91,outperforming competitive baselines such as CUSUM+Histograms and ADWIN+Alpha Miner.Visual analyses further confirm that identified drift points align with transitions in control-flow models and behavioral cluster structures.DriftXMiner offers a novel and interpretable solution for incremental concept drift detection and localization in dynamic,process-aware systems.By integrating statistical signal accumulation,temporal behavior profiling,and structural process mining,the framework enables finegrained drift explanation and supports adaptive process intelligence in evolving environments.Its modular architecture supports extension to streaming data and real-time monitoring contexts.
文摘This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)summary writing,or(3)reading comprehension.Eye-tracking data were collected during reading,measuring early(first fixation duration,first pass duration)and late(go-past time,total fixation duration)eye movements.During writing,source-text rereading was tracked via fixation counts and durations.Results showed that task type did not affect initial lexical access,as first fixation duration showed no group differences.However,both production groups exhibited significantly longer first pass durations than the reading comprehension group.Late measures revealed a gradient pattern:the continuation writing group spent significantly longer gopast time and total fixation duration than the summary writing group,which exceeded the reading comprehension group.This indicates that continuation tasks promoted deeper cognitive engagement during reading.During writing,the continuation writing group spent more time rereading the source text with higher fixation counts than the summary writing group.These findings suggest that continuation writing triggers more intensive reader-text interaction during pre-writing and enhances comprehension-production coupling through sustained attention to input during writing.This study sheds light on the cognitive mechanisms underlying the theoretical and pedagogical value of xu-argument.
文摘The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function.
基金financially supported by the Science and Technology Project of PetroChina Company Limited,China(No.2022DJ6314)the National Natural Science Foundation of China(No.52173056)。
文摘Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.
基金supported by the National Natural Science Foundation of China(Grant No.42130312)。
文摘The complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones.The outer rise earthquakes have been observed along the Sunda arc,following the estimated rupture area of the 2005 M_(W)8.6 Nias earthquakes.Here,we used kinematic waveform inversion(KIWI)to obtain the source parameters of the 14 May 2021 M_(W)6.6 event off the west coast of northern Sumatra and to define the fault plane that triggered this outer rise event.The KIWI algorithm allows two types of seismic source to be configured:the moment tensor model to describe the type of shear with six moment tensor components and the Eikonal model for the rupture of pure double-couple sources.This method was chosen for its flexibility to be applied for different sources of seismicity and also for the automated full-moment tensor solution with real-time monitoring.We used full waveform traces from 8 broadband seismic stations within 1000 km epicentral distances sourced from the Incorporated Research Institutions for Seismology(IRIS-IDA)and Geofon GFZ seismic record databases.The initial origin time and hypocenter values are obtained from the IRIS-IDA.The synthetic seismograms used in the inversion process are based on the existing regional green function database model and were accessed from the KIWI Tools Green's Function Database.The obtained scalar seismic moment value is 1.18×10^(19)N·m,equivalent to a moment magnitude M_(W)6.6.The source parameters are 140°,44°,and−99°for the strike,dip,and rake values at a centroid depth of 10.2 km,indicating that this event is a normal fault earthquake that occurred in the outer rise area.The outer rise events with normal faults typically occur at the shallow part of the plate,with nodal-plane dips predominantly in the range of 30°-60°on the weak oceanic lithosphere due to hydrothermal alteration.The stress regime around the plate subduction zone varies both temporally and spatially due to the cyclic influences of megathrust earthquakes.Tensional outer rise earthquakes tend to occur after the megathrust events.The relative timing of these events is not known due to the viscous relaxation of the down going slab and poroelastic response in the trench slope region.The occurrence of the 14 May 2021 earthquake shows the seismicity in the outer rise region in the strongly coupled Sunda arc subduction zone due to elastic bending stress within the duration of the seismic cycle.
基金Funded by the National Natural Science Foundation of China(No.52278446)。
文摘To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.
基金supported by he National Social Science Found of China(2022-SKJJ-B-112).
文摘In this paper,we propose a novel graph signal processing convolution recurrent network(GSP CRN)for signal enhancement against high suppressive interference(HSI)in wireless communications.GSPCRN consists of the short-time graph signal processing(SGSP)approach and a modified convolution recurrent network.Similar to the traditional shorttime time-frequency transformation,SGSP frames the complex-valued communication signal and transforms it to the graph-domain representations,where the connection and weight flexibility of each vertex are fully taken into account.In the presence of HSI,SGSP can extract signal features from new graph-domain dimensions and empower neural networks for weak signal enhancement.Two SGSP methods,adjacency singular value decomposition and implicit graph transformation,are designed to capture relationships among the sampling points in the segmented signals.Simulation results demonstrate that our proposed GSPCRN outperforms existing classic methods in extracting weak signals from the HSI environment.When the interference-to-signal ratio exceeds 27dB,only our proposed GSPCRN can achieve the interference mitigation.
基金supported by National Natural Science Foundation of China(Grant No.52171032)Hebei Natural Science Foundation(Grant No.E2023501002)Fundamental Research Funds for the Central Universities(Grant No.2024GFYD003)。
文摘High entropy alloys(HEAs)have recently attracted significant attention due to their exceptional mechanical properties and potential applications across various fields.Friction stir welding and processing(FSW/P),as notable solid-state welding and processing techniques,have been proved effectiveness in enhancing microstructures and mechanical properties of HEAs.This review article summarizes the current status of FSW/P of HEAs.The welding materials and conditions used for FSW/P in HEAs are reviewed and discussed.The effects of FSW/P on the evolutions of grain structure,texture,dislocation,and secondary phase for different HEAs are highlighted.Furthermore,the influences of FSW/P on the mechanical properties of various HEAs are analyzed.Finally,potential applications,challenges,and future directions of FSW/P in HEAs are forecasted.Overall,FSW/P enable to refine grains of HEAs through dynamic recrystallization and to activate diverse deformation mechanisms of HEAs through tailoring phase structures,thereby significantly improving the strength,hardness,and ductility of both single-and dual-phase HEAs.Future progress in this field will rely on comprehensive optimization of processing parameters and alloy composition,integration of multi-scale modeling with advanced characterization for in-depth exploration of microstructural mechanisms,systematic evaluation of functional properties,and effective bridging of the gap between laboratory research and industrial application.The review aims to provide an overview of recent advancements in the FSW/P of HEAs and encourage further research in this area.
文摘While the Ordos Basin is recognized for its substantial hydrocarbon exploration prospects,its rugged loess tableland terrain has rendered seismic exploration exceptionally challenging[1-3].Persistent obstacles such as complex 3D survey planning,low signal-tonoise ratio raw data,inadequate near-surface velocity modeling,and imaging inaccuracy have long hindered the advancement of seismic exploration across this region.Through a problem-solving approach rooted in geological target analysis,this research systematically investigates the behavioral patterns of nodal seismometer-based high-density seismic acquisition in loess plateau.Tailored advancements in waveform enhancement and depth velocity modelling methodologies have been engineered.Field validations confirm that the optimized workflow demonstrates marked improvements in amplitude preservation and imaging resolution,offering novel insights for future reservoir characterization endeavors.
基金financial support of the National Natural Science Foundation of China(No.52371103)the Fundamental Research Funds for the Central Universities,China(No.2242023K40028)+1 种基金the Open Research Fund of Jiangsu Key Laboratory for Advanced Metallic Materials,China(No.AMM2023B01).financial support of the Research Fund of Shihezi Key Laboratory of AluminumBased Advanced Materials,China(No.2023PT02)financial support of Guangdong Province Science and Technology Major Project,China(No.2021B0301030005)。
文摘Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening particles also deteriorates the processability and it is of great importance to establish accurate processing maps to guide the thermomechanical processes to enhance the formability.In this study,we performed particle swarm optimization-based back propagation artificial neural network model to predict the high temperature flow behavior of 0.25wt%Al2O3 particle-reinforced Cu alloys,and compared the accuracy with that of derived by Arrhenius-type constitutive model and back propagation artificial neural network model.To train these models,we obtained the raw data by fabricating ODS Cu alloys using the internal oxidation and reduction method,and conducting systematic hot compression tests between 400 and800℃with strain rates of 10^(-2)-10 S^(-1).At last,processing maps for ODS Cu alloys were proposed by combining processing parameters,mechanical behavior,microstructure characterization,and the modeling results achieved a coefficient of determination higher than>99%.
