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Tomato Growth Height Prediction Method by Phenotypic Feature Extraction Using Multi-modal Data
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作者 GONG Yu WANG Ling +3 位作者 ZHAO Rongqiang YOU Haibo ZHOU Mo LIU Jie 《智慧农业(中英文)》 2025年第1期97-110,共14页
[Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-base... [Objective]Accurate prediction of tomato growth height is crucial for optimizing production environments in smart farming.However,current prediction methods predominantly rely on empirical,mechanistic,or learning-based models that utilize either images data or environmental data.These methods fail to fully leverage multi-modal data to capture the diverse aspects of plant growth comprehensively.[Methods]To address this limitation,a two-stage phenotypic feature extraction(PFE)model based on deep learning algorithm of recurrent neural network(RNN)and long short-term memory(LSTM)was developed.The model integrated environment and plant information to provide a holistic understanding of the growth process,emploied phenotypic and temporal feature extractors to comprehensively capture both types of features,enabled a deeper understanding of the interaction between tomato plants and their environment,ultimately leading to highly accurate predictions of growth height.[Results and Discussions]The experimental results showed the model's ef‐fectiveness:When predicting the next two days based on the past five days,the PFE-based RNN and LSTM models achieved mean absolute percentage error(MAPE)of 0.81%and 0.40%,respectively,which were significantly lower than the 8.00%MAPE of the large language model(LLM)and 6.72%MAPE of the Transformer-based model.In longer-term predictions,the 10-day prediction for 4 days ahead and the 30-day prediction for 12 days ahead,the PFE-RNN model continued to outperform the other two baseline models,with MAPE of 2.66%and 14.05%,respectively.[Conclusions]The proposed method,which leverages phenotypic-temporal collaboration,shows great potential for intelligent,data-driven management of tomato cultivation,making it a promising approach for enhancing the efficiency and precision of smart tomato planting management. 展开更多
关键词 tomato growth prediction deep learning phenotypic feature extraction multi-modal data recurrent neural net‐work long short-term memory large language model
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Multi-dimension and multi-modal rolling mill vibration prediction model based on multi-level network fusion
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作者 CHEN Shu-zong LIU Yun-xiao +3 位作者 WANG Yun-long QIAN Cheng HUA Chang-chun SUN Jie 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第9期3329-3348,共20页
Mill vibration is a common problem in rolling production,which directly affects the thickness accuracy of the strip and may even lead to strip fracture accidents in serious cases.The existing vibration prediction mode... Mill vibration is a common problem in rolling production,which directly affects the thickness accuracy of the strip and may even lead to strip fracture accidents in serious cases.The existing vibration prediction models do not consider the features contained in the data,resulting in limited improvement of model accuracy.To address these challenges,this paper proposes a multi-dimensional multi-modal cold rolling vibration time series prediction model(MDMMVPM)based on the deep fusion of multi-level networks.In the model,the long-term and short-term modal features of multi-dimensional data are considered,and the appropriate prediction algorithms are selected for different data features.Based on the established prediction model,the effects of tension and rolling force on mill vibration are analyzed.Taking the 5th stand of a cold mill in a steel mill as the research object,the innovative model is applied to predict the mill vibration for the first time.The experimental results show that the correlation coefficient(R^(2))of the model proposed in this paper is 92.5%,and the root-mean-square error(RMSE)is 0.0011,which significantly improves the modeling accuracy compared with the existing models.The proposed model is also suitable for the hot rolling process,which provides a new method for the prediction of strip rolling vibration. 展开更多
关键词 rolling mill vibration multi-dimension data multi-modal data convolutional neural network time series prediction
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Research on Multi-modal In-Vehicle Intelligent Personal Assistant Design
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作者 WANG Jia-rou TANG Cheng-xin SHUAI Liang-ying 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第4期136-146,共11页
Intelligent personal assistants play a pivotal role in in-vehicle systems,significantly enhancing life efficiency,driving safety,and decision-making support.In this study,the multi-modal design elements of intelligent... Intelligent personal assistants play a pivotal role in in-vehicle systems,significantly enhancing life efficiency,driving safety,and decision-making support.In this study,the multi-modal design elements of intelligent personal assistants within the context of visual,auditory,and somatosensory interactions with drivers were discussed.Their impact on the driver’s psychological state through various modes such as visual imagery,voice interaction,and gesture interaction were explored.The study also introduced innovative designs for in-vehicle intelligent personal assistants,incorporating design principles such as driver-centricity,prioritizing passenger safety,and utilizing timely feedback as a criterion.Additionally,the study employed design methods like driver behavior research and driving situation analysis to enhance the emotional connection between drivers and their vehicles,ultimately improving driver satisfaction and trust. 展开更多
关键词 Intelligent personal assistants multi-modal design User psychology In-vehicle interaction Voice interaction Emotional design
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Tailoring the pore structure of hard carbon for enhanced sodium-ion battery anodes
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作者 SONG Ning-Jing MA Can-liang +3 位作者 GUO Nan-nan ZHAO Yun LI Wan-xi LI Bo-qiong 《新型炭材料(中英文)》 北大核心 2025年第2期377-391,共15页
Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiv... Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials. 展开更多
关键词 pore structure regulation Closed pore Corn cob Hard carbon anode material Sodium-ion batteries
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Changing the pore structure and surface chemistry of hard carbon by coating it with a soft carbon to boost high-rate sodium storage
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作者 ZHONG Qin MO Ying +9 位作者 ZHOU Wang ZHENG Biao WU Jian-fang LIU Guo-ku Mohd Zieauddin Kufian Zurina Osman XU Xiong-wen GAO Peng YANG Le-zhi LIU Ji-lei 《新型炭材料(中英文)》 北大核心 2025年第3期651-665,共15页
Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy wi... Changes to the microstructure of a hard carbon(HC)and its solid electrolyte interface(SEI)can be effective in improving the electrode kinetics.However,achieving fast charging using a simple and inexpensive strategy without sacrificing its initial Coulombic efficiency remains a challenge in sodium ion batteries.A simple liquid-phase coating approach has been used to generate a pitch-derived soft carbon layer on the HC surface,and its effect on the porosity of HC and SEI chemistry has been studied.A variety of structural characterizations show a soft carbon coating can increase the defect and ultra-micropore contents.The increase in ultra-micropore comes from both the soft carbon coatings and the larger pores within the HC that are partially filled by pitch,which provides more Na+storage sites.In-situ FTIR/EIS and ex-situ XPS showed that the soft carbon coating induced the formation of thinner SEI that is richer in NaF from the electrolyte,which stabilized the interface and promoted the charge transfer process.As a result,the anode produced fastcharging(329.8 mAh g^(−1)at 30 mA g^(−1)and 198.6 mAh g^(−1)at 300 mA g^(−1))and had a better cycling performance(a high capacity retention of 81.4%after 100 cycles at 150 mA g^(−1)).This work reveals the critical role of coating layer in changing the pore structure,SEI chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced fast charging capability. 展开更多
关键词 Hard carbon Pitch-derived carbon coating Sodium-ion batteries pore structure Surface chemistry
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Modifying the pore structure of biomass-derived porous carbon for use in energy storage systems
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作者 XIE Bin ZHAO Xin-ya +5 位作者 MA Zheng-dong ZHANG Yi-jian DONG Jia-rong WANG Yan BAI Qiu-hong SHEN Ye-hua 《新型炭材料(中英文)》 北大核心 2025年第4期870-888,共19页
The development of sustainable electrode materials for energy storage systems has become very important and porous carbons derived from biomass have become an important candidate because of their tunable pore structur... The development of sustainable electrode materials for energy storage systems has become very important and porous carbons derived from biomass have become an important candidate because of their tunable pore structure,environmental friendliness,and cost-effectiveness.Recent advances in controlling the pore structure of these carbons and its relationship between to is energy storage performance are discussed,emphasizing the critical role of a balanced distribution of micropores,mesopores and macropores in determining electrochemical behavior.Particular attention is given to how the intrinsic components of biomass precursors(lignin,cellulose,and hemicellulose)influence pore formation during carbonization.Carbonization and activation strategies to precisely control the pore structure are introduced.Finally,key challenges in the industrial production of these carbons are outlined,and future research directions are proposed.These include the establishment of a database of biomass intrinsic structures and machine learning-assisted pore structure engineering,aimed at providing guidance for the design of high-performance carbon materials for next-generation energy storage devices. 展开更多
关键词 Energy storage systems Porous carbon Biomass precursors pore structure Machine learning-assisted
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Pore structure variation characteristics of a Chinese local mudstone before and after the first cycle of wetting and drying
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作者 ZHANG Qing-song LIU Zhi-bin +3 位作者 TANG Ya-sen DENG Yong-feng LUO Ting-yi MENG Fan-xing 《Journal of Central South University》 2025年第2期582-596,共15页
As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD ... As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles. 展开更多
关键词 MUDSTONE wetting and drying cycle X-ray micro-computed tomography pore structure pore morphology
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Face stability analysis of longitudinally inclined shield tunnel considering the effect of tensile strength cut-off and pore water pressure
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作者 HUANG Fu WANG Yong-tao +1 位作者 ZHANG Min YANG Zi-han 《Journal of Central South University》 2025年第3期1080-1098,共19页
Because of actual requirement,shield machine always excavates with an inclined angle in longitudinal direction.Since many previous studies mainly focus on the face stability of the horizontal shield tunnel,the effects... Because of actual requirement,shield machine always excavates with an inclined angle in longitudinal direction.Since many previous studies mainly focus on the face stability of the horizontal shield tunnel,the effects of tensile strength cut-off and pore water pressure on the face stability of the longitudinally inclined shield tunnel are not well investigated.A failure mechanism of a longitudinally inclined shield tunnel face is constructed based on the spatial discretization technique and the tensile strength cut-off criterion is introduced to modify the constructed failure mechanism.The pore water pressure is introduced as an external force into the equation of virtual work and the objective function of the chamber pressure of the shield machine is obtained.Moreover,the critical chamber pressure of the longitudinally inclined shield tunnel is computed by optimal calculation.Parametric analysis indicates that both tensile strength cut-off and pore water pressure have a significant impact on the chamber pressure and the range of the collapse block.Finally,the theoretical results are compared with the numerical results calculated by FLAC3D software which proves that the proposed approach is effective. 展开更多
关键词 longitudinally inclined tunnel pore water pressure tensile strength cut-off spatial discretization technique limit analysis
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Elitism-based immune genetic algorithm and its application to optimization of complex multi-modal functions 被引量:4
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作者 谭冠政 周代明 +1 位作者 江斌 DIOUBATE Mamady I 《Journal of Central South University of Technology》 EI 2008年第6期845-852,共8页
A novel immune genetic algorithm with the elitist selection and elitist crossover was proposed, which is called the immune genetic algorithm with the elitism (IGAE). In IGAE, the new methods for computing antibody s... A novel immune genetic algorithm with the elitist selection and elitist crossover was proposed, which is called the immune genetic algorithm with the elitism (IGAE). In IGAE, the new methods for computing antibody similarity, expected reproduction probability, and clonal selection probability were given. IGAE has three features. The first is that the similarities of two antibodies in structure and quality are all defined in the form of percentage, which helps to describe the similarity of two antibodies more accurately and to reduce the computational burden effectively. The second is that with the elitist selection and elitist crossover strategy IGAE is able to find the globally optimal solution of a given problem. The third is that the formula of expected reproduction probability of antibody can be adjusted through a parameter r, which helps to balance the population diversity and the convergence speed of IGAE so that IGAE can find the globally optimal solution of a given problem more rapidly. Two different complex multi-modal functions were selected to test the validity of IGAE. The experimental results show that IGAE can find the globally maximum/minimum values of the two functions rapidly. The experimental results also confirm that IGAE is of better performance in convergence speed, solution variation behavior, and computational efficiency compared with the canonical genetic algorithm with the elitism and the immune genetic algorithm with the information entropy and elitism. 展开更多
关键词 immune genetic algorithm multi-modal function optimization evolutionary computation elitist selection elitist crossover
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Multi-modality liver image registration based on multilevel B-splines free-form deformation and L-BFGS optimal algorithm 被引量:1
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作者 宋红 李佳佳 +1 位作者 王树良 马婧婷 《Journal of Central South University》 SCIE EI CAS 2014年第1期287-292,共6页
A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography(CT) and magnetic resonance(MR) images of a liver.This hierarchical framework consisted of an affine transformation and a B-sp... A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography(CT) and magnetic resonance(MR) images of a liver.This hierarchical framework consisted of an affine transformation and a B-splines free-form deformation(FFD).The affine transformation performed a rough registration targeting the mismatch between the CT and MR images.The B-splines FFD transformation performed a finer registration by correcting local motion deformation.In the registration algorithm,the normalized mutual information(NMI) was used as similarity measure,and the limited memory Broyden-Fletcher- Goldfarb-Shannon(L-BFGS) optimization method was applied for optimization process.The algorithm was applied to the fully automated registration of liver CT and MR images in three subjects.The results demonstrate that the proposed method not only significantly improves the registration accuracy but also reduces the running time,which is effective and efficient for nonrigid registration. 展开更多
关键词 multi-modal image registration affine transformation B-splines free-form deformation (FFD) L-BFGS
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A survey of multi-modal learning theory
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作者 HUANG Yu HUANG Longbo 《中山大学学报(自然科学版)(中英文)》 CAS CSCD 北大核心 2023年第5期38-49,共12页
Deep multi-modal learning,a rapidly growing field with a wide range of practical applications,aims to effectively utilize and integrate information from multiple sources,known as modalities.Despite its impressive empi... Deep multi-modal learning,a rapidly growing field with a wide range of practical applications,aims to effectively utilize and integrate information from multiple sources,known as modalities.Despite its impressive empirical performance,the theoretical foundations of deep multi-modal learning have yet to be fully explored.In this paper,we will undertake a comprehensive survey of recent developments in multi-modal learning theories,focusing on the fundamental properties that govern this field.Our goal is to provide a thorough collection of current theoretical tools for analyzing multi-modal learning,to clarify their implications for practitioners,and to suggest future directions for the establishment of a solid theoretical foundation for deep multi-modal learning. 展开更多
关键词 multi-modal learning machine learning theory OPTIMIZATION GENERALIZATION
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Test method of laser paint removal based on multi-modal feature fusion
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作者 HUANG Hai-peng HAO Ben-tian +2 位作者 YE De-jun GAO Hao LI Liang 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第10期3385-3398,共14页
Laser cleaning is a highly nonlinear physical process for solving poor single-modal(e.g., acoustic or vision)detection performance and low inter-information utilization. In this study, a multi-modal feature fusion net... Laser cleaning is a highly nonlinear physical process for solving poor single-modal(e.g., acoustic or vision)detection performance and low inter-information utilization. In this study, a multi-modal feature fusion network model was constructed based on a laser paint removal experiment. The alignment of heterogeneous data under different modals was solved by combining the piecewise aggregate approximation and gramian angular field. Moreover, the attention mechanism was introduced to optimize the dual-path network and dense connection network, enabling the sampling characteristics to be extracted and integrated. Consequently, the multi-modal discriminant detection of laser paint removal was realized. According to the experimental results, the verification accuracy of the constructed model on the experimental dataset was 99.17%, which is 5.77% higher than the optimal single-modal detection results of the laser paint removal. The feature extraction network was optimized by the attention mechanism, and the model accuracy was increased by 3.3%. Results verify the improved classification performance of the constructed multi-modal feature fusion model in detecting laser paint removal, the effective integration of acoustic data and visual image data, and the accurate detection of laser paint removal. 展开更多
关键词 laser cleaning multi-modal fusion image processing deep learning
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Adaptive Bayesian inversion of pore water pressures based on artificial neural network : An earth dam case study
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作者 AN Lu CARVAJAL Claudio +4 位作者 DIAS Daniel PEYRAS Laurent JENCK Orianne BREUL Pierre ZHANG Ting-ting 《Journal of Central South University》 CSCD 2024年第11期3930-3947,共18页
Most earth-dam failures are mainly due to seepage,and an accurate assessment of the permeability coefficient provides an indication to avoid a disaster.Parametric uncertainties are encountered in the seepage analysis,... Most earth-dam failures are mainly due to seepage,and an accurate assessment of the permeability coefficient provides an indication to avoid a disaster.Parametric uncertainties are encountered in the seepage analysis,and may be reduced by an inverse procedure that calibrates the simulation results to observations on the real system being simulated.This work proposes an adaptive Bayesian inversion method solved using artificial neural network(ANN)based Markov Chain Monte Carlo simulation.The optimized surrogate model achieves a coefficient of determination at 0.98 by ANN with 247 samples,whereby the computational workload can be greatly reduced.It is also significant to balance the accuracy and efficiency of the ANN model by adaptively updating the sample database.The enrichment samples are obtained from the posterior distribution after iteration,which allows a more accurate and rapid manner to the target posterior.The method was then applied to the hydraulic analysis of an earth dam.After calibrating the global permeability coefficient of the earth dam with the pore water pressure at the downstream unsaturated location,it was validated by the pore water pressure monitoring values at the upstream saturated location.In addition,the uncertainty in the permeability coefficient was reduced,from 0.5 to 0.05.It is shown that the provision of adequate prior information is valuable for improving the efficiency of the Bayesian inversion. 展开更多
关键词 earth dam permeability coefficient pore water pressure monitoring data bayesian inversion artificial neural network
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四川盆地寒武系筇竹寺组新类型页岩气形成机理与勘探突破 被引量:5
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作者 郭彤楼 邓虎成 +2 位作者 赵爽 魏力民 何建华 《石油勘探与开发》 北大核心 2025年第1期57-69,共13页
基于四川盆地寒武系筇竹寺组页岩岩心、测井、地震和生产等资料,采用矿物扫描、有机与无机地球化学分析、突破压力及三轴力学测试等方法,开展筇竹寺组储层基本地质特征研究,分析筇竹寺组页岩气富集高产条件、页岩气形成机理和富集模式... 基于四川盆地寒武系筇竹寺组页岩岩心、测井、地震和生产等资料,采用矿物扫描、有机与无机地球化学分析、突破压力及三轴力学测试等方法,开展筇竹寺组储层基本地质特征研究,分析筇竹寺组页岩气富集高产条件、页岩气形成机理和富集模式。研究表明:①深水富有机质和浅水低有机质两类粉砂质页岩都具有很好的含气性;②页岩脆性矿物组成具有长石、石英含量相当的特征;③页岩孔隙以无机质孔为主,有机质孔含量低,孔隙发育受长英质矿物与总有机碳含量(TOC)共同控制;④页岩有机质类型为Ⅰ型,成烃生物为藻类和疑源类,成熟度高,生烃潜力高;⑤深水相、浅水相页岩气分别具有原地和混合成气的特点。⑥筇竹寺组页岩气富集基本规律是“TOC控藏、无机质孔控富”,富集模式为以ZY2井为代表的富有机质页岩“三高一超”(高TOC、高长英质矿物含量、高无机质孔、地层超压)原地富集模式和以JS103井为代表的低有机质页岩“两高一中一低”(高长英质、高地层压力、中无机质孔、低TOC)原地+输导层富集模式,是有别于志留系龙马溪组的新类型页岩气。研究成果丰富了深层—超深层页岩气形成机理,部署的多口探井实现页岩气勘探重大突破。 展开更多
关键词 四川盆地 寒武系 筇竹寺组 页岩气 无机质孔 长英质 富集模式
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基于改进型YOLOv5算法的IN718镍基合金激光熔覆孔隙高精度检测及其控制方法 被引量:1
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作者 盛杰 王勇 +6 位作者 徐天翊 林相奇 孟宪凯 周建忠 陈峰 李果 黄舒 《中国表面工程》 北大核心 2025年第3期139-151,共13页
为了提升激光熔覆损伤修复件中孔隙的检测精度,以调整激光熔覆工艺参数,从而减少熔覆层气孔、开裂等缺陷,提升激光熔覆层质量,开展IN718镍基合金不同工艺参数下的激光熔覆试验,并开发一种改进型SP-YOLOv5孔隙检测算法。在输入层与卷积... 为了提升激光熔覆损伤修复件中孔隙的检测精度,以调整激光熔覆工艺参数,从而减少熔覆层气孔、开裂等缺陷,提升激光熔覆层质量,开展IN718镍基合金不同工艺参数下的激光熔覆试验,并开发一种改进型SP-YOLOv5孔隙检测算法。在输入层与卷积层之间增加Coordatt注意力机制模块,从而增强特征图的空间位置信息权重;改写YOLOv5网络结构,以增强网络模型对孔隙类小目标的检测能力;采用Soft-NMS代替原有NMS(非极大值抑制)进行检测结果后处理,进一步降低网络漏检率;将SP-YOLOv5算法孔隙检测结果与YOLOv5、Faster RCNN、RCNN以及ImageJ软件分析结果进行对比,得出SP-YOLOv5算法模型比其他算法模型的精度最高提升了10.57%;在此基础上,通过对激光熔覆熔池温度、熔池面积及熔覆层横截面孔隙率、熔宽、熔高、熔深等的测量,基于Stacking算法建立激光熔覆工艺参数与孔隙率的回归预测模型,并采用目标优化算法获得了较优激光熔覆工艺参数组合(激光功率1330 W、扫描速度460 mm/min、送粉率13 g/min),对熔覆件进行孔隙参数测量,结果显示,在这些优化参数下,Stacking模型预测的孔隙率与实际测量值的一致性达到97.5%,验证了优化方法的有效性,研究结果可为激光熔覆层孔隙缺陷的有效控制提供理论依据。 展开更多
关键词 激光熔覆 孔隙 计算机视觉 深度学习 目标 优化
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新型高分子表面增强剂对混凝土耐久性的影响研究 被引量:1
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作者 朱燕 余湘娟 +2 位作者 陈佳佳 梅华 江升 《混凝土》 北大核心 2025年第1期120-124,共5页
混凝土表面强度不足及开裂是导致海堤结构耐久性降低的重要因素。采用自主研制的丙烯酸酯共聚乳液为主要原材料的新型高分子表面增强剂,将其涂抹在混凝土表面进行抗氯离子渗透、抗碳化以及抗硫酸盐侵蚀试验,基于水胶比和养护时间等因素... 混凝土表面强度不足及开裂是导致海堤结构耐久性降低的重要因素。采用自主研制的丙烯酸酯共聚乳液为主要原材料的新型高分子表面增强剂,将其涂抹在混凝土表面进行抗氯离子渗透、抗碳化以及抗硫酸盐侵蚀试验,基于水胶比和养护时间等因素评估了新型高分子表面增强剂的效果。利用X衍射试验和压汞试验,从微观角度探究新型高分子表面增强剂对混凝土表面强度和耐久性的影响机制。试验结果表明:对比涂抹新型高分子表面增强剂的混凝土与标准组,前者显著优于后者,其抗氯离子渗透能力提高约49%~59%,抗碳化能力提高约35%~40%,耐腐蚀系数提高约3%~5%;增加养护龄期亦可增强混凝土结构的耐久性能。新型高分子表面增强剂可渗入到混凝土内部9mm处,能有效减少混凝土结构中50nm以上的孔隙数量,改善混凝土孔径分布,提高混凝土表面强度及耐久性。 展开更多
关键词 丙烯酸酯共聚乳液 表面增强剂 混凝土 孔隙结构 耐久性
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基于沉积物孔隙水电动导排的氮磷污染沉积物修复技术 被引量:1
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作者 黎睿 汤显强 +3 位作者 胡艳平 卢士强 顾鋆鋆 孙远军 《工程科学与技术》 北大核心 2025年第1期234-243,共10页
孔隙水是沉积物和上覆水之间物质交换的重要媒介,污染物可以通过孔隙水对流、扩散等方式向上覆水中迁移,加剧上覆水体的污染。采用自制电动导排孔隙水装置,设置5组对照实验,模拟了导排沉积物孔隙水对氮磷污染沉积物的修复,分析了泥–水... 孔隙水是沉积物和上覆水之间物质交换的重要媒介,污染物可以通过孔隙水对流、扩散等方式向上覆水中迁移,加剧上覆水体的污染。采用自制电动导排孔隙水装置,设置5组对照实验,模拟了导排沉积物孔隙水对氮磷污染沉积物的修复,分析了泥–水界面氮磷释放通量,探讨了不同实验条件对沉积物内源释放与微生物多样性的影响。结果表明:导排孔隙水可以显著抑制泥–水界面氮磷释放,但是氮磷的响应存在差异。通电导排孔隙水后泥–水界面总氮(TN)释放通量总体呈逐步下降趋势,变化范围为–15.698~79.903 mg/(m^(2)·d),实验进行14 d即可使TN释放通量降低为最大释放通量的10%以内。与对照组相比,仅导排孔隙水可以使泥–水界面氮释放通量减低76.72%,通电后界面释放通量最终降幅可达95.53%以上。泥–水界面总磷(TP)释放通量在实验进行28 d内呈波动变化,其范围为–3.558~4.279 mg/(m^(2)·d),当实验时间超过70 d以后,除对照组以外,泥–水界面磷释放通量均为负值,最终沉积物从磷的“源”转为“汇”。实验结束后,沉积物中pH值、有机质含量(LOI)没有发生显著变化。导排孔隙水后沉积物中TP降低约1.06%~5.02%。TN含量减少主要发生在阳极,相对于初始状态减少了2.65%~13.63%。电动导排孔隙水对沉积物中微生物α多样性影响较小,在电场作用下沉积物中微生物的Chao1指数、ACE指数略有降低,但在统计学上无显著差异。沉积物中微生物群落组成相似,在门水平上,均以变形菌门(13.41%~24.40%)、拟杆菌门(12.77%~29.71%)和绿弯菌门(5.01%~18.64%)为主。冗余分析表明,对微生物群落结构影响较大的因素为沉积物pH值、含水率,其次为沉积物LOI和电导率,沉积物中总磷含量的影响最小。研究表明,通过电动导排孔隙水修复氮磷污染沉积物是一种具有应用前景的技术选择。 展开更多
关键词 孔隙水 沉积物 电动修复 释放通量 微生物多样性
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兰州地区堆填黄土微观孔隙结构特征 被引量:1
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作者 王之君 马彦杰 +1 位作者 张座雄 刘兴荣 《科学技术与工程》 北大核心 2025年第7期2703-2711,共9页
兰州地区开展平山造地工程产生了大量黄土堆填场,因其压实度低,缺乏必要防护,导致黄土洞穴、滑坡等地质灾害广泛发育,具有较大安全隐患。通过扫描电镜和Image J软件对不同含水率原状堆填黄土的孔隙微观结构进行定量研究,结合分形理论,... 兰州地区开展平山造地工程产生了大量黄土堆填场,因其压实度低,缺乏必要防护,导致黄土洞穴、滑坡等地质灾害广泛发育,具有较大安全隐患。通过扫描电镜和Image J软件对不同含水率原状堆填黄土的孔隙微观结构进行定量研究,结合分形理论,获取了不同含水率下堆填黄土的孔隙类型、数量、面积、分维数变化规律,并初步分析了孔隙结构与黄土湿陷、洞穴发育的动态关系。结果表明:堆填黄土随含水率增大,大、中架空孔隙数量、面积占比逐渐减小,而小架空孔隙数量占比虽有所下降,但面积占比呈增大趋势,大、中架空孔隙坍塌是其产生湿陷变形的主要原因;堆填黄土的孔隙分维数与含水率呈线性负相关关系,与湿陷性呈正相关关系,原状堆填黄土平均孔隙分维数为1.251;基于黄土堆填场洞穴发育特点,提出应从修建排水沟渠、加固洞穴、边坡防护等3方面进行防护处理。研究成果可为兰州堆填黄土区工程建设及地质灾害防治研究提供理论支撑。 展开更多
关键词 堆填黄土 孔隙结构 扫描电镜 黄土湿陷 分形理论
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深层灰岩孔隙发育与保持机理--以四川盆地中部上二叠统长兴组为例 被引量:3
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作者 文龙 罗冰 +6 位作者 张本健 陈骁 李文正 刘一锋 胡安平 张玺华 沈安江 《石油勘探与开发》 北大核心 2025年第2期292-305,共14页
近年来四川盆地蓬深10、合深9、潼深17和正阳1等井钻探证实深层上二叠统长兴组发育一套孔隙型礁滩复合体灰岩储层,突破了深层碳酸盐岩大油气田主要分布于孔隙型白云岩储层和岩溶缝洞型灰岩储层的传统认识。基于岩心和薄片观察、储层地... 近年来四川盆地蓬深10、合深9、潼深17和正阳1等井钻探证实深层上二叠统长兴组发育一套孔隙型礁滩复合体灰岩储层,突破了深层碳酸盐岩大油气田主要分布于孔隙型白云岩储层和岩溶缝洞型灰岩储层的传统认识。基于岩心和薄片观察、储层地球化学特征分析、井震联合的储层识别和追踪,开展深层礁滩灰岩孔隙形成机理研究,取得4个方面认识:①深层长兴组孔隙型礁滩复合体灰岩储集空间以粒间孔、格架孔、生物体腔孔、铸模孔和溶孔为主,形成于沉积和早表生环境;②断续分布的多孔礁滩复合体被相对致密的泥晶灰岩包裹,在复合体持续增温条件下导致局部异常高压的形成;③长兴组储层的底板为上二叠统吴家坪组互层的致密泥岩和灰岩,顶板为下三叠统飞仙关组一段致密泥晶灰岩夹泥岩,在致密顶底板的夹持下,导致长兴组区域异常高压的形成;异常高压(超压封存箱)是沉积和早表生环境形成的孔隙在深层得以保持的关键;④在顶底板和礁滩复合体识别基础上,通过井震联合预测有利礁滩灰岩储层分布面积达10.3×10^(4) km^(2)。上述认识奠定了深层孔隙型灰岩储层发育的理论基础,拓展了四川盆地深层灰岩储层勘探新领域。 展开更多
关键词 深层 灰岩 孔隙型礁滩灰岩储层 孔隙形成与保持 异常高压 长兴组 四川盆地
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纹层状页岩微观储层特征研究--以鄂尔多斯盆地西缘乌拉力克组为例
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作者 黄正良 曹斌风 +7 位作者 刘洋 罗晓容 闫伟 马占荣 程明 俞雨溪 于洲 王璐 《沉积学报》 北大核心 2025年第4期1251-1263,共13页
【目的】对鄂尔多斯盆地西缘中奥陶统乌拉力克组乌三段纹层状页岩的微观储层特征进行研究,深化认识纹层状页岩储层的有效性。【方法】通过岩性物理分离,综合X射线衍射全岩矿物,扫描电镜和矿物扫描,有机地球化学,二氧化碳、氮气吸附及压... 【目的】对鄂尔多斯盆地西缘中奥陶统乌拉力克组乌三段纹层状页岩的微观储层特征进行研究,深化认识纹层状页岩储层的有效性。【方法】通过岩性物理分离,综合X射线衍射全岩矿物,扫描电镜和矿物扫描,有机地球化学,二氧化碳、氮气吸附及压汞测试等技术方法,对比分析纹层状页岩不同组构之间矿物学、有机地球化学及孔隙结构等特征的差异性。【结果】乌三段纹层状页岩由灰岩纹层、凝灰岩纹层及富硅质层频繁互层形成,灰岩纹层、凝灰岩纹层密度介于60~180条/m,有机碳含量远低于富硅质层。纹层状页岩孔缝并存,其中富硅质层主要发育黏土矿物有关的粒间孔、粒内孔,有机孔发育很局限;灰岩纹层主要发育方解石、白云石粒内溶孔;凝灰岩纹层中主要发育黄铁矿晶间孔、黏土矿物粒间和粒内孔及白云石粒内溶孔。灰岩纹层、凝灰岩纹层中碳酸盐矿物溶孔的形成与毗邻富硅质层中有机质演化产生的酸性流体溶蚀相关。沿着这些纹层边界近水平裂缝发育丰富,裂缝密度介于63~130条/m,裂缝宽度介于0.2~4.9 mm。灰岩纹层、凝灰岩纹层的微孔发育程度较富硅质层低,但大孔发育程度高。灰岩纹层中大孔的孔体积是毗邻富硅质层的2.5~4.3倍,大孔对总孔体积的贡献率约是毗邻富硅质层的1.9~2.1倍;凝灰岩纹层中大孔的孔体积是毗邻富硅质层的1.5~2.3倍。【结论】在纹层状页岩中,富硅质层中有机质生成油气,沿孔缝发生微运移,优先运移至相邻灰岩纹层、凝灰岩纹层中。灰岩纹层和凝灰岩纹层大孔较多,游离气贡献多。乌拉力克组纹层状页岩游离气占比大,与灰岩纹层和凝灰岩纹层发育丰富密切相关。 展开更多
关键词 鄂尔多斯盆地 乌拉力克组 页岩气 纹层状页岩 孔隙类型 孔隙结构
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