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基于注意力机制的卷积神经网络机械钻速预测方法

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科学技术与工程 2024年第21期24卷 8910-8916页

作者：李博志杨明合许楷蔡旭龙张俊油气钻采工程湖北省重点实验室武汉430100 中国石化西北油田分公司石油工程技术研究院乌鲁木齐834000

传统机器学习方法在进行机械钻速(rate of penetration,ROP)预测时,受复杂特征提取和人为认知局限性的影响,难以满足现场预测精度要求。基于此,提出一种特征提取和回归预测相结合的机械钻速预测方法。首先,采用箱型图和独热编码对钻井... 详细信息

传统机器学习方法在进行机械钻速(rate of penetration,ROP)预测时,受复杂特征提取和人为认知局限性的影响,难以满足现场预测精度要求。基于此,提出一种特征提取和回归预测相结合的机械钻速预测方法。首先,采用箱型图和独热编码对钻井实测数据进行预处理,清除异常数据并将离散特征连续化。其次,应用卷积神经网络(convolutional neural network,CNN)挖掘数据特征,并在网络中引入通道注意力机制(squeeze-and-excitation network,SENet),实现对CNN特征通道重要性程度的合理分配,建立SE-CNN机械钻速预测模型。最后,将SE-CNN模型与CNN模型进行对比分析,结果表明:SE-CNN模型的拟合优度提高了2.1%,平均绝对误差和均方根误差分别降低了1.1%和1.5%。SE-CNN模型具有更高的预测精度,可以用于现场机械钻速预测,为钻井提速提供科学参考。

关键词：机械钻速钻速预测卷积神经网络注意力机制

不同刈割强度对晋北赖草草地生态系统CO_(2)交换的影响

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草地学报 2024年第10期32卷 3159-3166页

作者：杨鹤明王海南王常慧董宽虎刁华杰张晓琳山西农业大学草业学院山西太谷030801 山西右玉黄土高原草地生态系统国家定位观测研究站山西右玉037200 草地生态保护与乡土草种质创新山西省重点实验室山西太谷030801

刈割是草地的主要利用方式,合理的刈割强度对维持草地生态系统碳平衡具有重要意义。本研究以山西省右玉县赖草(Leymus secalinus)草地生态系统为研究对象,动态监测2021年生长季不刈割、轻度刈割、中度刈割和重度刈割对草地生态系统净碳... 详细信息

刈割是草地的主要利用方式,合理的刈割强度对维持草地生态系统碳平衡具有重要意义。本研究以山西省右玉县赖草(Leymus secalinus)草地生态系统为研究对象,动态监测2021年生长季不刈割、轻度刈割、中度刈割和重度刈割对草地生态系统净碳交换(Net ecosystem carbon exchange,NEE)、生态系统呼吸(Ecosystem respiration,ER)和生态系统总初级生产力(Gross ecosystem productivity,GEP)的影响,探究草地生态系统CO_(2)交换对不同刈割强度的响应。实验结果显示,刈割显著影响GEP,主要是由于GEP在中度刈割处理下较不刈割和重度刈割分别提高了21.4%和21.5%,NEE在中度刈割处理下较轻度刈割和重度刈割分别显著降低了54.4%和53.6%,但刈割对ER影响不显著。在不同刈割强度下,土壤温度和土壤无机氮含量是影响生态系统CO_(2)交换的重要因子。本研究结果表明中度刈割可以促进碳吸收而重度刈割会导致生态系统由碳汇转变为碳源,因此中度刈割为晋北赖草草地最适刈割强度。

关键词：生态系统呼吸生态系统总初级生产力赖草草地刈割生态系统净碳交换土壤理化性质

Molecular Dynamics Study of Effects of Si-Doping Upon Structure and Mechanical Properties of Carbon Nanotube

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Communications in Theoretical Physics 2006年第4期45卷 741-744页

作者： SONG Hai-yang SUN he-ming ZHANG Guo-Xiang Department of Physics Beijing Institute of Technology Beijing 100081 China

In this paper, a Si-doped single-walled carbon nanotube （SWCNT）（7,7） and several perfect armchair SWCNTs are investigated using the classical molecular dynamics simulations method. The inter-atomic short-range interaction is represented by empirical Tersoff bond order potential. The computational results show that the axial Young＇s modulus of the perfect SWCNTs are in the range of 1.099 ± 0.005 TPa, which is in good agreement with the existing experimental results. From our simulation, the Si-doping decreases the Young＇s modulus of SWCNT, and with the increased strain levels, the effect of Si-doped layer in enhancing the local stress level increases. The Young＇s modulus of armchair SWCNTs are weakly affected by tube radius.

关键词： molecular dynamics simulation carbon nanotubes Young's modulus Si-doping

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水肥添加对草田轮作系统土壤呼吸速率的影响

草地学报 2024年第2期32卷 562-569页

作者：巩泽琳额尔德木图苏小港成蓉蓉杨鹤明张晓琳翟鹏辉山西农业大学草业学院山西太谷030801 草地生态保护与乡土草种质创新山西省重点实验室山西太谷030801

土壤呼吸是生态系统碳排放最重要的途径,其微小变化将对陆地生态系统碳循环产生深远的影响。为探究不同管理方式对草田轮作系统土壤碳排放的影响,本研究开展水肥添加控制试验,动态监测紫花苜蓿(Medicago sativa L.)-冬小麦(Triticum aes... 详细信息

土壤呼吸是生态系统碳排放最重要的途径,其微小变化将对陆地生态系统碳循环产生深远的影响。为探究不同管理方式对草田轮作系统土壤碳排放的影响,本研究开展水肥添加控制试验,动态监测紫花苜蓿(Medicago sativa L.)-冬小麦(Triticum aestivum L.)草田轮作系统中冬小麦阶段的土壤呼吸速率、土壤微生物生物量碳/氮含量、土壤温度和土壤含水量等指标。结果显示水分添加使土壤呼吸速率提高28.5%(P<0.05),但肥料添加对其影响不显著。水分添加使土壤含水量提高24.7%,但使土壤温度降低9.7%;肥料添加使土壤温度降低11.0%,使0~10 cm, 10~20 cm土层土壤微生物生物量氮含量提高336%,131%。本研究说明水肥添加通过影响土壤温度、土壤含水量等土壤质量指标,影响植物根系生长发育和微生物活性,最终影响草田轮作系统土壤碳排放。

关键词：紫花苜蓿-冬小麦微生物生物量碳/氮含量土壤呼吸速率水肥添加

Vortex identification based on the Liutex method and its effect on fish passage upstream

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Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen Rui-guo yang Xiao-tao Shi ming-ming Wang Shi-hua he Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

A Simple-Prepared and Multi-Reusable Adhesive Based on Epoxy Vitrimer

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Chinese Journal of Polymer Science 2024年第10期42卷 1589-1594,I0015页

作者： Yu-Ting Wang Huan Liang Yen Wei Jian-Long Wang Xiang-ming he yang yang Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing100084China The Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing100084China

Adhesives play an important role in modern society's production and daily *** robust and sustainable adhesives remains a great *** we report a sustainable epoxy-vitrimer adhesive with high adhesive strength(about 10 MPa)and reusability(82%strength after 3 times).This adhesive can be fabricated from commercially available products through a straightforward hot-pressing method without the need of *** adhesive process is also simple,requiring only 30 min at 180℃.In addition,the vitrimer adhesive has the advantages of both erasability for reuse and excellent water *** work provides a facile strategy to fabricate high-strength adhesive that ensures reusability,recyclability,low cost of raw materials,and simple processing ***,it expands the range of potential applications for epoxy vitrimers.

关键词： Epoxy Vitrimer Adhesive Reusable Sustainable

A novel method for simulating nuclear explosion with chemical explosion to form an approximate plane wave: Field test and numerical simulation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2137-2153页

作者： Wei ming Xiaojie yang Yadong Mao Xiang Wang Manchao he Zhigang Tao College of Civil and Architecture Engineering North China University of Science and TechnologyTangshan063210China State Key Laboratory for Tunnel Engineering China University of Mining and Technology-BeijingBeijing100083China School of Mechanics and Civil Engineering China University of Mining and Technology-BeijingBeijing100083China

A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection *** the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new *** paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole ***,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was *** plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the *** to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole *** time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear *** comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion.

关键词： Approximate plane wave Multi-hole simultaneous blasting Chemical explosion Nuclear explosion Pressure sensor inclusion

Selective nano-buckling improves the performance of graphene logic transistors

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National Science Review 2024年第2期11卷 95-96页

作者： Tong yang ming yang Department of Applied Physics The Hong Kong Polytechnic University Research Centre for Nanoscience and Nanotechnology The Hong Kong Polytechnic University

The massive integration of silicon-based transistors into modern electronic devices greatly increases power consumption and heat generation/dissipation[1]. In this concern, transistors based on atomically-thin graphene that exhibit high electric and thermoelectric conductivities with negligible contact resistance,

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Meta-path reasoning of knowledge graph for commonsense question answering

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Frontiers of Computer Science 2024年第1期18卷 49-59页

作者： Miao ZHANG Tingting he ming DONG National Engineering Research Center for E-Learning Central China Normal UniversityWuhan 430079China Hubei Provincial Key Laboratory of Artificial Intelligence and Smart Learning Central China Normal UniversityWuhan 430079China National Language Resources Monitoring&Research Center for Network Media Central China Normal UniversityWuhan 430079China School of Computer Central China Normal UniversityWuhan 430079China

Commonsense question answering(CQA)requires understanding and reasoning over QA context and related commonsense knowledge,such as a structured Knowledge Graph(KG).Existing studies combine language models and graph neural networks to model ***,traditional knowledge graph are mostly concept-based,ignoring direct path evidence necessary for accurate *** this paper,we propose MRGNN(Meta-path Reasoning Graph Neural Network),a novel model that comprehensively captures sequential semantic information from concepts and *** MRGNN,meta-paths are introduced as direct inference evidence and an original graph neural network is adopted to aggregate features from both concepts and paths *** conduct sufficient experiments on the CommonsenceQA and OpenBookQA datasets,showing the effectiveness of ***,we conduct further ablation experiments and explain the reasoning behavior through the case study.

关键词： question answering knowledge graph graph neural network meta-path reasoning