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Improved Convolutional Neural Network for Traffic Scene Segmentation

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2691-2708页

作者： Fuliang Xu yong Luo Chuanlong Sun Hong zhao College of Mechanical and Electrical Engineering Qingdao UniversityQingdao266071China

In actual traffic scenarios,precise recognition of traffic participants,such as vehicles and pedestrians,is crucial for intelligent transportation.This study proposes an improved algorithm built on Mask-RCNN to enhance the ability of autonomous driving systems to recognize traffic participants.The algorithmincorporates long and shortterm memory networks and the fused attention module(GSAM,GCT,and Spatial Attention Module)to enhance the algorithm’s capability to process both global and local information.Additionally,to increase the network’s initial operation stability,the original network activation function was replaced with Gaussian error linear unit.Experiments were conducted using the publicly available Cityscapes dataset.Comparing the test results,it was observed that the revised algorithmoutperformed the original algorithmin terms of AP_(50),AP_(75),and othermetrics by 8.7%and 9.6%for target detection and 12.5%and 13.3%for segmentation.

关键词： Instance segmentation deep learning convolutional neural network attention mechanism

Review of roll-to-roll fabrication techniques for colloidal quantum dot solar cells

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Journal of Electronic Science and Technology 2023年第1期21卷 1-25页

作者： Yin-Fen Ma You-Mei Wang Jia Wen Ao Li Xiao-Liang Li Mei Leng yong-biao zhao Zheng-Hong Lu Key Laboratory of Yunnan Provincial Higher Education Institutions for Optoelectronics Device Engineering Department of PhysicsSchool of Physics and AstronomyYunnan UniversityKunming650091China International Joint Research Center for Optoelectronic and Engineering Research Yunnan UniversityKunming650091China Department of Materials Science and Engineering University of TorontoTorontoM5S 3E4Canada

Colloidal quantum dots(CQDs)are of great interest to photovoltaic(PV)technologies as they possess the benefits of solution-processability,size-tunability,and roll-to-roll manufacturability,as well as unique capabilities to harvest near-infrared(NIR)radiation.During the last decade,lab-scale CQD solar cells have achieved rapid improvement in the power conversion efficiency(PCE)from~1%to 18%,which will potentially exceed 20%in the next few years and approach the performance of other PV technologies,such as perovskite solar cells and organic solar cells.In the meanwhile,CQD solar cells exhibit long lifetimes either under shelf storage or continuous operation,making them highly attractive to industry.However,in order to meet the industrial requirements,mass production techniques are necessary to scale up the fabrication of those lab devices into large-area PV modules,such as roll-to-toll coating.This paper reviews the recent developments of large-area CQD solar cells with a focus on various fabrication methods and their principles.It covers the progress of typical large-area coating techniques,including spray coating,blade coating,dip coating,and slot-die coating.It also discusses next steps and new strategies to accomplish the ultimate goal of the low-cost large-area fabrication of CQD solar cells and emphasizes how artificial intelligence or machine learning could facilitate the developments of CQD solar cell research.

关键词： Colloidal quantum dots(CQDs) Large-area fabrication Roll-to-roll Solar cells

A continuous and long-term in-situ stress measuring method based on fiber optic. Part I: Theory of inverse differential strain analysis

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Petroleum Science 2024年第2期21卷 1171-1189页

作者： Kun-Peng Zhang Mian Chen Chang-Jun zhao Su Wang yong-Dong Fan State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China MOE Key Laboratory of Petroleum Engineering in China University of Petroleum Beijing102249China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing100871China

A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment pressure.Moreover, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.

关键词： In-situ stress Fiber optic Orthotropic elastic Differential evolution ABAQUS

Dynamic interwell connectivity analysis of multi-layer waterflooding reservoirs based on an improved graph neural network

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Petroleum Science 2024年第2期21卷 1062-1080页

作者： zhao-Qin Huang zhao-Xu Wang Hui-Fang Hu Shi-Ming Zhang yong-Xing Liang Qi Guo Jun Yao School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Exploration and Development Research Institute Shengli OilfieldSINOPECDongying257015ShandongChina

The analysis of interwell connectivity plays an important role in the formulation of oilfield development plans and the description of residual oil distribution. In fact, sandstone reservoirs in China's onshore oilfields generally have the characteristics of thin and many layers, so multi-layer joint production is usually adopted. It remains a challenge to ensure the accuracy of splitting and dynamic connectivity in each layer of the injection-production wells with limited field data. The three-dimensional well pattern of multi-layer reservoir and the relationship between injection-production wells can be equivalent to a directional heterogeneous graph. In this paper, an improved graph neural network is proposed to construct an interacting process mimics the real interwell flow regularity. In detail, this method is used to split injection and production rates by combining permeability, porosity and effective thickness, and to invert the dynamic connectivity in each layer of the injection-production wells by attention mechanism.Based on the material balance and physical information, the overall connectivity from the injection wells,through the water injection layers to the production layers and the output of final production wells is established. Meanwhile, the change of well pattern caused by perforation, plugging and switching of wells at different times is achieved by updated graph structure in spatial and temporal ways. The effectiveness of the method is verified by a combination of reservoir numerical simulation examples and field example. The method corresponds to the actual situation of the reservoir, has wide adaptability and low cost, has good practical value, and provides a reference for adjusting the injection-production relationship of the reservoir and the development of the remaining oil.

关键词： Graph neural network Dynamic interwell connectivity Production-injection splitting Attention mechanism Multi-layer reservoir

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中国县收缩的时空演化特征及其影响因素

世界地理研究 2024年第1期33卷 119-133页

作者：赵彪中国社会科学院中国边疆研究所北京100101

县是中国行政区划体系中最悠久最稳定的一级,然而,在中国从传统社会向现代社会快速转型的过程中,县的数量却在大规模收缩,研究县收缩对于探索城市化进程中县的出路问题具有重要意义。本研究采用最邻近点指数和收缩效应系数等方法,对改... 详细信息

县是中国行政区划体系中最悠久最稳定的一级,然而,在中国从传统社会向现代社会快速转型的过程中,县的数量却在大规模收缩,研究县收缩对于探索城市化进程中县的出路问题具有重要意义。本研究采用最邻近点指数和收缩效应系数等方法,对改革开放以来中国县收缩问题进行了研究,结果表明:中国的县收缩过程与改革开放的历史进程密切相关,存在明显的阶段性特征。在收缩特征上,县收缩向沿海沿江地区、副省级以上城市集聚的特征显著,与东部地区和副省级以上城市相比,中西部普通地级市县收缩的难度明显较大,部分区域存在着大量县集中分布的现象。在收缩路径上,县收缩经历了撤县设地级市、县改县级市和县改市辖区三次浪潮,由沿海向内陆渐次推进,由于各地区所处发展阶段的差异,出现了不同收缩类型并存的复杂状况;在收缩效应方面,县收缩对经济社会发展存在着显著的正面影响效应。在影响因素方面,县收缩是外部政策因素和内部自身因素共同作用的结果,一方面,县收缩受区域发展战略转变、城市发展政策变化、市管县体制推行、县改市审批暂停等政策性因素的影响较大;另一方面,县收缩受高级别建制、经济发展水平、空间区位特征、不合理调整回调等各县自身因素的影响也十分明显。

关键词：行政区划县收缩撤县设市撤县设区县

Fabrication of CuFe_(2)O_(4)/Bi_(12)O_(17)Cl_(2) photocatalyst with intrinsic p-n junction for highly efficient bisphenol A degradation

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Journal of Environmental Sciences 2024年第2期136卷 547-558页

作者： yong Wang Cheng Liu Haoyun Hu Qiujun Lu Haiyan Wang Chenxi zhao Fuyou Du Ningli Tang Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials College of Chemistry and BioengineeringGuilin University of TechnologyGuilin 541004China College of Biological and Environmental Engineering Changsha UniversityChangsha 410022China

The construction and application of novel highly efficient photocatalysts have been the focus in the field of environmental pollutant removal.In this work,a novel CuFe_(2)O_(4)/Bi_(12)O_(17)Cl_(2)photocatalysts were synthesized by simple hydrothermal and chemical precipitation method.The fabricated CuFe_(2)O_(4)/Bi_(12)O_(17)Cl_(2)composite exhibited much higher photocatalytic activity than pristine CuFe_(2)O_(4)and Bi_(12)O_(17)Cl_(2)in the removal of bisphenol A(BPA)under visible-light illumination,which ascribed to the intrinsic p-n junction of CuFe_(2)O_(4)and Bi_(12)O_(17)Cl_(2).The photocatalytic degradation rate of BPA on CuFe_(2)O_(4)/Bi_(12)O_(17)Cl_(2)with an optimized CuFe_(2)O_(4)content(1.0 wt.%)reached 93.0%within 30 min.The capture experiments of active species confirmed that the hydroxyl radicals(·OH)and superoxide radicals(·O_(2)^(-))played crucial roles in photocatalytic BPA degradation process.Furthermore,the possible degradation mechanism and pathways of BPA was proposed according to the detected intermediates in photocatalytic reaction process.

关键词： Bi_(12)O_(17)Cl_(2) CuFe_(2)O_(4) Heterojunction Bisphenol A Photocatalytic degradation

Microstructural characterization and mechanical properties of(TiC+TiB)/TA15 composites prepared by an in-situ synthesis method

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China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong Zhang Jiao-jiao Cheng Jia-qi Xie Shi-bing Liu Kun Shi Jun zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ synthesis

Beyond microbial carbon use efficiency

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National Science Review 2024年第4期11卷 33-35页

作者： Ke-Qing Xiao Chao Liang Zimeng Wang Jingjing Peng Yao zhao Ming Zhang Mingyu zhao Shuiqing Chen yong-Guan Zhu Caroline L.Peacock State Key Lab of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences University of Chinese Academy of Sciences Institute of Applied Ecology Chinese Academy of Sciences Department of Environmental Science and Engineering Fudan University College of Resources and Environmental Sciences China Agricultural University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences State Key Laboratory of Agricultural Microbiology College of Resources and Environment Huazhong Agricultural University Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences School of Earth and Environment University of Leeds

Microbial carbon use efficiency (CUE)is defined as the proportion of microbial biomass growth C versus substrate C uptake, and thus provides a useful measure of microbially driven accumulation and loss of soil organic carbon (SOC)[1]. In a recent study published in Nature [2],the authors used a data-driven machinelearning approach to conclude that CUE promotes global SOC storage based on a positive correlation between CUE and SOC content and that, based on sensitivity analysis, CUE is at least four times as important as six other evaluated factors,namely plant C inputs, C input allocation, non-microbial C transfer, substrate decomposability, environmental modifications and vertical transport.

关键词： SOIL-CARBON ORGANIC-MATTER

Magnetic resonance imaging techniques for lithium-ion batteries:Principles and applications

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Magnetic Resonance Letters 2024年第2期4卷 22-39页

作者： Hongxin Lin Yanting Jin Mingming Tao Yingao Zhou Peizhao Shan Danhui zhao yong Yang State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials and Department of ChemistryCollege of Chemistry and Chemical EngineeringTan Kah Kee Innovation Laboratory(IKKEM)Xiamen UniversityXiamen361005China School of Energy Xiamen UniversityXiamen361005China

Operando monitoring of internal and local electrochemical processes within lithium-ion batteries(LIBs)is crucial,necessitating a range of non-invasive,real-time imaging characterization techniques including nuclear magnetic resonance(NMR)techniques.This review provides a comprehensive overview of the recent applications and advancements of non-invasive magnetic resonance imaging(MRI)techniques in LIBs.It initially introduces the principles and hardware of MRI,followed by a detailed summary and comparison of MRI techniques used for characterizing liquid/solid electrolytes,electrodes and commercial batteries.This encompasses the determination of electrolytes'transport properties,acquisition of ion distribution profile,and diagnosis of battery defects.By focusing on experimental parameters and optimization strategies,our goal is to explore MRI methods suitable to a variety of research subjects,aiming to enhance imaging quality across diverse scenarios and offer critical physical/chemical insights into the ongoing operation processes of LIBs.

关键词： Lithium-ion batteries Magnetic resonance imaging(MRI) Electrolytes Electrodes Commercial batteries