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YOLOv5ST:A Lightweight and Fast Scene Text Detector

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Computers, Materials & Continua 2024年第4期79卷 909-926页

作者： Yiwei Liu Yingnan Zhao Yi Chen zheng Hu Min xia School of Computer and Science Nanjing University of Information Science and TechnologyNanjing210044China School of Automation Nanjing University of Information Science and TechnologyNanjing210044China

Scene text detection is an important task in computer *** this paper,we present YOLOv5 Scene Text(YOLOv5ST),an optimized architecture based on YOLOv5 v6.0 tailored for fast scene text *** primary goal is to enhance inference speed without sacrificing significant detection accuracy,thereby enabling robust performance on resource-constrained devices like drones,closed-circuit television cameras,and other embedded *** achieve this,we propose key modifications to the network architecture to lighten the original backbone and improve feature aggregation,including replacing standard convolution with depth-wise convolution,adopting the C2 sequence module in place of C3,employing Spatial Pyramid Pooling Global(SPPG)instead of Spatial Pyramid Pooling Fast(SPPF)and integrating Bi-directional Feature Pyramid Network(BiFPN)into the *** results demonstrate a remarkable 26%improvement in inference speed compared to the baseline,with only marginal reductions of 1.6%and 4.2%in mean average precision(mAP)at the intersection over union(IoU)thresholds of 0.5 and 0.5:0.95,*** work represents a significant advancement in scene text detection,striking a balance between speed and accuracy,making it well-suited for performance-constrained environments.

关键词： Scene text detection YOLOv5 lightweight object detection

Proppant transport in rough fracture networks using supercritical CO_(2)

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Petroleum Science 2024年第3期21卷 1852-1864页

作者： Yong zheng Meng-Meng Zhou Ergun Kuru Bin Wang Jun Ni Bing Yang Ke Hu hai Huang hai-Zhu Wang School of Petroleum Engineering Xi'an Shiyou UniversityXian710065ShaanxiChina Shaanxi Key Laboratory of Carbon Dioxide Sequestration and Enhanced Oil Recovery Xi'an710075ShaanxiChina State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China School of Mining and Petroleum Engineering University of AlbertaEdmontonTG2W2AlbertaCanad Shaanxi Yanchang Petroleum(Group)Co. Ltd.Xi'an710075ShaanxiChina

Proppant transport within fractures is one of the most critical tasks in oil,gas and geothermal reservoir stimulation,as it largely determines the ultimate performance of the operating *** transport in rough fracture networks is still a relatively new area of research and the associated transport mechanisms are still *** this study,representative parameters of rough fracture surfaces formed by supercritical CO_(2) fracturing were used to generate a rough fracture network model based on a spectral synthesis *** fluid dynamics(CFD)coupled with the discrete element method(DEM)was used to study proppant transport in this rough fracture *** reveal the turning transport mechanism of proppants into branching fractures at the intersections of rough fracture networks,a comparison was made with the behavior within smooth fracture networks,and the effect of key pumping parameters on the proppant placement in a secondary fracture was *** results show that the transport behavior of proppant in rough fracture networks is very different from that of the one in the smooth fracture *** turning transport mechanisms of proppant into secondary fractures in rough fracture networks are gravity-driven sliding,high velocity fluid suspension,and fracture structure *** the same injection conditions,supercritical CO_(2)with high flow Reynolds number still has a weaker ability to transport proppant into secondary fractures than *** of the supercritical CO_(2)needs to be increased beyond a certain value to have a significant effect on proppant carrying,and under the temperature and pressure conditions of this paper,it needs to be increased more than 20 times(about 0.94 m Pa s).Increasing the injection velocity and decreasing the proppant concentration facilitates the entry of proppant into the branching fractures,which in turn results in a larger stimulated reservoir *** results help to understand the pro

关键词： Reservoir stimulation CCUS Rough fracture network Supercritical CO_(2) Proppanttransport

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关于流域生态补偿机制与模式研究

云南师范大学学报（哲学社会科学版） 2010年第5期42卷 54-60页

作者：郑海霞北京联合大学管理学院北京100101

流域生态补偿机制是解决流域上下游水资源利用和冲突的重要手段之一。生态补偿的理论基础包括环境外部性理论、生态服务功能价值理论、生态资产理论和公共物品等。作为流域管理的一种制度创新,流域生态补偿的分析框架包括:补偿范围的确... 详细信息

流域生态补偿机制是解决流域上下游水资源利用和冲突的重要手段之一。生态补偿的理论基础包括环境外部性理论、生态服务功能价值理论、生态资产理论和公共物品等。作为流域管理的一种制度创新,流域生态补偿的分析框架包括:补偿范围的确定性和系统诊断、补偿主体、客体及其责任的界定、流域生态服务补偿的基本原则、补偿标准与环境补偿协议、补偿方式及资金筹集方式、建立生态补偿机制、补偿政策框架和补偿体系的构建、补偿政策的实践和试点经验。目前中国流域生态补偿以政府主导的财政转移支付为主,包括国家生态补偿项目、地方政府主导的补偿模式。同时,以自发组织的市场交易模式、开放的贸易体系为补充。基于中国生态补偿的问题,提出生态补偿的政策建议:建立基于主体功能区划构建全国层次的生态补偿框架,分层次实施生态补偿;增加生态资本投资的收益,构建多渠道融资机制;理顺体制机制,建立流域综合管理机构,并分初期补偿、产业结构调整和优化发展补偿等3个阶段进行资金使用、区域发展规划和管理;构建基于直接损失、机会成本、发展权限制的损失的生态补偿标准。

关键词：水源区生态补偿模式区域协调发展

基于电震耦合理论研究电极法储层岩石复电阻率频散特性

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地球物理学报 2016年第6期59卷 2266-2279页

作者：郑海霞关继腾薛庆忠中国石油大学(华东)理学院青岛266580

复电阻率测井在识别油水层的能力上优于常规电阻率测井,然而储层岩石复电阻率特性的微观机理还没有统一完整的解释和数学模拟方法,致使复电阻率测井技术的开发缺乏足够的理论基础.本文基于孔隙介质Pride电震耦合理论,结合谐变信号激励... 详细信息

复电阻率测井在识别油水层的能力上优于常规电阻率测井,然而储层岩石复电阻率特性的微观机理还没有统一完整的解释和数学模拟方法,致使复电阻率测井技术的开发缺乏足够的理论基础.本文基于孔隙介质Pride电震耦合理论,结合谐变信号激励下渗流场与电流场的耦合理论,推导出一级近似条件下的Pride电震耦合理论.采用格林函数方法建立了一维电震波场的波动方程及其解.构造了双电极法测量储层岩石复电阻率的物理模型和数学模型,从理论上阐明了岩石复电阻率频散特性的微观机制与电震效应的关系,定量分析了储层岩石复电阻率频散特性的影响因素.数学模拟结果表明:储层岩石复电阻率的频散现象是在电震快纵波和电震慢纵波的共同作用下,由孔隙介质中的电渗流机制形成的;储层岩石的复电阻率随孔隙度的增大而减小,随渗透率的增大而增大,地层水矿化度的增加或阳离子交换量的增大使得同频率的复电阻率减小.慢纵波界面极化频率受孔隙度、渗透率和地层弹性模量的影响较大,而快纵波界面极化频率受地层弹性模量的影响较大.

关键词：复电阻率电震效应储层岩石频散特性双电极法

A meta-analysis on the clinical efficacy of fire dragon cupping in the treatment of lumbar disc herniation

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Integrative Medicine Discovery 2024年第11期8卷 1-7页

作者： hai-xia Ma Dan Ma Bin Lin Juan-xia zheng Department of Rehabilitation Shenzhen Bao’an Traditional Chinese Medicine HospitalGuangzhou University of Chinese MedicineShenzhen 518000China Department of Rheumatology and Immunology Shenzhen University Affiliated South China HospitalShenzhen 518000China Department of Nutrition Shenzhen Hospital of Southern Medical UniversityShenzhen 518000China.

Background:The incidence of lumbar disc herniation(LDH)is notably *** among experts highlights non-surgical treatments as the primary therapeutic approach for *** medicine frequently employs pharmacotherapy and epidural injections in such treatments,which are associated with numerous adverse *** use can severely impair the liver and kidney functions of ***,the role of safe and effective traditional Chinese medicine techniques becomes *** various traditional Chinese medicine approaches for treating LDH,fire dragon cupping,renowned for its remarkable efficacy,cost-effectiveness,and ease of application,is extensively utilised in clinical settings for managing ***,there is a scarcity of systematic and standardised evidence from evidence-based medicine ***,conducting a meta-analysis is ***:A comprehensive computerised search was conducted in databases including China National Knowledge Infrastructure,WanFang Data,VIP,China Biology Medicine disc,PubMed,EMbase,The Cochrane Library,Web of Science,and *** search aimed to gather randomised controlled trials on fire dragon cupping therapy for LDH,spanning from the inception of these databases until December *** researchers independently screened the literature according to inclusion and exclusion criteria,extracted data,and assessed the methodological quality of the studies included,utilising RevMan 5.3 software for ***:The results show that the fire dragon cupping therapy group had better clinical effectiveness(relative risk=1.23,95%confidence interval(CI)(1.14,1.33),P<0.00001),less pain(standardized mean difference=–1.33,95%CI(–1.49,–1.16),P<0.00001),and some improvement in lumbar function(Japanese Orthopaedic Association scores:mean difference=3.37,95%CI(2.31,4.43),P<***:The fire dragon cupping therapy significantly alleviates LDH,warranting its extensive ***,consid

关键词： fire dragon cupping therapy lumbar disc herniation lumbar spine meta-analysis randomized controlled trial

Immobilizing Triphenylamine with Photoredox Inert Sr^(2+)Forming Sr-MOF with Controlled Electron Migration for Photocatalytic Oxidation of Thiols to Disulfides

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Chinese Journal of Chemistry 2024年第10期42卷 1093-1099页

作者： Ying-xia Wang Fang zheng Dong-xia Song Bao-Yue Niu Lu-Qian Deng xian-Ming Zhang Key Laboratory of Magnetic Molecules and Magnetic Information Materials(Ministry of Education) Schoolof Chemistry and Materials ScienceShanxi Normal UniversityTaiyuanShanxi 030006China Key Laboratory of Interface Science and Engineering in Advanced Material(Ministry of Education) College of ChemistryTaiyuan University of TechnologyTaiyuanShanxi 030024China

The photocatalytic oxidative coupling of thiols is one of the most popular methods to synthesize the *** and its derivatives(TPAs)are promising for the above reaction,but suffer from the easy polymerization and difficult *** overcome these obstacles while controlling the photogenerated electrons transfer directly to target substrates,herein,we constructed one TPA-based metal-organic framework(MOF),(Me_(2)NH_(2))[Sr(TCBPA)]·DMA·3H_(2)O(1),by direct self-assembly of tris(4′-carboxybiphenyl)amine(H_(3)TCBPA)and photoredox inert strontium ion(Sr^(2+)).DFT calculations revealed that the valence band maximum(VBM)and the conduction band minimum(CBM)are mainly located on TCBPA^(3-),successfully inhibiting the undesirable electron migration to metal *** results indicated that 1 displays superior performance than homogeneous H_(3)TCBPA,which may result from the abundant π…π and C—H…π interactions between the well-arranged TCBPA^(3-)and the build-in electric field between the anionic framework and the Me_(2)NH^(2+).This work highlights that immobilizing TPAs into MOFs is one promising approach to designing heterogeneous photocatalysts for the synthesis of disulfides by oxidative coupling of thiols.

关键词： Triphenylamine Metal-organic frameworks Strontium Photooxidation Thiols Disulfides

Prediction of surface settlement caused by synchronous grouting during shield tunneling in coarse-grained soils:A combined FEM and machine learning approach

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Underground Space 2024年第3期16卷 206-223页

作者： Chao Liu Zepan Wang hai Liu Jie Cui xiangyun Huang Lixing Ma Shuang zheng School of Civil Engineering Guangzhou UniversityGuangzhou 510006China Guangdong Engineering Research Center for Underground Infrastructural Protection in Coastal Clay Areas Guangzhou UniversityGuangzhou 510006China Earthquake Engineering Research&Test Center Guangzhou UniversityGuangzhou 510006China CSCEC4 Civil Engineering Co. Ltd.Shenzhen 518052China

This paper presents a surrogate modeling approach for predicting ground surface settlement caused by synchronous grouting during shield tunneling *** proposed method combines finite element simulations with machine learning algorithms and introduces an intelligent optimization algorithm to invert geological parameters and synchronous grouting variables,thereby predicting ground surface settlement without conducting numerous finite element *** surrogate models based on the random forest algorithm are *** first is a parameter inversion surrogate model that combines an artificial fish swarm algorithm with random forest,taking into account the actual number and distribution of complex soil *** second model predicts surface settlement during synchronous grouting by employing actual cover-diameter ratio,inverted soil parameters,and grouting *** avoid changes to input parameters caused by the number of overlying soil layers,the dataset of this model is generated by the finite element model of the homogeneous soil *** surrogate modeling approach is validated by the case history of a large-diameter shield tunnel in Beijing,providing an alternative to numerical computation that can efficiently predict surface settlement with acceptable accuracy.

关键词： Shield tunnel Machine learning Synchronous grouting Surrogate modeling Surface settlement

Hydrogen release of NaBH_(4) below 60 ℃ with binary eutectic mixture of xylitol and erythritol additive

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Chinese Journal of Chemical Engineering 2024年第7期71卷 225-234页

作者： Yugang Shu Jiaguang zheng Chengguo Yan Ao xia Meiling Lv Zhenxuan Ma Zhendong Yao School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China College of Materials and Chemistry China Jiliang UniversityHangzhou 310018China

NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exhibits strong stability and requires temperatures above 500℃ for hydrogen release in practical *** this study,two polyhydric alcohols,xylitol and erythritol(XE),were prepared as a binary eutectic sugar alcohol through a grinding-melting *** binary eutectic sugar alcohol was used as a proton-hydrogen carrier to destabilize NaBH_(4).The 19NaBH_(4)-16XE composite material prepared by ball milling could start releasing hydrogen at 57.5℃,and the total hydrogen release can reach over 88.8%(4.45%(mass))of the theoretical *** the 19NaBH_(4)-16XE composite was pressed into solid blocks,the volumetric hydrogen capacity of the block-shaped composite could reach 67.2 g·L^(–1).By controlling the temperature,the hydrogen desorption capacity of the NaBH_(4)-XE composite material was controllable,which has great potential for achieving solid-state hydrogen production from NaBH_(4).

关键词： Hydrogen Desorption Binary mixture NaBH_(4) Xylitol Erythritol

Catalyst-free and Reprocessable Aromatic Polydithiourethanes

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Chinese Journal of Polymer Science 2024年第10期42卷 1435-1441,I0007页

作者： Bo Yang hai-Jun Feng Tian-Tian Ni xiao-Rui Zhou Tao Xie Ning zheng State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310058China Department of Colorectal Surgery and Oncology Key Laboratory of Cancer Prevention and InterventionMinistry of EducationThe Second Affiliated HospitalZhejiang University School of MedicineHangzhou310009China

The incorporation of dynamic covalent bonds into thermosets facilitates the reprocessing of polymer networks,thereby meeting the sustainable requirements for polymer ***,the mechanical properties of many materials often decline significantly upon reprocessing due to side reactions caused by harsh processing *** this work,we find that the aromatic dithiocarbamate bond can undergo dissociation under mild conditions without the need for a catalyst,enabling the efficient reprocessing of the corresponding *** a consequence,the mechanical properties of the polydithiourethane can be largely preserved after *** discovery of this dynamic chemistry is anticipated to broaden the potential for material design in dynamic covalent polymer networks.

关键词： Reprocessing Polydithiourethane Dynamic covalent bond