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A c(RGDyK)-modified ROS-responsive polymeric micelle for hepatic stellate cell targeting
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作者 Xin-Yu Liu He-Ying Mao +5 位作者 Jun-Sheng Hu Tong-Rui Dou Ben-Chi Liu Chang-Xiu Lin Jing-Shu Piao Ming-Guan Piao 《Chinese Chemical Letters》 2026年第1期481-486,共6页
Hepatic fibrosis is regulated by the synergistic actions of various cells and cytokines,with the activation and proliferation of hepatic stellate cells(HSCs) being considered the central event in this process.To achie... Hepatic fibrosis is regulated by the synergistic actions of various cells and cytokines,with the activation and proliferation of hepatic stellate cells(HSCs) being considered the central event in this process.To achieve specific targeting of activated hepatic stellate cells(a HSCs) and precise treatment of hepatic fibrosis,this study developed a dual-functional drug delivery system(SIL/c RGD-PEG-PPS PMs) with both targeting and responsive release capabilities.It aims to target the αvβ 3 receptor specifically expressed on the surface of a HSCs using the cyclic peptide c(RGDyk),and to exploit the high reactive oxygen species(ROS) level in the cellular microenvironment to achieve concentrated burst release of drugs at the pathological sites of hepatic fibrosis.Based on multiple assessments,SIL/c RGD-PEG-PPS PMs specifically enhanced the targeted delivery of silybin(SIL) to a HSCs,inhibited the proliferation and migration of a HSCs,and exhibited good biosafety.Additionally,it demonstrated excellent anti-fibrotic activity in fibrotic mice.In summary,this study shows great potential in targeted treatment of hepatic fibrosis and provides a multifunctional tool for advancing the research and therapeutic strategies of hepatic fibrosis. 展开更多
关键词 Liver fibrosis Targeted delivery ROS responsive release ΑvΒ3 c(RGDyK)
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Retinitis pigmentosa elicits neurodegeneration within the visual pathway in REEP6 knockout mice
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作者 Yin Yang Maoxia Lv +6 位作者 Binbin Qiao Zhengjiang Yang Houbin Zhang Zhengzheng Wu Yang Xia Dezhong Yao Ke Chen 《Neural Regeneration Research》 2026年第8期3863-3869,共7页
While degenerative diseases of the central nervous system are commonly linked to age-related macular degeneration and glaucoma,they have also been infrequently associated with retinitis pigmentosa,a condition defined ... While degenerative diseases of the central nervous system are commonly linked to age-related macular degeneration and glaucoma,they have also been infrequently associated with retinitis pigmentosa,a condition defined by retinal degeneration that can be caused by an isoform of receptor expression enhancing protein 6(REEP6)expressed in rod photoreceptors.In this study,we used REEP6 knockout mice(REEP6^(-/-))and wild-type mice(REEP6^(+/+))to examine neurodegenerative pathology within the visual pathways and neural activity in the primary visual cortex(V1)at three specific time points(1,6,and 10 months)during retinitis pigmentosa progression.Microglial activation was observed in both the retina and the primary visual cortex starting at 1 month of age,but no such activation was detected in the lateral geniculate nucleus at any time point.Not only was increased microglial activation observed at 6 and 10 months within the primary visual cortex of REEP6^(-/-)mice,but also coinciding with elevated levels of phosphorylated Tau expression.At 6 and 10 months of age,primary visual cortex neurons in REEP6^(-/-)mice exhibited reduced responses to grating stimuli and increased spontaneous activity compared with neurons in the primary visual cortex of mice in the control group.Our findings show that retinitis pigmentosa induces neurodegenerative pathology within the visual pathway of mice,particularly in the primary visual cortex,suggesting that ocular disease contributes substantially to central nervous system degeneration.It may provide new clues for the selection of treatment opportunities and the development of therapeutic measures for the subsequent treatment of retinitis pigmentosa or even other retinal degenerative diseases. 展开更多
关键词 microglial activation nerve regeneration NEURODEGENERATION phosphorylated Tau photoreceptor degeneration primary visual cortex(v1) REEP6 retinitis pigmentosa rod photoreceptors visual pathway
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考虑V2H的智能社区能量交易方案
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作者 刘迪迪 姚欣欣 +3 位作者 廖志贤 杨文宇 沈阳 胡聪 《华北电力大学学报(自然科学版)》 北大核心 2026年第1期71-81,105,I0005,I0006,共14页
针对含光伏(photovoltaic,PV)、电动汽车(electric vehicle,EV)及家庭电器负荷的智能社区,以车入户(vehicle to home,V2H)的形式将EV纳入家庭需求响应框架,利用EV的双向输能特性并考虑EV充/放电带来的电池容量退化成本,协同PV、电网的... 针对含光伏(photovoltaic,PV)、电动汽车(electric vehicle,EV)及家庭电器负荷的智能社区,以车入户(vehicle to home,V2H)的形式将EV纳入家庭需求响应框架,利用EV的双向输能特性并考虑EV充/放电带来的电池容量退化成本,协同PV、电网的实时电价和用户需求的可容忍时延,基于Lyapunov优化理论提出随机环境下V2H用户的EV充/放电调度策略和每户家庭的负荷响应策略,最小化家庭用户的长期平均购电成本。并提出一种智能社区在线能量交易方案,旨在最小化智能社区总的购电成本、最大限度提高社区能源利用率。理论分析和仿真结果表明,所提算法无需实时电价、PV出力、用户负荷需求的先验概率信息,仅基于当前系统状态就可使优化目标趋于最优值,实现家庭用户的能量调度和家庭用户之间的能量共享,减少家庭购电成本,提高用户之间能量交易的灵活性。 展开更多
关键词 智能社区 Lyapunov优化 电动汽车 v2H 能量共享
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基于改进YOLOv8的安全帽佩戴检测算法
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作者 谢敏怡 蒋作 +2 位作者 万学俊 赵周洲 潘文林 《软件导刊》 2026年第1期172-183,共12页
针对工地安全帽检测中难以识别被遮挡目标和存在密集小目标的问题,提出一种基于改进YOLOv8的工地安全帽实时检测算法。首先,在特征提取网络中使用RVBS模块替换部分Conv模块,通过多分支结构和无信息损失的下采样操作提升了网络的特征提... 针对工地安全帽检测中难以识别被遮挡目标和存在密集小目标的问题,提出一种基于改进YOLOv8的工地安全帽实时检测算法。首先,在特征提取网络中使用RVBS模块替换部分Conv模块,通过多分支结构和无信息损失的下采样操作提升了网络的特征提取能力,有助于密集小目标的检测;其次,采用RepNCSPELAN4模块代替特征融合网络中所有的C2f模块,使模型能更有效地融合浅层与深层特征,从而改善被遮挡目标的检测效果;再次,新增小目标检测层以进一步融合多尺度特征,提升对小目标的检测能力;最后,使用WIoU v1损失函数代替原始的CIoU损失函数,加速模型收敛并提高回归精度。实验结果表明,改进后的YOLOv8算法在SHWD数据集上的mAP@0.5和mAP@0.5:0.95分别比原算法提高了2.8%和3.2%,每张图片检测用时为25.7 ms。与其他主流算法相比,改进算法的mAP@0.5最高。所提算法能有效检测密集遮挡小目标,具有较高的应用价值。 展开更多
关键词 YOLOv8 安全帽 目标检测 RvBS 小目标检测层 RepNCSPELAN4 WIoU v1
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Toward Efficient Traffic-Sign Detection via SlimNeck and Coordinate-Attention Fusion in YOLO-SMM
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作者 Hui Chen Mohammed A.H.Ali +6 位作者 Bushroa Abd Razak Zhenya Wang Yusoff Nukman Shikai Zhang Zhiwei Huang Ligang Yao Mohammad Alkhedher 《Computers, Materials & Continua》 2026年第2期1823-1848,共26页
Accurate and real-time traffic-sign detection is a cornerstone of Advanced Driver-Assistance Systems(ADAS)and autonomous vehicles.However,existing one-stage detectors miss distant signs,and two-stage pipelines are imp... Accurate and real-time traffic-sign detection is a cornerstone of Advanced Driver-Assistance Systems(ADAS)and autonomous vehicles.However,existing one-stage detectors miss distant signs,and two-stage pipelines are impractical for embedded deployment.To address this issue,we present YOLO-SMM,a lightweight two-stage framework.This framework is designed to augment the YOLOv8 baseline with three targeted modules.(1)SlimNeck replaces PAN/FPN with a CSP-OSA/GSConv fusion block,reducing parameters and FLOPs without compromising multi-scale detail.(2)The MCA model introduces row-and column-aware weights to selectively amplify small sign regions in cluttered scenes.(3)MPDIoU augments CIoU loss with a corner-distance term,supplying stable gradients for sub-20-pixel boxes and tightening localization.An evaluation of YOLO-SMMon the German Traffic Sign Recognition Benchmark(GTSRB)revealed that it attained 96.3% mAP50 and 93.1% mAP50-90 at a rate of 90.6 frames per second(FPS).This represents an improvement of+1.0% over previous performance benchmarks.Them APat 64×64 resolution was found to be 50% of the maximum attainable value,with an FPS of+8.3 when compared to YOLOv8.This result indicates superior performance in terms of accuracy and speed compared to YOLOv7,YOLOv5,RetinaNet,EfficientDet,and Faster R-CNN,all of which were operated under equivalent conditions. 展开更多
关键词 Traffic sign detection YOLO v8 YOLO v5 YOLO v7 SlimNeck modified coordinate attention MPDIoU
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Design of Virtual Driving Test Environment for Collecting and Validating Bad Weather SiLS Data Based on Multi-Source Images Using DCU with V2X-Car Edge Cloud
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作者 Sun Park JongWon Kim 《Computers, Materials & Continua》 2026年第3期448-467,共20页
In real-world autonomous driving tests,unexpected events such as pedestrians or wild animals suddenly entering the driving path can occur.Conducting actual test drives under various weather conditions may also lead to... In real-world autonomous driving tests,unexpected events such as pedestrians or wild animals suddenly entering the driving path can occur.Conducting actual test drives under various weather conditions may also lead to dangerous situations.Furthermore,autonomous vehicles may operate abnormally in bad weather due to limitations of their sensors and GPS.Driving simulators,which replicate driving conditions nearly identical to those in the real world,can drastically reduce the time and cost required for market entry validation;consequently,they have become widely used.In this paper,we design a virtual driving test environment capable of collecting and verifying SiLS data under adverse weather conditions using multi-source images.The proposed method generates a virtual testing environment that incorporates various events,including weather,time of day,and moving objects,that cannot be easily verified in real-world autonomous driving tests.By setting up scenario-based virtual environment events,multi-source image analysis and verification using real-world DCUs(Data Concentrator Units)with V2X-Car edge cloud can effectively address risk factors that may arise in real-world situations.We tested and validated the proposed method with scenarios employing V2X communication and multi-source image analysis. 展开更多
关键词 virtual driving test DCU bad weather SiLS autonomous environment v2X-Car edge cloud
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Optimization of selective laser melting parameters of Ti6Al4V alloys latticestructures utilizing taguchi method and grey relational analysis
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作者 Moqdad Juber Dakhil Abdulraheem Khadim AbidAli Zainab Al-Khafaji 《Biomedical Engineering Communications》 2026年第3期43-52,共10页
Background: This study focuses on the fabrication and optimization of Ti6Al4V alloy latticestructures produced by the Selective Laser Melting (SLM) process. Such structures areincreasingly used in biomedical implants ... Background: This study focuses on the fabrication and optimization of Ti6Al4V alloy latticestructures produced by the Selective Laser Melting (SLM) process. Such structures areincreasingly used in biomedical implants due to their potential to match the mechanicalproperties of human bone. Key features influencing their performance include porosity ratio,surface roughness, elastic modulus, and yield strength. Achieving a balance between theseparameters is essential for ensuring both mechanical integrity and biological compatibility.Methods: The Taguchi method integrated with Grey Relational Analysis (GRA) wasemployed to optimize the SLM process parameters—laser power (160-240 J), scanningspeed (1000-1500 mm/min), and hatch spacing (0.06-0.12 mm). The optimization aimed toproduce lattice structures with properties closely resembling human bone. Experimentaltrials were conducted to evaluate the effects of these parameters on porosity, surfaceroughness, elastic modulus, and yield strength, followed by statistical and relational analysisto determine the optimal configuration. Results: The results revealed that higher scanningspeed, wider hatch spacing, and lower laser power increased the porosity ratio compared toCAD models. A strong inverse relationship was observed between porosity and both yieldstrength and elastic modulus. Increasing laser power substantially reduced surfaceroughness. Through Taguchi-GRA optimization, the optimal parameter combination wasdetermined as laser power of 240 J, scanning speed of 1250 mm/min, and hatch spacing of0.06 mm. Under these conditions, the obtained values were: modulus of elasticity (0°) = 20GPa, modulus of elasticity (90°) = 18.874 GPa, yield strength (0°) = 265 MPa, yieldstrength (90°) = 260 MPa, porosity = 48.565%, and surface roughness = 6.223 μm.Conclusion: The optimized SLM parameters successfully produced Ti6Al4V latticestructures with mechanical and morphological characteristics compatible with human bone.The study highlights the critical balance between process parameters and structuralfeatures, providing a systematic approach for tailoring lattice structures for biomedicalapplications through Taguchi and GRA-based optimization. 展开更多
关键词 additive manufacturing selective laser melting(SLM) grey relational analysis Ti6Al4v alloys
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Microstructural tailoring and property enhancement via friction stir processing of additively manufactured steel and Ti6Al4V alloy
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作者 Md Parwez Alam Md Anwar Ali Anshari +1 位作者 Mohamed M.El-Sayed Seleman Murshid Imam 《China Welding》 2026年第1期17-33,共17页
Friction stir processing(FSP) has emerged as a transformative solid-state technique for enhancing the mechanical performance and microstructural integrity of metallic materials,particularly in the context of additive ... Friction stir processing(FSP) has emerged as a transformative solid-state technique for enhancing the mechanical performance and microstructural integrity of metallic materials,particularly in the context of additive manufacturing(AM).This study demonstrates the effectiveness of FSP as a post-processing strategy for two distinct AM systems:wire arc additive manufacturing(WAAM) of low-carbon steel and selective laser melting(SLM) of Ti6Al4V alloy.In the case of WAAM fabricated steel,FSP significantly refined the coarse dendritic microstructure into ultrafine equiaxed grains,resulting in a 21 %-24 % increase in hardness and enhanced tensile properties at the overlapping regions.Similarly,for SLM fabricated Ti6Al4V,FSP eliminated the columnar prior-β grains and residual porosity,yielding a homogenous α+β structure with improved strengthductility balance and reduced anisotropy.These improvements were attributed to the dynamic recrystallization,conversion of low-angle to high-angle grain boundaries,and homogenization of phase constituents induced by FSP.Despite challenges such as tool wear and fixturing complexity,the study confirms that FSP can reliably bridge the performance gap in AM components by healing solidification defects,mitigating anisotropy,and tailoring the local microstructure.The findings position FSP as a versatile and scalable post-processing technique,crucial for advancing high-performance,application-ready components in aerospace,biomedical,and structural applications. 展开更多
关键词 Friction stir processing Wire arc additive manufacturing Selective laser melting EN8 Steel Ti6Al4v alloy Microstructural modification
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BRAF^(V600E)Metastatic Synovial Sarcoma Treated with BRAF&MEK Inhibitors Achieves Complete Response.A Case Report&Literature Review
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作者 Daniel Burg Aryeh Babkoff +18 位作者 Omer Or Noam Olshinka Jonathan Abraham Demma Mohamad Adila Marc Wygoda Philip Blumenfeld Judith Diment Masha Galiner Yusef Azraq Daniela Katz Petachia Reissman Sadie Ostrowicki Gabriella Sebbag Narmine Elkhateeb Anat Hershko Moshe Dania Jaber Adi Hollander Limor Rubin Aviad Zick 《Oncology Research》 2026年第4期881-890,共10页
Background:—Synovial sarcoma is a rare soft tissue sarcoma.Treatment of synovial sarcoma includes surgery,radiation,pazopanib,and chemotherapy.Targeted therapies,such as B-Raf proto-oncogene,serine/threonine kinase(B... Background:—Synovial sarcoma is a rare soft tissue sarcoma.Treatment of synovial sarcoma includes surgery,radiation,pazopanib,and chemotherapy.Targeted therapies,such as B-Raf proto-oncogene,serine/threonine kinase(BRAF)inhibitors,are emerging as a potential treatment option.We describe the sixth case of a BRAF^(V600E)synovial sarcoma,the first extra-thoracic case.This case is the first to show a complete pathological response to BRAF&mitogen-activated protein kinase kinase(MEK)inhibitors.Case description:—We treated a 22-year-old male with a left groin BRAF^(V600E)synovial sarcoma with doxorubicin,Ifosphamide&Sodium 2-Mercaptoethanesulfonate.When we identified BRAF^(V600E)in the tumor,the BRAF^(V600E)and MEK inhibitors(dabrafenib&trametinib)were initiated,followed by surgery,with a complete pathological response.Nine months after the surgery,a local recurrence prompted the resumption of dabrafenib&trametinib followed by radiotherapy,resulting in complete radiological response and the development of hemophagocytic lymphohistiocytosis treated with corticosteroids with resolution of symptoms.Conclusion:—Panel sequencing of synovial sarcoma can identify targetable mutations.Treatment of BRAF^(V600E)synovial sarcoma with dabrafenib&trametinib can lead to complete pathological response and prolonged radiological response,as well as the rare adverse event of hemophagocytic lymphohistiocytosis.Prospective clinical trials are needed to evaluate the efficacy and safety of BRAF^(V600E)&MEK inhibitors as a therapeutic approach in BRAF^(V600E)synovial sarcoma. 展开更多
关键词 Synovial sarcoma B-Raf proto-oncogene serine/threonine kinase^(v600E) serine/threonine kinase inhibitor mitogen-activated protein kinase kinase inhibitor case report
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岩石开采中V型切口角度对岩石开裂的影响研究
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作者 高丙丽 陈世豪 +2 位作者 杨聪聪 张新 杨志法 《工程地质学报》 北大核心 2026年第1期120-130,共11页
V型切口角度大小对古洞室岩石开采中石板开裂有不容忽视的影响。以浙江省三门县蛇蟠岛的潜龙洞古洞室群为研究背景,以洞室围岩流纹质晶屑玻屑熔结凝灰岩为研究对象。采用断裂力学理论与室内V型切口断裂试验相结合的方法,通过不同顶角β... V型切口角度大小对古洞室岩石开采中石板开裂有不容忽视的影响。以浙江省三门县蛇蟠岛的潜龙洞古洞室群为研究背景,以洞室围岩流纹质晶屑玻屑熔结凝灰岩为研究对象。采用断裂力学理论与室内V型切口断裂试验相结合的方法,通过不同顶角β和切口角分线与水平方向的夹角α,研究凝灰岩裂纹起裂过程,并深入研究裂纹起裂角与起裂角方向复合应力强度因子之间的关系,判断裂纹面起裂破坏模式。研究结果表明:当V型切口角分线与水平方向成角α为60°、顶角β为20°时为最佳开采角度;古人充分利用了凝灰岩的层节理面特征,使得石板断裂时所施加的力远低于岩石的强度;岩石起裂破坏模式为闭合型。研究切口角度对岩石开裂的影响对非物质文化遗产保护具有重要意义,同时优化了凿孔裂石采石方法,为后续采石工作提供技术支撑,并对后人更理性认识岩石中的平面断层、节理有指导意义,为非物质文化遗产保护提供参考价值。 展开更多
关键词 凿孔裂石采石 v型切口 洞室充水 裂纹扩展 应力强度因子
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智能网联汽车区域式48 V电气架构关键技术综述
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作者 韦莉 郭斌 +1 位作者 周新灵 梁海泉 《汽车工程》 北大核心 2026年第1期1-12,共12页
随着智能网联汽车的智能化、线控化、舒适性程度的不断提高,传统12 V电气架构已难以满足其高功率、高可靠性与软件定义等需求。本文面向智能网联汽车的区域式48 V电气架构,围绕架构演变、关键技术、零部件设计及总体开发流程4个方面系... 随着智能网联汽车的智能化、线控化、舒适性程度的不断提高,传统12 V电气架构已难以满足其高功率、高可靠性与软件定义等需求。本文面向智能网联汽车的区域式48 V电气架构,围绕架构演变、关键技术、零部件设计及总体开发流程4个方面系统地综述了当前研究进展,并对未来发展方向进行了展望,可为相关研究提供理论参考。 展开更多
关键词 区域48 v电气架构 功能安全 预测性能量管理 潜在故障诊断 电子保险丝
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V形钢可更换耗能构件梁柱节点受力性能分析
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作者 吴瑞 匡星晨 +1 位作者 凌茹 谢颖 《地震工程学报》 北大核心 2026年第3期537-547,558,共12页
韧性结构不仅能抵抗高烈度地震作用,而且在震后只需更换损伤构件即可快速恢复功能,近年来受到广泛关注。文章提出一种配置V形钢可更换耗能构件的狗骨式翼缘削弱梁柱节点,并介绍其构造形式及设计理念。利用ABAQUS有限元软件,分析该节点... 韧性结构不仅能抵抗高烈度地震作用,而且在震后只需更换损伤构件即可快速恢复功能,近年来受到广泛关注。文章提出一种配置V形钢可更换耗能构件的狗骨式翼缘削弱梁柱节点,并介绍其构造形式及设计理念。利用ABAQUS有限元软件,分析该节点的破坏模式、应力与应变分布,揭示其破坏机理、传力路径及耗能机制;在此基础上,研究V形钢连接件和狗骨式削弱连接件的关键设计参数(包括厚度、材料强度以及削弱连接件的削弱宽度)对节点抗震性能的影响。研究结果表明:在传统狗骨式可更换节点的基础上配置V形钢可更换耗能构件,能显著提高节点的耗能能力和延性性能,其等效黏滞阻尼系数在0.257~0.331之间;V形钢连接件在受力过程中发生明显塑性变形,实现了损伤可控及震后可更换的抗震设计目标;狗骨式削弱连接件与V形钢连接件宜采用LY160或Q235钢;狗骨式削弱连接件厚度宜取梁翼缘厚度的0.9~1.5倍,削弱宽度宜取25~30 mm,而V形钢连接件厚度宜取梁翼缘厚度的0.3~0.6倍。 展开更多
关键词 可更换耗能构件 梁柱节点 v形钢连接件 抗震性能 有限元分析
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基于颜色特征量化和改进YOLO v8的番茄成熟度分级检测方法
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作者 张领先 周沁 +4 位作者 姚天雨 裴鑫达 赵立群 满杰 钱井 《农业机械学报》 北大核心 2026年第2期193-202,224,共11页
番茄的成熟度与其品质密切相关,是生产中采摘和分拣等环节的重要依据。针对作物成熟度分级检测系统功能简单,人工升级系统成本较大的问题,本文以番茄为例,采集并构建自然场景下番茄图像数据集,设计以番茄果实成熟度分级算法为基础的番... 番茄的成熟度与其品质密切相关,是生产中采摘和分拣等环节的重要依据。针对作物成熟度分级检测系统功能简单,人工升级系统成本较大的问题,本文以番茄为例,采集并构建自然场景下番茄图像数据集,设计以番茄果实成熟度分级算法为基础的番茄图像半自动标注算法对采集后的数据进行标注,在YOLO v8模型基础上,将FPN结构替换为BiFPN结构实现更高效的多尺度特征融合,利用SE注意力机制对空间和通道进行融合特征提取,引入Focal SIoU损失函数对预测框与真实框之间的角度差异进行度量,构建基于颜色特征量化和改进YOLO v8的番茄成熟度分级检测模型YOLO v8BFS,识别番茄生长过程的5个不同成熟度。试验结果表明,本文模型较好地解决了自然复杂场景下番茄成熟度分级检测的错漏检问题,在模型浮点运算量(FLOPs)、参数量(Params)和内存占用量有少量增加的条件下,本文模型的平均精度均值为94.10%相较原模型YOLO v8提高3.0个百分点。通过与Faster R-CNN-Resnet50、YOLO v5、YOLO v7-tiny、YOLO v8、YOLO v10和YOLO 11目标检测模型对比,本文在检测精度具有显著优势,为番茄成熟度的检测提供了一种可靠的方法。 展开更多
关键词 番茄成熟度 自然场景 颜色特征量化 YOLO v8
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SLM成形SiC_(w)/TiC/Ti6Al4V钛基复合材料的热压缩变形行为及组织性能研究
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作者 柳佶涛 霍鹏丞 +1 位作者 白培康 赵占勇 《应用激光》 北大核心 2026年第1期47-58,共12页
采用V形混粉方法制备SiC_(w)/Ti6Al4V合金复合粉末,并利用选区激光熔化(selective laser melting,SLM)制备SiC_(w)/TiC/Ti6Al4V钛基复合材料。对比SiC_(w)/TiC/Ti6Al4V钛基复合材料和Ti6Al4V合金在不同变形条件下的热压缩行为,建立了SiC... 采用V形混粉方法制备SiC_(w)/Ti6Al4V合金复合粉末,并利用选区激光熔化(selective laser melting,SLM)制备SiC_(w)/TiC/Ti6Al4V钛基复合材料。对比SiC_(w)/TiC/Ti6Al4V钛基复合材料和Ti6Al4V合金在不同变形条件下的热压缩行为,建立了SiC_(w)/TiC/Ti6Al4V钛基复合材料在高温压缩时的本构方程。结果显示,在压缩变形时,流变应力随着应变速率的增大而增大,随温度的升高而降低,复合材料的流变应力峰值均高于Ti6Al4V合金;在变形温度为900℃、应变速率为1s^(-1)时,SiC_(w)/TiC/Ti6Al4V钛基复合材料相较Ti6Al4V合金抗压缩性能提升了140%,强化效果最明显。SLM成形过程中原位反应生成TiC增强相引起的载荷传递强化及针状马氏细化引起的细晶强化是高温压缩性能得到提升的主要原因。 展开更多
关键词 Ti6Al4v合金 SiC_(w)/TiC/Ti6Al4v钛基复合材料 本构方程 高温压缩性能
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基于改进YOLOv7的复杂果园环境下苹果识别
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作者 张伟 侯畅 +2 位作者 陈雪 何思毅 陈勇 《中国农业科技导报(中英文)》 北大核心 2026年第2期107-115,共9页
针对复杂果园环境下的苹果识别准确率低、效率低的问题,提出了一种改进的YOLOv7模型。首先,引入MobileNet V3作为模型的骨干网络,减少网络参数;其次,引入SimAM注意力机制,有效地提取苹果特征;再次,将损失函数改为可伸缩交并比损失函数,... 针对复杂果园环境下的苹果识别准确率低、效率低的问题,提出了一种改进的YOLOv7模型。首先,引入MobileNet V3作为模型的骨干网络,减少网络参数;其次,引入SimAM注意力机制,有效地提取苹果特征;再次,将损失函数改为可伸缩交并比损失函数,提高模型的训练速度和识别能力;最后,使用k-means++算法改进初始锚框尺寸,提升对近距离苹果的识别能力。结果表明,改进的YOLOv7模型的准确率、平均精度均值比原模型分别提高3.5%、1.1%,识别时间减少0.0034 s·幅^(-1);对比Faster R-CNN、YOLOv5和YOLOX模型,改进的YOLOv7模型的综合性能最好;在复杂光照和遮挡情况下,改进的模型表现出极强的适应性和鲁棒性。改进的模型能够满足苹果采摘机器人在复杂果园环境下的识别要求,为苹果采摘的研究奠定基础。 展开更多
关键词 复杂果园环境 苹果识别 YOLOv7 MobileNet v3 SimAM注意力机制 损失函数
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基于改进YOLO v11-seg的无人机辅助船舶靠泊方法
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作者 章文俊 徐力为 +3 位作者 孟祥坤 杨雪 周翔宇 曲胜 《舰船科学技术》 北大核心 2026年第5期127-132,共6页
为解决船舶靠泊过程中视野受限问题,实现靠泊距离的可视化,提出一种无人机辅助视角下的船舶靠泊距离测定方法。首先,利用无人机采集船舶靠泊视频制作数据集,在YOLO v11-seg模型中加入视网膜分割掩膜任务框架,实现对船舶边缘的精细化分割... 为解决船舶靠泊过程中视野受限问题,实现靠泊距离的可视化,提出一种无人机辅助视角下的船舶靠泊距离测定方法。首先,利用无人机采集船舶靠泊视频制作数据集,在YOLO v11-seg模型中加入视网膜分割掩膜任务框架,实现对船舶边缘的精细化分割,生成高分辨率掩膜。其次,利用掩膜提取与几何分析方式,提取船舶与泊位多边形坐标,并确定两者边缘线。最后,使用点集距离矩阵以及动态距离匹配技术,计算像素距离并转化为实际距离。实验表明,改进模型平均精度提升5.7%,船舶与泊位间最近距离的误差不大于0.04 m。该方法能够以较高的测量精度实现船舶与泊位间距离的可视化。 展开更多
关键词 无人机 YOLO v11-seg 辅助靠泊 距离测量 可视化
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融合改进YOLO v8s-obb与NPRP-A的无人机遥感水稻估产方法
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作者 李继宇 李明霞 +5 位作者 李惠芬 高荣 卢广栋 刘婉卿 梁蕴婷 巫瀚 《农业机械学报》 北大核心 2026年第3期119-128,共10页
针对现有水稻估产方法忽略同种作物个体差异性及种植密度与单穗质量耦合影响,导致估产精度受限的核心问题,提出了一种融合改进YOLO v8s-obb模型与NPRP-A的水稻估产方法。通过优化YOLO v8s-obb结构,引入C2f_DCNv4模块、GSConv、EPSANet和... 针对现有水稻估产方法忽略同种作物个体差异性及种植密度与单穗质量耦合影响,导致估产精度受限的核心问题,提出了一种融合改进YOLO v8s-obb模型与NPRP-A的水稻估产方法。通过优化YOLO v8s-obb结构,引入C2f_DCNv4模块、GSConv、EPSANet和DAT注意力机制,提升模型对稻穗的多尺度精准检测能力。为提升估产结果的可信度,在水稻成熟期实地收割样本小区作物,采集实测产量数据作为模型验证参考,并引入高斯核密度估计与NPRP-A单穗质量建模方法,建立密度调控与单穗质量之间的非线性映射关系,实现估产精度提升。实验结果显示,在3个1 m^(2)估产小区中,本方法预测误差均低于5.3%,最小误差为2.2%,优于传统方法,展示出良好的实际应用前景。该研究为水稻高效、精准估产提供了可靠技术方案,也为智慧农业中的作物表型识别与产量分析提供了思路。 展开更多
关键词 稻穗检测 作物估产 单穗质量模型 YOLO v8s-obb NPRP-A 无人机遥感
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V形墩消力池消能影响因素及消能特性研究
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作者 牧振伟 欧文辉 +2 位作者 张红红 钟云 孙容泷 《长江科学院院报》 北大核心 2026年第4期107-114,共8页
针对消力池消能不充分、流态紊乱等问题,提出一种V形墩新型辅助消能工增加消能率η,并引入水跃位置前移率P作为评价指标用以量化V形墩对水跃位置的调控效果。通过模型试验与数值模拟相结合的方法分析弗劳德数Fr、夹角θ、排间距γ、首... 针对消力池消能不充分、流态紊乱等问题,提出一种V形墩新型辅助消能工增加消能率η,并引入水跃位置前移率P作为评价指标用以量化V形墩对水跃位置的调控效果。通过模型试验与数值模拟相结合的方法分析弗劳德数Fr、夹角θ、排间距γ、首排墩位置Γ、墩高比ξ、收缩比β等因素对η和P的影响。结果表明:Fr对η影响最显著,最优方案下η为95.58%;Γ及ξ对P影响最显著,最优方案下P为49.42%。V形墩通过增强紊动与漩涡耗能,跃前断面最大流速下降幅度达39.4%,有效抑制大尺度涡旋发展。V形墩消力池较传统消力池流态更平稳,能量耗散更充分。研究成果可为类似工程消能工设计提供理论依据。 展开更多
关键词 v形墩消力池 弗劳德数 消能影响因素 消能特性 紊动能耗散率 湍流耗散涡
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Q/V频段卫通地面站天线技术研究进展与分析
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作者 张强 张一凡 《通信技术》 2026年第1期9-15,共7页
随着卫星通信向高通量、低时延方向演进,Q/V频段由于具有带宽高、抗干扰性强和高波束定向性的优势,将成为高通量卫星通信系统的核心频段。研究了Q/V频段反射面天线系统的主要组成与技术特性,总结了该频段国内外卫星组网发射、天线结构... 随着卫星通信向高通量、低时延方向演进,Q/V频段由于具有带宽高、抗干扰性强和高波束定向性的优势,将成为高通量卫星通信系统的核心频段。研究了Q/V频段反射面天线系统的主要组成与技术特性,总结了该频段国内外卫星组网发射、天线结构、跟踪接收、功率放大等器件领域的研究及应用进展,重点分析了高频段天线设计面临的关键技术挑战,包括路径损耗和雨衰、制造精度、稳定性等。此外,还探讨了各项技术发展的趋势,提出了未来重点研究和应用方向,包括新型材料应用、高集成度制造工艺优化、与6G技术融合等。通过研究国内外技术进展与应用动态,为该领域的技术研究和应用提供参考。 展开更多
关键词 Q/v频段 天线 高通量卫星通信 雨衰 星座
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MRI联合血清miR-410-3p、ITGAV对鼻咽癌早期淋巴结转移的预测价值
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作者 张德江 郑树成 +3 位作者 赵媛 林秋全 王龙 陈頔 《中国CT和MRI杂志》 2026年第2期35-37,共3页
目的探讨MRI联合血清微小核糖核酸(miRNA)-410-3p、整合素αv(ITGAV)对鼻咽癌早期淋巴结转移的预测价值。方法选取2020年10月至2023年10月本院收治的鼻咽癌患者110例,患者术前均行MRI检测,根据患者术后病理结果淋巴结有无转移分为转移组... 目的探讨MRI联合血清微小核糖核酸(miRNA)-410-3p、整合素αv(ITGAV)对鼻咽癌早期淋巴结转移的预测价值。方法选取2020年10月至2023年10月本院收治的鼻咽癌患者110例,患者术前均行MRI检测,根据患者术后病理结果淋巴结有无转移分为转移组(66例)和未转移组(44例);实时荧光定量PCR(qRT-PCR)法检测miR-410-3p、ITGAV表达水平;鼻咽癌早期淋巴结转移的影响因素采用多因素Logistic回归分析;绘制ROC曲线分析MRI联合血清miR-410-3p、ITGAV对鼻咽癌早期淋巴结转移的预测价值。结果转移组检测出淋巴结坏死34枚(51.52%),转移组L/S显著低于未转移组(P<0.05)。转移组血清miR-410-3p显著低于未转移组(P<0.05),ITGAV高于未转移组(P<0.05)。多因素Logistic回归分析得知,L/S、miR-410-3p为影响鼻咽癌早期淋巴结转移的保护因素(P<0.05),ITGAV为危险因素(P<0.05)。根据ROC曲线得知,L/S预测鼻咽癌早期淋巴结转移的AUC为0.813,血清miR-410-3p预测鼻咽癌早期淋巴结转移的AUC为0.855,血清ITGAV预测鼻咽癌早期淋巴结转移的AUC为0.849,三者联合预测鼻咽癌早期淋巴结转移的AUC为0.910,三者联合优于各自单独预测(Z_(联合vs L/S)=2.537、Z_(联合vs miR-410-3p)=2.612,Z联合vs ITGAV=2.614,P均<0.05)。结论鼻咽癌早期淋巴结转移患者中血清miR-410-3p显著降低,ITGAV显著升高,MRI联合血清miR-410-3p、ITGAV可提高对鼻咽癌早期淋巴结转移的预测价值。 展开更多
关键词 磁共振成像 微小核糖核酸-410-3p 整合素Αv 鼻咽癌 淋巴结转移 预测
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