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Numerical study on transom stern ventilation and resistance of high-speed ship in calm water

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Journal of Hydrodynamics 2022年第5期34卷 864-875页

作者： Hui Wang Ren-chuan Zhu Meng-xiao Gu le Zha State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China

A transom stern is a common design feature for a high-speed *** the present study,the transom stern ventilation of NPL 3b,5b hull is investigated by three methods:H−H formula,Doctors’formula,and computational fluid dynamics(CFD)method at *** the CFD method,the ratios of the wave elevation and wetted area are used to determine the transom *** of results show that Doctors’formula is more accurate to calculate the critical transom draft Froude *** then a Rankine panel method(RPM)based on the high-order boundary element method incorporated the modified transom stern condition is implemented to evaluate the steady wave problem of a high-speed fishery patrol ship in calm ***,free-surface(FS)and double body(DB)simulations based on Star-CCM+are carried out to obtain the wave-making resistance and total *** results of the resistance and wave pattern around the fishery patrol ship computed by RPM show generally good agreement with experimental measurement and CFD *** results indicate that the developed Rankine panel method with transom condition could predict the resistance of high-speed displacement ships with good accuracy.

关键词： Transom ventilation computational fluid dynamics(CFD)method Rankine panel method(RPM) high-speed ship double body simulation resistance

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CFRP砂轮高速外圆磨削稳定性分析

航空制造技术 2024年第8期67卷 76-84页

作者：秦鹏冯伟刘斐张霖杨淮文曹乐张国建河南工业大学郑州450001 河南省超硬磨料磨削装备重点实验室郑州450001 白鸽磨料磨具有限公司郑州450199

为分析不同影响因素对CFRP砂轮高速外圆磨削稳定性的影响,采用铁木辛柯梁理论对具有阶梯特征的工件进行动力学分析,结合锤击试验测得砂轮动态特性,对高速磨削过程中的砂轮-工件两自由度系统进行了磨削稳定性分析。在对阶梯工件进行动力... 详细信息

为分析不同影响因素对CFRP砂轮高速外圆磨削稳定性的影响,采用铁木辛柯梁理论对具有阶梯特征的工件进行动力学分析,结合锤击试验测得砂轮动态特性,对高速磨削过程中的砂轮-工件两自由度系统进行了磨削稳定性分析。在对阶梯工件进行动力学分析的过程中,发现阶梯特征对于动态特性的影响较小,误差小于2%。在稳定性分析中发现,不同的砂轮转速和不同的工件磨削位置均会影响磨削稳定性。磨削位置越靠近工件中心,工件刚度越弱,磨削稳定性降低易诱发颤振;而在靠近顶尖支撑的位置,由于工件刚度增强,该位置的磨削稳定性将同时受到工件和砂轮的动力学性能的影响。通过磨削试验验证了分析方法的有效性,试验结果表明,工件磨削位置的刚度差异将会影响加工表面质量,由磨削失稳导致的粗糙度增幅可达51.6%。

关键词： CFRP砂轮高速磨削阶梯工件铁木辛柯梁理论磨削稳定性分析

基于红外热成像的地铁隧道渗漏水病害智能识别

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铁道建筑 2024年第7期64卷 116-120页

作者：李乐沈晨雨杜江波王耀东王尧国能运输技术研究院有限责任公司北京100190 北京交通大学机械与电子控制工程学院北京100044

为了准确、高效检测出隧道渗漏水病害,本文提出利用红外热成像技术采集图像数据,采用结合MobileNet V2的u-Net模型进行地铁隧道渗漏水病害智能识别的方法。结合MobileNet V2的u-Net模型既继承了MobileNet V2的轻量化优势,又保留了u-Net... 详细信息

为了准确、高效检测出隧道渗漏水病害,本文提出利用红外热成像技术采集图像数据,采用结合MobileNet V2的u-Net模型进行地铁隧道渗漏水病害智能识别的方法。结合MobileNet V2的u-Net模型既继承了MobileNet V2的轻量化优势,又保留了u-Net在小样本数据集上良好的分割功能。将从我国南方一地铁隧道内采集到的878张红外热成像图作为原始数据,对数据进行分割标注预处理后,建立标签为地铁隧道渗漏水的数据集。将数据集按9∶1的比例划分为训练集和测试集,使用本文方法进行渗漏水病害识别。结果表明:在保证识别精度的同时,计算参数量仅为原来的1/18,大幅降低了运算量;对小面积点状、中等面积条状和大面积复杂形状三类隧道渗漏水病害均有较好的识别效果;渗漏水区域和周围暗角均为蓝色时,采用传统数字图像处理方法比较容易受到暗角区域影响,而采用本文方法可以较准确识别渗漏水区域,说明本文方法识别效果优于传统数字图像处理方法,值得推广。

关键词：地铁隧道智能识别技术红外热成像渗漏水病害神经网络语义分割模型轻量化

HP+CVVH对重症急性胰腺炎并急性肾损伤患者血管内皮功能、肾小管功能的影响

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中国现代药物应用 2024年第8期18卷 33-37页

作者：温福铭王曼李乐贵港市人民医院急诊科 537100 贵港市人民医院重症医学科 537100

目的探讨血液灌流(HP)+连续性静脉-静脉血液滤过(CVVH)对重症急性胰腺炎并急性肾损伤患者血管内皮功能、肾小管功能的影响。方法118例重症急性胰腺炎并急性肾损伤患者,按治疗方法的不同分为观察组(68例)和对照组(50例)。对照组应用HP治... 详细信息

目的探讨血液灌流(HP)+连续性静脉-静脉血液滤过(CVVH)对重症急性胰腺炎并急性肾损伤患者血管内皮功能、肾小管功能的影响。方法118例重症急性胰腺炎并急性肾损伤患者,按治疗方法的不同分为观察组(68例)和对照组(50例)。对照组应用HP治疗,观察组应用HP+CVVH治疗。比较两组治疗情况、血管内皮功能指标[内皮素-1(ET-1)、血管内皮生长因子(VEGF)及血管性假血友病因子相关抗原(vWF:Ag)]、肾小管功能指标[尿视黄醇结合蛋白(RBP)、尿N-乙酰-β-D氨基葡萄糖苷酶(uNAG)]、血清炎症因子[C反应蛋白(CRP)、白细胞介素-2(IL-2)、肿瘤坏死因子-α(TNF-α)]。结果观察组病死率1.47%(1/68)低于对照组的8.00%(4/50),但差异无统计学意义(P>0.05);观察组腹痛消失时间(2.67±0.51)d、腹膜刺激征消失时间(3.14±0.65)d、住院时间(15.41±2.16)d短于对照组的(3.91±0.68)、(4.82±0.71)、(20.82±3.59)d(PuNAG水平低于本组治疗前,且观察组尿RBP(0.71±0.46)μg/ml、尿uNAG(1.01±0.52)u/g·Cr低于对照组的(1.62±0.51)μg/ml、(1.46±0.55)u/g·Cr(P<0.05)。治疗后,两组患者血清CRP、TNF-α、IL-2水平低于治疗前,且观察组血清CRP(8.51±1.23)mg/L、TNF-α(2.18±0.45)pg/ml、IL-2(6.53±1.08)pg/ml低于对照组的(13.48±2.58)mg/L、(3.06±0.52)pg/ml、(10.74±1.16)pg/ml(P<0.05)。结论HP+CVVH治疗重症急性胰腺炎并急性肾损伤患者取得较好效果,可改善患者血管内皮功能及肾小管功能,降低机体炎症反应,促进患者尽快恢复,值得应用。

关键词：急性胰腺炎急性肾损伤血液灌流连续性静脉-静脉血液滤过

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边缘智能与协同计算:前沿与进展

控制与决策 2024年第7期39卷 2385-2404页

作者：侯祥鹏兰兰陶长乐寇小勇丛佩金邓庆绪周俊龙南京理工大学计算机科学与工程学院南京210094 东北大学计算机科学与工程学院沈阳110819 东南大学移动通信全国重点实验室南京211111

随着万物互联时代的到来,边缘设备规模急剧增加,海量数据在网络边缘产生,人工智能技术的飞速发展为分析和处理这些数据提供了强大的支撑.然而,传统云计算的集中处理模式难以满足用户对任务低时延和设备低功耗的需求,并带来数据隐私泄露... 详细信息

随着万物互联时代的到来,边缘设备规模急剧增加,海量数据在网络边缘产生,人工智能技术的飞速发展为分析和处理这些数据提供了强大的支撑.然而,传统云计算的集中处理模式难以满足用户对任务低时延和设备低功耗的需求,并带来数据隐私泄露的潜在隐患.与此同时,嵌入式高性能芯片的发展显著提升了边缘设备的计算能力,使其能够在边缘侧实时处理部分计算密集型任务.在此背景下,边缘计算和人工智能有机融合,孕育了一种新的计算范式:边缘智能.鉴于此,聚焦边缘智能与协同计算的前沿与进展,首先概述边缘计算、人工智能和边缘智能的相关背景、基本原理与发展趋势;然后从训练、推理和缓存3个方面回顾面向单个设备的边缘智能方法;接着从架构、技术和功能3个维度介绍多个设备合作实现边缘智能协同的相关工作;最后总结边缘智能在工业物联网、智慧城市和虚拟现实等领域的广泛应用.

关键词：边缘智能边缘设备边缘训练边缘推理边缘缓存协同计算

FairCF: fairness-aware collaborative filtering

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Science China(Information Sciences) 2022年第12期65卷 127-141页

作者： Pengyang SHAO le Wu lei CHEN Kun ZHANG Meng WANG School of Computer Science and Information Engineering Hefei University of Technology Intelligent Interconnected Systems Laboratory of Anhui Province Institute of Artifcial Intelligence Hefei Comprehensive National Science Center

Collaborative filtering(CF) techniques learn user and item embeddings from user-item interaction behaviors, and are commonly used in recommendation systems to help users find potentially desirable items. Most CF models optimize recommendation accuracy; however, they may lead to unwanted biases for particular demographic groups. Thus, we focus on learning fair representations of CF-based recommendations. We formulate this problem as an optimization task with two competing goals: embedding representations better meet accuracy requirements of recommendations, and simultaneously obfuscate information hidden in the embedding space, which is related to the users’ sensitive attributes for fairness. Here,the intuitive idea is to use fair representation learning from machine learning to train a classifier with a sensitive attribute predictor from the user side to satisfy the fairness goal. However, such fair machine learning models assume entity independence, which differs greatly from CF because users and items are correlated collaboratively via user-item behaviors. Therefore, sensitive user information can be exposed from the users’ preferred items. Consequently, defining only fairness constraints on users cannot achieve fairness in recommendation systems. In this paper, we propose FairCF framework for fairness-aware collaborative *** particular, we first define fairness constraints in a fair embedding space, where both a user classifier and an item classifier are employed to fit the fairness constraints. We then design an item classifier without item sensitive labels. The proposed framework can be trained in an end-to-end manner under most embedding based CF models. Extensive experiments conducted on three datasets(Movie lens-100K, Movie lens-1M,and Lastfm-360K) clearly demonstrate the superiority of the proposed FairCF framework relative to various fairness metrics(i.e., performance of newly-trained classifiers) than other state-of-the-art fairness-aware CF mode

关键词： recommendation systems fairness adversarial learning

Phase-field framework with constraints and its applications to ductile fracture in polycrystals and fatigue

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npj Computational Materials 2022年第1期8卷 149-163页

作者： Fei Xue Tian-le Cheng Yinkai lei You-Hai Wen u.S.DOE National Energy Technology Laboratory AlbanyOR 97321USA leidos Research Support Team AlbanyOR 97321USA

Modeling of ductile fracture in polycrystalline structures is challenging,since it requires integrated modeling of cracks,crystal plasticity,and *** we extend the typical phase-field framework to the situations with constraints on the order parameters,and formulate two types of phase-field models on ductile *** Type-Ⅰ model incorporates three sets of order parameters,which describe the distributions of cracks,plastic strain,and grains,*** plasticity is employed within grain interiors accommodated by J_(2)plasticity at grain *** applications of the Type-Ⅰ model to single crystals and bicrystals demonstrate the influences of grain orientations and grain boundaries on crack *** the Type-Ⅱ model,J_(2)plasticity is assumed for the whole system and grain structures are *** advantage of the efficiency of the fast Fourier transform,our Type-Ⅱ model is employed to study low cycle *** closure and striation-like patterning of plastic strain are observed in the *** growth rate is analyzed as a function of the J-integral,and the simulated fatigue life as a function of plastic strain agrees with the Coffin–Manson relation without a priori assumption.

关键词： ductile fatigue grain

AuNP aggregation-induced quantitative colorimetric aptasensing of sulfadimethoxine with a smartphone

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Chinese Chemical letters 2022年第6期33卷 3078-3082页

作者： Xiaoliang Zhang le Wang Xiaochun Li Xiujun Li College of Biomedical Engineering Taiyuan University of TechnologyTaiyuan 030024China Department of Chemistry and Biochemistry University of Texas at El PasoEl PasoTexas 79968United States

A gold nanoparticle(AuNP)aggregation-induced colorimetric aptasensing method for quantitative detection of sulfadimethoxine(SDM)with a smartphone was *** were complexed with aptamers which protected Au NPs from aggregating in high-concentration salt *** the presence of SDM,SDM bound with the aptamer on the surface of Au NPs with higher affinity,which competitively desorbed the aptamer from the AuNP surface and resulted in AuNPs aggregation,accompanied with a color change from red to *** R,G and B values of images taken by a smartphone camera were analyzed with an app on the smartphone,and were utilized for quantitative analysis of *** the optimized conditions,the colorimetric aptasensing method using a smartphone showed high sensitivity for SDM,with the limit of detection of 0.023 ppm,lower than the allowed maximum SDM residue *** study provides a simple,fast,and easy to read method for on-site quantitative biochemical and cellular analysis.

关键词： Smartphone AuNP aggregation Quantitative colorimetric assay Antibiotics Aptamer biosensor Sulfadimethoxine

Research methods and influencing factors of interfacial heat transfer during sub-rapid solidification process of strip casting

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Journal of Iron and Steel Research(International) 2022年第1期29卷 3-16页

作者： Wan-lin Wang Cheng Lu le-jun Zhou Pei-sheng Lyu School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina National Center for International Research of Clean Metallurgy Central South UniversityChangsha 410083HunanChina

Interfacial heat transfer behavior between the molten steel and twin-rolls is a key issue in the strip casting process,and it has already attracted wide attention from industrial and academic communities of *** research methods and influencing factors on the interfacial heat transfer were *** simulation models,semi-industrial scale,and laboratory equipment have been developed in this field,and these methods were also improved by worldwide researchers based on the development of computer,automatic,and visual *** properties,naturally deposited film,and casting parameters are the main factors which affect the heat transfer *** lots of research has been carried out,the internal relations among these influencing factors,interfacial heat transfer,and the quality of the strip are still worth to be further *** Strip casting Interfacial heat transfer Simulation method Coating property Naturally deposited film Casting parameter.

关键词： Strip casting Interfacial heat transfer Simulation method Coating property Naturally deposited film Casting parameter