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High-tenacity in-situ Ti/Zr-based bulk metallic glasses composites fabricated by industrial high-pressure die casting

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Journal of Materials Science & Technology 2024年第3期170卷 177-185页

作者： Yang li Wenbo Luo Ying Jin Zhiyong Xue Guiqing Wang Yanan Ren haoxin li Haibo Ke Baoan Sun Weihua Wang Institute for Advanced Materials North China Electric Power UniversityBeijing 102206China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China

The glass-forming ability and mechanical properties of metallic glasses and their composites are well known to be sensitive to the preparation conditions and are highly deteriorated by industrial preparing conditions such as low-purity raw materials and low vacuum.Here,we showed that a series of in-situ bulk metallic glass composites(BMGCs)which exhibit excellent ductility and segmental work hardening were successfully developed utilizing a high vacuum high-pressure die casting(HV-HPDC)technology along with industrial-grade raw materials.The tensile properties of these BMGCs are systematically investigated and correlated with the alloy microstructure.As compared with the copper mold suction casting method,the volume fraction difference of the dendrite phase for the BMGCs with the same composition is not significant when fabricated by the HV-HPDC,whereas the size of theβ-phase is generally larger.Insitu BMGCs with the composition of Ti_(48)Zr_(20)(V_(12/17)Cu_(5/17))19 Be 13 obtained by the HV-HPDC process show ductility up to 11.3%under tension at room temperature and exhibit a certain amount of work hardening.Two conditions need to be met to enable the BMGCs,which are prepared by vacuum die-casting to retain favorable ductility:(1)The volume fraction ofβphase stays below 62%±2%;(2)The equiaxed crystals with a more uniform size in the range of 5-10μm.Meanwhile,the results of the present study provided guidance for developing BMGCs with good ductile properties under industrial conditions.

关键词： Vacuum die casting Bulk metallic glass composites Mechanical properties β-phase

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Weakly supervised action anticipation without object annotations

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Frontiers of Computer Science 2023年第2期17卷 101-110页

作者： Yi ZHONG Jia-Hui PAN haoxin li Wei-Shi ZHENG School of Computer Science and Engineering Sun Yat-sen UniversityGuangzhou 510006China Key Laboratory of Machine Intelligence and Advanced Computing Ministry of EducationGuangzhou 510006China

Anticipating future actions without observing any partial videos of future actions plays an important role in action prediction and is also a challenging task.To obtain abundant information for action anticipation,some methods integrate multimodal contexts,including scene object labels.However,extensively labelling each frame in video datasets requires considerable effort.In this paper,we develop a weakly supervised method that integrates global motion and local finegrained features from current action videos to predict next action label without the need for specific scene context labels.Specifically,we extract diverse types of local features with weakly supervised learning,including object appearance and human pose representations without ground truth.Moreover,we construct a graph convolutional network for exploiting the inherent relationships of humans and objects under present incidents.We evaluate the proposed model on two datasets,the MPII-Cooking dataset and the EPIC-Kitchens dataset,and we demonstrate the generalizability and effectiveness of our approach for action anticipation.

关键词： action anticipation weakly supervised learning relation modelling graph convolutional network

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Silicon carbide waste as a source of mixture materials for cement mortar

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Frontiers of Environmental Science & Engineering 2017年第5期11卷 47-54页

作者： Zhengwu Jiang Qiang Ren haoxin li Qing Chen Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University Shanghai 201804 China

This paper presents an investigation of the feasibility of recycling silicon carbide waste （SCW） as a source of mixture materials in the production of cement mortar. Mortars with SCW were prepared by replacing different amounts of cement with SCW, and the properties of the resulting mortars, such as the fluidity, strength and shrinkage, were studied in this work. Thermogravimetry-differential scanning calorimet;＇y and scanning electron microscopy were employed to understand the reasons for the property changes of the mortars. The results indicate that SCW decreases the initial and l-h fluidity of fresh mortar but improves the loss of fluidity. The mortar with SCW exhibits a lower strength at 3 d and7 d but a higher strength at 28 d and 56 d compared to the control. The shrinkage rate of cement mortar with SCW shows an obvious decrease as the replacement ratio increases. In addition, the content of calcium hydroxide in hardened paste also shows that SCW has some impact on the hydration of the cement-SCW system. The microstructures of the hardened paste also show evidence for a later strength change of mortar containing SCW. This work provides a strategic reference for possibly applying SCW as a mixture material in the production of cement mortar.

关键词： Silicon carbide waste Cement mortar Fluidity Strength Shrinkage

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奇异值分解五阶容积卡尔曼滤波汽车状态估计

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重庆理工大学学报（自然科学） 2024年第3期38卷 74-83页

作者：吴伟斌黄靖凯曾锦彬李浩欣华南农业大学工程学院广州510642

针对三阶滤波对高维汽车非线性模型估计精度有限的问题,以电动汽车为研究对象,提出了一种基于奇异值分解的五阶容积卡尔曼滤波(SVD-FCKF)车辆状态估计器。首先基于Dugoff轮胎模型,构建高维非线性7自由度车辆动力学模型。然后根据三阶球... 详细信息

针对三阶滤波对高维汽车非线性模型估计精度有限的问题,以电动汽车为研究对象,提出了一种基于奇异值分解的五阶容积卡尔曼滤波(SVD-FCKF)车辆状态估计器。首先基于Dugoff轮胎模型,构建高维非线性7自由度车辆动力学模型。然后根据三阶球面-径向容积规则将CKF拓展到五阶,使其具有五阶泰勒级数展开精度,同时利用奇异值分解代替传统Cholesky分解,提高估计器的鲁棒性。最后利用Carsim和Matlab/Simulink联合仿真平台对SVD-FCKF进行验证,结果表明:改进的SVD-FCKF估计器能够有效提高电动汽车纵向速度、侧向速度、质心侧偏角和四轮转速的估计精度和稳定性,多工况适应能力强,整体估计效果优于CKF估计器。研究结果为电动汽车主动安全研究提供了理论支撑,具有实际应用价值。

关键词：车辆动力学模型状态估计奇异值分解五阶容积卡尔曼滤波

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北京市城区肺癌高危人群低剂量螺旋CT筛查依从性及其影响因素分析

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中国肿瘤 2024年第6期33卷 486-491页

作者：李晴雨杨雷张希刘硕李慧超李浩鑫曹莉莉季加孚王宁北京大学肿瘤医院暨北京市肿瘤防治研究所北京市肿瘤防治研究办公室恶性肿瘤发病机制及转化研究教育部重点实验室北京大学第一医院北京大学肿瘤医院暨北京市肿瘤防治研究所胃肠肿瘤中心一病区消化系肿瘤整合防治全国重点实验室恶性肿瘤转化研究北京市重点实验室

[目的]分析2014—2019年北京市城区肺癌高危人群低剂量螺旋CT(LDCT)筛查依从性及其影响因素。[方法]采用整群抽样方法，选取来自北京市东城、西城、朝阳、海淀、丰台和石景山共6个城区癌症早诊早治项目点的40～69岁北京市户籍居民进行... 详细信息

[目的]分析2014—2019年北京市城区肺癌高危人群低剂量螺旋CT(LDCT)筛查依从性及其影响因素。[方法]采用整群抽样方法，选取来自北京市东城、西城、朝阳、海淀、丰台和石景山共6个城区癌症早诊早治项目点的40～69岁北京市户籍居民进行问卷调查以评估癌症风险，对评估出的肺癌高危人群开展LDCT筛查。采用χ2检验比较不同特征人群的LDCT筛查参与率（依从性）差异，采用多因素非条件Logistic回归模型分析其影响因素。[结果]共88 044名北京市城区居民参与调查，其中20 371人被评估为肺癌高危人群，高危率为23.1%。有10 645人接受了LDCT筛查，总体参与率为52.3%。多因素Logistic回归分析显示，女性、50岁及以上年龄组、大学/大专及以上学历、存在有害职业暴露、家庭做饭时油烟较多、有被动吸烟史、自报存在精神创伤或压抑的人群LDCT筛查依从性更好，目前正在吸烟的人群依从性较差。[结论]北京市城区肺癌高危人群的LDCT筛查依从性仍有提升空间。未来应针对不同特征人群实施更加精准的健康教育和管理策略，进一步提高肺癌高危人群的LDCT筛查依从性。

关键词：肺癌筛查低剂量螺旋CT 依从性影响因素北京

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Simulation of Ultrasonic Propagation in Transformers within Thermal Fields and Intelligent Methodology for Hot-spot Temperature Recognition

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Chinese Journal of Electrical Engineering 2024年第1期10卷 35-47页

作者： Dongxin He Dechao Yang Xinhua Guo Jiefeng liu haoxin Guo Qingquan li Gilbert Teyssedre School of Electrical Engineering Shandong UniversityJinan 250061China School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan 430070China School of Electrical Engineering Guangxi UniversityGuangxi 530004China UPS INPTCNRSLAPLACE(Laboratoire Plasma et Conversion d’Energie)University of ToulouseToulouse 31100France

Hot-spot temperature of transformer windings is a crucial indicator of internal defects.However,current methods for measuring the hot-spot temperature of transformers do not apply to those already in operation and suffer from data lag.This study introduces a novel inversion method that combines ultrasonic sensing technology,multiphysics simulation,and the K-nearest neighbors algorithm.Leveraging the penetrative ability and temperature sensitivity of ultrasonic sensing,a detailed physical field simulation model was established.This study extensively investigates the characteristics of ultrasonic wave signals inside transformers.The investigation includes different temperature fields,ranging from 40℃ to 110℃ at 10℃ intervals,and various ultrasonic wave emitter conditions.By extracting the key features of the acoustic signals,such as the peak time,propagation time,and peak amplitude,an accurate inversion of the winding hot-spot temperature is successfully achieved.The results demonstrate that this method achieves a high accuracy rate(98.57%)in inverting the internal winding hot-spot temperatures of transformers,offering an efficient and reliable new approach for measuring winding hot-spot temperatures.

关键词： Ultrasonic temperature measurement non-destructive testing oil-immersed transformers machine learning

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Effect of Waste Paper Fiber on Properties of Cementbased Mortar and Relative Mechanism

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Journal of Wuhan University of Technology(Materials Science) 2018年第2期33卷 419-426页

作者：王中平 li haoxin 蒋正武 chen qi Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University Shanghai 200092 China

The aim of this work was to investigate the effect of waste paper fiber on the properties of cement-based mortar and the relative mechanism. The cement-based mortars with various contents and mixing way of waste paper fibers were prepared and the slump flow, setting time and strength developments of all mortars were tested. Besides, Ca（OH）_2 content in hardened pastes at different ages and the microstructures of all mortar at 90 d were observed by scanning electron microscopy. The experimental results showed that in the process of mixing, more superplastizier was consumed to maintain the workability because of the absorption of water and superplastizer on waste paper fiber. With more waste paper fiber being added, longer setting time is available for the pastes with it because of the carbohydrate dissolving and its retarding to the cement hydration. Waste paper fiber is adverse to the early and later strength of cement-based mortar, but it increases the mortar strengths at 7 and 28 d. The strength, Ca（OH）_2 content and microstructure are related to the content and mixing way of waste paper fiber. Waste paper fiber helps produce the Ca（OH）_2 at 7 and 28 d, but this case is reverse at ages of 1 and 3 d. Overall, waste paper fiber leads to the appearance of more pores in the hardened paste. However, it increases the toughness of cement-based mortar.

关键词： waste paper fibers setting times strength Ca（OH）_2 content microstructure

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Properties of Bamboo Charcoal and Cement-based Composite Materials and Their Microstructure

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Journal of Wuhan University of Technology(Materials Science) 2017年第6期32卷 1374-1378页

作者：王中平 li haoxin 蒋正武 CHEN Qing Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University Shanghai 200092 China

The objective of this work was to study the properties of bamboo charcoal and cement-based composite materials and their microstructure. The pastes with various bamboo charcoals were prepared and the relative properties such as setting times and strength were tested and the microstructures and pore characteristics of pastes with various bamboos were also studied. The experimental results indicated that bamboo charcoal affects the setting times of cement paste, but the introduction of water reducer relieves this condition. Bamboo charcoal also poses an impact on the hardened paste strength. The prominent strength decrease is found when more and larger size bamboo charcoal is mixed into the cement paste. Bamboo charcoal alters the paste microstructure and increases the porosity and pore volume, but it increases the pores with the diameter of less than 50 μm. The pastes with various bamboo charcoals are given with the good functions such as adjusting humidity and adsorption.

关键词： bamboo charcoal cement-based materials setting time compressive strength porestructure

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Leaching kinetics of fluorine during the aluminum removal from spent li-ion battery cathode materials

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Journal of Environmental Sciences 2024年第4期138卷 312-325页

作者： Shengjie li Jianxin Zhu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

The high content of aluminum(Al)impurity in the recycled cathode powder seriously affects the extraction efficiency of Nickel,Cobalt,Manganese,and lithium resources and the actual commercial value of recycled materials,so Al removal is crucially important to conform to the industrial standard of spent li-ion battery cathode materials.In this work,we systematically investigated the leaching process and optimum conditions associated with Al removal from the cathode powder materials collected in a wet cathode-powder peeling and recycling production line of spent li-ion batteries(liBs).Moreover,we specifically studied the leaching of fluorine(F)synergistically happened along with the removal process of Al,which was not concerned about in other studies,but one of the key factors affecting pollution prevention in the recovery process.The mechanism of the whole process including the leaching of Al and F from the cathode powder was indicated by using NMR,FTIR,and XPS,and a defluoridation process was preliminarily investigated in this study.The leaching kinetics of Al could be successfully described by the shrinking core model,controlled by the diffusion process and the activation energy was 11.14 kJ/mol.While,the leaching of F was attributed to the dissolution of liPF6and decomposition of PVDF,and the kinetics associated was described by Avrami model.The interaction of Al and F is advantageous to realize the defluoridation to some degree.It is expected that our investigation will provide theoretical support for the large-scale recycling of spent liBs.

关键词： Al removal F leaching Cathode powder Heating alkali leaching Leaching kinetics

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Property and Degradation Characteristics of Concrete Prepared with Aggregate Contained Montmorillonite

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Journal of Wuhan University of Technology(Materials Science) 2019年第1期34卷 127-131页

作者：王艳伟 XU Chao 李好新 China Railway No.9 Engineering Testing CO. Ltd Key Laboratory of Advanced Civil Engineering Materials Ministry of Education Tongji University School of Materials Science and Engineering Tongji University

To evaluate the property and degradation characteristics of concrete prepared with aggregate contained montmorillonite, concretes were prepared with aggregates contained montmorillonite, and then concrete slump loss, compressive strength, electric flux, the resistance to carbonization, freezing-thawing and sulfate attack were evaluated. The results show that montmorillonite appearance alters concrete slump loss and compressive strength. But montmorillonite increases electric flux and compactness. The carbonization, freezingthawing and sulfate attack results indicate that montmorillonite enhances carbonization depth, increases mass loss after 300 cycle freezing-thawing, as well as mass loss after sulfate attack. Overall, it is adverse to the concrete resistance to the carbonization, freezing-thawing and sulfate attack.

关键词： property degradation montmorillonite slump durability

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