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Failure analysis of 3D woven composites under tension based on realistic model

Chinese Journal of Aeronautics 2024年第11期37卷 242-253页

作者： Binbin ZHANG Guangchang CHEN Bing WANG Jingran GE Mengran LI Zengfei LIU Jun LIANG Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China China Helicopter Research and Development Institute Jingdezhen 333001China Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150001China Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Beijing 100081China

The failure behavior of the three-dimensional(3D)woven composites under tension are evaluated via experimentation and *** accurately depict the intricate geometry of the woven composites,including the fluctuation of yarn paths,variations in cross-section,and resin distribution,the image-aided digital elements modeling approach is ***,to further assess both the tensile performance and damage response,a realistic voxel model is established with the integration of a well-suited progressive damage *** obtained stress-strain curves align with the experimental results,and damage progression and underlying mechanisms involved are clearly ***,when subjected to warp tension,severe transverse damage and fiber bundle pull-out towards the warp yarns are observed within the curved ***,under weft loading,longitudinal damage is found to occur in the weft yarns,while the warp yarns suffer from transverse damage,leading to the formation of a smooth and brittle ***,the findings of this study hold potential to advance the engineering applications of the3D woven composites.

关键词： Mechanical properties Failure analysis Woven composites Realistic model Digital element methodology

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Solid-conversion synthesis of three-dimensionally ordered mesoporous ZSM-5 catalysts for the methanol-to-propylene reaction

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 111-122页

作者： Weilong Chun Chenbiao Yang Xu Wang Xin Yang Huiyong Chen School of Chemical Engineering Northwest UniversityXi’an 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’an 710069China

A facile synthesis of hierarchical ZSM-5 with the three-dimensionally ordered mesoporosity(3DOm ZSM-5)was achieved by solid conversion(SC)of SiO_(2)colloidal crystals to high-crystalline *** products of 3DZ5_S/C and 3DZ5_S,which were severally transformed from the carbon-padded SiO_(2)colloidal crystals and the initial SiO_(2)colloidal crystals,exhibited not only a similar ordered structure and acidity but also higher crystallinity and more balanced meso-/micropore combination in comparison with 3DZ5_C obtained by the conventional confined space crystallization *** three synthesized 3DZ5 catalysts showed improved methanol-to-propylene performance than the commercially microporous ZSM-5(CZ5),embodied in five times longer lifetime,higher propylene selectivity and S_(propylene)/S_(ethylene) ratio(P/E),and superior coke toleration with lower formation rate of coke(R_(coke)).Moreover,the 3DZ5_S catalyst in situ converted from SiO_(2)colloidal crystals presented the highest selectivities of propylene(42.51%)and light olefins(74.6%)among all three 3DZ5 *** high efficiency in synthesis and in situ utilization of SiO_(2)colloidal crystals demonstrate the proposed SC strategy to be more efficiently and eco-friendly for the high-yield production of not only 3DOm ZSM-5 but also other types of hierarchical zeolites.

关键词： hierarchical zeolite three-dimensionally ordered mesoporosity ZSM-5 solid conversion methanol-to-propylene

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Electron scattering by Friedel oscillations in carbon nanotubes

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Nano research 2022年第2期15卷 889-897页

作者： Takumi Inaba Takahiro Morimoto Satoshi Yamazaki Toshiya Okazaki CNT-Application Research Center National Institute of Advanced Industrial Science and TechnologyTsukuba 305-8565Japan Research Association of High-Throughput Design and Development for Advanced Functional Materials Tsukuba 305-8565Japan

Multi-walled carbon nanotube networks were confirmed to exhibit a linear decrease in resistivity with increasing temperature from 100 to above 400 *** linearity was explained using a defect scattering model that involved Friedel oscillations(that is,electron-electron interactions).The applicability of this model,which was originally proposed for graphene,to carbon nanotubes was assessed based on a comparison of various experimental *** in the slopes of the resistivity-temperature plots following the introduction of defects,as well as an effect of charge concentration on the slope were key predictions of this *** results obtained from few-walled carbon nanotube networks are also *** the literature,linear resistivity-temperature plots were obtained from other graphene derivatives,indicating that the linearity originates from the hexagonal symmetry of these *** present work also indicated a relationship between the appearance of linearity and negative magnetoresistance above 100 *** on a mechanism incorporating scattering in association with Friedel oscillations and conventional electron conduction models,the universality of resistivity-temperature plots obtained from carbon nanotube networks is introduced.

关键词： carbon nanotube electron transport electron-electron interaction Friedel oscillations magnetoresistance

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Classification of Medical Image Notes for Image Labeling by Using MinBERT

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Tsinghua Science and technology 2023年第4期28卷 613-627页

作者： Bokai Yang Yujie Yang Qi Li Denan Lin Ye Li Jing Zheng Yunpeng Cai Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Health Development Research and Data Management Center Shenzhen 518055China

The lack of labeled image data poses a serious challenge to the application of artificial intelligence(AI)in medical image *** image notes contain valuable patient information that could be used to label images for machine learning ***,most image note texts are unstructured with heterogeneity and short-paragraph characters,which fail traditional keyword-based *** utilized a deep learning approach to recover missing labels for medical image notes automatically by using a combination of deep word embedding and deep neural network *** encoder representations from transformers trained on medical image notes corpus(MinBERT)were *** applied the proposed techniques to two typical classification tasks:Medical image type identification and clinical diagnosis *** two methods significantly outperformed baseline methods and presented high accuracies of 99.56%and 99.72%in image type identification and of 94.56%and 92.45%in clinical diagnosis *** analysis further indicated that word embedding could efficiently capture semantic similarities and regularities across diverse *** indicated that our proposed framework could accurately recover the missing label information of medical images through the automatic extraction of electronic medical record ***,it could serve as a powerful tool for exploring useful training data in various medical AI applications.

关键词： MinBERT convolutional neural network electronic medical record medical image labeling word embedding

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1241 | Study on Classification of Excavated Soil Using Internal Sensor Data of Hydraulic Excavator 21

1241 | Study on Classification of Excavated Soil Using Inter...

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21st International and 12th Asia-Pacific Regional Conference of the International Society for Terrain-Vehicle Systems, ISTVS 2024

作者： Morisawa, Naoki Imanishi, Masaya Yanagishita, Masaki Chiba, Teiichirou Yamamoto, Hiroshi Hashimoto, Takeshi Endo, Daisuke Komatsu.Ltd. Test Engineering Center Development Division Japan Komatsu.Ltd. Corporate Technology Department Office of the CTO Japan Advanced Technology Research Team National Research and Development Agency Public Works Research Institute Japan

ISBN: (纸本)9781942112570

In these days, construction sites are facing workforce shortages caused by declining labor and lack of young workers. Therefore, "Improve Productivity" is very important. Automation and autonomy of construction machinery is one of the solutions. As above, ICT hydraulic excavators and bulldozers are widely used in many sites, but the scope of the application is limited. In particularly, automated excavating in hydraulic excavators still has many difficulties in actual use. The root cause is needed to the complicated operation during excavation affected by the soil conditions. Since the soil conditions change anytime, if the operation is not adjusted to match to them, the efficiency will be decreased significantly. In other words, to achieve automated excavating, the hydraulic excavator must recognize variation of soil conditions first. While digging, the operator has been sensing the machine's response affected by the soil conditions to consider it and adjusting machine operation simultaneously. In other words, human senses were used to recognized soil conditions to perform efficient operations. In that case, we thought that if we could replace human senses with internal sensors of the machine, the machine could recognize the soil conditions by itself. In this study, based on this hypothesis, we conducted measuring sensor data during excavating in various soil conditions (e.g. hardness, materials…). The test results indicated that the soil hardness measured by simplified N-value meter, has a high correlation with the work efficiency and bucket tooth speed calculated from internal sensor data. This implicated that the sensor data from the hydraulic excavator can be used to be determine soil conditions. In addition, there is a possibility that excavator could recognize soil conditions by itself. © 2024 International Society for Terrain-Vehicle Systems. All rights reserved.

关键词： Excavators

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Ablation resistance of ZrC coating modified by polymer-derived SiHfOC ceramic microspheres at ultrahigh temperature

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Journal of Materials Science & technology 2024年第15期182卷 119-131页

作者： Xuemeng Zhang Yuyu Zhang Lingxiang Guo Bing Liu Yuqi Wang Hongbin Li Hejun Li Jia Sun Shaanxi Key Laboratory of Fiber Reinforced Light Composite Materials State Key Laboratory of Solidification ProcessingNorthwestern Polytechnical UniversityXi’an 710072China China Aerodynamics Research and Development Center Mianyang 621000China Science and Technology on Advanced Ceramic Fibers and Composites Laboratory National University of Defense TechnologyChangsha 410073China

Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale *** the current work,ZrC coatings incorporated with polymer-derived ceramic microspheres(CMS),SiH-fOC_CMS,were deposited to enhance the ablation resistance by supersonic atmosphere plasma *** 10.0 MW·m^(-2) plasma ablation at above 3000℃,the linear ablation rate of ZrC-SiHfOC_CMS coat-ing was reduced to 0.20μm·s^(-1),62%lower than that of the pristine ZrC *** improvement was ascribed to the presentence of viscous SiO_(2)/HfO_(2) molten mixed phase,rather than HfSiO4,which can ef-fectively seal pinholes and ***,the in-situ generated crystalline SiO_(2) had a lower oxygen diffusion rate than amorphous SiO_(2),meanwhile,m-HfO_(2) could improve the stability of SiO_(2) glassy film,thus further enhancing the ablation resistance.

关键词： ZrC Polymer-derived ceramics(PDCs) Carbon/Carbon composites Plasma spraying Plasma ablation

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An improved simulation of temperature field in Laser–low current MAG of thin galvanized steel sheets

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International Journal of advanced Manufacturing technology 2025年第7期138卷 3441-3455页

作者： Xu, Shixiang Sun, Zhenbang Han, Yongquan Sun, Haotian Xing, Yucheng Zhang, Shiquan School of Materials Science and Engineering Inner Mongolia University of Technology Hohhot010051 China Engineering Research Center of Development and Processing Protection of Advanced Light Metals Ministry of Education Hohhot010051 China Inner Mongolia Metal Material Research Institute Baotou014034 China

This study aimed to achieve efficient and precise connection of thin steel sheets for vehicles by analyzing the thermal process of Laser-MAG hybrid high-speed welding lap of thin galvanized steel sheets. A high-speed camera combined with an NI AD data acquisition system were used, and the transition behavior and electrical signals of low-current MAG and Laser-MAG hybrid welding were examined. The thin sheet MAG welding droplet transition method mainly comprised short-circuit transfer. During the short-circuit phase, the voltage decreased and the current increased sharply, forming a short-circuit liquid column. When current increased to a certain level, the liquid bridge burst, the droplets carried heat and kinetic energy to the weld pool, the arc voltage returned to a no-load state, and the arc was re-ignited. In the arcing phase, the current first decreased steeply and then slowly, while the voltage decreased slowly and smoothly. According to the different heat source characteristics of the arc combustion and short-circuit stages during short-circuit transition, a new MAG heat source for low-current short-circuit transition was developed. This study employed a double-ellipse heat source with different powers for the arc combustion stage as well as a uniform body heat source that considered the thermal and kinetic energies of the melt droplets for the short-circuit stage. The thermal input of low current MAG welding was described by double-ellipse and uniform body heat source periodic loading. Moreover, the laser exerted an attraction and compression influence over the arc during the hybrid welding, which promoted the droplet transfer. Therefore, based on the novel MAG heat source, a hybrid Laser-MAG heat source in the short-circuit transition mode was developed. The laser beam heat source was described using a three-dimensional column heat source, the arc attraction and compression by the laser were considered indirectly through distribution parameter tuning for th

关键词： High speed cameras

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Interfacial B-O bonding modulated S-scheme B-doped N-deficient C_(3)N_(4)/O-doped-C_(3)N_(5) for efficient photocatalytic overall water splitting

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Chinese Chemical Letters 2025年第1期36卷 355-361页

作者： Entian Cui Yulian Lu Zhaoxia Li Zhilei Chen Chengyan Ge Jizhou Jiang Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province Yancheng Institute of TechnologyYancheng 224051China School of Environmental Ecology and Biological Engineering Key Laboratory of Green Chemical Engineering Process of Ministry of EducationEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationWuhan Institute of TechnologyWuhan 430205China

Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild ***,this process is often hindered by sluggish electron-hole separation and *** address this,a step-scheme(S-scheme)B-doped N-deficient C_(3)N_(4)/O-doped C_(3)N_(5)(BN-C_(3)N_(4)/O-C_(3)N_(5))heterojunction with interfacial B-O bonds has been *** Pt and Co(OH)_(2) as co-catalysts,BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light,achieving H_(2) and O_(2) evolution rates of 40.12 and 19.62μmol/h,*** characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O ***,the strengthened built-in electric field provides sufficient force for rapid interfacial electron ***,by reducing the transport energy barrier and transfer distance,the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route,leaving the high-potential electrons and holes available for H^(+)reduction and OH^(-)oxidation ***,the photocatalytic efficiency of BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction was significantly improved,making it a promising approach for green hydrogen production through overall pure water splitting.

关键词： Interfacial B-O bonds BN-C_(3)N_(4) O-C_(3)N_(5) S-scheme heterojunction Water splitting

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THE QUESTIONNAIRE SURVEY ON IMPROVING WORKABILITY OF HIGH-STRENGTH CONCRETE FOR CONSTRUCTOR

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AIJ Journal of technology and Design 2023年第71期29卷 13-18页

作者： Kajita, Hideyuki Kasai, Hiroshi Urakawa, Kazuya Kojima, Masaro ICI General Center Advanced Technology Center Maeda Corporation Japan Building Construction and Materials Group KAJIMA Technical Research Institute Kajima Corporation Japan Building Research Department Technology Centre Sato Kogyo Co. Ltd Japan Construction Material Group Construction Technology Research Dept. Research & Development Institute Takenaka Corporation Japan

High-strength concrete has been put into practical use by technological development of air-entraining and high-range water-reducing admixture and low-heat type cement, and has become widespread mainly in high-rise RC buildings. However, high-strength concrete with a low water-cement ratio and a large amount of cement has a high viscosity, so construction problems such as pumpability and finishability have emerged with its widespread use. Therefore, we conducted a questionnaire survey on the specific details of defects and how to improve them by modifying the mix-proportions, for construction problems such as transportation of high-strength concrete, placing and compaction, and finishing. © 2023 Architectural Institute of Japan. All rights reserved.

关键词： Cements

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Power Cycle Reliability of Cu Sintered Die-Bonding Using of Pressure Contact Structure

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Journal of Japan Institute of Electronics Packaging 2022年第3期25卷 218-224页

作者： Negishi, Motohiro Sugama, Chie Ishikawa, Dai Natori, Michiko Kawana, Yuki Nakako, Hideo Reseach & Innovation Promotion Headquarters Advanced Technology Research & Development Center 7-7 Shinkawasaki Saiwai-ku Kanagawa Kawasaki-shi212-0032 Japan Reseach & Innovation Promotion Headquarters Advanced Technology Research & Development Center 48 Wadai Ibaraki Tsukuba-shi300-4247 Japan

We are conducting the advanced development of a sintering Cu paste (with/without pressure type) for use in power devices. For this report, we carried out a power cycle test and its Weibull analysis using sintering Cu as a bonding material and compared the results to the power cycle lives of Sintering Ag and high-lead solder. The characteristic life for sintering Cu without pressure was about 14 times higher than that of high lead solder when the power cycle condition was T j max = 175°C and ΔT j = 100°C, and about 40 times higher for sintering Cu with pressure. Therefore, the sintering Cu has a superior bonding reliability compared with sintering Ag and high lead solder. Copyright© The Japan Institute of Electronics Packaging.

关键词： Sintering

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