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Thickening progression mechanism of silica fume-oil well cement composite system at high temperatures

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Petroleum Science 2024年第4期21卷 2793-2805页

作者： Hang Zhang Miao-Miao Hu Peng-Peng Li Guo-Qing Liu Qing-Lu Chang Jie Cao Ming Liu Wen-Hua Xu Xiu-Jian Xia Jin-Tang Guo School of Chemical Engineering and Technology Tianjin University Zhejiang Institute of Tianjin University Haihe Laboratory of Sustainable Chemical Transformations CNPC Engineering Technology r&d Company Limited

This work studied the thickening progression mechanism of the silica fume-oil well cement composite system at high temperatures(110-180.C) in order to provide a theoretical guidance for the rational application of silica fume in the cementing engineering. results showed that silica fume seldom affected the thickening progression of oil well cement slurry at 110-120.C, but when temperature reached above130.C, it would aggravate the bulging degree of thickening curves and significantly extend the thickening time, meanwhile causing the abnormal “temperature-based thickening time reversal” and“dosage-based thickening time reversal” phenomena in the range of 130-160.C and 170-180.C respectively. At 130-160.C, the thickening time of oil well cement slurry was mainly associated with the generation rate of calcium hydroxide(CH) crystal. The introduced silica fume would be attracted to the cement minerals' surface that were hydrating to produce CH and agglomerate together to form an“adsorptive barrier” to hinder further hydration of the inner cement minerals. This “adsorptive barrier”effect strengthened with the rising temperature which extended the thickening time and caused the occurrence of the “temperature-based thickening time reversal” phenomenon. At 170-180.C, the pozzolanic activity of silica fume significantly enhanced and considerable amount of C-S-H was generated, thus the “temperature-based thickening time reversal” vanished and the “dosage-based thickening time reversal” was presented.

关键词： Silica fume Oil well cement Thickening time reversal Pozzolanic reaction Adsorptive barrier CH and C−S−H

Microstructure and Shear Properties Evolution of Minor Fe-doped SAC/Cu Substrate Solder Joint under Isothermal Aging

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1279-1290页

作者： Quanzhen Li Chengming Li Xiaojing Wang Shanshan Cai Jubo Peng Shujin Chen Jiajun Wang Xiaohong Yuan Jiangsu University of Science and Technology Zhenjiang212003China r&d Center Yunnan Tin Group(Holding)Co.LtdKunming650000China The 58 Research Institute of China Electronics Technology Group CorporationWuxi214100China Yunnan Precious Metals Lab Sino-Platinum Metals Co.LtdKunming650156China

different amounts of Fe(0.005,0.01,0.03,0.05,and 0.07 wt%)were added to SAC305 to study the shear behavior damage of Fe-doped SAC solder joints under thermal loading(170℃,holding time of 0,250,500,and 750 h).The results show that during isothermal aging at 170℃,the average shear force of all solder joints decreases with increasing aging time,while the average fracture energy first increases and then decreases,reaching a maximum at 500 *** Fe doping could both increase shear forces and related fracture energy,with the optimum Fe doping amount being 0.03 wt%within the entire aging *** is because the doping Fe reduces the undercooling of the SAC305 alloy,resulting in the microstructure refining of solder *** in turn causes the microstructure changing from network structure(SAC305 joint:eutectic network+β-Sn)to a single matrix structure(0.03Fe-doped SAC305 joint:β-Sn matrix+small compound particles).Specifically,Fe atoms can replace some Cu in Cu_(6)Sn_(5)(both inside the solder joint and at the interface),and then form(Cu,Fe)_(6)Sn_(5) compounds,resulting in an increase in the elastic modulus and nanohardness of the ***,the growth of Cu_(6)Sn_(5) and Cu_(3)Sn intermetallic compounds(IMC)layer are inhibited by Fe doping even after the aging time prolonging,and Fe aggregates near the interface compound to form FeSn_(2).This study is of great significance for controlling the growth of interfacial compounds,stabilizing the microstructures,and providing strengthening strategy for solder joint alloy design.

关键词： SAC305 solder Fe doping Shear mechanical behavior Isothermal aging Interfacial intermetallic compounds(IMC)

droplet morphology analysis of drop-on-demand inkjet printing

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China foundry 2024年第1期21卷 20-28页

作者： Hu-xiang Xia Takechi Kensuke Tajima Shin Kawamura Yoshiumi Qing-yan Xu Key Laboratory for Advanced Materials Processing Technology(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Toyota Central r&d Labs. Inc.41-1 Yokomichi NagakuteAichi 480-1192Japan Frontier research Center Toyota Motor Corporation1 Toyota-ChoToyotaAichi 471-8572Japan

As an accurate 2d/3d fabrication tool,inkjet printing technology has great potential in preparation of micro electronic *** morphology of droplets produced by the inkjet printer has a great impact on the accuracy of *** this study,the drop-on-demand(dod)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding *** simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of *** the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)).

关键词： microdevice fabrication inkjet printing droplet morphology modeling and simulation

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Intelligent dynamic Heterogeneous redundancy Architecture for IoT Systems

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China Communications 2024年第7期21卷 291-306页

作者： Zhang Han Wang Yu Liu Hao Lin Hongyu Chen Liquan School of Cyber Science and Engineering Southeast UniversityNanjing 211102China Purple Mountain Laboratories Nanjing 211111China ZTE corporation Nanjing 210012China Carbon Peaking&Carbon Neutrality Application Technology r&d Institute Nanjing University of Posts and TelecommunicationsNanjing 210002China

The conventional dynamic heterogeneous redundancy(dHr)architecture suffers from the security threats caused by the stability differences and similar vulnerabilities among the *** overcome these challenges,we propose an intelligent dHr architecture,which is more feasible by intelligently combining the random distribution based dynamic scheduling algorithm(rd-dS)and information weight and heterogeneity based arbitrament(IWHA)*** the proposed architecture,the random distribution function and information weight are employed to achieve the optimal selection of executors in the process of rd-dS,which avoids the case that some executors fail to be selected due to their stability difference in the conventional dHr ***,through introducing the heterogeneity to restrict the information weights in the procedure of the IWHA,the proposed architecture solves the common mode escape issue caused by the existence of multiple identical error output results of similar *** experimental results characterize that the proposed architecture outperforms in heterogeneity,scheduling times,security,and stability over the conventional dHr architecture under the same conditions.

关键词： dynamic heterogeneous redundancy heterogeneity IoT security security defense

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Intelligence driven Wireless Networks in B5G and 6G Era: A Survey

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ZTE Communications 2024年

作者： GAO Yin CHEN Jiajun LI dapeng State Key Laboratory of Mobile Network and Mobile Multimedia Technology Wireless Product r&d Institute， ZTE corporation

As the wireless communication network undergoes continuous expansion， the challenges associated with network management and optimization are becoming increasingly complex. To address these challenges， the emerging artificial intelligence (AI) and machine learning (ML) technologies have been introduced as a powerful solution. They empower wireless networks to operate autonomously， predictively， on-demand， and with smart functionality， offering a promising resolution to intricate optimization problems. This paper aims to delve into the prevalent applications of AI/ML technologies in the optimization of wireless networks. The paper not only provides insights into the current landscape but also outlines our vision for the future and considerations regarding the development of an intelligent 6G network.

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Constructing high-toughness polyimide binder with robust polarity and ion-conductive mechanisms ensuring long-term operational stability of silicon-based anodes

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Journal of Energy Chemistry 2024年第6期93卷 580-591,I0014页

作者： Yongjun Kang Nanxi dong Fangzhou Liu daolei Lin Bingxue Liu Guofeng Tian Shengli Qi dezhen Wu State Key Laboratory of Chemical resource Engineering Beijing University of Chemical TechnologyBeijing 100029China ENFI r&d Institute China ENFI Engineering CorporationBeijing 100038China China Automotive Battery research Institute Co. Ltd.Beijing 101407China Changzhou Institute of Advanced Materials Beijing University of Chemical TechnologyChangzhou 213164JiangsuChina

Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical ***,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion ***,a functionalized high-toughness polyimide(PdMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(OdPA) with 4,4'-oxydianiline(OdA),2,3-diaminobenzoic acid(dABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(dMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PdMI molecular chain via a rigidness/softness coupling mechanism contributes to high *** plentiful polar carboxyl(-COOH) groups establish robust bonding *** ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PdMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles ***,the assembled SiO_x@PdMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 *** perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.

关键词： Polyimide binder High toughness robust ionic transport Silicon-based anodes Lithium-ion batteries

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Special Topic on Near-Field Communication and Sensing Towards 6G

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ZTE Communications 2024年第1期22卷 1-2页

作者： WEI Guo ZHAO Yajun CHEN Li 不详 the Wireless and Computing Product r&d Institute ZTE Corporation department of Electronic Engineering and Information Science USTC

6G wireless technologies involve dense device deployment,utilize large-scale antenna arrays,and operate in the millimeter-wave and terahertz *** will shift the challenges of communication and sensing from the far field to the radiative near field,where traditional models and algorithms may incur errors or even become obsolete due to ***,there is an urgent need to discuss localization and communication issues in the near-field *** near-field assumption allows us to capture more information in electromagnetic signals,unlocking new possibilities for improving communication quality and localization *** can be anticipated that research on the near-field will play an increasingly important role in 6G and future wireless networks.

关键词： communication millimeter antenna

Special Topic on Near-Field Communication and Sensing Towards 6G

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ZTE Communications 2024年 1-2页

作者： WEI Guo ZHAO Yajun CHEN Li the department of Electronic Engineering and Information Science USTC the Wireless and Computing Product r&d Institute ZTE Corporation the School of Information Science and Technology USTC

6G wireless technologies involve dense device deployment, utilize large-scale antenna arrays, and operate in the millimeter-wave and terahertz bands. This will shift the challenges of communication and sensing from the far field to the radiative near field, where traditional models and algorithms may incur errors or even become obsolete due to mismatch. Therefore, there is an urgent need to discuss localization and communication issues in the near-field region.

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Intelligence driven Wireless Networks in B5G and 6G Era:A Survey

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ZTE Communications 2024年第3期22卷 99-105页

作者： GAO Yin CHEN Jiajun LI dapeng State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen 518055China Wireless Product r&d Institute ZTE CorporationShanghai 201203China

As the wireless communication network undergoes continuous expansion,the challenges associated with network management and optimization are becoming increasingly *** address these challenges,the emerging artificial intelligence(AI)and machine learning(ML)technologies have been introduced as a powerful *** empower wireless networks to operate autonomously,predictively,ondemand,and with smart functionality,offering a promising resolution to intricate optimization *** paper aims to delve into the prevalent applications of AI/ML technologies in the optimization of wireless *** paper not only provides insights into the current landscape but also outlines our vision for the future and considerations regarding the development of an intelligent 6G network.

关键词： intelligent network native AI load prediction trajectory prediction