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Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang rong liu Jing-Yuan liu Wen-Wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

Experimental Investigation on Vertical Hydraulic Transport of Ores in Deepsea Mining

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China Ocean Engineering 2024年第1期38卷 42-53页

作者： liu Lei liu Jian-cheng LI Xin XU Li-xin ZHANG xiu-zhan State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Sanya Yazhou Bay Institution of Deep-sea Sci-Tech Shanghai Jiao Tong UniversitySanya 572000China China Merchants Marine And Offshore Research Institute Co. Ltd.Shenzhen 518067China China Merchants Deepsea Research Institute(Sanya)Co. Ltd.Sanya 572000China School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Deepsea mining has been proposed since the 1960s to alleviate the lack of resources on *** hydraulic transport of collected ores from the seabed to the sea surface is considered the most promising method for industrial *** the present study,an indoor model test of the vertical hydraulic transport of particles was conducted.A noncontact optical method has been proposed to measure the local characteristics of the particles inside a vertical pipe,including the local concentration and particle *** hydraulic gradient of ore transport was evaluated with various particle size distributions,particle densities,feeding concentrations and mixture flow *** transport,the local concentration is larger than the feeding concentration,whereas the particle velocity is less than the mixture *** qualitative effects of the local concentration and local fluid velocity on the particle velocity and slip velocity were *** local fluid velocity contributes significantly to particle velocity and slip velocity,whereas the effect of the local concentration is marginal.A higher feeding concentration and mixture flow velocity result in an increased hydraulic *** effect of the particle size gradation is slight,whereas the particle density plays a crucial role in the transport.

关键词： deepsea mining vertical hydraulic transport experiment flow characteristics

Wearable Leg Movement Monitoring System for High-Precision Real-Time Metabolic Energy Estimation and Motion Recognition

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Research 2024年第2期2023卷 417-429页

作者： Jinfeng Yuan Yuzhong Zhang Shiqiang liu rong Zhu State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Comprehensive and quantitative assessment of human physical activity in daily life is valuable for healthcare,especially for those who suffer from obesity and neurological disorders or are at high risk of *** wearable devices,e.g.,smartwatches,are insufficient and inaccurate for monitoring highly dynamic limb movements and assessing human ***,we report a new wearable leg movement monitoring system incorporating a custom-made motion sensor with machine learning algorithm to perceive human motion accurately and comprehensively during diverse walking and running *** system enables real-time multimodal perceptions of personal identity,motion state,locomotion speed,and energy expenditure for wearers.A general law of extracting real-time metabolic energy from leg movements is verified although individual gaits show *** addition,we propose a novel sensing configuration combining unilateral lower leg movement velocity with its angular rate to achieve high accuracy and good generalizability while simplifying the wearable *** performances in personal identification(accuracy of 98.7%)and motion-state recognition(accuracy of 93.7%)are *** wearable system also exhibites high-precision real-time estimations of locomotion speed(error of 3.04%to 9.68%)and metabolic energy(error of 4.18%to 14.71%)for new subjects across various time-varying *** wearable system allows reliable leg movement monitoring and quantitative assessment of bodily kinematic and kinetic behaviors during daily activities,as well as safe identity authentication by gait parameters,which would greatly facilitate smart life,personal healthcare,and rehabilitation training.

关键词： smart enable monitoring

Capillary Property of Entangled Porous Metallic Wire materials and Its Application in Fluid Buffers:Theoretical Analysis and Experimental Study

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Defence Technology（防务技术） 2024年第1期31卷 400-416页

作者： Yu Tang Yiwan Wu Hu Cheng rong liu Engineering Research Center for Metal Rubber School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350156China AECC Guizhou Liyang Aviation Power Co. LTDGuiyang 550014China College of Computer and Information Sciences Fujian Agriculture and Forestry UniversityFuzhou 350156China

Strong impact does serious harm to the military industries so it is necessary to choose reasonable cushioning material and design effective buffers to prevent the impact of *** on the capillary property entangled porous metallic wire materials(EPMWM),this paper designed a composite buffer which uses EPMWM and viscous fluid as cushioning materials under the low-speed impact of the recoil force device of weapon equipment(such as artillery,mortar,etc.).Combined with the capillary model,porosity,hydraulic diameter,maximum pore diameter and pore distribution were used to characterize the pore structure characteristics of *** calculation model of the damping force of the composite buffer was *** low-speed impact test of the composite buffer was *** parameters of the buffer under low-speed impact were identified according to the model,and the nonlinear model of damping force was *** test results show that the composite buffer with EPMWM and viscous fluid can absorb the impact energy from the recoil movement effectively,and provide a new method for the buffer design of weapon equipment(such as artillery,mortar,etc.).

关键词： Entangled porous metallic wire materials Capillary property Viscousfluid Low-speed impact Damping force

Global status and trends of metabolomics in diabetes: A literature visualization knowledge graph study

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World Journal of Diabetes 2024年第5期15卷 1021-1044页

作者： Hong Li liu Li Qiu-Qing Huang Si-Yao Yang Jun-Ju Zou Fan Xiao Qin Xiang xiu liu rong Yu College of Chinese Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina College of International Education Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Department of Science and Technology Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Hunan Key Laboratory of TCM Prescription and Syndromes Translational Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina College of Graduate Hunan University of Chinese MedicineHunan ChangshaHunan ProvinceChina

BACKGROUND Diabetes is a metabolic disease characterized by hyperglycemia,which has increased the global medical burden and is also the main cause of death in most *** To understand the knowledge structure of global development status,research focus,and future trend of the relationship between diabetes and metabolomics in the past 20 *** The articles about the relationship between diabetes and metabolomics in the Web of Science Core Collection were retrieved from 2002 to October 23,2023,and the relevant information was analyzed using CiteSpace6.2.2R(CiteSpace),VOSviewer6.1.18(VOSviewer),and Bibliometrix software under R *** A total of 3123 publications were included from 2002 to *** the past two decades,the number of publications and citations in this field has continued to *** United States,China,Germany,the United Kingdom,and other relevant funds,institutions,and authors have significantly contributed to this *** Reports and PLoS One are the journals with the most publications and the most *** keyword co-occurrence and cluster analysis,the closely related keywords are"insulin resistance","risk","obesity","oxidative stress","metabolomics","metabolites"and"biomarkers".Keyword clustering included cardiovascular disease,gut microbiota,metabonomics,diabetic nephropathy,molecular docking,gestational diabetes mellitus,oxidative stress,and insulin *** detection analysis of keyword depicted that"Gene","microbiota","validation","kidney disease","antioxidant activity","untargeted metabolomics","management",and"accumulation"are knowledge frontiers in recent *** The relationship between metabolomics and diabetes is receiving extensive *** nephropathy,diabetic cardiovascular disease,and kidney disease are key diseases for future research in this *** microbiota,molecular docking,and untargeted metabolomics are key research directions in the *** a

关键词： Diabetes Metabolomics Bibliometric CiteSpace VOSviewer

The coupling control of biological precursors and environmental factors onβ-carotane enrichment in alkaline lacustrine source rocks:A case study from the Fengcheng formation in the western Junggar Basin,NW China

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Petroleum Science 2024年第2期21卷 836-854页

作者： Mao-Guo Hou Ming Zha Hua liu Hai-Lei liu Jiang-xiu Qu Ablimit Imin xiu-Jian Ding Zhong-Fa Jiang School of Geosciences China University of PetroleumQingdaoShandong266580China Research Institute of Exploration and Development Xinjiang Petroleum Administration BureauKaramayXinjiang834000China

The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-*** β-carotane has been well acknowledged as an effective indicator of biological sources or depositional ***,the specific biological sources of β-carotane and the coupling control of biological sources and environmental factors on the enrichment of β-carotane in the Fengcheng *** *** on a comprehensive investigation of the bulk,molecular geochemistry,and organic petrology of sedimentary rocks and the biochemistry of phytoplankton in modern alkaline lakes,we proposed a new understanding of the biological precursors of β-carotane and elucidated the enrichment mechanism of β-carotane in the Fengcheng *** results show that the biological precursors crucially control the enrichment of β-carotane in the Fengcheng *** haloalkaliphilic cyanobacteria are the primary biological sources of β-carotane,which is suggested by a good positive correlation between the 2-methylhopane index,7-+8-methyl heptadecanes/C_(max),C_(29%),and β-carotane/C_(max)in sedimentary rocks and the predominance of cyanobacteria with abundantβ-carotene in modern alkaline *** enrichment of β-carotane requires the reducing condition,and the paleoredox state that affects the enrichment of β-carotane appears to have a *** paleoclimate conditions do not considerably impact the enrichment of β-carotane,but they have some influence on the water's paleosalinity by affecting evaporation and *** it does not directly affect the enrichment of β-carotane in the Fengcheng Fm.,paleosalinity does have an impact on the cyanobacterial precursor supply and the preservation conditions.

关键词： β-carotane enrichment Cyanobacterial input Environmental impact Alkaline lacustrine source rocks The Fengcheng formation

F-doped orthorhombic Nb_(2)O_(5) exposed with 97% (100) facet for fast reversible Liþ-Intercalation

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Green Energy & Environment 2024年第4期9卷 723-731页

作者： Xiaodi liu Yufeng Tang Dan Zhang Guangyin liu Xinwei Luo Yi Shang xiu Li Jianmin Ma College of Chemistry and Pharmaceutical Engineering Nanyang Normal UniversityNanyang473061China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu611731China

Orthorhombic Nb_(2)O_(5)(T-Nb_(2)O_(5))is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion ***,F-doped T-Nb_(2)O_(5) microﬂowers(F-Nb_(2)O_(5))are rationally synthesized through topotactic ***,F-Nb_(2)O_(5) are assembled by single-crystal nanoﬂakes with nearly 97%exposed(100)facet,which maximizes the exposure of the feasible Li^(+)transport pathways along loosely packed 4g atomic layers to the electrolytes,thus effectively enhancing the Li^(+)-intercalation ***,the band gap of F-Nb_(2)O_(5) is reduced to 2.87 eV due to the doping of F atoms,leading to enhanced electrical *** synergetic effects between tailored exposed crystal facets,F-doping,and ultrathin building blocks,speed up the Li^(+)/electron transfer kinetics and improve the pseudocapacitive properties of F-Nb_(2)O_(5).Therefore,F-Nb_(2)O_(5) exhibit superior rate capability(210.8 and 164.9 mAh g^(-1) at 1 and 10 C,respectively)and good long-term 10 C cycling performance(132.7 mAh g^(-1) after 1500 cycles).

关键词： Exposed facets Orthorhombic Nb_(2)O_(5) F-doping Pseudocapacitive intercalation anode Li-ion storage

QBIoT:A Quantum Blockchain Framework for IoT with an Improved Proof-of-Authority Consensus Algorithm and a Public-Key Quantum Signature

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Computers, Materials & Continua 2024年第7期80卷 1727-1751页

作者： Ang liu Qing Zhang Shengwei Xu Huamin Feng xiu-bo Chen Wen liu Network and Information Management Division Beijing Electronic Science and Technology InstituteBeijing100070China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China Information Security Institute Beijing Electronic Science and Technology InstituteBeijing100070China General Office Beijing Electronic Science and Technology InstituteBeijing100070China Information Security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and TelecommunicationsBeijing100876China

The Internet of Things(IoT)is a network system that connects physical devices through the Internet,allowing them to ***,IoT has become an integral part of our lives,offering convenience and smart ***,the growing number of IoT devices has brought about a corresponding increase in cybersecurity threats,such as device vulnerabilities,data privacy concerns,and network *** blockchain technology with IoT has proven to be a promising approach to enhance IoT ***,the emergence of quantum computing poses a significant challenge to the security of traditional classical cryptography used in blockchain,potentially exposing it to quantum *** support the growth of the IoT industry,mitigate quantum threats,and safeguard IoT data,this study proposes a robust blockchain solution for IoT that incorporates both classical and post-quantum security ***,we present the Quantum-Enhanced Blockchain Architecture for IoT(QBIoT)to ensure secure data sharing and integrity ***,we propose an improved Proof of Authority consensus algorithm called“Proof of Authority with Random Election”(PoARE),implemented within QBIoT for leader selection and new block ***,we develop a publickey quantum signature protocol for transaction verification in the ***,a comprehensive security analysis of QBIoT demonstrates its resilience against cyber threats from both classical and quantum *** summary,this research introduces an innovative quantum-enhanced blockchain solution to address quantum security concernswithin the realmof *** proposedQBIoT framework contributes to the ongoing development of quantum blockchain technology and offers valuable insights for future research on IoT security.

关键词： IoT quantum blockchain public-key quantum signature quantum hash function

Pt nanodendrites with a PtIr alloy surface structure exhibit excellent stability toward acidic hydrogen evolution reaction

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Nano Research 2024年第6期17卷 4844-4849页

作者： Chang liu Zongnan Wei Minna Cao rong Cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

The development of effective and stable electrocatalysts for the hydrogen evolution reaction(HER)in acidic electrolytes is a significant *** this work,homogeneous Pt nanodendrites(Pt NDs)with a PtIr shell were successfully synthesized by a two-step wet chemical *** open three-dimensional(3D)dendritic structure exhibited exceptional electrocatalytic characteristics,exposing as many active sites as ***,by alloying Ir with Pt on the surface,catalytic activity was greatly enhanced while ensuring extremely high *** surface-enriched platinum nanodendritic catalysts(Pt@PtIr NDs)outperformed the control samples and the commercial *** acidic HER test,Pt@PtIr NDs had a lower overpotential(22 mV)than Pt NDs(26 mV)and commercial Pt/C(31 mV)at 10 mA/cm^(2),and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h,which was much superior to the performance of commercial Pt/C(10 h)under identical test *** study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER.

关键词： Pt nanodendrites iridium high stability hydrogen evolution reaction alloy