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Bioinspired supramolecular macrocycle hybrid membranes with enhanced proton conductivity

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Nano Research 2024年第2期17卷 797-805页

作者： Pengfei Yang linlin xu Panagiotis Trogadas Marc-Olivier Coppens Yang Lan Centre for Nature Inspired Engineering Department of Chemical EngineeringUniversity College LondonLondon WC1E 7JEUK

Enhancing the proton conductivity of proton exchange membranes(PEMs)is essential to expand the applications of proton exchange membrane fuel cells(PEMFCs).Inspired by the proton conduction mechanism of bacteriorhodopsin,cucurbit[n]urils(CB[n],where n is the number of glycoluril units,n=6,7,or 8)are introduced into sulfonated poly(ether ether ketone)(SPEEK)matrix to fabricate hybrid PEMs,employing a nature-inspired chemical engineering(NICE)*** carbonyl groups of CB[n]act as proton-conducting sites,while the host–guest interaction between CB[n]and water molecules offers extra protonconducting ***,the molecular size of CB[n]aids in their dispersion within the SPEEK matrix,effectively bridging the unconnected proton-conducting sulfonic group domains within the SPEEK ***,all hybrid membranes exhibit significantly enhanced proton ***,the SPEEK membrane incorporating 1 wt.%CB[8](CB[8]/SPEEK-1%)demonstrates the highest proton conductivity of 198.0 mS·cm^(−1) at 60°C and 100%relative humidity(RH),which is 228%greater than that of the pure SPEEK membrane under the same ***,hybrid membranes exhibit superior fuel cell *** CB[8]/SPEEK-1%membrane achieves a maximum power density of 214 mW·cm^(−2),representing a 140%improvement over the pure SPEEK membrane(89 mW·cm^(−2))at 50°C and 100%*** findings serve as a foundation for constructing continuous proton-conducting pathways within membranes by utilizing supramolecular macrocycles as fuel cell electrolytes and in other applications.

关键词： supramolecular macrocycle proton conductivity cucurbit[n]uril proton exchange membrane fuel cell

Insight of enriched basalts into the nature and evolution of mantle lithosphere beneath craton margins

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Science China Earth Sciences 2024年第10期67卷 3128-3142页

作者： Hong-Kun dAI Jianping ZHENG Qing xIONG linlin HU xiang ZHOU State Key Laboratory of Geological Processes and Mineral Resources School of Earth SciencesChina University of GeosciencesWuhan 430074China

Refractory lithospheric deep roots are the cornerstone for the prolonged stability of cratons and mantle xenoliths are normally the key targets for study on the evolution of such deep roots. In regions with few mantle xenoliths, the basalts enriched in radiogenic isotopic compositions due to marked lithospheric mantle contribution are crucial to unmask the lithospheric mantle evolution based on a comprehensive study involving petrology, geochemistry and thermodynamic modelling. Here, the Early Cretaceous basalts from the northwest North China Craton with few mantle xenoliths are taken as an example to show the significance of enriched basalts on the study of lithospheric mantle. These basalts are characterized by high silica and alkali contents(SiO_(2)=45.8–59.8 wt.%, K_(2)O+Na_(2)O=4.81–9.88 wt.%), arc-type trace-element patterns and enriched radiogenic isotope compositions(e.g., ε_(Nd)=-2.64–-12.88,^(87)Sr/^(86)Sr=0.7063–0.7093). The TiO_(2) and FeO(total) contents are higher than those of natural and experimental melts from refractory mantle peridotite but comparable to those of partial melts of fertile mantle *** high contents of fluid-loving elements(e.g., Rb and Ba) suggest source metasomatism by aqueous fluids. Combined with thermodynamic modelling and regional tectonic history, these enriched basalts likely record simultaneous decompression melting of asthenosphere and low-extent melting of thin and fertile lithospheric mantle fluxed by aqueous fluids from the subducted Paleo-Asian oceanic slab. The newly unmasked lithospheric mantle under the western NCC contrasts with the coeval thick and refractory one supporting the eastern NCC, and highlights that the craton destruction, especially the loss of its ancient refractory mantle root, should take place in a diachronous manner related to the craton-girded subduction episodes. Our study illustrates the potential of enriched basalts to recover the nature and evolution of mantle lithosphere beneath craton m

关键词： Enriched basalts Lithospheric mantle Northwest North China Craton Tectonic histories Early Cretaceous

Physical Layer Security Performance Analysis in Multi-Antenna NOMA-Based UAV Relay Networks

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China Communications 2024年第9期21卷 98-108页

作者： Huang Haiyan Zhang Hongsheng Liang linlin Li Yahong School of Electronic and Information Engineering Lanzhou Jiaotong UniversityLanZhou 730070China School of Cyber Engineering Xidian UniversityXi’an 710071China

With the increasing number of communication devices and the complexity of communication environments,unmanned aerial vehicles(UAV),due to their flexible deployment and convenient networking capabilities,have shown significant advantages in tasks such as high-density communication areas and emergency rescue within special communication *** the openness of air-toground wireless communication,it is more susceptible to eavesdropping *** a result,the introduction of physical layer security(PLS)in UAV communication systems is crucial to safeguard the security of transmitted *** this paper,we investigate the PLS issues in a UAV cooperative communication system operating in Nakagami-m fading channels with the presence of friendly *** considers the effects of imperfect successive interference cancellation(i SIC)and power allocation coefficients on system performance based on non-orthogonal multiple access(NOMA)*** deriving closed-form expressions for the outage probabilities at the receiving users and the intercept probability of UAV eavesdropper(U-EAV),the performance of the considered cooperative UAV-assisted NOMA relay system with the presence of friendly interference is evaluated.

关键词： intercept probability NOMA outage

Shape Memory Polymer Composites:4d Printing,Smart Structures,and Applications

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Research 2024年第3期2023卷 319-343页

作者： Shiyu Yan Fenghua Zhang Lan Luo linlin Wang Yanju Liu Jinsong Leng Centre for Composite Materials and Structures Harbin Institute of Technology(HIT)No.2 Yikuang StreetHarbin 150000People's Republic of China department of Astronautic Science and Mechanics Harbin Institute of Technology(HIT)No.92 West Dazhi StreetHarbin 150000People's Republic of China.

Shape memory polymers (SMPs) and their composites (SMPCs) are smart materials that can be stably deformed and then return to their original shape under external stimulation, thus having a memory of their shape. Three-dimensional (3d) printing is an advanced technology for fabricating products using a digital software tool. Four-dimensional (4d) printing is a new generation of additive manufacturing technology that combines shape memory materials and 3d printing technology. Currently, 4d-printed SMPs and SMPCs are gaining considerable research attention and are finding use in various fields, including biomedical science. This review introduces SMPs, SMPCs, and 4d printing technologies, highlighting several special 4d-printed structures. It summarizes the recent research progress of 4d-printed SMPs and SMPCs in various fields, with particular emphasis on biomedical applications. Additionally, it presents an overview of the challenges and development prospects of 4d-printed SMPs and SMPCs and provides a preliminary discussion and useful reference for the research and application of 4d-printed SMPs and SMPCs.

关键词： composites printing Smart

Current optimization-based control of dual three-phase PMSM for low-frequency temperature swing reduction

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defence Technology（防务技术） 2024年第4期34卷 238-246页

作者： linlin Lu xueqing Wang Luhan Jin Qiong Liu Yun Zhang Yao Mao Key Laboratory of Optical Engineering Chinese Academy of SciencesChengdu 610209China Institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China University of Chinese Academy of Sciences Beijing 100049China College of Electrical Engineering Sichuan UniversityChengdu 610065China

In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(dTP-PMSM)drive to reduce the low-frequency temperature *** reduction of temperature swing can be equivalent to reducing maximum instantaneous phase copper loss in this ***,a two-level optimization aiming at minimizing maximum instantaneous phase copper loss at each electrical angle is ***,the optimization is transformed to a singlelevel optimization by introducing the auxiliary variable for easy *** that singleobjective optimization trades a great total copper loss for a small reduction of maximum phase copper loss,the optimization considering both instantaneous total copper loss and maximum phase copper loss is proposed,which has the same performance of temperature swing reduction but with lower total *** this way,the proposed control scheme can reduce maximum junction temperature by 11%.Both simulation and experimental results are presented to prove the effectiveness and superiority of the proposed control scheme for low-frequency temperature swing reduction.

关键词： dual three-phase PMSM Low-frequency temperature swing Copper loss Current optimization Connected neutral points

Experimental and numerical study on ignition and combustion characteristics of boron-magnesium composite powders

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Particuology 2024年第1期84卷 12-29页

作者： Shuyuan Liu Luyang Han Hongmei Liu Yingkai Song linlin Liu Songqi Hu Science and Technology on Combustion Internal Flow and Thermo-Structure LaboratoryNorthwestern Polytechnical UniversityXi'an710072China School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou213164China Shanghai Institute of Space Propulsion Shanghai201112China Shanghai Engineering Research Center of Space Engine Shanghai201112China

A high-pressure laser ignition and combustion system with adjustable oxidizer gas atmosphere is established to investigate the ignition and combustion characteristics of boron-magnesium(BM)com-posite *** ignition and combustion model of BM powders is established and validated in the present *** results show that increasing water content,O_(2) content and Mg content all result in shorter ignition delay time of BM powders,among which the effect of water content is the most ***,ignition delay time increases as pressure *** combustion time decreases with increasing Mg content and ambient pressure but increases with water *** the increase of O_(2) content,combustion time of BM powders first increases and then decreases,which means a critical O_(2) content exists above which combustion time *** results show that there exists a trade-off between ignition and combustion performance of BM composite powders.

关键词： Boron magnesium powder Laser ignition Ignition and combustion model Reaction mechanism Numerical model

Global stability for age-infection-structured human immunodeficiency virus model with heterogeneous transmission

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Infectious disease Modelling 2024年第2期9卷 437-457页

作者： Juping Zhang linlin Wang Zhen Jin Complex Systems Research Center Shanxi UniversityTaiyuanShanxi030006China Shanxi Key Laboratory of Mathematical Techniques and Big data Analysis on disease Control and Prevention Shanxi UniversityTaiyuanShanxi030006China

In this paper,we analyze the global asymptotic behaviors of a mathematical susceptible-infected(SI)age-infection-structured human immunodeficiency virus(HIV)model with heterogeneous *** analysis shows that the local and global dynamics are completely determined by the basic reproductive number R_(0).If R_(0)disease-free equilibrium is globally asymptotically *** R_(0)>1,it shows that disease-free equilibrium is unstable and the unique endemic equilibrium is globally asymptotically *** proofs of global stability utilize Lyapunov ***,the numerical simulations are illustrated to support these theoretical results and sensitivity analysis of each parameter for is R_(0)performed by the method of partial rank correlation coefficient(PRCC).

关键词： Age-infection-structured Basic reproductive number Global stability Lyapunov function Sensitivity analysis

Tunnel silicon nitride manipulated reconfigurable bi-mode nociceptor analog

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Photonics Research 2024年第8期12卷 1820-1827页

作者： CHENGdONG YANG YILONG LIU linlin SU xINWEI LI LIHUA xU QIMEI CHENG Jiangsu Province Engineering Research Center of Integrated Circuit Reliability Technology and Testing System Wuxi UniversityWuxi 214105China

Neuromorphic applications have shown great promise not only for efficient parallel computing mode to hold certain computational tasks,such as perception and recognition,but also as key biomimetic elements for th intelligent sensory system of next-generation ***,achieving such a biomimetic nociceptor tha can adaptively switch operation mode with a stimulation threshold remains a *** rational design of material properties and device structures,we realized an easily-fabricated,low-energy,and reconfigurable no *** is capable of threshold-triggered adaptive bi-mode jump that resembles the biological alarm system With a tunnel silicon nitride(Si_(3)N_(4))we mimicked the intensity-and rehearsal-triggered jump by means of th tunneling mode transition of Si_(3)N_(4)*** threshold signals the device can also express some common synaptic functions with an extremely low energy density of 33.5 f J∕μm^(2).In addition,through the modulation o Si_(3)N_(4)thickness it is relatively easy to fabricate the device with differing pain *** nociceptor analog based on a tunneling layer provides an opportunity for the analog pain alarm system and opens up a new path toward threshold-related novel applications.

关键词： Tunnel tunneling rational

An Innovative K-Anonymity Privacy-Preserving Algorithm to Improve data Availability in the Context of Big data

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Computers, Materials & Continua 2024年第4期79卷 1561-1579页

作者： linlin Yuan Tiantian Zhang Yuling Chen Yuxiang Yang Huang Li State Key Laboratory of Public Big data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China College of Information Engineering Guizhou Open UniversityGuiyang550025China Guizhou Academy of Tobacco Science Guiyang550025China

The development of technologies such as big data and blockchain has brought convenience to life,but at the same time,privacy and security issues are becoming more and more *** K-anonymity algorithm is an effective and low computational complexity privacy-preserving algorithm that can safeguard users’privacy by anonymizing big ***,the algorithm currently suffers from the problem of focusing only on improving user privacy while ignoring data *** addition,ignoring the impact of quasi-identified attributes on sensitive attributes causes the usability of the processed data on statistical analysis to be *** on this,we propose a new K-anonymity algorithm to solve the privacy security problem in the context of big data,while guaranteeing improved data ***,we construct a new information loss function based on the information quantity *** that different quasi-identification attributes have different impacts on sensitive attributes,we set weights for each quasi-identification attribute when designing the information loss *** addition,to reduce information loss,we improve K-anonymity in two ***,we make the loss of information smaller than in the original table while guaranteeing privacy based on common artificial intelligence algorithms,i.e.,greedy algorithm and 2-means clustering *** addition,we improve the 2-means clustering algorithm by designing a mean-center method to select the initial center of ***,we design the K-anonymity algorithm of this scheme based on the constructed information loss function,the improved 2-means clustering algorithm,and the greedy algorithm,which reduces the information ***,we experimentally demonstrate the effectiveness of the algorithm in improving the effect of 2-means clustering and reducing information loss.

关键词： Blockchain big data K-anonymity 2-means clustering greedy algorithm mean-center method