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Low-permittivity LiLn(PO_(3.)_(4)(Ln=La,Sm,Eu)dielectric ceramics for microwave/millimeter-wave communication

Journal of Advanced Ceramics 2024年第5期13卷 602-620页

作者： Huanrong Tian Xiaohan Zhang Zidong Zhang Yao Liu Haitao Wu Key Laboratory for Liquid-Solid Structural Evolution and Processing of materials(Ministry of Education) Shandong UniversityJinan 250061China school of materials science and {3. Shandong UniversityJinan 250061China school of Environmental and material engineering Yantai UniversityYantai 264005China

The development of dielectric materials with low permittivity and low loss is a great challenge in wireless *** this study,LiLn(PO_(3.)_(4)(Ln=La,Sm,Eu)ceramic systems were successfully prepared using the traditional solid-state method.X-ray diffraction analysis indicated that the LiLn(PO_(3.)_(4)ceramics crystallized in a monoclinic structure when sintered at 850–940℃.The characteristic peak shifted to higher angles with variations in the Ln element,which was ascribed to a reduction in the cell *** analysis by structure refinement revealed that the reduction in the cell volume resulted from the decrease in chemical bond lengths and the compression of[LiO_(4)]and[PO_(4)]***,the LiLn(PO_(3.)_(4)ceramic system displayed exceptional performance at low sintering temperatures(910–925℃),including a high quality factor(Q·f)of 41,607–75,968 GHz,low temperature coefficient of resonant frequency(τ_(f))ranging from−19.64 to−47.49 ppm/℃,low permittivity(ε_(r))between 5.04 and 5.26,and low density(3.04–3.26 g/cm^(3.).The application of Phillips–van Vechten–Levine(P–V–L)theory revealed that the increased Q·f value of the LiLn(PO_(3.)_(4)systems can be attributed to the enhanced packing fraction,bond covalency,and lattice energy,and the stability of τ_(f) was associated with the increase in the bond ***,a prototype microstrip patch antenna using LiEu(PO_(3.)_(4) ceramics was *** measurement results demonstrated excellent antenna performance with a bandwidth of 3.0 MHz and a peak gain of 5.11 dB at a central frequency of 5.08 ***,low-εr LiLn(PO_(3.)_(4)ceramic systems are promising candidates for microwave/millimeter-wave communication.

关键词： low permittivity LiLn(PO_(3.)_(4) microwave dielectric properties Phillips-van Vechten-Levine(P-V-L)theory microstrip patch antenna

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Deterministic learning-based neural output-feedback control for a class of nonlinear sampled-data systems

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science China(Information sciences) 2024年第9期67卷 164-183页

作者： Yu ZENG Fukai ZHANG Tianrui CHEN Cong WANG school of Automation science and engineering South China University of Technology school of Control science and engineering Shandong University

This study investigates the deterministic learning(DL)-based output-feedback neural control for a class of nonlinear sampled-data systems with prescribed performance(PP). Specifically, first, a sampleddata observer is employed to estimate the unavailable system states for the Euler discretization model of the transformed system dynamics. Then, based on the observations and backstepping method, a discrete neural network(NN) controller is constructed to ensure system stability and achieve the desired tracking performance. The noncausal problem encountered during the controller deduction process is resolved using a command filter. Moreover, the regression characteristics of the NN input signals are demonstrated with the observed states. This ensures that the radial basis function NN, based on DL theory, meets the partial persistent excitation condition. Subsequently, a class of discrete linear time-varying systems is proven to be exponentially stable, achieving partial convergence of neural weights to their optimal/actual values. Consequently, accurate modeling of unknown closed-loop dynamics is achieved along the system trajectory from the output-feedback control. Finally, a knowledge-based controller is developed using the modeling *** controller not only enhances the control performance but also ensures the PP of the tracking error. The effectiveness of the scheme is illustrated through simulation results.

关键词： deterministic learning neural networks adaptive neural control predefined performance nonlinear sampled-data systems

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Recent Progress in All-Solution-Processed Organic Solar Cells

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Chinese Journal of Chemistry 2024年第2期42卷 190-198页

作者： Yixuan Xu Qian Wang Wentao Zou Xu Zhang Yanna Sun Yuanyuan Kan Ping Cai Ke Gao school of materials science and {3.&Guangxi Key Laboratory of Information materials Guilin University of Electronic TechnologyGuilinGuangxi 541004China Shandong Provincial Key Laboratory for science of material Creation and Energy Conversion Science Center for Material Creation and Energy ConversionInstitute of Frontier and Interdisciplinary ScienceShandong UniversityQingdaoShandong 266237China

All-solution-processed organic solar cells(OSCs)(from the bottom electrode to the top electrode)are highly attractive thanks to their low cost,lightweight and high-throughput ***,achieving highly efficient all-solution-processed OSCs remains a significant *** of the key issues is the lack of high-quality solution-processed electrode systems that can replace indium tin oxide(ITO)and vacuum-deposited metal *** this paper,we comprehensively review recent advances in all-solution-processed osCs,and classified the devices as the top electrode materials,including silver nanowires(AgNWs),conducting polymers and composite conducting *** correlation between electrode materials,properties of electrodes,and device performance in all-solution-processed OSCs is *** addition,the critical roles of the active layer and interface layer are also ***,the prospects and challenges of all-solution-processed OSCs are presented.

关键词： Organic solar cells All-solution-processed organic solar cells Solution-processed electrodes High performance Silver nanowires Conductive polymers Composite conducting materials

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A novel cylindrical sandwich plate inspired by beetle elytra and its compressive properties

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science China Technological sciences 2024年第11期67卷 3465-3476页

作者： SONG YiHeng RUAN SiHan HAO Ning OKABE YoJi school of engineering The University of Tokyo school of Civil engineering Southeast University school of engineering RMIT University Institute of Industrial science The University of Tokyo

The design and experimental analysis of a semi-cylindrical structure known as the cylindrical beetle elytron plate(CBEP) were presented. Radial compression tests and finite element simulation were performed on CBEPs under 3.° and 45° inclined sliding support constraints, with a comparison made to cylindrical honeycomb plate(CHP). The study aims to investigate the superior compression performance and enhancement mechanisms of CBEPs. The results demonstrate that CBEPs exhibit a 14%–26% increase in specific load-bearing capacity and a 20% increase in specific energy absorption compared with CHPs with equal core wall thickness. Distinct “Z-shaped” tearing failures were observed, with honeycomb plates showing tearing at the center of the honeycomb walls, while beetle elytron plates exhibited tearing along the midline of the trabeculae. Three different stress patterns,including elastic-plastic development stage of arch, plastic hinge node stage, and rigid node stage, were identified and analyzed to explain the mechanical performance improvements and failure characteristics. Considering that structural damage to trabeculae mostly occurs at its junction with the skin, it is recommended to add chamfers to the junctions of CBEP. Therefore, this paper lays the groundwork for the engineering application of CBEP.

关键词： beetle elytron cylindrical beetle elytron plate compression performance failure characteristics enhancement mechanism

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Small but mighty:Empowering sodium/potassium-ion battery performance with S-doped SnO_(2) quantum dots embedded in N,S codoped carbon fiber network

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Carbon Energy 2024年第5期6卷 186-200页

作者： Shengnan He Hui Wu Shuang Li Ke Liu Yaxiong Yang Hongge Pan Xuebin Yu Institute of science and Technology for New Energy Xi'an Technological UniversityXi'anChina Department of materials science Fudan UniversityShanghaiChina Wanxiang A123.Systems Corporation HangzhouChina school of material science and {3. Shanghai UniversityShanghaiChina

SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low ***,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and *** rational structures with fast charge/ion transfer and robust stability is important to overcoming these ***,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3.nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping *** analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer *** synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term ***,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in ***,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.

关键词： carbon fiber network heteroatom doping potassium-ion battery sodium-ion battery S-SnO_(2)quantum dot

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Novel self-embedding holographic watermarking image encryption protection scheme

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Chinese Physics B 2024年第5期33卷 281-290页

作者：王励年周楠润孙博曹颖鸿牟俊 school of Information science and engineering Dalian Polytechnic UniversityDalian 116034 China school of Electronic and Electrical engineering Shanghai University of Engineering ScienceShanghai 201620China

For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is ***,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency ***,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image ***,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of *** introduced scheme can provide some support for relevant theoretical research,and has practical significance.

关键词： color image encryption Hilbert transform self-embedding watermark holographic technology

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High micropore-utilization carbon aerogel with controlled nanostructures via adjusting aggregation state of polyacrylonitrile for energy storage systems

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SusMat 2024年第4期4卷 27-38页

作者： Yuanyou Peng Yihan Fu Meimei Yu Lei Zhao Huanzhong Zeng Shengtao Niu Jie Zhang Junlong Chen Guang Liu Youzhi Wu Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Department of Polymeric Materials EngineeringSchool of Material Science and EngineeringLanzhou University of TechnologyLanzhouChina

Designing and optimizing the pore structure of porous carbon electrodes is essen-tial for diverse energy storage *** this study,an innovative approach spray phase-inversion strategy was developed for the rapid and efficient fabri-cation of controlled porous carbon ***,the aggregation structure of polyacrylonitrile is controlled by adjusting the Hansen’s solubility parameter,thereby regulating the electrode material ***,the theoretical analysis of the spray phase-inversion process revealed that this regulation pro-cess is jointly regulated by solvent hydrodynamic diameter and phase-inversion *** optimization,a novel porous carbon material was obtained that exhibited excellent performance as an electrode *** utilized in supercapacitors for energy storage,it demonstrated a high specific capacitance of 3.3.1 F g^(-1) in a 6 M KOH electrolyte ***,it has been observed that the preparation strategy for porous electrodes offers notable advan-tages in terms of excellent designability,broad universality,simplicity,and high efficiency,thereby holding promise for large-scale fabrication of diverse porous electrode materials and various types of electrodes for diverse energy storage applications.

关键词： aggregation structure electrode materials phase inversion porous carbon supercapacitors

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Mg-Al-hydrotalcite with alkaline sites protects Ni/KIT-6 from formation of amorphous coke in glycerol steam reforming via tailoring reaction intermediates

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Frontiers of Chemical science and engineering 2024年第4期18卷 25-39页

作者： Yunyu Guo Yiran Wang Yuewen Shao Shu Zhang Yi Wang Song Hu Jun Xiang Xun Hu school of material science and {3. University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China

During steam reforming,the performance of a catalyst and amount/property of coke are closely related to reaction intermediates reaching surface of a ***,modification of reaction intermediates by placing Mg-Al-hydrotalcite above Ni/KIT-6 catalyst in steam reforming of glycerol was conducted at 3.0 to 600°*** results revealed that the catalytic activity of Ni/KIT-6 in the lower bed was enhanced with either Mg1-Al5-hydrotalcite(containing more acidic sites)or Mg5-Al1-hydrotalcite(containing more alkaline sites)as upper-layer *** in situ infrared characterization of steam reforming demonstrated that Mg-Al-hydrotalcite catalyzed the deoxygenation of glycerol,facilitating the reforming of the partially deoxygenated intermediates over Ni/***-Al-hydrotalcite as protective catalyst,however,did not protect the Ni/KIT-6 from formation of more ***,this did not lead to further deactivation of Ni/KIT-6 while Mg5-Al1-hydrotalcite even substantially enhanced the catalytic stability,even though the coke was much more significant than that in the use of single Ni/KIT-6(52.7%vs.28.6%).The reason beneath this was change of the property of coke from more aliphatic to more ***5-Al1-hydrotalcite catalyzed dehydration of glycerol,producing dominantly reaction intermediates bearing C=C,which formed the catalytic coke of with carbon nanotube as the main form with smooth outer walls as well as higher aromaticity,C/H ratio,crystallinity,crystal carbon size,thermal stability,and resistivity toward oxidation on Ni/KIT-6 in the lower *** comparison,the abundance of acidic sites on Mg1-Al5-hydrotalcite catalyzed the formation of more oxygen-containing species,leading to the formation of carbon nanotubes of rough surface on Ni/KIT-6.

关键词： steam reforming of glycerol Mg-Alhydrotalcite sacrificial catalyst reaction intermediates property of coke

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Urchin-like Na-doped zinc oxide nanoneedles for low-concentration and exclusive VOC detections

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Journal of Advanced Ceramics 2024年第4期13卷 507-517页

作者： Yiwen Zhou Yifan Luo Zichen Zheng Kewei Liu Xiaoxi He Kaidi Wu Marc Debliquy Chao Zhang College of Mechanical engineering Yangzhou UniversityYangzhou 225127China material science Department University of MonsMons 7000Belgium

In the early-stage diagnosis of lung cancer,the low-concentration(<5 ppm)volatile organic compounds(VOCs)are extensively identified to be the biomarkers for breath ***,the urchin-like sodium(Na)-doped zinc oxide(ZnO)n... 详细信息

In the early-stage diagnosis of lung cancer,the low-concentration(3.1 molar ratio of Na^(+)and citric acid showed outstanding sensing properties with an optimal selectivity to various VOCs(formaldehyde(HCOH),isopropanol,acetone,and ammonia)based on working temperature ***,significantly enhanced sensitivity(21.3.5 ppm)compared with pristine ZnO(~7-fold),low limit of detection(LOD)(298 ppb),robust humidity resistance,and long-term stability of formaldehyde sensing performances were obtained,which can be attributed to the formation of a higher concentration of oxygen vacancies(20.98%)and the active electron ***,the improved sensing mechanism was demonstrated by the exquisite band structure and introduction of the additional acceptor level,which resulted in the narrowed bandgap of ZnO.

关键词： zinc oxide(ZnO) heterovalent ions doping citric acid gas sensor volatile organic compound(VOC)detection lungcancer

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Progress and prospects of chiral nanomaterials for biosensing platforms

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Rare Metals 2024年第6期43卷 2469-2497页

作者： Yu-Cheng Ouyang Bong-Jun Yeom Yuan Zhao Wei Ma school of Food science and Technology State Key Laboratory of Food Science and ResourcesJiangnan UniversityWuxi 214122China Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnanUniversityWuxi214122China Department of Chemical engineering Hanyang UniversitySeoul04763RepublicofKorea

Chiral nanomaterials have distinct chiroptical properties of preferential interactions to circularly polarized ***-based biosensors have emerged for detection of biomolecules,ions and cells in recent *** review provides an extensive overview of biosensors based on chiral nanomaterials,starting with approaches to chiral nanomaterials construction in terms of fabrication *** of chiral nanomaterials and their biosensor applications is presented for different material types,with special emphasis on the role and importance of material properties and signal generation in *** assessed the technological prospects of the emerging fields of chiral construction,circularly polarized luminescence,Raman optical activity and so on along with their current *** venues for future research on chiral nanomaterials in fabrication,biosensing,disease diagnosis and treatment are also presented in the review.

关键词： Chiral nanomaterials Circular dichroism Biosensors

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