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Carbon nanotube-carbon black/CaCu_(3)Ti_(4)O_(12) ternary metacomposites with tunable negative permittivity and thermal conductivity fabricated by spark plasma sintering

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Rare Metals 2023年第12期42卷 4201-4211页

作者： Yun-Peng Qu Hai-Kun Wu pei-tao xie Ni Zeng Yan-Li Chen Xiu Gong Jing-Liang Yang Qiong Peng Yu xie Xiao-Si Qi College of Physics Guizhou UniversityGuiyang 550025China Department of Chemistry City University of Hong KongHong Kong 999077China College of Materials Science and Engineering Qingdao UniversityQingdao 266071China Foshan(Southern China)Institute for New Materials Foshan 528200China Faculty of Science and Engineering Department of MaterialsThe University of ManchesterManchester M139PLUK Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005China

Metacomposites with negative permittivity usually possess huge dielectric loss,showing potential for micro-wave attenuation devices where huge heat would ***,carbon nanotube-carbon black/CaCu_(3-)Ti_(4)O_(12)(CNT-CB/CCTO)ternary metacomposites were fabricated by spark plasma *** CNT-CB dualphase filler was pre-pared through electrostatic selfassembly process in order to construct an effective 3-dimensional(3D)carbon network in CCTO *** percolation threshold of CNT-CB/CCTO composites was identified at filler content of 12.52 wt%which accompanied with an essential change of conduction *** negative permittivity was derived from low-frequency plasmonic state of the 3D carbon network,described by Drude *** problem of heat transport,generally occurring in negative permittivity materials,has been solved and optimized in obtained ternary metacomposites beneftting from the substantially high thermal conductivity(9.49-2.00 W·m^(-1)·K^(-1))and diffusivity(2.74-1.22mm^(2)·s^(-1)).This work could spark significant development of practical application of metacomposites on novel electronic devices and electromagnetic apparatus.

关键词： Metacomposites Ceramic matrix composites Negative permittivity Thermal conductivity

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Magnetic properties and special morphology of barium ferrite via electrospinning

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Rare Metals 2017年第2期36卷 113-117页

作者： Gui-Fang Liu Run-Hua Fan Zi-Dong Zhang Jing Li Min Chen Qian-Qian Li Lu Lu pei-tao xie Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

Barium ferrite micro-/nanofibers with special morphology,nanowires with diameters of 100 nm,nanoribbons with diameters of 1μm,and nanotubes with outer diameter of about 300 nm while inner diameter of 100 nm were successfully prepared via electrospinning using different solvents（dimethyl formamide（DMF）,solutions of deionized water and ethyl alcohol,and solutions of deionized water and acetic acid,respectively）.The barium ferrite micro-/nanofibers were characterized by scanning electron microscope（SEM）,X-ray diffraction analysis（XRD）,and vibration sample magnetometer（VSM）.The results demonstrate that the pure BaFe12O19 ferrite phase is successfully *** the SEM results show excellent *** magnetic hysteresis loops demonstrate that their magnetic properties are quite different with different *** specific saturation magnetization is approximately the same（46.12-49.17 A·m^2·kg^-1）,but the coercivity of the BaFe12O19 increases from wires（190.08 kA·m^-1）,ribbons（224.16 kA·m^-1） to tubes（258.88 kA·m^-1）.

关键词： Electrostatic spinning Barium ferrite Hollow fiber Ribbon fiber

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Electromagnetic attenuation property of multiphase Fe–Fe_3O_4–Al_2O_3 cermets near percolation threshold

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Rare Metals 2017年第1期36卷 42-45页

作者： Kai Sun Run-Hua Fan Zi-Dong Zhang Ke-Lan Yan Xi-Hua Zhang Chuan-Bing Cheng Min Chen pei-tao xie Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Shandong University Jinan 250061China

Cermets are widely applied as attenuating materials due to high electromagnetic loss and better mechanical properties. In this paper, multiphase cermets composed of iron, iron oxide and alumina were successfully prepared by a two-step in situ synthesis process,which includes pressureless sintering and a selective reduction in hydrogen atmosphere. The phase composition and microstructure of cermets were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM), respectively. It is shown that nanosized cuboid Fe particles and octahedral FeOparticles are distributed in alumina matrix. The permittivity and permeability of composites were tested with radio frequency impedance analyzer(0.01–1.00 GHz). The results show that permittivity presents obvious frequency dispersion. Furthermore,dielectric constants of multiphase cermets get enlarged due to the enhancement of interfacial polarization. On the other hand, there is a magnetic loss peak in permeability spectra,which indicates typical relaxation behavior. It is possible to achieve better electromagnetic attenuation property by adjusting process parameters.

关键词： Cermets Attenuating materials Percolative phenomenon Microwave absorption Metamaterials

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Spatio-temporal variability of surface chlorophyll a in the Yellow Sea and the East China Sea based on reconstructions of satellite data of 2001-2020

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Journal of Oceanology and Limnology 2024年第2期42卷 390-407页

作者： Weichen xie tao WANG Wensheng JIANG Key Laboratory of Marine Environment and Ecology Ocean University of ChinaQingdao 266100China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China

Chlorophyll-a(Chl-a)concentration is a primary indicator for marine environmental *** spatio-temporal variations of sea surface Chl-a concentration in the Yellow Sea(YS)and the East China Sea(ECS)in 2001-2020 were investigated by reconstructing the MODIS Level 3 products with the data interpolation empirical orthogonal function(DINEOF)*** reconstructed results by interpolating the combined MODIS daily+8-day datasets were found better than those merely by interpolating daily or 8-day ***-a concentration in the YS and the ECS reached its maximum in spring,with blooms occurring,decreased in summer and autumn,and increased in late autumn and early *** performing empirical orthogonal function(EOF)decomposition of the reconstructed data fields and correlation analysis with several potential environmental factors,we found that the sea surface temperature(SST)plays a significant role in the seasonal variation of Chl a,especially during spring and *** increase of SST in spring and the upper-layer nutrients mixed up during the last winter might favor the occurrence of spring *** high sea surface temperature(SST)throughout the summer would strengthen the vertical stratification and prevent nutrients supply from deep water,resulting in low surface Chl-a *** sea surface Chl-a concentration in the YS was found decreased significantly from 2012 to 2020,which was possibly related to the Pacific Decadal Oscillation(PDO).

关键词： chlorophyll a(Chl a) data interpolation empirical orthogonal function(DINEOF) empirical orthogonal function(EOF)analysis Yellow Sea East China Sea

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Guanine-derived F,N co-doped carbon-shell encapsulated iron carbide nanoparticles for enhanced CO_(2)electroreduction activity

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Nano Research 2024年第6期17卷 4744-4752页

作者： Shuo Chen Lishun pei Ying Peng Xuefei Zhang Zailai xie Key Laboratory of Advanced Carbon-Based Functional Materials(Fujian Province University) Fuzhou UniversityFuzhou 350016China

The development of highly selective,cost-effective,and energy-efficient electrocatalysts is critical for carbon dioxide reduction reaction(CO_(2)RR)to produce high-value ***,we propose a facile strategy to obtain F,N co-doped carbon-coated iron carbide(Fe3C)nanoparticles by using biomolecule guanine and hexadecafluorophthalocyanine iron as raw ***,this method involves only one-step pyrolysis and does not require any guiding agent or sacrificial *** from the advantageous surface microenvironment adjustments achieved through graphitic N(GN)and F co-doping,Fe3C@NF-G-1000 demonstrates exceptional efficacy in the electroreduction of CO_(2)to carbon monoxide(CO)with an impressive Faradic efficiency(FEco)up to 98%at the potential of−0.55 V(*** hydrogen electrode(RHE)).Furthermore,it delivers a remarkable current density of up to−43 mA·cm^(−2)and exhibits virtually no current attenuation over a span of 20 h within the flow *** from density functional theory(DFT)calculations reveal that the composite structure of GN and F co-doped graphitic layer and Fe3C exhibits different electron density distributions from that of iron carbide *** is attributed to the synergistic effect of the composite structure leading to the enrichment of electrons in the graphite layer on the surface,which contributes to the stability of the key reaction intermediate*COOH,thus,resulting in an enhanced catalytic activity and ***,this work introduces a new and promising approach to the design of green and low-cost carbon-coated metal materials for CO_(2)reduction reactions.

关键词： guanine F,N co-doped carbon dioxide reduction reaction(CO_(2)RR) Fe-based catalyst

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A review of microwave-metal discharge interaction:Mechanism,regulation,and application for synthesis of nanomaterials

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Nano Research 2024年第10期17卷 9225-9254页

作者： Yixuan xie Ruiqian Shi Benwei Fu Chengyi Song Wen Shang Peng tao tao Deng State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering Shanghai 200030China

Placing metals within microwave ovens has been generally viewed as a dangerous practice because of occurrence of violent discharge,but in recent years such discharge phenomenon has attracted increasing attention and has enabled a variety of exciting *** this work,we provide a comprehensive review of fundamental understanding of microwave-metal discharge interaction and its state-of-the-art application for nanomaterials *** introduce the microscopic interaction between different categories of materials and the electric and magnetic field of *** microwave-metal interaction,we highlight its size-dependence and point out the influence of the oxide layer on the surface of *** discuss the required conditions for occurrence of discharge,microscopic formation mechanism,and characteristic features of microwave-metal discharge *** analyzing the influence from the microwave input,discharging metals,and surrounding discharging media,we discuss the strategy for systematical regulation of the discharge *** describe the applications of the microwave-metal discharge for facile synthesis of various functional nanomaterials including core-shell carbon/metal,metal oxides,metal chalcogenides,intermetallic compounds,metallic nanoparticles and metallic compounds,and organic ***,the challenges in precise characterization and dynamic regulation of the discharge process as well as exciting application opportunities are discussed.

关键词： microwave-metal interaction discharge microwave heating skin depth nanomaterial synthesis

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Tetraphenylethene-based hole transporting material for highly efficient and stable perovskite solar cells

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Science China Chemistry 2024年第6期67卷 2009-2015页

作者： Peng Wang pei Yuan Chenghao Ge Rongjun Zhao Lin xie Yong Hua School of Materials and Energy Yunnan UniversityKunming650091China

2,2,7,7-Tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene(Spiro-OMeTAD)has been identified as the most widely used and effective hole transporting material(HTM)in perovskite solar cells(PSCs).However,the complicated multistep synthesis and low intrinsic hole mobility of Spiro-OMe TAD limit its commercialized ***,developing highly efficient HTMs with less synthetic steps becomes increasingly ***,understanding hot carriers transfer dynamics at the interface of perovskite layer and hole transport layer is crucial for further enhancing PSCs performance towards Shockley-Queisser limit,which still lacks full investigation to ***,a new HTM based on tetraphenylethene(WP1)was successfully synthesized by a simple one-step reaction *** was found that WP1-based HTM exhibits more matched energy level,higher hole mobility and conductivity than those of the control Spiro-OMe *** femtosecond transient absorption results reveal that the transfer rate of hot holes in perovskite/WP1 sample is four times higher than that of perovskite/Spiro-OMeTAD,thereby helping enhance the device ***,the efficiency of PSCs is enhanced to 24.04%(WP1)from 22.85%(Spiro-OMeTAD).Moreover,the un-encapsulated device prepared with WP1 exhibits better long-term stability,retaining 87%of its initial PCE value after storing for 72 days under air environment,while the reference device shows76%of its initial *** work indicates that simple tetraphenylethene-based organic small molecule could be a very promising HTM candidate for highly efficient PSCs,and gives some significant insights for understanding intrinsic hot carriers transfer dynamics in device.

关键词： tetraphenylethene hole transporting material perovskite solar cells mobility hot carrier

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Special Issue:Dynamic Polymer Networks

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Chinese Journal of Polymer Science 2024年第10期42卷 1401-1402页

作者： Jun-Qi Sun Zhi-Bo Li tao xie 不详

The ease of processing and light weight have made polymeric materials uniquely suited for numerous general ***,realization of their switchable chain configuration/mobility and molecular design versatility has pushed p... 详细信息

关键词： uniquely realization polymeric

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Screening of glucosinolates degrading lactic acid bacteria and their utilization in rapeseed meal fermentation

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Grain & Oil Science and Technology 2024年第3期7卷 168-176页

作者： Yifang Chen Chong xie Muhammad Bilal pei Wang Runqiang Yang College of Food Science and Technology Whole Grain Food Engineering Research CenterNanjing Agricultural UniversityNanjing 210095JiangsuChina The Sanya Institute of Nanjing Agricultural University Sanya 572024HainanChina National Technique Innovation Center for Regional Wheat Production/Key Laboratory of Crop Physiology Ecologyand ManagementMinistry of Agriculture/National Engineering and Technology Center for Information AgricultureNanjing Agricultural UniversityNanjing 210095JiangsuChina

Rapeseed meal is a promising food ingredient, but its utilization is limited by the presence of some potentially harmful ingredients, such as glucosinolates. Fermentation is a cost-effective method of detoxication but a food-grade starter culture with glucosinolates degradation capacity is required. In this study, 46 strains of lactic acid bacteria from traditional paocai brines were screened for their ability to glucosinolate degradation. The results showed that more than 50% of the strains significantly degraded glucosinolates. Two strains of Lactiplantibacillus(p7 and s7) with high capacity of glucosinolates degradation through producing enzymes were identified. Then,an optimized condition for rapeseed meal fermentation by p7 was established to degrade glucosinolates, which can achieve about 80% degradation. UPLC/Q-TOF-MS analysis showed that the degradation rate of individual glucosinolates was different and the degradation rate of gluconapin and progoitrin in rapeseed meal can reach more than 90%. Meanwhile, fermentation with p7 can improve safety of rapeseed meal by inhibiting the growth of Enterobacteriaceae and improve its nutritional properties by degrading phytic acid. The in vitro digestion experiments showed that the content of glucosinolates in rapeseed meal decreased significantly during gastric digestion. Meanwhile, fermentation with p7 can greatly improve the release of soluble protein and increase the contents of free essential amino acids, such as lysine(increased by 12 folds) and methionine(increased by 10 folds).

关键词： Rapeseed meal Glucosinolates Fermentation Lactic acid bacteria In vitro digestion

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A combined experimental and DEM investigation of grain interlocking in sheared granular assemblies

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Particuology 2024年第7期90卷 436-451页

作者： Rui Lu Qiang Luo Tengfei Wang David P.Connolly tao xie School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering(Southwest Jiaotong University) Ministry of EducationChengdu 610031China School of Civil Engineering University of LeedsLeeds LS29JTUK Department of Civil Engineering McMaster UniversityHamiltonONCanada

Compacted granular material,integral to geotechnical engineering,undergoes translation,rotation,and interlocking when subject to shear displacements or external *** present study focuses on the interlocking of heterogeneous granular materials,a complex behavior influenced by gradation,compaction,and varying particle geometry,and has consequently received limited attention in existing *** address this research gap,we conducted an analysis on the effect of grain interlocking on the shear resistance of granular assemblies,using a combination of laboratory testing and the discrete element method(DEM).Initially,large-scale direct shear tests were conducted on gravel−sand mixes with varying degrees of compaction and normal *** of the mixes also underwent subsequent shear reversal to explore the differences in grain interlocking between the two shearing processes on the shear *** analyzing the laboratory results,a mesoscopic scale investigation was performed by replicating the test using discrete element *** facilitate this,granular particle geometries were measured using 3D laser scanning based on the physical lab ***,based on these scans,discrete element R-block and ball models were utilized to construct both the coarse and fine particles within the *** vibro-compaction was employed to regulate the degree of *** results indicate that an increase in vertical pressure,coupled with a zero dilatancy angle,results in a rising stress ratio,indicative of grain *** interlocking exhibits a positive correlation with both the coarse content and the degree of compaction,and varies depending on the shear *** interlocking progresses,the shear band,induced by particle movement,expands and is associated with reduced particle rotation near the shear *** study further reveals a consistent positive correlation between interlocking and the principal orientation angle of strong normal c

关键词： Granular material Interlocking Shear resistance Direct shear Discrete element method Vibro-compaction

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