检索结果-南通市图书馆

Enhancement of mechanical and tribological performance of Ti-6Al-4V alloy by laser surface alloying with Inconel 625 and SiC precursor materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第9期12卷 2089-2107页

作者： Hao-Ran CHENG Ki-Hoon SHIN Hong Seok KIM department of Mechanical engineering Graduate School of Seoul National University of Science and TechnologySeoul 01811Republic of Korea department of Mechanical and automotive engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea

This study focused on producing metal matrix composite(MMC)coatings on Ti–6Al–4V alloy through laser surface alloying using a novel combination of Inconel 625 and SiC precursor *** ratios of alloying powders were examined to evaluate surface properties such as microhardness,wear resistance,and friction coefficient,along with analyzing the phase composition and microstructure of the *** in situ synthesized MMC coatings exhibited the presence ofα-Ti,NiTi,NiTi_(2),and TiC ***,Ti_(5)Si_(3)andα-Ti/Ti_(5)Si_(3)eutectic structures were observed when the SiC content exceeded 20%.In comparison to the titanium substrate,the MMC coating significantly enhanced microhardness by over threefold and reduced wear by 95%.However,it was crucial to carefully select the appropriate combination of alloying powders to avoid a substantial decrease in friction performance and excessive formation of *** a comparative analysis of experimental results,the optimal precursor material composition was identified as 85%Inconel 625 and 15%*** study demonstrated the effective utilization of Inconel 625 and SiC alloying materials to enhance the surface properties of titanium alloys,thereby expanding their application in challenging environments.

关键词： titanium alloy Inconel 625 SiC ceramic laser surface alloying metal matrix composite(MMC)

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin Jang Yejoon Kim Hojoong Choi Jiwoong Yang Yoonsung Jung Sungkyun Choi Donghyeon Lee Ho Won Jang Sanghan Lee School of Materials science and engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea department of Materials science and engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： Photoelectrochemical Photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Porously Reduced 2-Dimensional Bi_(2)O_(2)CO_(3) Petals for Strain-Mediated Electrochemical CO_(2) Reduction to HCOOH

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第1期7卷 215-221页

作者： Won Seok Cho Dae Myung Hong Wan Jae Dong Tae Hyung Lee Chul Jong Yoo Donghwa Lee Ho Won Jang Jong-Lam Lee department of Materials science and engineering Pohang University of Science and Technology(POSTECH)Pohang Gyungbuk 37673Korea department of Materials science and engineering Research Institute of Advanced Materials Seoul National UniversitySeoul 08826Korea

Here we introduce bismuth-based catalysts for the efficient electrochemical reduction of CO_(2)to formic acid(HCOOH),which are composed of petal-shaped Bi_(2)O_(2)CO_(3)(BOC)that spontaneously formed from Bi thin film in aqueous carbonate solution at room *** the electrochemical reduction process,the BOC petals transform to reduced BOC(R-BOC)consisting of individual BOC and Bi *** mismatch between both domains induces biaxial strain at the *** functional theory calculations suggest that the tensile strain on the Bi domain stabilizes the*OCHO intermediate,reducing the thermodynamic barrier toward CO_(2)conversion to *** with the thermodynamic benefit and the unique nanoporous petal-shaped morphology,R-BOC petals have a superior Faradaic efficiency of 95.9%at-0.8 V_(RHE)for the electrochemical conversion of CO_(2)to *** work demonstrates that the spontaneously formed binary phases with desirable lattice strain can increase the activity of bismuth catalysts to the CO_(2)reduction reaction;such a strategy can be applicable in design of various electrocatalysts.

关键词： bismuth carbon dioxide reduction formic acid heterointerfaces strain

Image enhancement with intensity transformation on embedding space

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CAAI Transactions on Intelligence technology 2024年第1期9卷 101-115页

作者： Hanul Kim Yeji Jeon Yeong Jun Koh department of Applied Artificial Intelligence Seoul National University of Science and TechnologySeoulSouth Korea department of Computer science and engineering Chungnam National UniversityDaejeonSouth Korea

In recent times,an image enhancement approach,which learns the global transformation function using deep neural networks,has gained ***,many existing methods based on this approach have a limitation:their transformation functions are too simple to imitate complex colour transformations between low-quality images and manually retouched high-quality *** order to address this limitation,a simple yet effective approach for image enhancement is *** proposed algorithm based on the channel-wise intensity transformation is ***,this transformation is applied to the learnt embedding space instead of specific colour spaces and then return enhanced features to *** this end,the authors define the continuous intensity transformation(CIT)to describe the mapping between input and output intensities on the embedding ***,the enhancement network is developed,which produces multi-scale feature maps from input images,derives the set of transformation functions,and performs the CIT to obtain enhanced *** experiments on the MIT-Adobe 5K dataset demonstrate that the authors’approach improves the performance of conventional intensity transforms on colour space ***,the authors achieved a 3.8%improvement in peak signal-to-noise ratio,a 1.8%improvement in structual similarity index measure,and a 27.5%improvement in learned perceptual image patch ***,the authors’algorithm outperforms state-of-the-art alternatives on three image enhancement datasets:MIT-Adobe 5K,Low-Light,and Google HDRþ.

关键词： computer vision deep learning image enhancement image processing

Size effects of polydopamine-coated BaTiO_(3) nanoparticles on the piezoelectric performance of P(VDF-TrFE)/BaTiO_(3) composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materiomics 2024年第4期10卷 857-869页

作者： Hyeokjun Si Donghyun Lee Donghyuck Park Jeonghoon Oh Junseo Gu Inje Lee Kwanlae Kim department of Manufacturing Systems and Design engineering(MSDE) Seoul National University of Science and Technology(SeoulTech)Seoul01811Republic of Korea

The size effect of the polydopamine(PDA)-coated BaTiO_(3)(BTO)(BTO@PDA)nanoparticles(NPs)on the interfacial compatibility between BTO NPs and the polymer matrix and the resultant piezoelectric performance of the composite films remain *** this study,BTO and BTO@PDA NPs of various sizes were incorporated into a P(VDF-TrFE)matrix to prepare two series of P(VDF-TrFE)/BTO and P(VDF-TrFE)/BTO@PDA ***,the effects of the NP size on the dielectric,ferroelectric,and piezoelectric properties of the composite films were comprehensively *** the size of the BTO@PDA NPs increased,residual hole defects were clearly observed in the cross section of the composite *** deteriorated interfacial compatibility due to the large size of the BTO@PDA NPs was also confirmed by the increased dielectric permittivity of the composite film,which was induced by the intensified interfacial *** P(VDF-TrFE)/BTO@PDA composite with NPs of the smallest size(100 nm)exhibited superior piezoelectric performance owing to the excellent interfacial compatibility between the fillers and the *** piezoelectric performance was significantly enhanced by the reduced leakage current during electrical poling and reduced trap ***,the pulse waveform originating from the radial artery was precisely measured using the optimised P(VDF-TrFE)/BTO@PDA composite film.

关键词： Barium titanate and titanates Piezoelectric properties Composites Sensors

Depolarization mitigated in ferroelectric Hf_(0.5)Zr_(0.5)O_(2)ultrathin films(<5 nm)on Si substrate by interface engineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第3期13卷 282-292页

作者： Se Hyun Kim Younghwan Lee Dong Hyun Lee Geun Hyeong Park Hyun Woo Jeong Kun Yang Yong Hyeon Cho Young Yong Kim Min Hyuk Park department of Materials science and engineering College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Research Institute of Advanced Materials College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Inter-university Semiconductor Research Center College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Pohang Accelerator Laboratory Pohang University of Science&TechnologyPohang 790784Republic of Korea

(Hf,Zr)O_(2)offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the ***,scaling this material to sub-5 nm thickness poses several challenges,including the formation of an interfacial layer and high trap *** particular,a low-k SiO_(2)interfacial layer is naturally formed when(Hf,Zr)O_(2)films are directly grown on a Si substrate,leading to high depolarization fields and rapid reduction of the remanent *** address these issues,we conducted a study to significantly improve ferroelectricity and switching endurance of(Hf,Zr)O_(2)films with sub-5 nm thicknesses by inserting a TiO_(2)interfacial *** deposition of a Ti film prior to Hf_(0.5)Zr_(0.5)O_(2)film deposition resulted in a high-k TiO_(2)interfacial layer and prevented the direct contact of Hf_(0.5)Zr_(0.5)O_(2)with *** findings show that the high-k TiO_(2)interfacial layer can reduce the SiO_(2)/Si interface trap density and the depolarization field,resulting in a switchable polarization of 60.2μC/cm^(2)for a 5 nm thick Hf_(0.5)Zr_(0.5)O_(2)***,we propose that inserting a high-k TiO_(2)interfacial layer between the Hf_(0.5)Zr_(0.5)O_(2)film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of(Hf,Zr)O_(2)grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance.

关键词： ferroelectric charge trapping hafnia depolarization

Incorporation of Ionic Conductive Polymers into Sulfide Electrolyte-Based Solid-State Batteries to Enhance Electrochemical Stability and Cycle Life

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第6期7卷 4-12页

作者： Juhyoung Kim Woonghee Choi Seong-Ju Hwang Dong Wook Kim Advanced Materials Division Korea Research Institute of Chemical Technology(KRICT)Daejeon 34114Korea department of Material science and engineering Yonsei UniversitySeoul 03722Korea department of Material science and engineering Seoul National UniversitySeoul 08826Korea Advanced Materials and Chemical engineering University of Science and Technology(UST)Daejeon 34113Korea

Sulfide-based inorganic solid electrolytes are promising materials for high-performance safe solid-state *** high ion conductivity,mechanical characteristics,and good processability of sulfide-based inorganic solid electrolytes are desirable properties for realizing high-performance safe solid-state batteries by replacing conventional liquid ***,the low chemical and electrochemical stability of sulfide-based inorganic solid electrolytes hinder the commercialization of sulfide-based safe solid-state ***,the instability of sulfide-based inorganic solid electrolytes is intensified in the cathode,comprising various *** this study,carbonate-based ionic conductive polymers are introduced to the cathode to protect cathode materials and suppress the reactivity of sulfide *** instruments,including electrochemical spectroscopy,X-ray photoelectron spectroscopy,and scanning electron microscopy,confirm the chemical and electrochemical stability of the polymer electrolytes in contact with sulfide-based inorganic solid ***-based solid-state cells show stable electrochemical performance over 100 cycles when the ionic conductive polymers were applied to the cathode.

关键词： composite cathode electrochemical stability ionic conductive polymer solid-state battery sulfide solid electrolyte

Oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)particles in the air:Nonisothermal kinetic and reaction mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1839-1848页

作者： Junyi Xiang Xi Lu Luwei Bai Hongru Rao Sheng Liu Qingyun Huang Shengqin Zhang Guishang Pei Xuewei Lü School of Metallurgy and Materials engineering Chongqing University of Science and TechnologyChongqing 401331China department of Materials science and engineering Seoul National UniversitySeoul 08826Rep.of Korea College of Materials science and engineering Chongqing UniversityChongqing 400044China

High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium ***,the nonisothermal oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/*** apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek ***,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for FeV_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for FeV_(2)O_(4)and FeCr_(2)O_(4)during *** stages of the oxidation process are observed based on the oxidation conversion rate of each *** oxidation mechanisms of FeV_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct *** particular,the chemical reaction controls the entire oxidation process for FeV_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction *** to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FeVO_(4)and V2O_(5)for FeV_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.

关键词： FeV_(2)O_(4) FeCr_(2)O_(4) oxidation nonisothermal kinetics mechanism

Highly efficient vanadium redox flow batteries enabled by a trilayer polybenzimidazole membrane assembly

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第7期6卷 191-204页

作者： Trung Tuyen Bui Mingyu Shin Mohammad Rahimi Anders Bentien Yongchai Kwon Dirk Henkensmeier Hydrogen·Fuel Cell Research Center Korea Institute of Science and Technology(KIST)SeoulRepublic of Korea department of Chemical and Biomolecular engineering Seoul National University of Science and TechnologySeoulRepublic of Korea department of Biological and Chemical engineering Aarhus UniversityAarhusDenmark KIST School Division of Energy and Environment TechnologyUniversity of Science and TechnologySeoulRepublic of Korea Graduate School of Energy and Environment Korea UniversitySeoulRepublic of Korea

A novel polybenzimidazole(PBI)-based trilayer membrane assembly is developed for application in vanadium redox flow battery(VRFB).The membrane comprises a 1μm thin cross-linked poly[2,2′-(p-oxydiphenylene)−5,5′-bibenzimidazole](OPBI)sandwiched between two 20μm thick porous OPBI membranes(p-OPBI)without further lamination *** trilayer membrane demonstrates exceptional properties,such as high conductivity and low area-specific resistance(ASR)of 51 mS cm−1 and 81mΩcm^(2),*** with vanadium electrolyte increases the ASR of trilayer membrane only to 158mΩcm^(2),while that of Nafion is 193mΩcm^(2).VO^(2+)permeability is 2.73×10^(-9) cm^(2) min^(−1),about 150 times lower than that of Nafion *** addition,the membrane has high mechanical strength and high chemical stability against VO^(2+).In VRFB,the combination of low resistance and low vanadium permeability results in excellent performance,revealing high Coulombic efficiency(>99%),high energy efficiency(EE;90.8%at current density of 80mA cm^(−2)),and long-term *** EE is one of the best reported to date.

关键词： polybenzimidazole porous membrane proton conductivity trilayer VRFBs