检索结果-南通市图书馆

CO Catalytic Oxidation of Pt-Loaded Perovskite BaTiO_3 Near Ferroelectric-Phase Transition Temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第10期31卷 1031-1037页

作者： Si-Min Yin Jia-Jie Duanmu Yong-Feng Yuan Shao-Yi Guo zhi-chao zhu Zhao-Hui Ren Gao-Rong Han College of Machinery and Automation Zhejiang Sci-Tech University State Key Lab of Silicon Materials School of Materials Science and Engineering Zhejiang University

Perovskite BaTiO3 （BTO） nanocrystals with a size of 150-200 nm have successfully been synthesized via a facile hydrothermal method by employing titanate nanowires as synthetic precursor. Tetragonality and spontaneous ferroelectric polarization of BTO nanocrystals have been determined by X-ray diffraction and transmission electron microscopy investigations. BTO nanocrystals loaded with Pt nanoparticles in a size of 2-5 nm have been explored as a catalyst towards CO oxidation to CO2. It is interesting to find that CO catalytic conversion rate over Pt-BTO nanocrystals gradually decreased and further increased near 100 ℃ when the catalytic temperature keeps increasing, whereas the conversion behavior in oxides is expected to be enhanced upon the catalytic temperature grows. Using differential scanning calorimetry and first-principle calculations, the observed catalytic behavior has been discussed on the basis of the ferroelectric polarization effect and the ferroelectric-paraelectric transition of BTO nanocrystals with a Curie temperature of 110 ℃. Below Curie temperature, CO catalytic oxidation could be significantly tailored by ferroelectric polarization of BTO nanocrystals via a promoted dissociation of O2 molecules. The findings suggest that a ferroelectric polarization in perovskite oxides could be an alternative way to modify the CO catalytic oxidation.

关键词： Perovskite Ferroelectric materials BaTiO3 Pt Catalysis

A general framework for describing photofission observables of actinides at an average excitation energy below 30 MeV

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第8期46卷 170-183页

作者： Guan-Lin Wang Hao-Yang Lan Xiao-Ming Shi zhi-chao zhu Wen Luo School of Nuclear Science and Technology University of South ChinaHengyang 421001China

A reasonable prediction of photofission observables plays a paramount role in understanding the photofission process and guiding various photofission-induced applications,such as short-lived isotope production,nuclear waste disposal,and nuclear ***,the available experimental data for photofission observables are limited,and the existing models and programs have mainly been developed for neutron-induced fission *** this study,a general framework is proposed for characterizing the photofission observables of actinides,including the mass yield distributions(MYD) and isobaric charge distributions(ICD) of fission fragments and the multiplicity and energy distributions of prompt neutrons(n_(p)) and prompt γ rays(γ_(p)).The framework encompasses various systematic neutron models and empirical models considering the Bohr hypothesis and does not rely on the experimental data as *** models are then validated individually against experimental data at an average excitation energy below 30 MeV,which shows the reliability and robustness of the general ***,we employ this framework to predict the characteristics of photofission fragments and the emissions of prompt particles for typical actinides including ^(232)Th,^(235,238)U and ^(240)*** is found that the ^(238)U(γ,f) reaction is more suitable for producing neutron-rich nuclei compared to the ^(232)Th(γ,f) *** addition,the average multiplicity number of both n_(p) and yp increases with the average excitation energy.

关键词： general framework photofission observables mass yield distributions isobaric charge distributions prompt neutron andγrays

Growth and physical characterization of high resistivityFe:β-Ga2O3 crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第8期29卷 424-427页

作者： Hao Zhang Hui-Li Tang Nuo-Tian He zhi-chao zhu Jia-Wen Chen Bo Liu Jun Xu MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringInstitute for Advanced StudyTongji UniversityShanghai 200092China School of Chemical Science and Engineering Tongji UniversityShanghai 200092China Shanghai Engineering Research Center for Sapphire Crystals Shanghai 201899China

High quality 0.02 mol%,0.05 mol%,and 0.08 mol%Fe:β-Ga2O3 single crystals were grown by the floating zone *** crystal structure,optical,electrical,and thermal properties were measured and ***:β-Ga2O3 single crystals showed transmittance of higher than 80%in the near infrared *** the increase of the Fe doping concentration,the optical bandgaps reduced and room temperature resistivity *** resistivity of 0.08 mol%Fe:β-Ga2O3 crystal reached to 3.63×1011Ω·*** high resistivity Fe:β-Ga2O3 single crystals could be applied as the substrate for the high-power field effect transistors(FETs).

关键词： Fe:β-Ga2O3 crystal high resistivity crystal growth

Edge and lithium concentration effects on intercalation kinetics for graphite anodes

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第3期90卷 337-347,I0009页

作者： Keming zhu Denis Kramer chao Peng School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048ShanxiChina Faculty of Mechanical Engineering Helmut-Schmidt UniversityHamburg 22043Germany School of Engineering University of SouthamptonSouthampton SO171BJUK Multiscale Crystal Materials Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina

Graphite interfaces are an important part of the anode in lithium-ion batteries(LIBs),significantly influencing Li intercalation *** anodes adopt different stacking sequences depending on the concentration of the intercalated Li *** this work,we performed first-principles calculations to comprehensively address the energetics and dynamics of Li intercalation and Li vacancy diffusion near the no n-basal edges of graphite,namely the armchair and zigzag-edges,at high Li *** find that surface effects persist in stage-Ⅱ that bind Li strongly at the edge ***,the pronounced effect previously identified at the zigzag edge of pristine graphite is reduced in LiC_(12),penetrating only to the subsurface site,and eventually disappearing in LiC_(6).Consequently,the distinctive surface state at the zigzag edge significantly impacts and restrains the charging rate at the initial lithiation of graphite anodes,whilst diminishes with an increasing degree of *** diffusion time for Li hopping to the bulk site from either the zigzag edge or the armchair edge in LiC_(6) was observed during high state of charge due to charge *** controlling Li occupation and diffusion kinetics at this stage is also crucial for enhancing the charge rate.

关键词： Graphite anode Edge Interface Lithium-ion batteries Density functional theory

Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： Yong-zhi Lin Lu-Kun Feng Ya-Dong Li chao-Fan Chang Cai-Zhen zhu Ming-Liang Wang Jian Xu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

Chemoselective and Living/Controlled Polymerization of Alkenyl Methacrylates by the Phosphonium Ylide/Organoaluminum Lewis Pairs

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 159-167,I0005页

作者： zhi-Kang Chen Wu-chao Zhao Yi-Ling Zhao Cong-Lei Liu Liu-Yin Jiang Yue-Tao Zhang Hong-Ping zhu State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun130012China

Chemoselective,living/controlled polymerizations of allyl methacrylate(AMA) and vinyl methacrylate(VMA) with/without methyl methacrylate(MMA) by using the phosphonium ylide/organoaluminum based Lewis pairs(LPs) have been *** P-ylide-2/AIMe(BHT)_(2)(Pylide-2=Ph_(3)P=CHMe and BHT=2,6-iBu_(2)-4-MeC_(6)H_(2)O) was demonstrated to be superior by which homopolymers PAMAs(M_(n)=27.6-111.5kg/mol and ■=1.14-1.25) and PVMAs(M_(n)=28.4-78.4 kg/mol and ■=1.12-1.18) and block copolymers PMMA-b-PAMA,PAMA-b-PVMA,PAMA-bPMMA,PMMA-b-PAMA-b-PMMA,PAMA-b-PMMA-b-PAMA,and PAMA-b-PVMA-b-PAMA were *** the polymerizations,all of the monomers were reacted by the conjugated ester vinyl groups leaving intactly the nonconjugated acryloxy *** pendant acryloxy groups attached to the main chain enable further to post-functionalization by the AIBN-induced radical "thiol-ene" reaction using PhCH_(2)*** thiolether side group-containing polymers PAMA-SCH_(2)Ph and PAMA-SCH_(2)Ph-b-PMMA-b-PAMA-SCH_(2)Ph were thus prepared.

关键词： Phosphonium ylide Alkenyl methacrylate Chemoselectivity Living/controlled polymerization Post-functionalization

Reinforcing oxygen electrocatalytic activity via selective dualphase heterointerface engineering for rechargeable Zn-air batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1524-1536页

作者： chao Cheng Chuang zhi Zhong-Ti Sun Yong-Qiang Ming Ting-Ting Xiang Qing-chao zhu Zi-Rui Wu Bing Li Yi Li Cheng Jin Yong Cao Juan Yang School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming650093China

Dual-phase heterointerface electrocatalysts(DPHE)constructed by oxygen reduction reaction(ORR)-and oxygen evolution reaction(OER)-active elements exhibit excellent bifunctional activity and long-term durability due to the abundant interface exposure and synergistic catalytic ***,low-dimensional N-doped graphene nanoribbons(N-GNRs)coupling with ultrathin CoO nanocomposites(N-GNRs/CoO)were controllably fabricated through a facile two-step approach using synthesized Co(OH)_2 nanosheet as CoO *** functional theory(DFT)calculations and experimental characterizations prove that the formation of interface between N-GNRs and CoO can induce local charge redistribution,contributing to the improvement of catalytic activity and *** optimal N-GNRs/CoO DPHE possesses hierarchically porous architectures and presents outstanding bifunctional activities with a small potential gap of 0.729 V between the potential at 10 mA·cm^(-2)for OER and the halfwave potential for ORR,which outperforms Pt/C+IrO_(2)and the majority of noble-metal-free bifunctional ***-and solid-state rechargeable Zn-air batteries assembled with N-GNRs/CoO as the cathode also display high peak power density and fantastic cycle stability,superior to that of benchmark Pt/C+IrO_(2)*** is anticipated to offer significant benefits toward high activity,stability and mechanical flexibility bifunctional oxygen electrocatalysts for rechargeable Zn-air batteries.

关键词： Interface engineering Graphene nanoribbons CoO Bifunctional electrocatalyst Zn-air batteries

Design of artificial biomimetic channels with Na^(+)permeation rate and selectivity potentially outperforming the natural sodium channel

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8638-8646页

作者： zhi zhu Yan Zhao chao Chang Shaojian Yan Tingyu Sun Shiyu Gu Yangmei Li Dengsong Zhang Chunlei Wang Xiao Cheng Zeng School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense TechnologyBeijing 100071China School of Physics Peking UniversityBeijing 100871China International Joint Laboratory of Catalytic Chemistry College of SciencesShanghai UniversityShanghai 200444China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Artificial ion channels that enable high-efficiency ion transport have important implications in nanofluidics and biomedical applications such as drug ***,we show a simulation-based chemical design of a biomimetic sodium channel that possesses permeation rate and selectivity potentially higher than those of the state-of-the-art natural vertebrate voltage-gated sodium ***,our theoretical findings have undergone empirical testing,aligning well with the Arrhenius law as derived from a diverse range of experimental *** high-efficiency ion transport is achieved by anchoring the carboxylate functional groups within the channel filter.A key chemical guiding principle underlying the ion channel design is that the free-energy barrier for the Na^(+)passage across the channel should be comparable to typical thermal energy at room *** the implementation of the chemical design,we found that the relatively low free-energy barrier can be attributed to the compensation effect of the carboxylate groups to the partially lost oxygen shell of the ion within the ion channel,as well as to the consonant vibration of the ions inside and outside the *** mechanistic understanding brings new insight,at the molecular level,into the high-efficiency ion transport across the designed membrane *** proof of principle achieved from the simulations will stimulate future experimental confirmation and potential applications of the high-performance artificial channels in nanofluidics and in bioinspired iontronics.

关键词： sodium channels anchoring carboxylate functional groups molecular dynamics simulations low free-energy barrier for ion passage thermal kinetic energy

Research on blade tip clearance cavitation and turbulent kinetic energy characteristics of axial flow pump based on the partially-averaged Navier-Stokes model

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 Hydrodynamics 2024年第1期36卷 184-201页

作者： Xiao-qi Jia Shuai-kang Zhang Zu-chao zhu Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou310018China

To reveal the cavitation forms of tip leakage vortex(TLV)of the axial flow pump and the flow mechanism of the flow field,this research adopts the partially-averaged Navier-Stokes(PANS)model to simulate the cavitation values of an axial flow pump,followed by experimental *** experimental result shows that compared with the shear stress transport(SST)k-ωmodel,the PANS model significantly reduces the eddy viscosity of the flow field to make the vortex structure clearer and allow the turbulence scale to be more robustly *** cavitation area within the axial flow pump mainly comprises of TLV cavitation,clearance cavitation and tip leakage flows combined effect of triangular cloud cavitation *** formation and development of cavitation are accompanied by the formation and evolution of vortex,and variations in vortex structure also generate and promote the development of *** addition,an in-depth analysis of the relationship between the turbulent kinetic energy(TKE)transport equation and cavitation patterns was also conducted,finding that the regions with relatively high TKE are mainly distributed around gas/liquid boundaries with serious cavitation and evident gas-liquid *** phenomenon is mainly attributed to the combined effect of the pressure action term,stress diffusion term and TKE production term.

关键词： Cavitation axial flow pump tip leakage vortex(TLV) partially-averaged Navier-Stokes(PANS)model turbulent kinetic energy(TKE)