检索结果-南通市图书馆

Ferroelectric and piezoelectric properties of SrZrO_3-modified Bi_(0.5)Na_(0.5)TiO_3 lead-free ceramics

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2014年第S1期24卷 146-151页

作者： Adnan MAQBOOL Ali HUSSAIN Jamil Ur RAHMAN Jong Kyu park Tae Gone park Jae Sung SONG myong ho KIM Engineering Research Center for Integrated Mechatronics Materials and Components Changwon National University Korea Electrotechnology Research Institute

The lead-free SrZrO3-modified Bi0.5Na0.5TiO3(BNT-SZ100 x, with x=0-0.15) ceramics were fabricated by a conventional solid-state reaction method. The effects of SZ addition on BNT ceramics were investigated through X-ray diffraction(XRD), scanning electron microscopy(SEM), ferroelectric and electric field-induced strain characterizations. XRD analysis revealed a pure perovskite phase without any traces of secondary phases. Ferroelectric and bipolar field induced-strain curves indicated a disruption of ferroelectric order upon SZ addition into BNT ceramics. A maximum value of remnant polarization(32 μC/cm2) and piezoelectric constant(102 pC/N) was observed at 5%(mole fraction) of SZ. Maximum value of the electric field-induced strain(Smax=0.24%) corresponding to normalized strain(Smax/Emax= d*33= 340 pm/V) was obtained at BNT-SZ9.

关键词： lead-free ceramics BNT perovskite structure field induced strain

Construction of a High‑Performance Composite Solid Electrolyte Through In‑Situ Polymerization within a Self‑Supported Porous Garnet Framework

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第5期16卷 56-70页

作者： An‑Giang Nguyen Min‑ho Lee Jaekook Kim Chan‑Jin park Department of Materials Science and Engineering Chonnam National University77 Yongbong‑roBuk‑guGwangju 61186South Korea

Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).however,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for *** overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the *** synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room ***,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode *** synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V ***/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.

关键词： Scalable tape-casting method Self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12) Composite solid electrolyte LiF-and B-rich interphase layers

Radiologic evaluation of nonalcoholic fatty liver disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第23期20卷 7392-7402页

作者： Seung Soo Lee Seong ho park Department of Radiology and Research Institute of Radiology University of Ulsan College of MedicineAsan Medical CenterSeoul 138-736South Korea

Nonalcoholic fatty liver disease(NAFLD)is a frequent cause of chronic liver diseases,ranging from simple steatosis to nonalcoholic steatohepatitis(NASH)-related liver *** liver biopsy is still the gold standard for the diagnosis of NAFLD,especially for the diagnosis of NASH,imaging methods have been increasingly accepted as noninvasive alternatives to liver *** is a well-established and costeffective imaging technique for the diagnosis of hepatic steatosis,especially for screening a large population at risk of *** has a reasonable accuracy in detecting moderate-to-severe hepatic steatosis although it is less accurate for detecting mild hepatic steatosis,operator-dependent,and rather *** tomography is not appropriate for general population assessment of hepatic steatosis given its inaccuracy in detecting mild hepatic steatosis and potential radiation ***,computed tomography may be effective in specific clinical situations,such as evaluation of donor candidates for hepatic *** resonance spectroscopy and magnetic resonance imaging are now regarded as the most accurate practical methods of measuring liver fat in clinical practice,especially for longitudinal followup of patients with *** elastography and magnetic resonance elastography are increasingly used to evaluate the degree of liver fibrosis in patients with NAFLD and to differentiate NASH from simple *** article will review current imaging methods used to evaluate hepatic steatosis,including the diagnostic accuracy,limitations,and practical applicability of each *** will also briefly describe the potential role of elastography techniques in the evaluation of patients with NAFLD.

关键词： Nonalcoholic fatty liver disease Nonalcoholic steatohepatitis Liver steatosis Magnetic resonance spectroscopy Magnetic resonance imaging Ultrasonography Computed tomography Elastography

Consistent Analytic Embedded Atom Potential for Face-Centered Cubic Metals and Alloys

维普期刊数据库评论

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 Materials Science & Technology 2009年第6期25卷 835-846页

作者： Iyad A. Hijazi Young ho park Mechanical and Aerospace Engineering Department New Mexico State University Las Cruces

A consistent empirical embedded-atom potential that includes a long range force was developed for fcc （face-centered cubic） metals and alloys. The proposed potential for pure metals does not require modification of the initial function form when being applied to alloy systems. The potential parameters of this model were determined by fitting lattice constant, three elastic constants, cohesive energy, and vacancy formation energies of the pure metals and the heats of solution of the binary alloys via an optimization technique. Parameters for Ag, AI, Au, Cu, Ni, Pd and Pt were obtained. The obtained parameters were used to calculate the bulk modulus, divacancy formation energy, crystal stability, stacking fault energy, vacancy migration energy, and melting point for each pure metal and the heats of formation and lattice constants for binary alloys. The predicted values were in good agreement with experimental results.

关键词： EAM (embedded-atom method) Consistent analytic potential Molecular dynamics Face-centered cubic alloy

Base pair distance analysis in single DNA molecule by direct stochastic optical reconstruction microscopy

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2015年第12期26卷 1490-1495页

作者： Suresh Kumar Chakkarapani Guenyoung park Seong ho Kang Department of Chemistry Graduate School Kyung Hee University Department of Applied Chemistry and Institute of Natural Sciences Kyung Hee University

Precise fluorescence imaging of single l-DNA molecules for base pair distance analysis requires a superresolution technique, as these distances are on the order of diffraction limit. Individual l-DNA molecules intercalated with the fluorescent dye YOYO-1 were investigated at subdiffraction spatial resolution by direct stochastic optical reconstruction microscopy（d STORM）. Various dye-to-DNA base pair ratios were imaged by photoswitching YOYO-1 between the fluorescent state and the dark state using two laser sources. The acquired images were reconstructed into a super-resolution image by applying Gaussian fitting to the centroid of the point spread function. By measuring the distances between localized fluorophores, the base pair distances in single DNA molecules for dye-to-DNA base pair ratios of 1：50,1：100, and 1：500 were calculated to be 17.1 0.8 nm, 34.3 2.2 nm, and 170.3 8.1 nm[17_TD$IF], respectively,which were in agreement with theoretical values. These results demonstrate that intercalating dye in a single DNA molecule can be photoswitched without the use of an activator fluorophore, and that super-localization precision at a spatial resolution of 17 nm was experimentally achieved.

关键词： stochastic DNA reconstructed fitting applying localization correction frames label localized

Properties of ZnO Thin Films Grown on Si (100) Substrates by Pulsed Laser Deposition

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2010年第11期26卷 973-976页

作者： Young Rae Jang Keon-ho Yoo Seung Min park Department of Physics Kyung Hee University Department of Chemistry Kyung Hee University

ZnO thin films were grown on Si （100） substrates by pulsed laser deposition using a ZnO *** substrate temperature was varied in the range of room temperature to 800 ℃,and the oxygen partial pressure of 0.1333 Pa （1 m Torr） to 1333 Pa （10 Torr）.The properties of the resulting films were investigated by photoluminescence （PL）,grazing incidence X-ray diffraction （GIXRD）,X-ray photoelectron spectroscopy （XPS）,and field emission scanning electron microscopy （FESEM）.Based on the ultraviolet （UV,～380 nm） to visible emission ratio in the PL spectrum,the optimum growth conditions were determined to be 600 ℃ and 133.3 Pa （1 Torr）,*** oxygen 1s peak in the XPS spectrum was decomposed into two *** peak at lower binding energy increased in intensity with the oxygen partial pressure from 0.1333 Pa （1 m Torr） to 133.3 Pa （1 Torr） while the other peak *** GIXRD curve at the optimum condition showed strong two peaks （002） and （103）.A strong correlation between the （103） peak intensity and the UV emission intensity was found.

关键词： ZnO Pulsed laser deposition Photoluminescence

Fabrication and Mechanical Properties of Sm2O3 Doped CeO2 Reinforced Ti3AlC2 Nano Composite

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2004年第z2期22卷 85-88页

作者： Jae ho Han Sang Whan park Young Do Kim Division of Materials Science & Engineering Hanyang UniversitySeoul133-791Korea Korea Institute of Science and TechnologyMulti-Functional Ceramics Research CenterSeoul136-791Korea Division of Materials Science & EngineeringHanyang UniversitySeoul133-791Korea

The fabrication process of Sm2O3 doped CeO2 reinforced Ti3AlC2 nano composites including the nano particle dispersion process by a hetero-coagulation process was developed using in-situ synthesis and densification process of Ti3AlC2. The effects of Sm2O2 doped CeO2 nano particles on mechanical properties of Ti3AlC2 were investigated. It was found that the presence of 20SDC nano particles in Ti3AlC2 was very effective to improve the mechanical properties of Ti3AlC2 without spoiling the unique characteristics of Ti3AlC2temary carbide.

关键词： nano ceramic composite Ti3AlC2 CeO2 fabrication rare earths

Improved thermal performance of a hydronic radiant panel heating system by the optimization of tube shapes

维普期刊数据库评论

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 Zhejiang University-Science A(Applied Physics & Engineering) 2011年第6期12卷 428-437页

作者： Young T.CHAE Kwang ho LEE Jae Sung park School of Architecture University of Illinois at Urbana-Champaign Department of Architectural Engineering Hanbat National University Department of Mechanical Engineering University of Illinois at Urbana-Champaign

The thermal performance enhancement of the hydronic radiant floor heating system by tube shape refinements is investigated in this *** analytical and detailed numerical modelings are carried out to predict the performance of the radiant *** the simple analytical model briefly investigates the possibility of the effect of the tube shape improvement with the parametric analysis,the commercial computational fluid dynamics(CFD) code(Ansys/CFX) is used to perform the detailed 3D analysis under different tube shape *** fin thickness,the number of fins,and the tube thermal conductivity turn out to have significant effects on the radiant system *** potential energy saving impacts of the tube shape refinements are also *** tube shape improvement turns out to increase the floor surface temperature and to decrease the hot water temperature drop across the system,resulting in heating energy savings.

关键词： Radiant panel system Analytical modeling Computational fluid dynamics(CFD) Tube shape Energy saving

Data driven computational design of stable oxygen evolution catalysts by DFT and machine learning:Promising electrocatalysts

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 645-655页

作者： Hwanyeol park Yunseok Kim Seulwon Choi ho Jun Kim Department of Display Materials Engineering Soonchunhyang UniversityAsanChung-nam 31538Republic of Korea Department of Electronic Materials Devicesand Equipment EngineeringSoonchunhyang Uni-versityAsanChungnam 31538Republic of Korea Department of Mechanical Engineering Hanyang University ERICA Campus55 Hanyangdaehak-roSangnok-guAnsanGyeonggi-do 15588Republic of Korea

The revolutionary development of machine learning(ML),data science,and analytics,coupled with its application in material science,stands as a significant milestone of the scientific community over the last *** active,stable,and cost-efficient catalysts is crucial for oxygen evolution reaction owing to the significance in a range of electrochemical energy co nversion *** this work,we have demonstrated an efficient approach of high-throughput screening to find stable transition metal oxides under acid condition for high-performance oxygen evolution reaction(OER)catalysts through density functional theory(DFT)calculation and a machine learning algorithm.A methodology utilizing both the Materials Project database and DFT calculations was introduced to assess the acid stability under specific reaction *** upon this,OER catalytic activity of acid-stable materials was examined,highlighting potential OER catalysts that meet the required *** identified IrO_(2),Fe(SbO_(3))_(2),Co(SbO_(3))_(2),Ni(SbO_(3))_(2),FeSbO_(4),Fe(SbO_(3))4,MoWO_(6),TiSnO_(4),CoSbO_(4),and Ti(WO_(4))_(2)as promising catalysts,several of which have already been experimentally discovered for their robust OER performance,while others are novel for experimental exploration,thereby broadening the chemical scope for efficient OER *** of the bond length of TM-O and the first ionization energy were used to unveil the OER activity *** the calculated results,guidance has been derived to effectively execute advanced high-throughput screenings for the discovery of catalysts with favorable ***,the intrinsic correlation between catalytic performance and various atomic and structural factors was elucidated using the ML *** these approaches,we not only streamline the choice of the promising electrocatalysts but also offer insights for the design of varied catalyst models and the discovery of superior c

关键词： Transition metal oxides Oxygen evolution reaction High-throughput screening First-principles calculation Machine learning