检索结果-南通市图书馆

Journal of Materials Science & Technology 2020年第6期41卷 1-11页

作者： Majid Jafari chan-Woo Bang Jong-chan Han Kyeong-Min Kim Seon-Hyeong Na chan-Gyung Park Byeong-Joo lee Department of Materials Science and Engineering POSTECH Pohang 37673 South Korea

Manufacturing temperatures of severely cold-drawn hyper-eutectoid steel wires are sufficiently high to influence the mobility of dislocations and alloy elements,thereby affecting the materials’mechanical ***,we describe the evolution of microstructure and tensile strength of the as-drawn 3.45 GPa steel wire during post-deformation annealing for 30 min at 150-450℃.Annealing at 150℃raised the strength to 3.77 GPa by age-hardening through activation of dislocations pinning by carbon,while further temperature rising up to 450℃caused a severe loss of *** was proved that annealing at 300 and 450℃destabilizes the lamellar microstructure,promoting the formation of carbon-deficient(Fe,Mn,Cr)3 C-type cementite particles with preferentially rounded and partially faceted *** at 450℃yielded the accumulation of Mn and Cr at the ferrite/particle interfaces,and their concentrations at the interfaces were dependent on the interface structure;i.e.,lower concentrations at rounded interfaces(formed through capillarity–driven coarsening of the spheroidized cementite),and higher concentrations at faceted interfaces(that are initially existing in the as-drawn state).Our proof-of-principle observations,supported by thermodynamic calculations and kinetic assessments,provide a pathway for understanding the changes in microstructural and tensile properties during manufacturing of the hyper-eutectoid steel wires.

关键词： Three-dimensional atom probe(3DAP) High resolution transmission electron microscopy(HRTEM) Nano-grained low-carbon steel Annealing Tensile behavior

Superior anti-icing strategy by combined sustainable liquid repellence and electro/photo-responsive thermogenesis of oil/MWNT composite

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第14期47卷 106-116页

作者： Aeree Kim Seonghyeon Kim Myoung Huh Hyungmo Kim chan lee Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)Pohang37673Republic of Korea Korea Atomic Energy Research Institute(KAERI) Daejeon34057Republic of Korea

This paper introduces an effective anti-icing strategy that uses passive anti-icing property and active de-icing functions *** dual capabilities can alleviate the icing problem more effectively than either a passive or active function *** developed material is a slippery liquid-repellent elastic conductor(SLEC);it is an organogel that is composed of multi-walled carbon nanotubes,oil,and *** SLEC maintains passive water-droplet sliding ability even on wet surfaces that frequently occur in cold conditions(e.g.,during condensation and defrosting),suppresses ice nucleation,and shows ice adhesion strength as low as^20 *** SLEC releases heat when it is subject to electrical or photonic stimulation,and can therefore it can prevent ice formation and melt ice that has already formed on a *** material has sustainable liquid repellence by syneresis and replenishment;this ability ensures long-lasting anti-icing property,and results in exceptional *** durability is stable against mechanical *** superior dual anti-icing capabilities together with the sustainable and stable liquid repellence should generate synergistic effects,and yield a powerful anti-icing tool that can broaden the range of icing applications.

关键词： Anti-icing De-icing Icephobic Soft conductor Self-healing Nanocomposite Liquid repellence

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

Security Enhanced Anonymous User Authenticated Key Agreement Scheme Using Smart Card

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2018年第1期16卷 45-49页

作者： Jaewook jung Donghoon lee Hakjun lee Dongho Won Department of Computer Engineering Sungkyunkwan UniversityGyeonggi-do 16419

Nowadays, the password-based remote user authentication mechanism using smart card is one of the simplest and convenient authentication ways to ensure secure communications over the public network environments. Recently, Liu et al. proposed an efficient and secure smart card based password authentication scheme. However, we find that Liu et al.’s scheme is vulnerable to the off-line password guessing attack and user impersonation attack. Furthermore, it also cannot provide user anonymity. In this paper, we cryptanalyze Liu et al.’s scheme and propose a security enhanced user authentication scheme to overcome the aforementioned problems. Especially, in order to preserve the user anonymity and prevent the guessing attack, we use the dynamic identity technique. The analysis shows that the proposed scheme is more secure and efficient than other related authentication schemes.

关键词： Authentication off-line password guessing attack smart card user anonymity

Integrated Framework for Vehicle Interior Design Using Digital Human Model

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2009年第6期24卷 1149-1161页

作者： Moonki jung Hyundeok Cho Taehwan Roh Kunwoo lee Department of Mechanical and Aerospace Engineering Seoul National University Institute of Advanced Machinery and Design Seoul National University

Evaluating the human friendliness of vehicles is essential for designing new vehicles since large numbers of human-machine interactions occur frequently inside vehicles. In this research, we develop an integrated framework for vehicle interior design using a digital human model （DHM）. In this framework, the knowledge-based parametric modelling function of vehicles is implemented using a commercial computer-aided design （CAD） system. The combination of the DHM and the CAD system enables designers into carry out ergonomic evaluations of various human-vehicle interactions and understand the effects of modifications of vehicle design parameters on occupants during designing. Further, the information on human-vehicle interaction obtained using this system can be transmitted to dedicated biomechanical analysis software. By analysing human motions inside vehicles using such software, we can obtain optimized interior design parameters.

关键词： digital human models ergonomics human-centred CAD vehicle interior design

FEA technique of hot plate forming process using cell-typed die with cooling device

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2012年第S3期22卷 831-837页

作者： jung-Min lee In-Kyu lee Kyung-Hun lee Dae-Soon KIM Byung-Min KIM Dongnam Regional Division Korea Institute of Industrial Technology School of Mechanical Engineering Pusan National University Industrial Technology Division Hyundai Heavy Industries

Hot plate forming using a cell-typed die is a process for forming a large thick plate with a spherical shape for the manufacture of a large spherical LNG ***-typed upper and lower dies made of a framework of steel plates fitted to make a grid pattern are used in this process,and an air-cooling device is separately installed inside the lower die.A finite element analysis (FEA) technique was developed,which included hot forming,air flow,cooling and thermal deformation analysis for the hot plate forming process using the cell-typed ***,the convective and interface heat transfer coefficients were used to reproduce analytically the effects of the cooling device in the hot plate forming analysis.A small-scale model test of the process was conducted to verify the FEA *** analysis results show that the curvature of the final plate agrees well with that of the designed experiment within a maximum relative error of 0.03% at the corner of the plate.

关键词： cell-typed die hot plate forming spherical LNG tank heat transfer coefficient

Spatial Ecology of Translocated and Resident Amur Ratsnakes(Elaphe schrenckii) in Two Mountain Valleys of South Korea

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2011年第4期2卷 223-229页

作者： jung-Hyun lee Daesik PARK Department of Biology Kangwon National UniversityChuncheonKangwon 200-701South Korea Department of Environmental Resources Research National Institute of Environmental ResearchSeo-GuIncheon 404-708South Korea Division of Science Education Kangwon National UniversityChuncheonKangwon 200-701South Korea

The translocation of snakes has been viewed as a useful tool to augment declining populations and to mitigate human-wildlife conflicts, even though released snakes often exhibit relatively high mortality. We radio-tracked 13 Amur Ratsnakes （Elaphe schrenckii） in the Woraksan National Park in South Korea from July 2008 to May 2009. Two of these snakes were residents, and 11 had been illegally captured in areas remote from the study site and were donated by the park office. During the study period, six of the translocated snakes were lost： two were killed by predators, one died of unknown causes, and the radio signals of three of the snakes were lost. In the field, the ratsnakes laid eggs in early August, moved into hibemacula in late November, and moved away from the hibemacula in mid-April. Compared to the resident snakes, five of the translocated snakes traveled approximately 1.3 times farther per week, and the home ranges of the translocated snakes were three to six times larger than those of the resident snakes. In addition, the translocated snakes were found underground more frequently than the resident snakes. The management recommendations resulting from this study will guide biologists and land use managers in making appropriate decisions regarding release sites and the use of gravid females in the translocation of this endangered ratsnake.

关键词： Amur Ratsnake conservation Elaphe schrenckii radiotelemetry translocation

Dual function of a high-contrast hydrophobic-hydrophilic coating for enhanced stability of perovskite solar cells in extremely humid environments

在线全文

学校读者我要写书评

暂无评论

Nano Research 2017年第11期10卷 3885-3895页

作者： Jin Sun Yoo Gill Sang Han Seongha lee Min Cheol Kim Mansoo Choi Hyun Suk jung jung-Kun lee School of Advanced Materials Science amp Engineering Sungkyunkwan University Suwon 440-746 Republic of Korea Department of Mechanical Engineering and Materials Science University of Pittsburgh Pittsburgh Pennsylvania 15261 USA Department of Mechanical and Aerospace Engineering Seoul National University Seoul 08826 Republic of Korea

In spite of a continuous increase in their power conversion efficiency （PCE） and an economically viable fabrication process,organic-inorganic perovskite solar cells （PSCs） pose a significant problem when used in practical applications：They show fast degradation of the PCE when exposed to very humid *** this study,the stability of PSCs under very humid conditions is greatly enhanced by coating the surface of the PSC devices with a multi-layer film consisting of ultrahydrophobic and relatively hydrophilic layers.A hydrophobic composite of poly（methyl methacrylate）（PMMA）,polyurethane （PU）,and SiO2 nanoparticles successfully retards the water molecules from very humid ***,the hydrophilic layer with moderately PMMA captures the residual moisture within the perovskite layer;subsequently,the perovskite layer *** dual function of the coating film keeps the PCE of PSCs at 17.3% for 180 min when exposed to over 95% humidity.

关键词： perovskite solar cell stability surface coating ultrahydrophobic self-recovery

In situ thickness control of black phosphorus field-effect transistors via ozone treatment

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

Nano Research 2016年第10期9卷 3056-3065页

作者： Suhyun Kim Younghun jung Jong-Young lee Gwan-Hyoung lee Jihyun Kim Department of Chemical and Biological Engineering Korea University Seou102841 Republic of Korea Department of Materials Science and Engineering Yonsei University Seou103722 Republic of Korea

A simple and reproducible method to control the thickness of black phosphorus flakes in real time using a UV/ozone treatment is demonstrated. Back-gated black phosphorus field-effect transistors （FETs） were fabricated using thick black phosphorus flakes obtained by thinning of black phosphorus, as oxygen radicals generated by UV irradiation formed phosphorus oxides on the surface. In order to monitor the thickness effect on the electrical properties, the fabricated FETs were loaded in the UV/ozone chamber, where both the optical （micro-Raman spectroscopy and optical microscopy） and electrical properties （current-voltage characteristics） were monitored in situ. We observed an intensity decrease of the Raman modes of black phosphorus while the field-effect mobility and on/off ratio increased by 48% and 6,800%, respectively. The instability in ambient air limits the investigation and implementation of ultra-thin black phosphorus. However, the method reported in this study allowed us to start with thick black phosphorous flakes, providing a reliable approach for optimizing the electrical performance of black phosphorus-based electronic devices. We believe that these results can motivate further studies using mono- and few-layer black phosphorus.

关键词： black phosphorus in situ thinning UV/ozone treatment

Regulation of sleep by astrocytes in the hypothalamic ventrolateral preoptic nucleus

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

Neural Regeneration Research 2025年第4期20卷 1098-1100页

作者： Jae-Hong Kim Ruqayya Afridi Il-Sung Jang Maan Gee lee Kyoungho Suk Brain Korea 21 four KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of MedicineKyungpook National UniversityDaeguRepublic of Korea Department of Pharmacology School of DentistryKyungpook National UniversityDaeguRepublic of Korea Brain Science&Engineering Institute Kyungpook National UniversityDaeguRepublic of Korea

Astrocytes are functionally dynamic cells that support neurons in multiple ways throughout an organism’s *** astrocytic regulation of neuronal activity has been increasingly recognized in recent *** are now recognized as playing a more complex role than mere bystanders in the central nervous ***,their role in regulating the sleep neurocircuitry is not well *** this perspective,we highlight the role of astrocytes in sleep modulation,with a particular focus on regulatory mechanisms related to the ventrolateral preoptic nucleus(VLPO)of the *** briefly discuss recent literature reporting the role of VLPO astrocytes in regulating sleep-associated behaviors.

关键词： sleep ventrolateral astrocytes