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A flexible magnetoelectric field-effect transistor with magnetically responsive nanohybrid gate dielectric layer

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Nano Research 2015年第10期8卷 3421-3429页

作者： Nguyen Minh Triet Tran Quang Trung Nguyen Thi Dieu Hien Saqib Siddiqui Do-ll Kim jai Chan lee Nae-Eung lee SchoolofAdvancedMaterialsScienceandEngineering SungkyunkwanUniversitySuwonKyunggi-do440-746RepublicofKorea sungkyunkwanUniversity(SKKU)AdvancedInstituteofNanotechnology(SAINT) 5ungkyunkwanUniversitySuwonKyunggi-do440-746RepublicofKorea SamsungAdvancedInstituteforHealthSciencesandTechnology(SAIHST) SungkyunkwanUniversitySuwonKyunggi-do440-746RepublicofKorea

Flexible magnetoelectric （ME） materials have been studied for new applications such as memory, energy harvesters, and magnetic field sensors. Herein, with the widely studied and progressive advantages of ME phenomena in the multiferroic field, we demonstrate a new approach for utilizing flexible ME materials as gate dielectric layers in ME organic field-effect transistors （ME-OFET） that can be used for sensing a magnetic field and extracting the ME properties of the gate dielectric itself. The magnetoelectric nanohybrid gate dielectric layer comprises sandwiched stacks of magnetostrictive CoFe2O4 nanoparticles and a highly piezoelectric poly（vinylidene fluoride-co-trifluoroethylene） layer. While varying the magnetic field applied to the ME gate dielectric, the ME effect in the functional gate dielectric modulates the channel conductance of the ME-OFET owing to a change in the effective gate field. The clear separation of the ME responses in the gate dielectric layer of ME-OFET from those of the other parameters was demonstrated using the AC gate biasing method and enabled the extraction of the ME coefficient of ME materials. Additionally, the device shows high stability after cyclic bending of 10,000 cycles at a banding radius of 1.2 cm. The device has significant potential for not only the extraction of the intrinsic characterization of ME materials but also the sensing of a magnetic field in integrated flexible electronic systems.

关键词： magnetoelectric magnetostriction CoFe2O4 nanoparticles P(VDF-TrFE) organic field-effecttransistor magnetic sensor

Simulations of the Dependence of Gas Physical Parameters on Deposition Variables during HFCVD Diamond Films

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Journal of Materials Science & Technology 2006年第5期22卷 599-604页

作者： Aiying WANG Kwangryeol lee Chao sun Lishi WEN Future Technology Research Division Korea Institute of Science and Technology P.O.Box 131 CheongryangSeoul 130-650 Korea Plasma Lab J＆L Tech. Co. Ltd Siheung city Kyunggi-do 2185-7 Korea Department of Surface Engineering of Materials Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

During the growth of the hot filament chemical vapor deposition （HFCVD） diamond films, numerical simulations in a 2-D mathematical model were employed to investigate the influence of various deposition parameters on the gas physical parameters, including the temperature, velocity and volume density of gas. It was found that, even in the case of optimized deposition parameters, the space distributions of gas parameters were heterogeneous due primarily to the thermal blockage come from the hot filaments and cryogenic pump effect arisen from the cold reactor wall. The distribution of volume density agreed well with the thermal round-flow phenomenon, one of the key obstacles to obtaining high growth rate in HFCVD process. In virtue of isothermal boundary with high temperature or adiabatic boundary condition of reactor wall, however, the thermal roundflow was profoundly reduced and as a consequence, the uniformity of gas physical parameters was considerably improved, as identified by the experimental films growth.

关键词： Gas physical parameters Simulations Diamond films HFCVD

Characterization of Micro-arc Oxidized Titanium

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Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 178-180页

作者： Inho Han jai Hyuk Choi Bao Hong Zhao Hong Koo Baik In-Seop lee Department of Metallurgical Engineering Yonsei University Seoul 120-749 Korea Atomic-scale Surface Science Research Center Yonsei University Seoul 120-749 Korea Institute of Physics ＆ Applied Physics Yonsei University Seoul 120-749 Korea

The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro- arc oxidized titanium was evaluated by human body derived osteoblasts and sligtaly better than those of blasted surface.

关键词： Micro-arc oxidation titanium oxide dental implant morphology

An integrated approach to improve the performance of lean–electrolyte lithium–sulfur batteries

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Journal of Energy Chemistry 2022年第4期31卷 585-592页

作者： Hualin Ye Jianguo sun Yun Zhao Jim Yang lee Department of Chemical and Biomolecular Engineering National University of Singapore119260Singapore Department of Mechanical Engineering National University of Singapore117575Singapore

While the sulfur conversion reaction kinetics in Li–S batteries is nowadays improved by the use of appropriate electrocatalysts,it remains a challenge for the batteries to perform well under the lean electrolyte condition where polysulfide shuttle,electrode passivation and the loss of electrolyte due to side reactions,are *** challenges are addressed in this study by the tandem use of a polysulfide conversion catalyst and a redox–targeting mediator in a gel sulfur ***,the gel cathode reduces the polysulfide mobility and hence the polysulfide shuttle and the passivation of the lithium anode by the crossover *** redox mediator restrains the deposition of inactive sulfur species in the cathode thereby enabling the Fe–N and Co–N co–doped carbon catalyst to prolong its catalytic ***,the integrated catalytic system is able to increase the discharge capacity of high–loading (6.8 mg cm^(-2)) lean–electrolyte (4.0μL mg^(-1)) Li–S batteries from~630 to~1316 m Ah g^(-1),concurrently with an improvement of the cycle life (600 cycles with 46%capacity retention at 1.0 m A cm^(-2)).Redox mediator assisted catalysis in a gel cathode is therefore an effective strategy to extend the application of the sulfur conversion catalyst in lean electrolyte Li–S batteries.

关键词： Redox mediators Gel electrolytes Polysulfide catalysis Lean electrolyte Lithium–sulfur batteries

Variability and trends of near-surface wind speed over the Tibetan Plateau:The role played by the westerly and Asian monsoon

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Advances in Climate Change Research 2024年第3期15卷 525-536页

作者： Gang-Feng ZHANG Cesar AZORIN-MOLINA Deliang CHEN Tim RMCVICAR Jose AGUIJARRO Kai-Qiang DENG Lorenzo MINOLA Jaeyeon lee Seok-Woo SON Heng MA Pei-Jun SHI State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Engineering Center of Desertification and Blown-Sand Control of Ministry of Education Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education Beijing Normal UniversityBeijing 100875China Centro de Investigaciones Sobre Desertificaci'on Consejo Superior de Investigaciones Cientı'ficas(CIDECSIC-UV-Generalitat alenciana)ClimateAtmosphere and Ocean Laboratory(Climatoc-Lab)Moncada 46113Spain Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburg 40530Sweden CSIRO Environment CanberraACT 2600Australia Australian Research Council Centre of Excellence for Climate Extremes CanberraACT 2600Australia State Meteorological Agency Balearic Islands OfficePalma de Mallorca 07015Spain School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Interuniversity Department of Regional and Urban Studies and Planning(DIST) Politecnico and University of TurinTurin 10125Italy School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826South Korea Atmospheric and Oceanic Sciences Program Princeton UniversityPrinceton NJ 08544USA Geophysical Fluid Dynamics Laboratory NOAAPrinceton NJ 08544USA

Near-surface wind speed exerts profound impacts on many environmental issues,while the long-term(≥60 years)trend and multidecadal variability in the wind speed and its underlying causes in global high-elevation and mountainous areas(e.g.,Tibetan Plateau)remain largely ***,by examining homogenized wind speed data from 104 meteorological stations over the Tibetan Plateau for 1961-2020 and ERA5 reanalysis datasets,we investigated the variability and long-term trend in the near-surface wind speed and revealed the role played by the westerly and Asian *** results show that the homogenized annual wind speed displays a decreasing trend(-0.091 m s^(−1)per decade,p<0.05),with the strongest in spring(-0.131 m s^(−1)per decade,p<0.05),and the weakest in autumn(-0.071 m s^(−1)per decade,p<0.05).There is a distinct multidecadal variability of wind speed,which manifested in an prominent increase in 1961-1970,a sustained decrease in 1970-2002,and a consistent increase in *** observed decadal variations are likely linked to large-scale atmospheric circulation,and the correlation analysis unveiled a more important role of westerly and East Asian winter monsoon in modulating near-surface wind changes over the Tibetan *** potential physical processes associated with westerly and Asian monsoon changes are in concordance with wind speed change,in terms of overall weakened horizontal air flow(i.e.,geostrophic wind speed),declined vertical thermal and dynamic momentum transfer(i.e.,atmospheric stratification thermal instability and vertical wind shear),and varied Tibetan Plateau *** indicates that to varying degrees these processes may have contributed to the changes in near-surface wind speed over the Tibetan *** study has implications for wind power production and soil wind erosion prevention in the Tibetan Plateau.

关键词： Tibetan Plateau Wind speed Decadal change Atmospheric circulation Physical processes

A p53 genetic polymorphism of gastric cancer: Difference between early gastric cancer and advanced gastric cancer

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World Journal of Gastroenterology 2006年第40期12卷 6536-6539页

作者： sun Young Yi Woon Jung lee Department of Internal Medicine and Medical Research Center College of Medicine Ewha Womans University Seoul Korea

AIM: To investigate the role of the polymorphism of p53 codon 72 in early gastric cancer (EGC) and advanced gastric cancer (AGC) in Korean patients. METHODS: DNA was extracted from blood samples of gastric cancer patients (n = 291) and controls (n = 216). In the p53 codon 72 genotypes were determined by ***: Patients with gastric cancer had a significantly higher frequency of the homozygous proline (Pro) allele than the control (P = 0.032). Patients with AGC had a significantly higher frequency of the Arg/Arg (arginine) allele (P = 0.038) than EGC and a similar Pro/Pro allele. The signet ring cell type had a higher frequency of the Pro/Pro allele than other types (P = 0.031). The Pro/Pro genotype carries a 3.9-fold increased risk of developing gastric cancer (95% CI, 1.3-15.4, P = 0.039) when compared to Arg/Arg and Arg/Pro genotypes and to develop EGC is a 5.25 fold increased risk (95% CI, 1.8-19.6, P = 0.021). CONCLUSION: The Pro/Pro genotype of the p53 codon 72 polymorphism carries a higher risk for gastric cancer in general and is also associated with a much higher risk for EGC than AGC.

关键词： p53 gene Polymorphism Gastric cancer

Mechanical properties of high-strength concrete subjected to high temperature by stressed test

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中国有色金属学会会刊：英文版 2009年第B9期19卷 128-133页

作者： Gyu-Yong KIM Young-sun KIM Tae-Gyu lee Division of Architecture Engineering Chun gnam National University

Recently, the effects of high temperature on compressive strength and elastic modulus of high strength concrete were experimentally investigated. The present study is aimed to study the effect of elevated temperatures ranging from 20 ℃ to 700 ℃ on the material mechanical properties of high-strength concrete of 40, 60 and 80 MPa grade. During the strength test, the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating, and when the target temperature is reached, the specimens are loaded to failure. The tests were conducted at various temperatures (20-700 ℃) for concretes made with W/B ratios of 46%, 32% and 25%, respectively. The results show that the relative values of compressive strength and elastic modulus decrease with increasing compressive strength grade of specimen.

关键词：高强混凝土高温作用力学性能测试抗压强度温度升高弹性模量强度试验

Fruits extracts of Hovenia dulcis *** lipopolysaccharide—stimulated inflammatory responses through nuclear factor—kappaB pathway in Raw 264.7 cells

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Asian Pacific Journal of Tropical Medicine 2016年第4期9卷 349-355页

作者： Ju-Yeon Park Jin-Young Moon sun-Dong Park Won-Hwan Park Hyuck Kim jai-Eun Kim Department of Acupoint College of Korean Medicine.Dongguk University Department of Prescription College of Korean MedicineDongguk University Department of Diagnostics College of Korean Medicine.Dongguk University Department of Pathology College of Korean Medicine.Dongguk University

Objective:To investigate the anti-inflammatory effects and the action mechanism of the fruits of Horenia dulcis(***) in lipopolysaccharide(LPS)-induced mouse macrophage Raw ***:The extract of *** fruits(EHDF) were extracted with 70%*** macrophages were treated with different concentrations of EHDF in the presence and absence of LPS(1 μg/mL).To demonstrate the inflammatory mediators including nitric oxide,inducible nitric oxide synthase and cyclooxygenase(COX)-2 expression levels were analyzed by usingin vitro assay ***-derived pro-inflammatory cytokines including interleukin-1 β.tumor necrosis factor- α and prostaglandin F_2 were determined using ELISA *** viability,heme oxygenase-1 expression,nuclear factor-kappaB and nuclear factor F.2-related factors 2 translocation were also ***:EHDF potently inhibited the LPS-stimulated nitric oxide,inducible nitric oxide ***-2,interleukin-1 β and tumor necrosis factor- α expression in a dose-dependent *** suppressed the phosphorylation of inhibited kappaB-alpha and p65 nuclear *** of macrophage cells with EHDF alone induced the heme oxygenase-1 and nuclear translocation of nuclear factor E2-reIated factor ***:These results suggest that the ethanol extract of *** fruit exerts its anti-inflammatory effects by inhibiting inhibited kappaBalpha phorylation and nuclear translocation of nuclear factor-kappaB.

关键词： Fruits of Hovenia dulcis Inflammation Macrophage Nuclear factor-kappaB Heme oxygenase-1

An Effective Threat Detection Framework for Advanced Persistent Cyberattacks

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Computers, Materials & Continua 2023年第5期75卷 4231-4253页

作者： So-Eun Jeon sun-Jin lee Eun-Young lee Yeon-Ji lee Jung-Hwa Ryu Jung-Hyun Moon sun-Min Yi Il-Gu lee Department of Future Convergence Technology Engineering Sungshin Women’s UniversitySeoul02844Korea Department of Convergence Security Engineering Sungshin Women’s UniversitySeoul02844Korea

Recently,with the normalization of non-face-to-face online environments in response to the COVID-19 pandemic,the possibility of cyberattacks through endpoints has *** endpoint devices are managed meticulously to prevent cyberattacks and ensure timely responses to potential security *** particular,because telecommuting,telemedicine,and teleeducation are implemented in uncontrolled environments,attackers typically target vulnerable endpoints to acquire administrator rights or steal authentication information,and reports of endpoint attacks have been increasing *** persistent threats(APTs)using various novel variant malicious codes are a form of a sophisticated ***,conventional commercial antivirus and anti-malware systems that use signature-based attack detectionmethods cannot satisfactorily respond to such *** this paper,we propose a method that expands the detection coverage inAPT attack *** this model,an open-source threat detector and log collector are used synergistically to improve threat detection *** the scope of attack log collection through interworking between highly accessible open-source tools can efficiently increase the detection coverage of tactics and techniques used to deal with APT attacks,as defined by MITRE Adversarial Tactics,Techniques,and Common Knowledge(ATT&CK).We implemented an attack environment using an APT attack scenario emulator called Carbanak and analyzed the detection coverage of Google Rapid Response(GRR),an open-source threat detection tool,and Graylog,an open-source log *** proposed method expanded the detection coverage against MITRE ATT&CK by approximately 11%compared with that conventional methods.

关键词： Advanced persistent threat cybersecurity endpoint security MITRE ATT&CK open-source threat detector threat log collector