古代開封水環境變化考察

程遂營 중국사학회 2006 中國史硏究 Vol.41 No.-

Fabrication of self-assembled Au droplets by the systematic variation of the deposition amount on various type-B GaAs surfaces

Sui, Mao,Li, Ming-Yu,Kim, Eun-Soo,Lee, Jihoon Springer 2014 NANOSCALE RESEARCH LETTERS Vol.9 No.1

<P>The fabrication of self-assembled Au droplets is successfully demonstrated on various GaAs (<I>n</I>11)B, where <I>n</I> is 2, 4, 5, 7, 8, and 9, by the systematic variation of the Au deposition amount (DA) from 2 to 12 nm with subsequent annealing at 550°C. Under an identical growth condition, the self-assembled Au droplets of mini to supersizes are successfully synthesized via the Volmer-Weber growth mode. Depending on the DA, an apparent evolution is clearly observed in terms of the average height (AH), lateral diameter (LD), and average density (AD). For example, compared with the mini Au droplets with a DA of 2 nm, AH of 22.5 nm, and LD of 86.5 nm, the super Au droplets with 12-nm DA show significantly increased AH of 316% and LD of 320%, reaching an AH of 71.1 nm and LD of 276.8 nm on GaAs (211)B. In addition, accompanied with the dimensional expansion, the AD of Au droplets drastically swings on 2 orders of magnitudes from 3.2 × 10<SUP>10</SUP> to 4.2 × 10<SUP>8</SUP> cm<SUP>-2</SUP>. The results are systematically analyzed with respect to the atomic force microscopy (AFM) and scanning electron microscopy (SEM) images, energy-dispersive X-ray spectrometry (EDS) spectra, cross-sectional line profiles, Fourier filter transform (FFT) power spectra, and root-mean-square (RMS) roughness as well as the droplet dimension and density summary, respectively.</P>

Temperature-Dependent Structural and Transport Properties of Liquid Transition Metals

Sui Yang,Xuping Su,Jianhua Wang,Nai-Yong Tang 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.6

The evolution of the atomic structures and diffusivity of liquid transition metals with increasing temperature has been studied here using molecular dynamics. An analysis of Honeycutt and Andersen (HA) Indices indicates that relatively low order atomic clusters of rhombohedra-related structures increase with an increase in temperature. The results illustrate that the distortion in the local structural order with a predominant rhombohedra character enhances the diffusivity in liquid metals. The excess entropy approximated by the two-body contribution increases with the distortion of the local structural order traced by the HA Indices. The relationship between the excess entropy and the reduced diffusion coefficient supports the universal scaling law proposed by M. Dzugutov. The calculated diffusivities were compared with predictions of four diffusion models. The temperature dependence of the diffusivity cannot be described by the Arrhenius Law, the moving oscillator model or the free volume model but rather by the density fluctuation model with the square proportionality of temperature.

A Dynamic Offset and Delay Differential Assembly Method for OBS Network

Sui Zhicheng,Xiao Shilin,Zeng Qingji The Korea Institute of Information and Commucation 2006 Journal of communications and networks Vol.8 No.2

We study the dynamic burst assembly based on traffic prediction and offset and delay differentiation in optical burst switching network. To improve existing burst assembly mechanism and build an adaptive flexible optical burst switching network, an approach called quality of service (QoS) based adaptive dynamic assembly (QADA) is proposed in this paper. QADA method takes into account current arrival traffic in prediction time adequately and performs adaptive dynamic assembly in limited burst assembly time (BAT) range. By the simulation of burst length error, the QADA method is proved better than the existing method and can achieve the small enough predictive error for real scenarios. Then the different dynamic ranges of BAT for four traffic classes are introduced to make delay differentiation. According to the limitation of BAT range, the burst assembly is classified into one-dimension limit and two-dimension limit. We draw a comparison between one-dimension and two-dimension limit with different prediction time under QoS based offset time and find that the one-dimensional approach offers better network performance, while the two-dimensional approach provides strict inter-class differentiation. Furthermore, the final simulation results in our network condition show that QADA can execute adaptive flexible burst assembly with dynamic BAT and achieve a latency reduction, delay fairness, and offset time QoS guarantee for different traffic classes.

Fabrication and determination of growth regimes of various Pd NPs based on the control of deposition amount and temperature on <i>c</i>-plane GaN

Sui, Mao,Kunwar, Sundar,Pandey, Puran,Zhang, Quanzhen,Li, Ming-Yu,Lee, Jihoon Published for the Materials Research Society by th 2017 Journal of materials research Vol.32 No.18

<▼1><B>Abstract</B><P/></▼1><▼2><P>Palladium (Pd) nanostructures have been actively adapted for various applications and their properties and applicability closely depend on their shape, size, and density. In this paper, the evolution of self-assembled Pd nanostructures on the hexagonal <I>c</I>-plane GaN is presented by the systematical control of Pd deposition amount (DA) at distinctive temperatures. Pd nanostructures of various configurations, sizes, and densities are demonstrated based on the solid-state dewetting of Pd thin films and a clear distinction in the growth regimes is observed. Three growth regimes are clearly observed depending on the variation of DA, i.e., (i) the agglomeration of Pd nanoparticles, (ii) the coalescence of wiggly Pd nanostructures, and finally (iii) the growth of nanovoids and layers. Owing to the temperature-dependent dewetting process, the growth regimes are markedly shifted, resulting in the distinctive Pd nanostructures within the identical DA range. The results are discussed in conjunction with the surface diffusion, Volmer-Weber and coalescence growth model, and surface/interface energy minimization mechanism. In addition, the evolution of optical properties, emission band, and lattice properties are probed by reflectance, photoluminescence, and Raman spectroscopy, which exhibit varying spectral intensity and peak positions according to the surface morphology of Pd nanostructures.</P></▼2>

Der p2 Internalization by Epithelium Synergistically Augments Toll-like Receptor-Mediated Proinflammatory Signaling

Sui-Chu Yin,En-Chih Liao,Chih-Liang Chiu,Ching-Yun Chang,Jaw-Ji Tsai 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.4

Purpose: House-dust-mite (HDM) major allergen Der p2 shares homology and function with Toll-like receptor (TLR) signaling protein myeloid differentiation- 2 (MD2) and may lead to airway inflammation. Should Der p2 be internalized by human airway epithelium, it has the theoretical propensity to potentiate epithelium activation. This study aimed to demonstrate the internalization of Der p2 by airway epithelium and to investigate the effects of Der p2 on MD2 expression and epithelium activation. Methods: Internalization of recombinant, enhanced green fluorescent protein-labelled Der p2 (rDer p2-EGFP) into human airway epithelium (BEAS-2B) was tracked by laser confocal microscopy and confirmed by immunoblotting. Reverse-transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical staining were used to determine the effect of Der p2 on MD2 expression in vitro and ex vivo. Expression of messenger RNA (mRNA) encoding receptors/cytokines was measured by RT-PCR. Secretion of interleukin-6/interleukin-8 (IL-6/IL-8) was measured by enzyme-linked immunosorbent assay (ELISA). Results: Internalization of Der p2 by BEAS-2B was confirmed by confocal microscopy and immunoblotting using rDer p2-EGFP and rDer p2, respectively. Expression of MD2 protein was increased in BEAS-2B and human nasal polyp airway epithelium cultured with rDer p2. Recombinant Der p2-cultured BEAS-2B caused little spontaneous IL-6/IL-8 secretion but significantly augmented by TLR ligand LPS. IL-6 secretion was up-regulated after MD2 transfection. Internalization of Der p2 was reduced by TLR2 RNA knockdown. Dexamethasone, calcitriol, anti-MD2/anti-TLR2 antibodies, and signalling inhibitors significantly reduced LPS+Der p2-induced IL-6/IL-8 secretion. Conclusions: Human airway epithelium may internalize Der p2, which potentiates the response to environmental proinflammatory stimuli through MD2 and TLRs. This study highlights a novel mechanism and alleviates IL-6/IL-8 secretion in mite-induced airway inflammation

Analysis of news bigdata on ‘Gather Town’ using the Bigkinds system

Sui Choi(최수이) 한국컴퓨터정보학회 2022 韓國컴퓨터情報學會論文誌 Vol.27 No.3

4차 산업혁명 기술의 발전으로 가상과 현실의 경계가 모호한 디지털 환경 속에서 MZ세대와 메타버스가 가장 큰 주목을 받고 있다. 이러한 MZ세대에 부합되는 교수학습 방식으로 메타버스가 주목받고 있다. 본 연구에서는 에듀테크 관점에서 언론사 뉴스 분석을 통해 메타버스 플랫폼 중의 하나인 게더타운의 활성화 요인을 탐색해 보고자 하였다. 이를 위해 한국언론재단에서 제공하는 빅카인즈 시스템을 이용하여 빅데이터 관점에서 분석해 보았다. 그 결과 COVID-19 팬데믹 이후에 나타날 미래교육에서 ‘게더타운’의 활용도는 크게 증가할 것으로 예상된다. 둘째, 연관어와 워드크라우드 분석에서, ‘비대면’이나 ‘대학’ 그리고 ‘신입생’ 등 교육 관련 용어들의 가중치가 비교적 높게 나타났으며, ‘메타버스’, ‘메타버스 플랫폼’을 포함하여, ‘코로나19’나 ‘아바타’ 등의 용어도 중심적인 위치에 있는 것으로 나타났다. 셋째, 네트워크 분석에서 도출된 주요 용어로는 ‘코로나19, 아바타, 대학생, 진로, 유튜브’ 가 포함되어 있는 것으로 나타났다. 이러한 여건 하에서, 본 연구 결과는 메타버스 플랫폼의 하나인 게더타운의 향후 교육 영역에서의 활용이 보다 활성화 되는데 크게 기여할 것으로 기대된다. Recent years have drawn a great attention to generation MZ and Metaverse, due to 4th industrial revolution and the development of digital environment that blurs the boundary between reality and virtual reality. Generation MZ approaches the information very differently from the existing generations and uses distinguished communication methods. In terms of learning, they have different motivations, types, skills and build relationships differently. Meanwhile, Metaverse is drawing a great attention as a teaching method that fits traits of gen MZ. Thus, the current research aimed to investigate how to increase the use of Metaverse in Educational Technology. Specifically, this research examined the antecedents of popularity of Gather Town, a platform of Metaverse. Big data of news articles have been collected and analyzed using the Bigkinds system provided by Korea Press Foundation. The analysis revealed, first, a rapid increasing trend of media exposure of Gather Town since July 2021. This suggests a greater utilization of Gather Town in the field of education after the COVID-19 pandemic. Second, Word Association Analysis and Word Cloud Analysis showed high weights on education related words such as ‘remote’, ‘university’, and ‘freshman’, while words like ‘Metaverse’, ‘Metaverse platform’, ‘Covid19’, and ‘Avatar’ were also emphasized. Third, Network Analysis extracted ‘COVID19’, ‘Avatar’, ‘University student’, ‘career’, ‘YouTube’ as keywords. The findings also suggest potential value of Gather Town as an educational tool under COVID19 pandemic. Therefore, this research will contribute to the application and utilization of Gather Town in the field of education.

Annealing temperature effect on self-assembled Au droplets on Si (111)

Sui, Mao,Li, Ming-Yu,Kim, Eun-Soo,Lee, Jihoon Springer 2013 NANOSCALE RESEARCH LETTERS Vol.8 No.1

<P>We investigate the effect of annealing temperature on self-assembled Au droplets on Si (111). The annealing temperature is systematically varied while fixing other growth parameters such as deposition amount and annealing duration clearly to observe the annealing temperature effect. Self-assembled Au droplets are fabricated by annealing from 50°C to 850°C with 2-nm Au deposition for 30 s. With increased annealing temperatures, Au droplets show gradually increased height and diameter while the density of droplets progressively decreases. Self-assembled Au droplets with fine uniformity can be fabricated between 550°C and 800°C. While Au droplets become much larger with increased deposition amount, the extended annealing duration only mildly affects droplet size and density. The results are systematically analyzed with cross-sectional line profiles, Fourier filter transform power spectra, height histogram, surface area ratio, and size and density plots. This study can provide an aid point for the fabrication of nanowires on Si (111).</P>

Giant enhancement of the intrinsic spin Hall conductivity in β -tungsten via substitutional doping

Sui, Xuelei,Wang, Chong,Kim, Jinwoong,Wang, Jianfeng,Rhim, S. H.,Duan, Wenhui,Kioussis, Nicholas American Physical Society 2017 Physical Review B Vol.96 No.24

<P>A key challenge in manipulating the magnetization in heavy-metal/ferromagnetic bilayers via the spin-orbit torque is to identify materials that exhibit an efficient charge-to-spin current conversion. Ab initio electronic structure calculations reveal that the intrinsic spin Hall conductivity (SHC) for pristine beta-W is about 60% larger than that of alpha-W. More importantly, we demonstrate that the SHC of beta-W can be enhanced via Ta alloying. This is corroborated by spin Berry curvature calculations of W1-x Ta-x (x similar to 12.5%) alloys which show a giant enhancement of the spin Hall angle of up to approximate to-0.5. The underlying mechanism is the synergistic behavior of the SHC and longitudinal conductivity with the Fermi level position. These findings not only pave the way for enhancing the intrinsic spin Hall effect in beta-W, but also provide guidelines to exploit substitutional alloying to tailor the spin Hall effect in various materials.</P>

Evolution of self-assembled Ag nanostructures on c-plane sapphire by the systematic control of annealing temperature

Sui, M.,Pandey, P.,Kunwar, S.,Li, M.-Y.,Zhang, Q.,Lee, J. Elsevier 2016 Superlattices and microstructures Vol.100 No.-

<P><B>Abstract</B></P> <P>The morphological evolution of various Ag nanostructures on <I>c</I>-plane sapphire is systematically investigated through the solid-state-dewetting by the control of annealing temperature between 200 and 950 °C with the Ag films of 60 and 10 nm. Various configurations of Ag nanostructures including Ag voids, wiggly and round nanoparticles are fabricated with the 60 nm due to the annealing temperature dependent surface diffusion, surface energy minimization and Ag sublimation. As a sharp distinction, highly dense semi-spherical nanoparticles are fabricated with the 10 nm set throughout the temperature range due to a much higher dewetting degree induced by the enhanced surface diffusion with a much thinner film. The reflectance spectra shows a spectral shift along with the size variation, i.e. blue shift with the decreased size and vice versa. The reflectance and Raman spectra reveal a sharp distinction between the two sets along with the strong correlation to the nanostructure morphology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Various configurations of self-assembled Ag nanostructures on c-plane sapphire. </LI> <LI> Single configuration Ag nanoparticles throughout the range with a thinner film. </LI> <LI> Detailed morphology study by SEM and AFM. </LI> <LI> Energy-dispersive X-ray spectroscopy confirmation of consistent sublimation above 650 °C. </LI> <LI> Reflectance and Raman of various configurations of Ag nanostructures. </LI> </UL> </P>