http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The bubble problem of the plasma facing material: A finite element study
Xiaoyan Kang,Xiyue Cheng,Shuiquan Deng 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.10
The damage of first wall material in fusion reactor due to the bubbles caused by plasma has been studied by introducing a relation between the von Mises equivalent stress and the temperature field. The locations and shapes of the bubbles and the synergetic effect between the different bubbles under steady operational conditions have been studied using the finite elements method. Under transient heat loads, plastic deformations have been found to occur, and are significantly enhanced by the presence of the bubbles. The calculated concentration locations of von Mises equivalent stress are well consistent with the observed crack positions of the tungsten surface in many test experiments. Our simulations show that the damage of the bubbles is not severe enough to lead to catastrophic failure of the tungsten armor; however, it can cause local and gradual detachment of tungsten surface, which provides a reasonable explanation for the observed pits and rough or hairy surface morphology etc. Considering the transient heat loads, the lower bound of the security thickness of the tungsten tile is estimated to be greater than 2 mm.
Kang, Bohyun,Jin, Xiaoyan,Oh, Seung Mi,Patil, Sharad B.,Kim, Min Gyu,Kim, Sun Hee,Hwang, Seong-Ju Elsevier 2018 Applied catalysis. B, Environmental Vol.236 No.-
<P><B>Abstract</B></P> <P>A critical role of bond competition in tailoring Mn valence state and bifunctional electrocatalyst activity of manganese oxide is evidenced by the remarkable improvement of the electrocatalyst activity of α-MnO<SUB>2</SUB> upon the partial substitution of electronegative Ru<SUP>4+</SUP> ion. The replacement of Mn<SUP>4+</SUP> ion with more electronegative Ru<SUP>4+</SUP> one is quite effective in weakening adjacent (Mn−O) bonds in terms of bond competition, leading to the stabilization of Jahn-Teller active Mn<SUP>3+</SUP> species, as well as in providing electrocatalytically active Ru sites. The resulting Ru-substituted α-Mn<SUB>1−x</SUB>Ru<SUB>x</SUB>O<SUB>2</SUB> nanowires show much higher electrocatalyst activities for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) than does the physical mixture of α-MnO<SUB>2</SUB> and RuO<SUB>2</SUB>, indicating the main role of (Mn−O) bond covalency in the optimization of the bifunctional electrocatalyst activity of manganese oxide. The present study underscores that, like the previous strategy of structural disorder enhancement, the substitution of highly electronegative cation can provide a novel efficient way of improving the electrocatalyst performance of manganese oxide via the bond competition between adjacent (Ru−O) and (Mn−O) bonds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Efficient bifunctional electrocatalysts are developed by hydrothermal method. </LI> <LI> Cation substitution can improve electrocatalyst performance of manganese oxide. </LI> <LI> Substituted Ru ions enhance the stability of Jahn-Teller active Mn<SUP>3+</SUP> species. </LI> <LI> Bond competition is critical in tailoring the Mn valence state and functionality. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Efficient Cu(OTf)2-catalyzed synthesis of novel and diverse 2,3-dihydroquinazolin-4(1H)-ones.
Zhu, Xiaoyan,Kang, So Rang,Xia, Likai,Lee, Jihye,Basavegowda, Nagaraj,Lee, Yong Rok ESCOM Science Publishers 2015 Molecular diversity Vol.19 No.1
<P>An efficient one-pot synthesis of various 2,3-dihydroquinazolin-4(1H)-one derivatives was accomplished using Cu(OTf)2-catalyzed multi-component reactions between isatoic anhydride, ketones, and amines. The method has several significant advantages; mild reaction conditions, easy handling, and efficiency of catalyst.</P>
Jin, Xiaoyan,Shin, Seung-Jae,Kim, Najin,Kang, Bohyun,Piao, Huiyan,Choy, Jin-Ho,Kim, Hyungjun,Hwang, Seong-Ju Elsevier 2018 Nano energy Vol.53 No.-
<P><B>Abstract</B></P> <P>A superior efficiency of MXene (Ti<SUB>3</SUB>C<SUB>2</SUB>) nanosheet as a hybridization matrix over graphene is evidenced by comparative investigation on uniformly-stacked MnO<SUB>2</SUB>–Ti<SUB>3</SUB>C<SUB>2</SUB> and MnO<SUB>2</SUB>–reduced graphene oxide (rGO) nanohybrids. Density functional theory calculation and spectroscopic analyses demonstrate a stronger interfacial electronic coupling and greater charge transfer of polar MnO<SUB>2</SUB> with hydrophilic Ti<SUB>3</SUB>C<SUB>2</SUB> nanosheet than with hydrophobic rGO one, which maximizes the hybridization effect with the conductive nanosheet. Also, hybridization with Ti<SUB>3</SUB>C<SUB>2</SUB> nanosheet is more effective in enhancing the ion diffusivity and porosity of MnO<SUB>2</SUB> than that with strongly self-stacking rGO, which is attributable to weaker self-stacking tendency of Ti<SUB>3</SUB>C<SUB>2</SUB>. Due to these hybridization effects, the MnO<SUB>2</SUB>–Ti<SUB>3</SUB>C<SUB>2</SUB> nanohybrid delivers larger specific capacitance with improved rate performance than does the MnO<SUB>2</SUB>–rGO nanohybrid, underscoring higher efficiency of MXene hybridization in improving electrode performance. This study clearly demonstrates that exfoliated MXene nanosheet can act as a superior hybridization matrix over rGO to explore strongly-coupled nanohybrids with improved energy-related functionality.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MXene nanosheet shows superior efficiency as a hybridization matrix over graphene. </LI> <LI> Efficient electrode materials are synthesized by hybridization with MXene nanosheet. </LI> <LI> There is a stronger interfacial electronic coupling of MnO<SUB>2</SUB> with MXene than with rGO. </LI> <LI> Hybridization with less self-stacking MXene nanosheet remarkably increases porosity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Systematic characterization of A-to-I RNA editing hotspots in microRNAs across human cancers
Wang, Yumeng,Xu, Xiaoyan,Yu, Shuangxing,Jeong, Kang Jin,Zhou, Zhicheng,Han, Leng,Tsang, Yiu Huen,Li, Jun,Chen, Hu,Mangala, Lingegowda S.,Yuan, Yuan,Eterovic, A. Karina,Lu, Yiling,Sood, Anil K.,Scott, Cold Spring Harbor Laboratory Press 2017 Genome research Vol.27 No.7
<P>RNA editing, a widespread post-transcriptional mechanism, has emerged as a new player in cancer biology. Recent studies have reported key roles for individual miRNA editing events, but a comprehensive picture of miRNA editing in human cancers remains largely unexplored. Here, we systematically characterized the miRNA editing profiles of 8595 samples across 20 cancer types from miRNA sequencing data of The Cancer Genome Atlas and identified 19 adenosine-to-inosine (A-to-I) RNA editing hotspots. We independently validated 15 of them by perturbation experiments in several cancer cell lines. These miRNA editing events show extensive correlations with key clinical variables (e.g., tumor subtype, disease stage, and patient survival time) and other molecular drivers. Focusing on the RNA editing hotspot in miR-200b, a key tumor metastasis suppressor, we found that the miR-200b editing level correlates with patient prognosis opposite to the pattern observed for the wild-type miR-200b expression. We further experimentally showed that, in contrast to wild-type miRNA, the edited miR-200b can promote cell invasion and migration through its impaired ability to inhibit <I>ZEB1/ZEB2</I> and acquired concomitant ability to repress new targets, including <I>LIFR</I>, a well-characterized metastasis suppressor. Our study highlights the importance of miRNA editing in gene regulation and suggests its potential as a biomarker for cancer prognosis and therapy.</P>
A-to-I RNA Editing Contributes to Proteomic Diversity in Cancer
Peng, Xinxin,Xu, Xiaoyan,Wang, Yumeng,Hawke, David H.,Yu, Shuangxing,Han, Leng,Zhou, Zhicheng,Mojumdar, Kamalika,Jeong, Kang Jin,Labrie, Marilyne,Tsang, Yiu Huen,Zhang, Minying,Lu, Yiling,Hwu, Patrick Cell Press 2018 CANCER CELL Vol. No.
Son, Suji,Lee, Jang Mee,Kim, Se-Jun,Kim, Hyejin,Jin, Xiaoyan,Wang, Kang Kyun,Kim, Minho,Hwang, Jeong Wook,Choi, Wonyong,Kim, Yong-Rok,Kim, Hyungjun,Hwang, Seong-Ju Elsevier BV 2019 Applied Catalysis B Vol.257 No.-
<P><B>Abstract</B></P> <P>Hybridization with conductive 2D nanosheets (NSs) attracts plenty of research activities because of its effectiveness for improving the photocatalyst performance of diverse semiconductors. Here, versatile roles of conductive NSs in hybrid-type photocatalysts are systematically investigated with three representative conductive 2D NSs to synthesize highly efficient visible light-active photocatalysts. Among several conductive NS-based nanohybrids, the RuO<SUB>2</SUB> NS-based nanohybrid exhibits the highest photocatalytic activities. Based on systematic spectroscopic analyses, polar RuO<SUB>2</SUB> NS appears to be more effective as electron reservoir, photosensitizer, cocatalyst and charge carrier pathway in hybrid-type photocatalyst than MoS<SUB>2</SUB> and graphene NSs. The high efficiency of RuO<SUB>2</SUB> NS as hybridization matrix is attributable to the high surface hydrophilicity, high surface bond polarity, and enhanced interfacial electronic coupling of this hydrophilic NS with semiconductor. The present study underscores that hydrophilic conductive metal oxide NS can act as the most efficient hybridization matrix for exploring high-performance photocatalysts with strong interfacial electronic coupling.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 2D conductive nanosheets play versatile roles in hybrid-type photocatalysts. </LI> <LI> Hybridization with conductive nanosheet remarkably enhances photocatalyst activity. </LI> <LI> Interfacial electronic coupling is the most crucial factor for hybrid-type photocatalyst. </LI> <LI> Hydrophilic metal oxide nanosheet is the most efficient hybridization matrix. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>