http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Tetragonal Phase Germanium Nanocrystals in Lithium Ion Batteries
Cho, Yong Jae,Im, Hyung Soon,Kim, Han Sung,Myung, Yoon,Back, Seung Hyuk,Lim, Young Rok,Jung, Chan Su,Jang, Dong Myung,Park, Jeunghee,Cha, Eun Hee,Cho, Won Il,Shojaei, Fazel,Kang, Hong Seok American Chemical Society 2013 ACS NANO Vol.7 No.10
<P>Various germanium-based nanostructures have recently demonstrated outstanding lithium ion storage ability and are being considered as the most promising candidates to substitute current carbonaceous anodes of lithium ion batteries. However, there is limited understanding of their structure and phase evolution during discharge/charge cycles. Furthermore, the theoretical model of lithium insertion still remains a challenging issue. Herein, we performed comparative studies on the cycle-dependent lithiation/delithiation processes of germanium (Ge), germanium sulfide (GeS), and germanium oxide (GeO<SUB>2</SUB>) nanocrystals (NCs). We synthesized the NCs using a convenient gas phase laser photolysis reaction and attained an excellent reversible capacity: 1100–1220 mAh/g after 100 cycles. Remarkably, metastable tetragonal (ST12) phase Ge NCs were constantly produced upon lithiation and became the dominant phase after a few cycles, completely replacing the original phase. The crystalline ST12 phase persisted through 100 cycles. First-principles calculations on polymorphic lithium-intercalated structures proposed that the ST12 phase Ge<SUB>12</SUB>Li<SUB><I>x</I></SUB> structures at <I>x</I> ≥ 4 become more thermodynamically stable than the cubic phase Ge<SUB>8</SUB>Li<SUB><I>x</I></SUB> structures with the same stoichiometry. The production and persistence of the ST12 phase can be attributed to a stronger binding interaction of the lithium atoms compared to the cubic phase, which enhanced the cycling performance.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2013/ancac3.2013.7.issue-10/nn403674z/production/images/medium/nn-2013-03674z_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn403674z'>ACS Electronic Supporting Info</A></P>
Cho, Seung Hee,Park, Mi Hee,Lee, Hee Peom,Back, Myong Ki,Sung, Ha Chang,Chang, Hee Won,Kim, Joo Hwan,Jeong, Heon-Sang,Han, Sang Bae,Hong, Jin Tae 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.5
Ovarian cancer is a cancerous growth arising from the ovary and with poor prognosis that usually have resistant to all currently available treatments. Whether (E)-2,4-bis(p-hydroxyphenyl)-2-butenal (butenal) synthesized by Maillard reaction from fructose-tyrosine, has potential therapeutic activity against human ovarian cancer was investigated using two ovarian cancer cell lines (PA-1, SK-OV-3). We found that butenal could inhibit NF-${\kappa}B$/STAT3 activity, thereby inducing apoptotic cell death of ovarian cancer cells. We treated with several concentration of butenal each cell line differently (PA-1; 5, 10 and $15{\mu}g/ml$, SK-OV-3; 10, 20 and $30{\mu}g/ml$). First, ovarian cancer cell lines exhibited constitutively active NF-${\kappa}B$, and treatment with butenal abolished this activation as indicated by DNA binding activity. Second, butenal suppressed activation of signal transducer and activator of transcription-3 as indicated by decreased phosphorylation and inhibition of Janus kinase-2 phosphorylation. Third, butenal induced expression of pro-apoptotic proteins such as proteolytic cleavage of PARP, Bax and activation of caspase-3, -8 and -9. Lastly, combination of butenal and TRAIL causes enhanced induction of apoptosis. Overall, our results indicate that butenal mediates its anti-proliferative and apoptotic effects through activation of multiple cell signaling pathways and enhances the TRAIL-induced apoptosis. These data suggested that butenal may be a potential anti-cancer agent in ovarian cancer.
Cho, Yong Jae,Im, Hyung Soon,Myung, Yoon,Kim, Chang Hyun,Kim, Han Sung,Back, Seung Hyuk,Lim, Young Rok,Jung, Chan Su,Jang, Dong Myung,Park, Jeunghee,Cha, Eun Hee,Choo, Sung Ho,Song, Min Seob,Cho, Won The Royal Society of Chemistry 2013 Chemical communications Vol.49 No.41
<P>Germanium sulfide (GeS and GeS<SUB>2</SUB>) nanoparticles were synthesized by novel gas-phase laser photolysis and subsequent thermal annealing. They showed excellent cycling performance for lithium ion batteries, with a maximum capacity of 1010 mA h g<SUP>−1</SUP> after 100 cycles. Metastable tetragonal phase Ge nanoparticles were suggested as active materials for a reversible lithium insertion–extraction process.</P> <P>Graphic Abstract</P><P>Novel gas-phase photolysis produces germanium sulfide(<SMALL>II</SMALL> and <SMALL>IV</SMALL>) nanoparticles as excellent anode materials of lithium ion batteries. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cc41853g'> </P>
Germanium–tin alloy nanocrystals for high-performance lithium ion batteries
Cho, Yong Jae,Kim, Chang Hyun,Im, Hyung Soon,Myung, Yoon,Kim, Han Sung,Back, Seung Hyuk,Lim, Young Rok,Jung, Chan Su,Jang, Dong Myung,Park, Jeunghee,Lim, Sang Hoo,Cha, Eun Hee,Bae, Ki Yoon,Song, Min S The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.28
<P>Germanium–tin (Ge<SUB>1−<I>x</I></SUB>Sn<SUB><I>x</I></SUB>) alloy nanocrystals were synthesized using a gas-phase laser photolysis reaction of tetramethyl germanium and tetramethyl tin. A composition tuning was achieved using the partial pressure of precursors in a closed reactor. For <I>x</I> < 0.1, cubic phase alloy nanocrystals were exclusively produced without separation of the tetragonal phase Sn metal. In the range of <I>x</I> = 0.1–0.4, unique Ge<SUB>1−<I>x</I></SUB>Sn<SUB><I>x</I></SUB>–Sn alloy–metal hetero-junction nanocrystals were synthesized, where the Sn metal domain becomes dominant with <I>x</I>. Thin graphitic carbon layers usually sheathed the nanocrystals. We investigated the composition-dependent electrochemical properties of these nanocrystals as anode materials of lithium ion batteries. Incorporation of Sn (<I>x</I> = 0.05) significantly increased the capacities (1010 mA h g<SUP>−1</SUP> after 50 cycles) and rate capabilities, which promises excellent electrode materials for the development of high-performance lithium batteries.</P> <P>Graphic Abstract</P><P>Gas-phase laser photolysis produces high-yield composition-tuned germanium–tin nanocrystals for high-performance lithium ion batteries. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp51366a'> </P>
Performance Evaluation of a Plate-Type Membrane Humidifier for PEMFC
고백균(Kho, Back Kyun),박종철(Park, JongCheol),한인수(Han, In-Su),신현길(Shin, Hyun Khil),허태욱(Hur, Tae Uk),조성백(Cho, Sungbaek) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05
For optimal performance of a proton exchange membrane fuel cell (PEMFC), the membrane electrode assembly (MEA) requires hydration, and the membrane's conductivity depends on water content. A humidifier is required to ensure that the reactant gas, usually hydrogen and air, is hydrated before entering the fuel cell. Dry membrane operation or improper hydration causes performance degradation. Typically, the humidification of a fuel cell is carried out by means of an internal or external humidifier. A membrane humidifier is applied to the external humidification of transportation or residential power generation fuel cell due to its convenience and high performance. In this study, The experiments were constructed with a plate-type membrane humidifier in terms of geometric parameters and operating parameters. The results show that the temperature and pressure, the channel length, the membrane thickness and gas flow rate are critical parameters affecting the performance of the humidifier.
Park, Kwonoh,Cho, Kyung Ja,Lee, Miji,Yoon, Dok Hyun,Kim, Jiyoun,Kim, Sang Yoon,Nam, Soon Yuhl,Choi, Seung-Ho,Roh, Jonh-Lyel,Han, Myung Woul,Lee, Sang-Wook,Song, Si Yeol,Back, Jeong Hwan,Kim, Sung-Bae Informa Healthcare 2013 Acta oto-laryngologica Vol.133 No.3
<P><I>Conclusions:</I> p16 immunohistochemistry (IHC) status correlated with less exposure to smoking and/or alcohol in Korean patients with locally advanced tonsillar squamous cell carcinoma (TSCC), and was an independent prognostic factor for survival. <I>Objective:</I> TSCC is more likely to be human papillomavirus (HPV)-positive than other head and neck squamous cell carcinoma (HNSCC) subtypes. The objective of this study was to ascertain the HPV status of TSCC in Korean patients and to determine its relationship with clinical parameters and prognosis. <I>Methods:</I> The locally advanced TSCCs of 79 patients who were treated between 2000 and 2008 were tested by p16 IHC and HPV in situ hybridization (ISH) with a tissue microarray. <I>Results:</I> Sixty-three patients (80%) were positive for p16 IHC, while 54 (68%) were positive by HPV ISH. p16 IHC status correlated significantly with lower exposure to smoking and alcohol (<I>p</I> < 0.05) but did not correlate with T and N stage classification, histological differentiation, age, or gender. The p16-positive group had a significantly higher 5-year overall survival rate in comparison with the p16-negative group (78% vs 63%, hazard ratio (HR) = 0.347, 95% CI = 0.14, 95% C<I>p</I> = 0.025). p16 IHC was a favorable independent prognostic factor for overall survival, even after adjustment for age and T stage (HR = 0.283, 95% CI = 0.103, 95% <I>p</I> = 0.015).</P>
Open New Horizon with L4 Mission: Vision and Planning
Kyung-Suk Cho(조경석),Junga Hwang(황정아),Jeong-Yeol Han(한정열),Seonghwan Choi(최성환),Eun-Kyung Lim(임은경),Jungjoon Seough(서정준),Rok-Soon Kim(김록순),Sung-Hong Park(박성홍),Jongdae Sohn(손종대),Jie-Hae Back(백지혜),Young-Jae 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.6
A Study on Observer-Based Robut Algorithm for Voltage Regulated Current Source Power Filter
Geum-Bae Cho,Hyung-Lae Back,Jong-Gyu Hwang,Han-Sung Kim,Hyong-Soo Mok,Byung-Moon Han 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10
Active Power Filters(APF) have been developed recently to' solve the harmonics disturbance problems on power system networks The voltage regulation technique controlled the voltage of inverter output capacitor 15 used for current source power filter or precise control, voltage drop at ac side is .needed expressed differentiator If external noise is included in detected voltage drop signal, then the noise is differentiated and thus the resultant signal will be distorted seriously To reduce this amplified differential noise, observer algorithm is proposed Noise characteristics at active filter control system are investigated by digital simulation Also, the experimental results are shown to verify the validity of proposed technique.