http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Growth of Highly Single Crystalline IrO<sub>2</sub> Nanowires and Their Electrochemical Applications
Lee, Yumin,Kang, Minkyung,Shim, Jun Ho,Lee, Nam-Suk,Baik, Jeong Min,Lee, Youngmi,Lee, Chongmok,Kim, Myung Hwa American Chemical Society 2012 The Journal of Physical Chemistry Part C Vol.116 No.34
<P>We present the facile growth of highly single crystalline iridium dioxide (IrO<SUB>2</SUB>) nanowires on SiO<SUB>2</SUB>/Si and Au substrates via a simple vapor phase transport process under atmospheric pressure without any catalyst. Particularly, high-density needle-like IrO<SUB>2</SUB> nanowires were readily obtained on a single Au microwire, suggesting that the melted surface layer of Au might effectively enhance the nucleation of gaseous IrO<SUB>3</SUB> precursors at the growth temperature. In addition, all the electrochemical observations of the directly grown IrO<SUB>2</SUB> nanowires on a single Au microwire support favorable electron-transfer kinetics of [Fe(CN<SUB>6</SUB>)]<SUP>4–/3–</SUP> as well as Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP> at the highly oriented crystalline IrO<SUB>2</SUB> nanowire surface. Furthermore, stable pH response is shown, revealing potential for use as a miniaturized pH sensor, confirmed by the calibration curve exhibiting super-Nernstian behavior with a slope of 71.6 mV pH<SUP>–1</SUP>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2012/jpccck.2012.116.issue-34/jp306900m/production/images/medium/jp-2012-06900m_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp306900m'>ACS Electronic Supporting Info</A></P>
Kang, Minkyung,Lee, Yumin,Jung, Hayoung,Shim, Jun Ho,Lee, Nam-Suk,Baik, Jeong Min,Lee, Sang Cheol,Lee, Chongmok,Lee, Youngmi,Kim, Myung Hwa American Chemical Society 2012 ANALYTICAL CHEMISTRY - Vol.84 No.21
<P>We demonstrate highly efficient electocatalytic activities of single crystalline RuO<SUB>2</SUB> nanorods grown on carbon fiber (CF), i.e., RuO<SUB>2</SUB> nanorod-CF hybrid microelectrode, prepared by a simple thermal annealing process from the Ru(OH)<SUB>3</SUB> precursor at 300 °C. The general electrochemical activity of a RuO<SUB>2</SUB> nanorod-CF microelectrode represents faster electron transfer for the [Fe(CN)<SUB>6</SUB>]<SUP>3–/4–</SUP> couple than that of the bare CF microelectrode which are confirmed from the cyclic voltammetry (CV) measurement. Also, the amperometric response for the H<SUB>2</SUB>O<SUB>2</SUB> oxidation is remarkably facilitated at the RuO<SUB>2</SUB> nanorod-CF microelectrode by not only the enlarged surface area but the high electrocatalytic activity of the RuO<SUB>2</SUB> nanorod material itself. Furthermore, a single microelectrode of RuO<SUB>2</SUB> nanorod-CF exhibits the superior tolerance to Cl<SUP>–</SUP> ion poisoning unlike Pt-based electrocatalysts, indicating the promising sensor candidate in physiological conditions.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2012/ancham.2012.84.issue-21/ac302334t/production/images/medium/ac-2012-02334t_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac302334t'>ACS Electronic Supporting Info</A></P>
Chun, Sung Hee,Choi, Hyun-A,Kang, Minkyung,Koh, Moonjee,Lee, Nam-Suk,Lee, Sang Cheol,Lee, Minyung,Lee, Youngmi,Lee, Chongmok,Kim, Myung Hwa American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.17
<P>Highly efficient single crystalline ruthenium–vanadium mixed metal oxide (Ru<SUB>1–<I>x</I></SUB>V<SUB><I>x</I></SUB>O<SUB>2</SUB>, 0 ≤ <I>x</I> ≤ 1) nanowires were prepared on a SiO<SUB>2</SUB> substrate and a commercial Au microelectrode for the first time through a vapor-phase transport process by adjusting the mixing ratios of RuO<SUB>2</SUB> and VO<SUB>2</SUB> precursors. Single crystalline Ru<SUB>1–<I>x</I></SUB>V<SUB><I>x</I></SUB>O<SUB>2</SUB> nanowires show homogeneous solid-solution characteristics as well as the distinct feature of having remarkably narrow dimensional distributions. The electrochemical observations of a Ru<SUB>1–<I>x</I></SUB>V<SUB><I>x</I></SUB>O<SUB>2</SUB> (<I>x</I> = 0.28 and 0.66)-decorated Au microelectrode using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrate favorable charge-transfer kinetics of [Fe(CN)<SUB>6</SUB>]<SUP>3–/4–</SUP> and Ru(NH<SUB>3</SUB>)<SUB>6</SUB><SUP>3+/2+</SUP> couples compared to that of a bare Au microelectrode. The catalytic activity of Ru<SUB>1–<I>x</I></SUB>V<SUB><I>x</I></SUB>O<SUB>2</SUB> for oxygen and H<SUB>2</SUB>O<SUB>2</SUB> reduction at neutral pH increases as the fraction of vanadium increases within our experimental conditions, which might be useful in the area of biofuel cells and biosensors.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-17/am4016445/production/images/medium/am-2013-016445_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am4016445'>ACS Electronic Supporting Info</A></P>
Lee, Seul,Park, Haeryun,Lee, Youngmi,Choi, Onjeong,Kim, Jiwon,Gray, Heewon L,Song, Kyunghee The Korean Nutrition Society 2019 Nutrition Research and Practice Vol.13 No.3
BACKGROUND/OBJECTIVES: Diabetes is diagnosed after an average of 10-12 years of diabetic development. Strict glycemic control in diabetic patients promotes the normalization of blood glucose and reduces cardiovascular diseases (CVDs) and diabetic complications. Therefore, early diagnosis in non-aware individuals is very important. SUBJECTS/METHODS: Clinical indices and nutrient intakes in Korean diabetic adults aged 19-64 years were examined according to the awareness of diabetes, using 2012 and 2013 Korea National Health and Nutrition Examination Survey (KNHANES) data. The aware group was defined as individuals who were aware of having diabetes from diagnosis by physician before the survey and the non-aware group as individuals who were not aware of having diabetes. RESULTS: The average age was higher in the aware group compared to the non-aware group in both men (P = 0.002) and women (P = 0.004). The prevalences of hypertension and dyslipidemia were not different between the two groups, but the diagnosis rate was significantly lower in the non-aware group. In the non-aware group, total and LDL-cholesterol were significantly higher (P < 0.001), the risk for total cholesterol over 240 mg/dL was 3.4 times (95% CI: 1.58-7.52) higher (P = 0.002) and the risk for LDL-cholesterol over 160 mg/dL was 4.59 times (95% CI: 2.07-10.17) higher (P < 0.001). The calorie intake of the female non-aware group was significantly higher compared to the female aware group (P = 0.033). CONCLUSION: The results suggested that the recommendation of screening test is necessary even for young adults. Studies on the methodology for early diagnosis of diabetes are also needed.
Parameter change test for zero-inflated generalized Poisson autoregressive models
Lee, Sangyeol,Lee, Youngmi,Chen, Cathy W.S. Taylor Francis 2016 Statistics Vol.50 No.3
<P>In this paper, we consider the problem of testing for parameter change in zero-inflated generalized Poisson (ZIGP) autoregressive models. We verify that the ZIGP process is stationary and ergodic and that the conditional maximum likelihood estimator (CMLE) is strongly consistent and asymptotically normal. Based on these results, we construct CMLE- and residual-based cumulative sum tests and show that their limiting null distributions are a function of independent Brownian bridges. The simulation results are provided for illustration. A real data analysis is performed on some crime data of Australia.</P>
Monitoring Distributional Changes in Autoregressive Models
Lee, Sangyeol,Lee, Youngmi,Na, Okyoung Taylor Francis 2009 Communications in Statistics Vol.38 No.16
<P> In this artilce, we develop a monitoring procedure for an early detection of distributional changes in autoregressive models. We design the monitoring procedure based on residuals since the test based on the observations is inappropriate. We verify that under regularity conditions, the stopping rule designed to detect changes behaves asymptotically the same as that in iid samples. Simulation results are provided for illustration.</P>