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121.
Daiwon Choi Donghai Wang Vish V. Viswanathan In-Tae Bae Wei Wang Zimin Nie Ji-Guang Zhang Gordon L. Graff Jun Liu Zhenguo Yang Tien Duong 《Electrochemistry communications》2010,12(3):378-381
Li-ion batteries made from LiFePO4 cathode and anatase TiO2/graphene composite anode were investigated for potential application in stationary energy storage. Fine-structured LiFePO4 was synthesized by a novel molten surfactant approach whereas anatase TiO2/graphene nanocomposite was prepared via self-assembly method. The full cell that operated at 1.6 V demonstrated negligible fade even after more than 700 cycles at measured 1 C rate. While with relative lower energy density than traditional Li-ion chemistries interested for vehicle applications, the Li-ion batteries based on LiFePO4/TiO2 combination potentially offers long life and low cost, along with safety, all which are critical to the stationary applications. 相似文献
122.
Ji Sun Im Tae-Sung Bae Young-Seak Lee 《Journal of Physics and Chemistry of Solids》2011,72(10):1175-1179
ZrO2-embedded carbon fibers were prepared for use as an electromagnetic interference (EMI) shielding material by electrospinning and heat treatment methods. Structural changes were observed in the ZrO2 and in the carbon structures by XRD and Raman spectroscopy, respectively. During heat treatment, XRD analysis results revealed a transition from a monoclinic structure to a tetragonal structure in ZrO2 and a graphitization in the structural formation of carbon fibers was observed by Raman spectroscopy. It was observed that these structural changes in the ZrO2 and the carbon fibers improved the real and imaginary permittivities by a factor of more than 3.5. The EMI shielding efficiency (SE) improved along with the permittivity with higher treatment temperatures and greater amounts of embedded ZrO2; the highest average EMI SE achieved was 31.79 dB in 800-8500 MHz. The heat treatment played an important role in the improvements in the permittivity and in the EMI SE because of the heat-induced structural changes of the ZrO2-embedded electrospun carbon fibers. We suggest that the EMI shielding of the fibers is primarily due to the absorption of electromagnetic waves, which prevents secondary EMI by reflection of electromagnetic waves. 相似文献
123.
We report the first experimental realization of an approximate partial transpose for photonic two-qubit systems. The proposed scheme is based on the local operation on single copies of quantum states and classical communication, and therefore can be easily applied for other quantum information tasks within current technologies. Direct detection of entanglement, i.e., without performing quantum state tomography, using the partial transpose operation, is also demonstrated. 相似文献
124.
Kihong Son Haijo Jung Sang Hun Shin Hyun-Ho Lee Mi-Sook Kim Young Hoon Ji Kum Bae Kim 《Radiation measurements》2011,46(10):1117-1122
We aimed to evaluate the suitability of a glass dosimeter (GD) for high-energy photon and electron beams in experimental and clinical use, especially for radiation therapy. We examined the expanded dosimetric characteristics of GDs including dose linearity up to 500 Gy, uniformity among GD lots and for individual GDs, the angular dependence, and energy dependence of 4 therapeutic x-ray qualities. In addition, we measured the dosimetric features (dose linearity, uniformity, angular dependence, and energy dependence) of the GD for electron beams of 10 different electron energy qualities. All measurements with the exception of dose linearity for photon beam were performed in a water phantom. For high-energy photon beams, dose linearity has a linear relationship for a dose ranging from 1 to 500 Gy with the coefficient of determination; R2 of 0.998. The uniformity of each GD of dose measurements was within ±0.5% for four GD lots and within ±1.2% for 80 GDs. In terms of the effects of photon beam angle, lower absorbed doses of within 1.0% were observed between 60° and 105° than at 90°. The GD energy dependence of 4 photon beam energy qualities was within ±2.0%. On the other hand, the result of the dose linearity for high-energy electron beams showed well fitted regression line with the coefficient of determination; R2 of 0.999 between 6 and 20 MeV. The uniformity of GDs exposed to the nominal electron energies 6, 9, 12, 16, and 20 MeV was ±1.2%. In terms of the angular dependence to electron beams, absorbed doses were within 2.0% between 60° and 105° than at 90°. In evaluation of the energy dependence of the GD at nominal electron energies between 5 and 20 MeV, we obtained responses between 1.1% and 3.5% lower than that for a cobalt-60 beam. Our results show that GDs can be used as a detector for determining doses when a high-energy photon beam is used, and that it also has considerable potential for dose measurement of high-energy electron beam. 相似文献
125.
I.-H. Bae H. S. Moon S. Zaske C. Becher S. K. Kim S.-N. Park D.-H. Lee 《Applied physics. B, Lasers and optics》2011,103(2):311-319
We present a 532 nm-pumped singly-resonant cw optical parametric oscillator based on MgO-doped PPLN with a minimum threshold
pump power of 0.3 W. The OPO with a two-mirror standing-wave cavity is optimized by using a tunable diode laser on the path
of the resonant signal beam. The maximum output power is 200 mW at an idler wavelength near 1330 nm at a pump power of 2 W.
We report the degradation of the output power and beam characteristics at high pump power indicating a strong thermal lensing
in the crystal. The continuous tuning range of the OPO is measured to be 800 MHz which is close to 90% of the free spectral
range of the OPO cavity. 相似文献
126.
A single-mode fiber (SMF) acousto-optic tunable filter (AOTF) with a tuning range of more than 300 nm is demonstrated. The SMF used in the experiment has a ring of symmetric holes within the cladding, which causes a larger mode-index difference between the first and the second higher-order antisymmetric modes than those of a conventional SMF. As a result, the difference in beatlengths between the core mode and the higher-order modes is highly increased, which makes it possible for the SMF AOTF to exhibit a single resonance peak in the transmission spectrum over the wavelength range of 1.3-1.6 μm for given acoustic frequencies of 3.1-3.8 MHz. 相似文献
127.
M.?FouchierEmail author E.?Pargon L.?Azarnouche K.?Menguelti O.?Joubert T.?Cardolaccia Y.?C.?Bae 《Applied Physics A: Materials Science & Processing》2011,105(2):399-405
193 nm photoresists which are methacrylate-based polymers are very sensitive to vacuum ultra violet (VUV) light (100 nm<λ<200 nm) generated by plasmas used for pattern transfer technologies. Upon plasma treatment the physical properties of the
polymers can be deeply modified. To better understand the chemical changes involved, the absorption coefficient of a commercial
193 nm photoresist has been measured in the 120–280 nm wavelength range using a home built experimental set-up. The different
contributions to the absorption were identified by also measuring the spectra of model polymers and simpler polymer chains.
This knowledge was then used to identify the chemical changes in the photoresist upon heating up to 240°C. 相似文献
128.
Youngjin Bae 《Israel Journal of Mathematics》2014,204(1):417-430
We study the growth rate of a sequence which measures the uniform norm of the differential under the iterates of maps. On symplectically hyperbolic manifolds, we show that this sequence has at least linear growth for every non-identical symplectomorphisms which are symplectically isotopic to the identity. 相似文献
129.
Bo Hyun Kong Hyung Koun Cho Mi Yang Kim Rak Jun Choi Bae Kyun Kim 《Journal of Crystal Growth》2010,312(14):2128-2132
InGaN/GaN multiple quantum well-based blue light emitting diodes (LEDs) with different spacer layer structures were grown by metalorganic chemical vapor deposition. Fast-Fourier-transformed high-resolution transmission electron microscopy was used to determine the influence of the strain status in the spacer layer on Mg distribution and device performance. A comparison of the (1 1¯ 0 0) planar distance showed that the high-temperature grown InGaN layer in the spacer had a high level of stored strain. This led to the formation of a continuous facet contrast induced by Mg segregation in the p-layer, which was responsible for the deterioration of the electroluminescence performance of the LEDs. These results show that the delicate control of stored strain in nitride films is important for improving the device performance. 相似文献
130.
Jung‐Woo Bae Chang‐Ik Choi Choon‐Gon Jang Seok‐Yong Lee 《Biomedical chromatography : BMC》2011,25(11):1181-1188
A simple and sensitive liquid chromatography–electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS) technique was developed and validated for the determination of sibutramine and its N‐desmethyl metabolites (M1 and M2) in human plasma. After extraction with methyl t‐butyl ether, chromatographic separation of analytes in human plasma was performed using a reverse‐phase Luna C18 column with a mobile phase of acetonitrile–10 mm ammonium formate buffer (50:50, v/v) and quantified by ESI‐MS/MS detection in positive ion mode. The flow rate of the mobile phase was 200 μL/min and the retention times of sibutramine, M1, M2 and internal standard (chlorpheniramine) were 1.5, 1.4, 1.3 and 0.9 min, respectively. The calibration curves were linear over the range 0.05–20 ng/mL, for sibutramine, M1 and M2. The lower limit of quantification was 0.05 ng/mL using 500 μL of human plasma. The mean accuracy and the precision in the intra‐ and inter‐day validation for sibutramine, M1 and M2 were acceptable. This LC‐MS/MS method showed improved sensitivity and a short run time for the quantification of sibutramine and its two active metabolites in plasma. The validated method was successfully applied to a pharmacokinetic study in human. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献