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151.
Gyung-Ho Hwang Dong-Ho Cho 《Wireless Communications, IEEE Transactions on》2006,5(12):3355-3359
The distributed coordination function (DCF) scheme of IEEE 802.11 MAC protocol does not support any concepts of quality of service (QoS) but the enhanced distributed channel access (EDCA) scheme in IEEE 802.11e standard provides QoS according to access categories using different access parameters. However, the legacy DCF stations may be used together with EDCA stations. In this letter, we investigate and analyze the performance discrimination when EDCA and DCF stations operate simultaneously 相似文献
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154.
Aryl pyridyl ethers were prepared from phenols and active halopyridines under essentially neutral condition via fluoride ion assisted reaction. 相似文献
155.
156.
Kyeong‐Ryoon Lee Sung Heum Choi Jin‐Sook Song Hyewon Seo Yoon‐Jee Chae Hwang Eui Cho Jin Hee Ahn Sung‐Hoon Ahn Myung Ae Bae 《Biomedical chromatography : BMC》2013,27(7):846-852
In this study, we developed a method for the determination of PF‐04620110 (2‐{(1r,4r)‐4‐[4‐(4‐amino‐5‐oxo‐7,8‐dihydropyrimido[5,4‐f][1,4]oxazepin‐6(5H)‐yl)phenyl]cyclohexyl}acetic acid), a novel diacylglycerol acyltransferase 1 (DGAT‐1) inhibitor, in rat plasma and validated it using liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Rat plasma samples were processed following a protein precipitation method by using acetonitrile and were then injected into an LC‐MS/MS system for quantification. PF‐04620110 and imipramine (internal standard) were separated using a Hypersil Gold C18 column, with a mixture of acetonitrile and 10 mm ammonium formate (90:10, v/v) as the mobile phase. The ion transitions monitored in positive‐ion mode [M + H]+ of multiple‐reaction monitoring were m/z 397.0 → 260.2 for PF‐04620110 and m/z 280.8 → 86.0 for imipramine. The detector response was specific and linear for PF‐04620110 at concentrations within the range 0.05–50 µg/mL and the signal‐to‐noise ratios for the samples were ≥10. The intra‐ and inter‐day precision and accuracy of the method matched the acceptance criteria for assay validation. PF‐04620110 was stable under various processing and/or handling conditions. PF‐04620110 concentrations in the rat plasma samples could be measured up to 24 h after intravenous or oral administration of PF‐04620110, suggesting that the assay is useful for pharmacokinetic studies in rats. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
157.
Soo Ouk Jang Hyun Jong You Young-Woo Kim Yong Ho Jung In Uk Hwang Jae Yang Park Heon Lee 《Plasma Chemistry and Plasma Processing》2014,34(1):229-237
To deposit copper seed layer on ultra large scale integration devices, a large-area (Ø 378 mm) electron cyclotron resonance plasma has been generated by using permanent magnets-embedded Lisitano antenna. The plasma source operates in the pressure range of 0.2–1.5 mTorr with microwave power range of 500–2,000 W. By using a Langmuir probe, the electron density and temperature have been measured near the DC sputter target position. Measurements indicate argon plasmas having electron densities of ~5 × 1010/cm and electron temperatures of 5 eV with 750 W microwave power at gas pressures of 0.5 mTorr. Using this plasma source and a DC sputter, we obtained excellent conformal copper seed layer with high aspect ratios of 12:1. This is in contrast with conventional methods using magnetron sputter, which has aspect ratios of 2–3:1. Also, improvements are observed in the smoothness (root mean square roughness of 1.345 nm), uniformity (2.5 % at 300 mm wafer), and sidewall symmetricity (more than 95 %) of the copper seed layer. 相似文献
158.
Ji‐Hoon Kim Sunyoung Lee In‐Nam Kang Moo‐Jin Park Do‐Hoon Hwang 《Journal of polymer science. Part A, Polymer chemistry》2012,50(16):3415-3424
An alternating copolymer composed of heal‐to‐tail‐structured 3,4′‐dihexyl‐2,2′‐bithiophene (DHBT) and pyrene units [poly(DHBT‐alt‐PYR)] was synthesized using a Stille coupling reaction for use in photovoltaic devices as a p‐type donor. For the reduction of the bandgap energy of poly(DHBT‐alt‐PYR), 4,7‐bis(3′‐hexyl‐2,2′‐bithiophen‐5‐yl)benzo[c][1,2,5]thiadiazole (BHBTBT) units were introduced into the polymer. Poly(DHBT‐co‐PYR‐co‐BHBTBT)s were synthesized using the same polymerization reaction. The synthesized polymers were soluble in common organic solvents and formed smooth thin films after spin casting. The optical bandgap energies of the polymers were obtained from the onset absorption wavelengths. The measured optical bandgap energy of poly(DHBT‐alt‐PYR) was 2.47 eV. As the BHBTBT content in the ter‐polymers increased, the optical bandgap energies of the resulting polymers decreased. The bandgap energies of poly(50DHBT‐co‐40PYR‐co‐10BHBTBT) and poly(50DHBT‐co‐20PYR‐co‐30BHBTBT) were 1.84 and 1.73 eV, respectively. Photovoltaic devices were fabricated with a typical sandwich structure of ITO/PEDOT:PSS/active layer/LiF/Al using the polymers as electron donors and [6,6]‐phenyl C71‐butyric acid methyl ester as the electron acceptor. The device using poly(50DHBT‐co‐20PYR‐co‐30BHBTBT) showed the best performance among the fabricated devices, with an open‐circuit voltage, short‐circuit current, fill factor, and maximum power conversion efficiency of 0.68 V, 5.54 mA/cm2, 0.35, and 1.31%, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
159.
Chih-Hung Chang Tzonelih Hwang Prosanta Gope 《International Journal of Theoretical Physics》2016,55(4):2125-2138
This article proposes a collective-noise resistant QPC protocol with the help of an almostdishonest third party (TP) who may try to perform any sort of attacks to derive participants’ private secrets except colluding with any participant. The proposed scheme has some considerable advantages over the state-of-the-art QPC protocols over collective-noise channels, where it does not require any pre-shared key between the participants (Alice and Bob). Nevertheless, the proposed scheme can resist Trojan horse attacks without consuming half of the transmitted qubits and any additional equipment (wavelength filter and PNS) support. As a consequence, the proposed QPC protocol can guarantee higher qubit efficiency as compared to the others over collective noise channels. 相似文献
160.
Junwye Lee Jonghyun Koo Si Un Hwang Sunmin Min Sang Jung Ahn Yonghan Roh Sung Ha Park 《Current Applied Physics》2012,12(4):1207-1211
We report the structural and functional stabilities of artificially synthesized DNA ultra-thin films. Fully covered DNA ultra-thin films on a silica substrate were fabricated by the silica-assisted growth method and those samples were then incubated in various chemicals and physical conditions. The DNA ultra-thin films showed high maintainability under those harsh conditions and these results would aid to facilitate the use of artificial DNA ultra-thin films in advanced research areas such as biophotonics and bioelectronics. 相似文献