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排序方式: 共有657条查询结果,搜索用时 15 毫秒
81.
Corlu A Choe R Durduran T Lee K Schweiger M Arridge SR Hillman EM Yodh AG 《Applied optics》2005,44(11):2082-2093
We present an algorithm that explicitly utilizes the wavelength dependence of tissue optical properties for diffuse optical tomography. We have previously shown that the method gives superior separation of absorption and scattering. Here the technique is described and tested in detail, and optimum wavelength sets for a broad range of chromophore combinations are discovered and analyzed. 相似文献
82.
Seoung-Hwan Park Weon-Guk Jeong Byung-Doo Choe 《Photonics Technology Letters, IEEE》1994,6(11):1297-1299
The effect of high temperature on the threshold current density and the gain of InxGa1-xAs/InGaAsP (Eg=1.6 eV) QW lasers lattice matched to GaAs is investigated theoretically. These results are also compared with those of Inx Ga1-xAs/GaAs QW lasers. It is found that better performance can be achieved in InGaAs/InGaAsP lasers compared to InGaAs/GaAs lasers at high temperature. This is due to the fact that the temperature dependence of the threshold carrier density for InGaAs/InGaAsP lasers is weaker than that for InGaAs/GaAs lasers. The calculated characteristic temperature is in good agreement with reported experimental results 相似文献
83.
Han S. Uhm Joon Y. Choe Chung M. Kim 《Journal of Infrared, Millimeter and Terahertz Waves》1983,4(3):361-374
Stability properties of the free streaming mode in an electron beam propagating through a cylindrical waveguide loaded with a tape helix are investigated, including influence of high space harmonic perturbations. Closed algebraic dispersion relation of the free streaming mode are obtained. Properties of the high space harmonic perturbations are numerically investigated in connection with application on a high frequency microwave amplifier. One of the most important features in this analysis is that instability of high harmonic perturbations occurs at a very large value of microwave frequency. In this regard, millimeter microwave can be easily attainable by reducing the helix radius to a subcentimeter. 相似文献
84.
Hak-Su Kang Kyeong-Nam Park Young-Rae Cho Dae-Won Park Youngson Choe 《Journal of Industrial and Engineering Chemistry》2009,15(5):752-757
C60-doped 2-TNATA (4,4′,4″-tris(2-naphthylphenylamino)triphenylamine) as a hole injection material and NPD (4,4′bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl) as a hole transport material are used to fabricate OLEDs via vacuum deposition process in this study. C60-doped 2-TNATA film was treated by means of thermal annealing and in situ electromagnetic field. According to AFM, SEM, XRD, and Raman spectra results, by both thermal annealing and in situ electromagnetic field treatments, the smoothened surface and the closely packed morphology of 2-TNATA:C60 film was obtained without any evidences of crystalline nature after those treatments. The treatments eventually lead to enhancing the current density and efficiency of the multi-layered ITO/2-TNATA:C60 (5% doped) (70 nm)/NPD (30 nm)/Alq3 (50 nm)/LiF (1 nm)/Al (100 nm) devices by facilitating hole injection/transport in the multi-layered organic devices. Consequently, thermal annealing treatment for the 2-TNATA:C60 film is preferred rather than in situ electromagnetic field treatment so as to improve the overall performance of the organic light-emitting diodes in this study. 相似文献
85.
Yu Hyung-Seok Lee Na-Kyoung Choi Ae-Jin Choe Jeong-Sook Bae Chun Ho Paik Hyun-Dong 《Food science and biotechnology》2019,28(3):851-855
Food Science and Biotechnology - The objective of this study was to evaluate the functional properties of Weissella cibaria JW15 (JW15) by investigating its antagonistic and antioxidant activities.... 相似文献
86.
This study compared stabilities of tocopherols and lutein in oil extracted from roasted mustard seeds (RMSO) with those in
oil from unroasted seeds (URMSO) during oil oxidation at 60°C in the dark for 12 days. Tocopherols and lutein were determined
by high performance liquid chromatography, and the oil oxidation was monitored with conjugated dienoic acid (CDA) content
and fatty acid composition by gas chromatography. The rate of CDA increase was lower in RMSO (0.038%/day) than in URMSO (0.047%/day)
during 12-day oxidation in the dark, with little change in fatty acid composition in both oils. Tocopherols and lutein were
more abundant in RMSO, initially 465.38 and 100.55 μg/g, respectively, than in URMSO, and their stability was higher in RMSO
(−4.63 and −5.94%/day of degradation in tocopherols and lutein, respectively) than in URMSO during 12-day oxidation of oil,
both of which contributed to higher autoxidative stability of RMSO than URMSO. 相似文献
87.
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89.
El-Tahawy Moustafa Jenei Péter Kolonits Tamás Han Gigap Park Hyeji Choe Heeman Gubicza Jenő 《Metallurgical and Materials Transactions A》2020,51(7):3447-3460
Metallurgical and Materials Transactions A - The tensile and compressive behaviors of 316L stainless steel at room temperature were compared. The differences between the stress–strain... 相似文献
90.
Ravi Shanker Seungse Cho Ayoung Choe Minsoo P. Kim Ziyauddin Khan Saewon Kang Hyunhyub Ko 《Advanced functional materials》2019,29(39)
Flexible alternating‐current electroluminescent (ACEL) devices have attracted considerable attention for their ability to produce uniform light emission under bent conditions and have enormous potential for applications in back lighting panels, decorative lighting in automobiles, and panel displays. Nevertheless, flexible ACEL devices generally require a high operating bias, which precludes their implementation in low power devices. Herein, solution‐processed La‐doped barium titanate (BTO:La) nanocuboids (≈150 nm) are presented as high dielectric constant (high‐k) nanodielectrics, which can enhance the dielectric constant of an ACEL device from 2.6 to 21 (at 1 kHz), enabling the fabrication of high‐performance flexible ACEL devices with a lower operating voltage as well as higher brightness (≈57.54 cd m?2 at 240 V, 1 kHz) than devices using undoped BTO nanodielectrics (≈14.3 cd m?2 at 240 V, 1 kHz). Furthermore, a uniform brightness across the whole panel surface of the flexible ACEL devices and excellent device reliability are achieved via the use of uniform networks of crossaligned silver nanowires as highly conductive and flexible electrodes. The results offer experimental validation of high‐brightness flexible ACELs using solution‐processed BTO:La nanodielectrics, which constitutes an important milestone toward the implementation of high‐k nanodielectrics in flexible displays. 相似文献