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911.
Kobayashi S Inoue T Ando A Tamanoi H Ryu I Masuyama A 《The Journal of organic chemistry》2012,77(13):5819-5822
The total synthesis of hericerin, a pollen growth inhibitor from Hericium erinaceum, was achieved. We found that the reported structure of hericerin should be revised to be the carbonyl regioisomer. 相似文献
912.
Jin Ho Ryu Ju Young Heo Eun-Kyoung Bang Gil Tae Hwang Byeang Hyean Kim 《Tetrahedron》2012,68(1):72-78
In this study we synthesized the 2-ethynylfluorenone-containing deoxyuridine derivative UFO and incorporated it at the central positions of oligodeoxynucleotides (ODNs) in an attempt to develop a new type of quencher-free linear beacon probe and to understand the effect of functionalization of the fluorene scaffold on the photophysical properties of the fluorescent ODNs. Herein, we describe our photophysical studies of UFO DNA probes and their application to single-nucleotide polymorphism typing. 相似文献
913.
Dowan KimJinseong Kim Taimin NohJiseung Ryu Yong-nam KimHeesoo Lee 《Current Applied Physics》2012,12(3):952-956
The influence of La2O3 and Tm2O3 co-doping on the dielectric properties and the temperature stability of BaTiO3 was investigated. BaTiO3 ceramics were prepared with the compositional formula of (Ba1−xLax)(Ti1-x/4−yTmy)O3. La2O3 and Tm2O3 co-doping in BaTiO3 mainly had effects on an increase in the dielectric constant and the temperature stability, respectively. The increase of La2O3 concentration and the decrease of Tm2O3 concentration in BaTiO3 resulted in a decrease of lattice parameter and tetragonality because La3+ ion substituting for Ba site is smaller than Ba2+ ion and Tm3+ ion substituting for Ti site is larger than Ti4+ ion. With the increase of La2O3 and the decrease of Tm2O3, the dielectric constant of BaTiO3 was enhanced in spite of the reduction of tetragonality. P-E hysteresis measurements revealed that this phenomenon was based on the improvement of remanent polarization with the increase of La2O3 concentration. The introduction of excess Tm2O3 in BaTiO3 suppressed the grain growth and BaTiO3 ceramics showed higher temperature stability due to the stable tetragonal structure and the small grain size with the increase of Tm2O3 concentration. 相似文献
914.
S. Iwan S. Bambang J.L. Zhao S.T. Tan H.M. Fan L. Sun S. Zhang H.H. Ryu X.W. Sun 《Physica B: Condensed Matter》2012,407(14):2721-2724
Erbium-doped ZnO (ZnO:Er) thin films with various doping concentrations were deposited on p-Si substrates by ultrasonic spray pyrolysis (USP). The n-ZnO:Er/p-Si heterojunctions were further employed to fabricate light-emitting diodes (LEDs). The devices showed diode-like rectifying current–voltage characteristics with a low reverse breakdown voltage, attributed to the avalanche breakdown. A distinct green electroluminescence peaking at 537 nm and 558 nm were observed at room temperature under reverse bias. The green electroluminescence originated from the electron impact excitation of Er3+ ions doped in ZnO films. 相似文献
915.
Seon Young Ryu Hae Young Choi Ki Soo Chang Geon Hee Kim Woo June Choi Sang-Gun Ahn Yong Chul Kim Jung-Hoon Yoon Byeong Ha Lee 《Optics Communications》2012,285(9):2478-2482
We propose a fiber optic single-unit but dual-mode optical imaging system that can provide fast cross-sectional imaging capabilities of swept-source optical coherence tomography (SS-OCT) and functional capabilities of fluorescence spectroscopy (FS). By adopting a fiber optic FS system into a fiber-based SS-OCT system, a compact and effective multimodal single-unit SSOCT-FS system is achieved. Here, the key element of the proposed multimodal imaging system is a specially designed fiber coupler based on double-clad fiber (DCF), which has only cladding-mode coupling capability. The DCF couplers are fabricated with home-drawn DCF by several fabrication methods; a twisting method, a side-polishing method and a fused biconical tapered (FBT) method. Experimentally, the FBT method provides rather flat cladding mode coupling efficiency over 40% in a wide wavelength range. With this specially designed DCF coupler, the OCT signal and the fluorescence signal is measured independently but with a single-unit system. The performance of the SSOCT-FS system is confirmed by measuring the cross-sectional image and the fluorescence signal of a photosensitizer chlorin e6 injected in-vivo rat tumor model. 相似文献
916.
917.
Jun Ho Chung Sang Yeop Lee Kwang Bo Shim Soon-Yong Kweon Soon-Chul Ur Jeong Ho Ryu 《Applied Physics A: Materials Science & Processing》2012,108(2):369-373
Li+/Tm3+/Yb3+ co-doped CaMoO4 upconversion (UC) phosphor was prepared by complex citrate-gel method and UC luminescence properties were investigated. Li+/Tm3+/Yb3+ co-doped CaMoO4 has intense blue emission induced by 1G4??3H6 transition at 476?nm that is improved 10 times more than that of Li+ undoped sample and weak red emission at 647 nm generated by 3F2??3H6 transition under excitation at 980?nm. The optimum doping concentration of Li+ ions was investigated and UC mechanism of Li+/Tm3+/Yb3+ co-doped CaMoO4 was discussed in detail. 相似文献
918.
In this paper, we model a possible deception system with the explicit purpose of enticing unauthorized users and restricting their access to the real system. The proposed model represents a system designer’s defensive actions against intruders in a way that maximizes the difference between the intruders’ cost and the system designer’s cost of system protection. Under the assumption of a dual entity system, the proposed model shows that intruders differ in behavior depending on the system’s vulnerability at the time of intrusion as well as depending on their own economic incentives. The optimal results of the proposed model provide the system designer with insights on how to configure the level of protection for the two systems. 相似文献
919.
Hard carbon nanofiber (HCNF) bundles were prepared using reverse hexagonal micelle (H2) phase formed by a template of an amphiphilic block copolymer surfactant and their anode performance in lithium ion batteries was analyzed. Prepared HCNF showed a higher discharge capacity at voltage region above 0.8 V (vs. Li/Li+) than that of control carbon. Rate capability was also examined in order to demonstrate merit of the fibrous morphology of CNF, with current values corresponding to 0.1, 0.2, 0.5, 1 and 2 C rate. Prepared HCNF electrode exhibited higher rate capability than control carbon, which was attributed to morphological difference. 相似文献
920.
Seung Hwan Lee Sunjong Lee Hyun Woog Ryu Hongkwan Park Yong Seok Kim Jung Hyun Kim 《Journal of polymer science. Part A, Polymer chemistry》2014,52(16):2329-2336
The synthesis of doped polypyrrole (PPy) nanocomplexes and their size, morphology, doping level, and electrical conductivity are discussed. The synthetic route of doped PPy nanocomplexes is presented by means of the chemical oxidative polymerization and in situ doping process in the presence of a binary acid mixture (hydrochloric acid and perchloric acid). The electrical conductivities of the doped PPy nanocomplexes are enhanced from 0.88 to 4.5 S/cm by the optimum molar ratio of HClO4 and HCl in the binary acid mixture. In addition, the average particle size of the doped PPy nanocomplexes decreases from 280 to 30 nm with a narrow particle size distribution when increasing the proportion of HClO4 relative to HCl in the binary acid mixture; this result is confirmed by scanning electron microscopy, transmission electron microscopy, and capillary hydrodynamic fractionation instrument analyses. Moreover, at different molar ratios in the binary acid mixture, the zeta‐potential and oxidation level of the doped PPy nanocomplexes have a confirmed association with particle size and electrical properties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2329–2336 相似文献