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81.
82.
Vladimir Svrcek Katerina Dohnalova Davide Mariotti Minh Tuan Trinh Rens Limpens Somak Mitra Tom Gregorkiewicz Koiji Matsubara Michio Kondo 《Advanced functional materials》2013,23(48):6051-6058
Substantial improvements of the absolute photoluminescence quantum yield (QY) for surfactant‐free silicon nanocrystals (Si‐ncs) by atmospheric pressure microplasma 3‐dimensional surface engineering are reported. The effect of surface characteristics on carrier multiplication mechanisms is explored using transient induced absorption and photoluminescence QY. Surface engineering of Si‐ncs is demonstrated to lead to more than 120 times increase in the absolute QY (from 0.1% up to 12%) within an important spectral range of the solar emission (2.3–3 eV). The Si‐ncs QY is shown to be stable when Si‐ncs are stored in ethanol at ambient conditions for three months. 相似文献
83.
Weerathep Kueathaweekun Noppin Anantrasirichai Chawalit Benjangkaprasert Jintana Nakasuwan Toshio Wakabayashi 《ETRI Journal》2012,34(5):674-683
We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular‐ring‐shaped tuning stub that can be deployed in ultra‐wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band‐notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L‐ and J‐shaped parasitic elements. The antenna characteristics can be modified to tune the band‐notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L‐ and J‐shaped parasitic elements also provide the band‐rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies. 相似文献
84.
K Ogura M Nishiuchi AS Pirozhkov T Tanimoto A Sagisaka TZh Esirkepov M Kando T Shizuma T Hayakawa H Kiriyama T Shimomura S Kondo S Kanazawa Y Nakai H Sasao F Sasao Y Fukuda H Sakaki M Kanasaki A Yogo SV Bulanov PR Bolton K Kondo 《Optics letters》2012,37(14):2868-2870
Using a high-contrast (10(10):1) and high-intensity (10(21) W/cm(2)) laser pulse with the duration of 40 fs from an optical parametric chirped-pulse amplification/Ti:sapphire laser, a 40 MeV proton bunch is obtained, which is a record for laser pulse with energy less than 10 J. The efficiency for generation of protons with kinetic energy above 15 MeV is 0.1%. 相似文献
85.
K. Tshoo Y. Satou H. Bhang S. Choi T. Nakamura S. Deguchi Y. Kawada Y. Kondo N. Kobayashi Y. Nakayama K. N. Tanaka N. Tanaka N. Aoi M. Ishihara T. Motobayashi H. Otsu H. Sakurai S. Takeuchi Y. Togano K. Yoneda Z. H. Li F. Delaunay J. Gibelin F. M. Marques N. A. Orr T. Honda M. Matsushita T. Kobayashi Y. Miyashita T. Sumikama K. Yoshinaga S. Shimoura D. Sohler T. Zheng Z.X. Cao 《Few-Body Systems》2013,54(1-4):459-463
The unbound excited states of the most neutron-rich dripline oxygen isotope, 24O, have been investigated by using the 24O(p,p′)24O* reaction at the beam energy of 62 MeV/nucleon in inverse kinematics. The first and second unbound excited states of 24O have been observed at ${E_{\rm x}= 4.63_{-0.14}^{+0.30}}$ MeV and ${E_{\rm x}= 5.13_{-0.24}^{+0.19}}$ MeV (preliminary) along with the evidence for another higher lying state at around 7.3 MeV. The quadrupole deformation parameter ${\beta_{2^+}}$ was deduced to be ${0.15_{-0.03}^{+0.08}}$ (preliminary) for the first time. The systematics of the ${\beta_{2^+}}$ and the ${E_{\rm x}(2_1^+)}$ in the Z = 8 isotopes shows the N = 16 spherical shell closure in 24O. 相似文献
86.
The positron annihilation lifetime method (PAL) has been applied to study the characteristics of polyethylenes (PEs) at low temperatures between 273 and 100 K. It has been found that the intensity (I
3) of the long-lived component of positronium (Ps) showed an increase in non-annealed PE and annealed PE in vacuo. However, PAL in PEs annealed in an atmosphere containing oxygen did not show such an increase. It has been indicated that the latter effect is due to formation of carbonyl groups through oxidation during the annealing. 相似文献
87.
Abstract Color centers in rutile-structured MgF2 single crystals irradiated at 20K/360K by reactor neutrons are investigated spectroscopically at LNT. Four different types of the F-F vacancy bond in MgF2 are possibly identified to the observed absorption bands as due to the F2 centers; instead of previous assignments, the 300nm band to the F2(D2h), the 325nm band to the F2(C1), the 355nm band to the F2(C2v), and the 400nm band to the F2(C2h) centers. 相似文献
88.
89.
90.
Hideo Kaiju Akito Ono Kenji Kondo Jonghan Won Manabu Ishimaru 《Applied Surface Science》2009,255(6):3706-3712
We study the structural properties of the surface roughness, the surface mound size and the interfacial structure in Ni thin films vacuum-deposited on polyethylene naphthalate (PEN) organic substrates with and without the application of magnetic field and discuss its feasibility of fabricating quantum cross (QC) devices. For Ni/PEN evaporated without the magnetic field, the surface roughness decreases from 1.3 nm to 0.69 nm and the surface mound size increases from 32 nm to 80 nm with the thickness increased to 41 nm. In contrast, for Ni/PEN evaporated in the magnetic field of 360 Oe, the surface roughness tends to slightly decrease from 1.3 nm to 1.1 nm and the surface mound size shows the almost constant value of 28-30 nm with the thickness increased to 35 nm. It can be also confirmed for each sample that there is no diffusion of Ni into the PEN layer, resulting in clear Ni/PEN interface and smooth Ni surface. Therefore, these experimental results indicate that Ni/PEN films can be expected as metal/insulator hybrid materials in QC devices, leading to novel high-density memory devices. 相似文献