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951.
S.-Y. Lee T.-H. Kim D.-I. Suh J.-E. Park J.-H. Kim C.-J. Youn B.-K. Ahn S.-K. Lee 《Physica E: Low-dimensional Systems and Nanostructures》2007,36(2):194-198
This is a report on the electrical characterization of gallium nitride (GaN) nanowire (NW) p–n junction diodes. These diodes were formed by assembling n-GaN NWs on p-Si (1 0 0) substrates using alternating current (AC) dielectrophoresis (DEP). The AC DEP was optimized with a bias voltage of 15 Vp−p at a frequency of 1 kHz. The hetero-junction single GaN nanowire p-n diode (n-GaN NW/p-Si) showed well-defined current rectifying behavior with a forward voltage drop of 1.2–2.0 V at a current density of 10–60 A/cm2. The GaN nanowire p–n diodes had a high parasite resistance in the range of >470 kΩ. We observed that these high resistances were mostly the result of the metal contacts to the n-GaN NWs. We also found that these parasite resistances were reduced by the formation of an additional capping layer on the top of the n-GaN NW as well as high temperature annealing. 相似文献
952.
A. D. Panov J. H. Adams Jr. H. S. Ahn K. E. Batkov G. L. Bashindzhagyan John W. Watts J. P. Wefel J. Wu O. Ganel T. G. Guzik R. M. Gunashingha V. I. Zatsepin J. Isbert K. C. Kim M. Christl E. N. Kouznetsov M. I. Panasyuk E. S. Seo N. V. Sokolskaya J. Chang W. K. H. Schmidt A. R. Fazely 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(4):494-497
This paper reports on the results of measurements performed in the course of the ATIC-2 balloon experiment (2002–2003) for the energy spectra of particles (such as protons; He, C, O, Ne, Mg, Si, and Fe nuclei; and some groups of nuclei) and the all-particle energy spectrum in primary cosmic rays at energies ranging from 50 GeV to 200 TeV. The conclusion is drawn that the energy spectra of protons and helium nuclei differ substantially (the spectrum of protons is steeper) and that the shape of the energy spectra of protons and heavy nuclei cannot be described by a power function. 相似文献
953.
The αη protocol given by Barbosa et al. [G.A. Barbosa, E. Corndorf, P. Kumar, H.P. Yuen, Phys. Rev. Lett. 90 (2003) 227901, quant-ph/0212018] claims to be a secure way of encrypting messages using mesoscopic coherent states. We show that transmission under αη exposes information about the secret key to an eavesdropper, and we estimate the rate at which an eavesdropper can learn about the key. We also consider the consequences of using further randomization to protect the key and how our analysis applies to this case. We conclude that αη is not informationally secure. 相似文献
954.
Starting from the Bethe Ansatz solution of the open integrable spin-1 XXZ quantum spin chain with diagonal boundary terms, we derive a set of nonlinear integral equations (NLIEs), which we propose to describe the boundary supersymmetric sine-Gordon model BSSG+ with Dirichlet boundary conditions on a finite interval. We compute the corresponding boundary S matrix, and find that it coincides with the one proposed by Bajnok, Palla and Takács for the Dirichlet BSSG+ model. We derive a relation between the (UV) parameters in the boundary conditions and the (IR) parameters in the boundary S matrix. By computing the boundary vacuum energy, we determine a previously unknown parameter in the scattering theory. We solve the NLIEs numerically for intermediate values of the interval length, and find agreement with our analytical result for the effective central charge in the UV limit and with boundary conformal perturbation theory. 相似文献
955.
Tae-Moon Ahn Sampath Purushothaman John K. Tien 《Journal of Physics and Chemistry of Solids》1976,37(8):777-784
A particle coarsening mechanism is derived for the case where the rate controlling step is the nucleation of atomic pillboxes on the external surfaces of the growing particles. The kinetics of such coarsening is derived, based on an extension of the Lifshitz-Slyozov-Wagner asymptotic hydrodynamic theory described in Part I of this paper. The derived coarsening kinetics are discussed with respect to the recent Wynblatt-Gjostein data on the inhibited coarsening of faceted platinum particles on flat alumina substrates. 相似文献
956.
Ahn MH Aoki S Ashie Y Bhang H Boyd S Casper D Choi JH Fukuda S Fukuda Y Gran R Hara T Hasegawa M Hasegawa T Hayashi K Hayato Y Hill J Ichikawa AK Ikeda A Inagaki T Ishida T Ishii T Ishitsuka M Itow Y Iwashita T Jang HI Jang JS Jeon EJ Joo KK Jung CK Kajita T Kameda J Kaneyuki K Kato I Kearns E Kibayashi A Kielczewska D Kim BJ Kim CO Kim JY Kim SB Kobayashi K Kobayashi T Koshio Y Kropp WR Learned JG Lim SH Lim IT Maesaka H Maruyama T Matsuno S Mauger C Mcgrew C Minamino A Mine S Miura M Miyano K 《Physical review letters》2004,93(5):051801
We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2). 相似文献
957.
Ahn DJ Chae EH Lee GS Shim HY Chang TE Ahn KD Kim JM 《Journal of the American Chemical Society》2003,125(30):8976-8977
To investigate the role of hydrogen-bonding on colorimetric transition of polydiacetylene supramolecules, novel diacetylene derivatives allowing various hydrogen-bonding states were synthesized by coupling carboxy-substituted (ortho-, meta-, and para-) anilide groups with a typical single-chain diacetylene lipid. One with a terminal carboxyl group at the meta position provided the resulting supramolecular Langmuir-Schaefer films with enhanced hydrogen-bonding, and hence resulted in unprecedented colorimetric reversibility under both thermal and pH stimuli. 相似文献
958.
959.
Kyu Hyun Kyung Hyun Ahn Seung Jong Lee Masataka Sugimoto Kiyohito Koyama 《Rheologica Acta》2006,46(1):123-129
In this study, linear and branched polypropylenes (PP) were compared under medium strain amplitude oscillatory shear (usually
strain amplitude range from 10 to 100%) with Fourier-transform rheology (FT rheology). On a log–log diagram, the third relative
intensity (I
3/I
1), which is a parameter to represent nonlinearity, shows a linear relationship with the strain amplitude in the range of medium
strain amplitude. The slope of I
3/I
1 of linear PP with various molecular weight and molecular weight distribution was 2 as most constitutive equations predict,
while that of branched PP was 1.64, which is lower than that of linear PP. When the linear and branch PP were blended, the
slope of I
3/I
1 was proportional to the composition of the branch PP. Therefore, it is suggested that the degree of branching can be defined
in terms of the slope of I
3/I
1 under medium amplitude oscillatory shear. 相似文献
960.
Melt rheology of long-chain-branched polypropylenes 总被引:2,自引:0,他引:2
Masataka Sugimoto Yasuhiro Suzuki Kyu Hyun Kyung Hyun Ahn Tsutomu Ushioda Akihiro Nishioka Takashi Taniguchi Kiyohito Koyama 《Rheologica Acta》2006,46(1):33-44
Rheological properties of long-chain-branched isotactic polypropylene (PP) via copolymerization with a very small amount of
nonconjugated α,ω-diene monomer using metallocene catalyst system in both linear and nonlinear regions were investigated,
comparing with conventional linear and long-chain-branched PP modified at postreactor. Although comonomer incorporation was
equal to 0.05 mol% or less, it caused high molecular weight, broad molecular weight distribution, and long-chain branching.
A detailed study on the effect of diene incorporation on the polymer properties was conducted, comparing with modified PP
in postreactor. Polymer chain microstructures were characterized by gel permeation chromatography with multiangle laser light
scattering (MALLS), differential scanning calorimetry, and rheological means: dynamic viscoelasticity, step-strain, uniaxial
elongational flow measurements, and large amplitude oscillatory shear. The PP, which incorporated a small amount of diene
monomer, showed significantly improved viscoelastic behaviors. The diene-propylene copolymer containing long-chain branches
showed extremely long relaxation mode under shear and outstanding viscosity increase under elongational flow, so-called strain
hardening. The difference in microstructure of diene-propylene copolymer with modified PP with long-chain branches is investigated
by MALLS and rheological characterizations. 相似文献