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81.
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83.
We report inelastic neutron scattering measurements on polystyrene thin films in a glassy state in the meV region. We found in elastic scattering that the mean square displacement decreased with film thickness, and hence the corresponding force constant f increased. In inelastic and quasielastic scattering, we observed the so-called boson peak at around 1.5 meV and the picosecond fast process for the first time in thin films, both of which decreased in intensity with film thickness. These results were discussed in terms of the potential hardening due to the confinement of polymer chains and/or the interfacial dead layer. 相似文献
84.
Hinson JW Huang GS Lee J Miller DH Pavlunin V Rangarajan R Sanghi B Shibata EI Shipsey IP Cronin-Hennessy D Park CS Park W Thayer JB Thorndike EH Coan TE Gao YS Liu F Stroynowski R Artuso M Boulahouache C Blusk S Dambasuren E Dorjkhaidav O Mountain R Muramatsu H Nandakumar R Skwarnicki T Stone S Wang JC Csorna SE Danko I Bonvicini G Cinabro D Dubrovin M McGee S Bornheim A Lipeles E Pappas SP Shapiro A Sun WM Weinstein AJ Briere RA Chen GP Ferguson T Tatishvili G Vogel H Watkins ME Adam NE 《Physical review letters》2005,94(19):191801
Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay lambda(+)(c)lambda--> e(+)nu(e). By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R= f(2)/f(1) = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole mass, M(pole) = [2.21 +/- 0.08(stat) +/- 0.14(syst)] GeV/c(2), and the decay asymmetry parameter of the lambda(+)(c), alpha (lambda(c)) = -0.86 +/-0.03(stat) +/- 0.02(syst), for q(2) = 0.67 (GeV/c(2))(2). We compare the angular distributions of the lambda(+)(c) and lambda(-)(c) and find no evidence for CP violation: A(lambda(c)) = (alpha(lambda(c)) + alpha (lambda(c)))/(alpha(lambda(c))-alpha(lambda(c))) = 0.00 +/- 0.03(stat) +/- 0.01(syst) +/- 0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A(lambda), for ppi(-). 相似文献
85.
We propose an optical circuit design method for coherent waves as a boundary value problem. The method produces a very compact circuit in which the refractive index pattern is automatically synthesized for given input and output fields with a numerical calculation. We employ the method to design a 1.3/1.55 microm wavelength demultiplexer and also describe the features of a circuit generated by use of the method. 相似文献
86.
Asner DM Dytman SA Mehrabyan S Mueller JA Nam S Savinov V Huang GS Miller DH Pavlunin V Sanghi B Shibata EI Shipsey IP Adams GS Chasse M Cummings JP Danko I Napolitano J Cronin-Hennessy D Park CS Park W Thayer JB Thorndike EH Coan TE Gao YS Liu F Stroynowski R Artuso M Boulahouache C Blusk S Butt J Dambasuren E Dorjkhaidav O Haynes J Menaa N Mountain R Muramatsu H Nandakumar R Redjimi R Sia R Skwarnicki T Stone S Wang JC Zhang K Mahmood AH Csorna SE Bonvicini G Cinabro D Dubrovin M Bornheim A 《Physical review letters》2004,92(14):142001
We report on the observation of the eta(')(c)(2(1)S0), the radial excitation of the eta(c)(1(1)S0) ground state of charmonium, in the two-photon fusion reaction gammagamma-->eta(')(c)-->K(0)(S)K+/-pi(-/+) in 13.6 fb(-1) of CLEO II/II.V data and 13.1 fb(-1) of CLEO III data. We obtain M(eta(')(c))=3642.9+/-3.1(stat)+/-1.5(syst) MeV and M(eta(c))=2981.8+/-1.3(stat)+/-1.5(syst) MeV. The corresponding values of hyperfine splittings between 1S0 and 3S1 states are DeltaM(hf)(1S)=115.1+/-2.0 MeV and DeltaM(hf)(2S)=43.1+/-3.4 MeV. Assuming that the eta(c) and eta(')(c) have equal branching fractions to K(S)Kpi, we obtain Gamma(gammagamma)(eta(')(c))=1.3+/-0.6 keV. 相似文献
87.
Shibata T Fujimoto T Yokota K Takagi K 《Journal of the American Chemical Society》2004,126(27):8382-8383
An asymmetric [2+2+2] cycloaddition of an alpha,omega-diyne, possessing ortho-substituted aryl groups on its terminus, and a monoalkyne with oxygen functionalities gave various axially chiral teraryl compounds. The coupling proceeded with extremely high enantio- (>99.5% ee) and diastereoselectivities (dl/meso = >95/5) when catalyzed by an iridium-chiral phosphine complex. As the products were readily transformed into diol compounds by deprotection without racemization, the present procedure provides access to a new chiral pool of diol compounds with C2 symmetry. 相似文献
88.
Yusuke Arai Tetsuji Yano Shuichi Shibata 《Journal of Sol-Gel Science and Technology》2004,32(1-3):189-194
Microspheres of refractive index of nD > 2.0 have been investigated. The organic-inorganic hybrid microspheres of nD = 1.72 were prepared by the vibrating orifice technique using titanium-tetra-n-butoxide (TTBu) and diphenyldimethoxysilane (DPhDMS). For lasing demonstration, Eu3+-doped microspheres were prepared using europium (III) thenoyltrifluoroacetonate [Eu(TTFA)3] as the dopant. The particles have good spherical shape, smooth surface and high optical transparency. The diameters of the particles could be controlled to within 0.1 m. Subsequent heating of the microspheres at 550°C under oxygen atmosphere resulted in an increase in the refractive index up to nD = 2.6 with retention of the spherical shape. Resonant emission was confirmed from Eu3 +-doped microspheres after heating at 400–550°C, by pumping with the 514.5 nm line of a CW- Ar+laser. 相似文献
89.
Li G Dobhal MP Graham A Shibata M Zheng G Kozyrev A Pandey RK 《The Journal of organic chemistry》2003,68(10):3762-3772
The thermolysis products obtained by refluxing a series of vic-dihydroxychlorins in o-dichlorobenzene are characterized. Depending on the nature of substrates, this methodology provides an access for novel carbon-carbon linked chlorin-chlorin dimers and chlorin-porphyrin dimers with fixed and flexible orientations. The configuration of the linkers in the symmetrical and unsymmetrical dimers was confirmed by extensive NMR (COSY, ROESY) and molecular modeling studies. The molecular modeling studies of the energy-optimized dimers with flexible orientation confirmed that one of the chlorin units of the dimeric structure is tilted toward the opposite ring as evident by the shielding effect in the resonances of some of the protons in the (1)H NMR spectroscopy. Among the dimers with fixed orientation, compared to the free-base analogues, the related mono- and di-Zn(II) complexes produced a decreased fluorescence intensity, suggesting a possibility of the faster energy transfer via intersystem crossing (ISC) in the metalated derivatives than the corresponding free-base analogues to produce the corresponding excited triplet states. The photosensitizing efficacy of the monomers and the related dimers was also compared in radiation-induced fibrosarcoma (RIF) tumor cells at variable drug/light doses. In preliminary screening, compared to monomers, the corresponding carbon-carbon linked dimers produced enhanced photosensitizing efficacy. 相似文献
90.