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81.
T. Ohtsubo H. Hirano S. Takahashi K. Matsuta M. Mihara M. Fukuda T. Nagatomo T. Izumikawa S. Momota D. Nishimura J. Komurasaki D. Ishikawa D. M. Zhou Y. N. Zheng S. Y. Zhu A. Kitagawa M. Kanazawa M. Torikoshi S. Sato T. Minamisono Y. Nojiri R. Matsumiya T. Sumikama K. Tanaka K. Yamada A. Ozawa T. Suzuki T. Yamaguchi S. Nakajima K. Yoshida Y. Nakashima H. Fujiwara S. Kumashiro M. Ota D. Shinojima H. Tanaka T. Yasuno K. Muranaka T. Maemura A. Chiba S. A. Pahlovy M. Nagao R. Watanabe T. Kubo I. Tanihata M. Takechi K. Minamisono J. R. Alonso G. F. Krebs T. J. M. Symons 《Hyperfine Interactions》2007,180(1-3):85-89
We measured the polarization of the $\upbeta $ -emitting 23Ne (I π ?= 5/2?+?, T 1/2?= 37.24 s) and 25Al(I π ?= 5/2?+?, T 1/2?= 7.18 s) produced through the one nucleon pickup reactions and 24mAl(I π ?= 1?+?, T 1/2?= 131 ms, E ex?= 426 keV) and 28P(I π ?= 3?+?, T 1/2?= 270 ms) produced through charge-exchange reactions in the intermediate energy heavy ion collisions. We compared them with those from the projectile fragmentation process. The larger polarization seems to persistently be positive throughout the momentum distribution, and sharper momentum distributions suggest that nuclear friction mechanism is responsible for the polarization phenomena. 相似文献
82.
Based on analysis of ESR spectra, it is suggested that the initial species formed by electron loss from oxirane (13C) in CFCl3 at 77 K is the ring-closed o(n) radical, rather than the ring-opened “allylic” radical. 相似文献
83.
Sato K. Miyake T. Morishita A. Matsuta K. Minamisono T. Tanigaki M. Takeda S. Mihara M. Fukuda M. Nojiri Y. Minamisono K. Fukao T. Matsumoto Y. Ohtsubo T. Fukuda S. Momota S. Yoshida K. Ozawa A. Kobayashi T. Tanihata I. Sagawa H. Kitagawa H. Krebs Gray F. Alonso Jose R. Symons T. James M. 《Hyperfine Interactions》1999,120(1-8):661-665
The electric quadrupole interaction of 19O(Iπ=(5/2)+, T1/2=27.0 s) in TiO2 single crystal was studied in detail by means of the β-NQR to determine the electric quadrupole moments Q of short-lived
β-emitting nuclei 19O and 13O(Iπ=(3/2)-, T1/2=8.6 ms). Two implantation sites were found for the implanted O nucleus and the quadrupole coupling constants of 19O at these sites were determined. We observed FT-NMR of the enriched stable isotope 17O in TiO2 and obtained the electric field gradient (EFG) at the oxygen substitutional site. With this knowledge, we have determined
Q(13O)=11.0 ± 1.3 mb and Q(19O)=3.7 ± 0.4 mb. The present results are compared with the theoretical values calculated by the shell model code, OXBASH and
by the Hartree–Fock calculation with the realistic potential.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
84.
Matsuta K. Minamisono T. Tanigaki M. Onishi T. Fukuda M. Mihara M. Akai H. Sasaki M. Yamaguchi T. Miyake T. Sato K. Minamisono K. Ha C. Tanaka K. Kidera K. Morishita A. Kaminaka S. Tsubota T. Sumikama T. Kitagawa A. Torikoshi M. Kanazawa M. Nishio T. Koda S. Ohtsubo T. Nojiri Y. Momota S. Hanna S.S. Alonso J.R. Krebs G.F. Symons T.J.M. 《Hyperfine Interactions》1999,120(1-8):719-723
The Knight shifts K for short-lived β emitters 12N and 27Si implanted in Pt have been measured by means of β-NMR technique. The results were K(12N in Pt)= +(5.8 ± 2.1)× 10-4 and K(27Si in Pt)= +(1.4 ± 0.8)× 10-3. The spin–lattice relaxation time T1 was measured for 12N in Pt. The result was T1(12N in Pt, T=300 K)= 66 ± 8 ms, thus, T1T= 20 ± 2 Ks. The present Knight shifts are in good agreement with the KKR band structure calculation with local lattice relaxation
determined theoretically.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
85.
S. Momota M. Mihara D. Nishimura M. Fukuda Y. Kamisho M. Wakabayashi K. Matsuta S. Suzuki M. Nagashima Shengyun Zhu Daqing Yuan Yongnan Zheng Zuo Yi Ping Fan T. Izumikawa A. Kitagawa S. Sato M. Kanazawa M. Torikoshi T. Minamisono Y. Nakamura K. Tashiro A. Honma N. Yoshida H. Shirai T. Ohtsubo T. Nagatomo H. Uenishi K. Iwamoto M. Yaguchi T. Ogura T. Ito K. Yamamura Y. Ichikawa Y. Nojiri J. R. Alonso T. J. M. Symons 《Hyperfine Interactions》2013,218(1-3):53-58
Hyperfine interactions were studied in the intermetallic compound GdRh2Si2 by perturbed angular correlation (PAC) technique using 181Hf(181Ta) probe nuclei. The measurements were performed in the temperature range 15–285 K. The PAC spectra above the antiferromagnetic ordering temperature of the GdRh2Si2 compound (T N ~ 106 K), were analyzed using a model that included only electric quadrupole interactions. The observed major fraction was assigned to the 181Hf(181Ta) probe substituting the Gd atoms. The PAC spectra below Néel temperature were analyzed using combined electric quadrupole and magnetic dipole interactions. The Bhf value at Gd, measured at 15 K was found to be 1.4(1) T which, is smaller, when compared with the values obtained in this compound using other nuclear probes, 155Gd (Bhf ~ 30 T) and 140Ce (Bhf ~ 26 T). The present result using 181Hf(181Ta) probe is quite interesting since it shows that the contribution to Bhf at Gd due the host is smaller than other components which contribute to the hyperfine field. The temperature dependence of Bhf shows an anomalous behavior. 相似文献
86.
M.C.R. Symons 《Molecular physics》2013,111(2):461-463
Monte Carlo calculations are reported for the radial distribution function g 2(r; λ) of a fluid in which the intermolecular pair potential is [u ref(r) + λu p(r)], u ref(r) being the Weeks-Chandler-Andersen (WCA) reference fluid, and [u ref(r) + u p(r)] being the Lennard-Jones (6, 12) fluid. The calculations are performed for λ values in the range 0 to 1, at the state condition ρσ3 = 0·80, kT/ε = 0·719. It is shown that at high densities the perturbation expansion of g 2(r; λ = 1) about g 2(r; λ = 0) is rapidly convergent, but that the corresponding expansion for y 2(r; λ) = exp [βu(r; λ)] × g 2(r; λ) is not. In addition Monte Carlo estimates of the individual terms that contribute to the first-order perturbation term, (?g 2/?λ)λ=0, are presented. It is shown that these terms are individually large, but that (?g 2/?λ)λ=0 is small because there is strong cancellation between the various terms. Consequently, the calculation of (?g 2/?λ)λ=0 is highly sensitive to the approximation used to evaluate the individual terms. 相似文献
87.
D.D. Symons 《Journal of the mechanics and physics of solids》2005,53(8):1855-1874
The Kagome Double-Layer Grid (KDLG) is a sandwich-like structure, based on the planar Kagome pattern, which has properties that make it attractive for application as a morphing material. In order to understand the passive and active properties of the KDLG with rigid joints, an analysis is made of the determinacy of the pin-jointed version. The number of internal mechanisms and states of self-stress of the finite pin-jointed structure are calculated as a function of the size of the structure. A statically and kinematically determinate version is obtained by relocating the internal nodes and by prescribing a set of patch bars around the periphery. The actuation performance of the rigid-jointed version is then explored theoretically by replacing a single bar in the structure by an actuator. The resistance to actuation is determined in terms of the stiffness and the allowable actuation strain as dictated by yield and buckling. The paper concludes with the optimal design of a double-layer grid to maximise actuation performance. 相似文献
88.
This paper characterises completely the circumstances in which maximum likelihood estimation of the factor model is feasible when the sample covariance matrix is rank deficient. This situation will arise when the number of variables exceeds the number of observations. 相似文献
89.
S. F. J. Cox D. A. Geeson C. J. Rhodes E. Roduner C. A. Scott M. C. R. Symons 《Hyperfine Interactions》1986,32(1-4):763-768
A representative series is studies of organic radicals formed by the effective addition of muonium to the carbonyl oxygen
atom of aldehydes, ketones, esters and amides. Low values of the muonelectron hyperfine coupling are measured which are particularly
sensitive to radical structure and dynamics. The systematics of these values are discussed in terms of the opposing contributions
of conjugation and hyperconjugation. 相似文献
90.
L.K. Fifield F.P. Calaprice C.H. Zimmerman M.J. Hurst A. Pakkanen T.J.M. Symons F. Watt K.W. Allen 《Nuclear Physics A》1977,288(1):57-81
The radiative widths for decays of the 20Ne T = 1, 2+ (10.27 MeV) state were measured by resonance α-capture in the reaction 16O(α, γ)20Ne. A special windowless gas-cell target yielded a low-background spectrum enabling six γ-branches to be observed with a Ge(Li) detector. The six branches correspond to decays from the 10.27 MeV level to the following levels: 2+(7.83 MeV), 2+(7.42 MeV), 3?(5.62 MeV), 2?(4.97 MeV), 2+(1.63 MeV) and 0+(g.s.). The branching ratios and radiative widths Γγ to these levels are: 7.83 MeV [(0.22 ± 0.06)%, 0.008 ± 0.002 eV], 7.42 MeV [(6.9 ± 0.4)%, 0.31 ± 0.04 eV], 5.62 MeV [(2.1 ± 0.2)%, 0.097 ± 0.014 eV], 4.97 MeV [(1.3 ± 0.1)%, 0.060 ± 0.008 eV], 1.63 MeV [(88.9 ± 0.5)%, 4.08 ± 0.43 eV] and 0.0 MeV [(0.64 ± 0.14)%, 0.029 ± 0.008 eV]. The radiative widths to the 1.63 MeV and 7.42 MeV levels are used to determine the CVC predictions of the weak magnetism form factors and their effects on certain β-decay observables are evaluated. 相似文献