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71.
T. Ohtsubo M. Tanigaki S. Fukuda Y. Nakayama S. Takeda N. Nakamura H. Tanji M. Fukuda K. Matsuta Y. Nojiri T. Minamisono 《Hyperfine Interactions》1993,78(1-4):185-190
Hyperfine interactions of12B(I
=1+,T
1/2=21 ms) implanted in the substitutional site of B in BN (hexagonal) was studied by detecting -NMR. In order to measure the quadrupole coupling constant efficiently, we employed a newly developed quadrupole resonance technique (NNQR). The quadrupole moment of12B was determined to be |Q(12B)|=13.21±0.26 mb. 相似文献
72.
M. Fukuda T. Izumikawa T. Ohtsubo M. Tanigaki S. Fukuda Y. Nakayama K. Matsuta Y. Nojiri T. Minamisono 《Hyperfine Interactions》1993,78(1-4):117-121
The magnetic moment of the23Mg (I
=3/2+, T1/2=11.3 s), has been determined as |(23Mg)|=0.5364±0.003 µN by use of -NMR detection with the recoil polarization obtained through a low energy nuclear reaction. 相似文献
73.
Ogura M. Minamisono K. Sumikama T. Nagatomo T. Iwakoshi T. Miyake T. Hashimoto K. Kudo S. Arimura K. Ota M. Akutsu K. Sato K. Mihara M. Fukuda M. Matsuta K. Akai H. Minamisono T. 《Hyperfine Interactions》2001,136(3-8):195-199
It was confirmed by detecting the β-NMR of 12B (I
π=1+, T
1/2=20.2 ms) in a TiO2 (rutile) crystal that the nuclear spin polarization of 12B was totally maintained in the crystal as produced through a nuclear reaction before implantation. Two locations, site 1
and site 2, were found with the relative populations 9 and 1, respectively, and the electric field gradients (EFGs) at those
sites were obtained to be q(site 1)=+(37.1±0.5)1015 V/cm2, η(site 1)<0.03, q(site 2)=+(185±5)1015 V/cm2 and η(site 2)=0.62±0.02. We also found that about 30% of the initial polarization of 8Li (I
π=2+, T
1/2=838 ms) was maintained in the crystal. Since the polarizations of other β emitting nuclei, 12,16N, 13,19O, and 41Sc were also totally maintained in the crystal, the crystal can be a “Spin Dewar” in which many short-lived nuclides can be
implanted with their polarizations totally maintained during their lifetimes for the studies not only on the electronic structure
of impurities in it but also on the nuclear properties.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
74.
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
75.
Sato K. Akai H. Maruyama Y. Minamisono T. Matsuta K. Fukuda M. Mihara M. 《Hyperfine Interactions》1999,120(1-8):145-149
We present ab initio calculations of electric field gradients (EFGs) at impurity sites in ionic crystals TiO2, Al2O3 and CaCO3. The electronic structure was calculated self-consistently by the KKR method in the framework of the local spin density approximation
of the density functional theory. The system with a single impurity was simulated by the super cell method. It was found that
EFGs for the transition metal impurities (Sc, Nb, Cd and Ta) in TiO2 were well reproduced by the calculations if the charge state of them in TiO2 was taken into account. The present method was applied to the determination of the implantation sites of N and O nuclei in
TiO2. The calculation of EFGs at a Si impurity in Al2O3 and at Ca site in CaCO3 were used to derive the quadrupole moments of 27Si and 39Ca from their quadrupole coupling constants.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
76.
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
77.
78.
Feruloyl,caffeoyl, and flavonol glucosides from <Emphasis Type="Italic">Equisetum hyemale</Emphasis>
Feruloyl, caffeoyl, and flavonol glucosides were isolated from the stems of Equisetum hyemale L. The structures of the compounds were elucidated as trans-feruloyl-4-β-glucoside (1), cis-feruloyl-4-β-glucoside (2), trans-caffeoyl-3-β-glucoside (3), kaempferol-3-sophoroside (4), kaempferol-3-sophoroside-7-β-glucoside (5), and herbacetin-3-sophoroside-8-β-glucoside (6) based on the spectral evidence. 相似文献
79.
Emisson spectra and time-resolved two-dimensional (2D) emission images of the electron-ion dielectronic recombination (i.e. a reversal process of auto-ionization) line of neutral Cu atoms, the selectively excited Cu ionic line, and normal Cu atomic line were observed for understanding the excitation mechanisms of Cu neutral and ionic lines in a low-pressure laser-induced plasma (LP-LIP) of Ar. From the observations, the number of charged particles around the emitting species seems to increase with increasing Ar pressure. Different time-resolved 2D emission images were observed among the selectively excited Cu ionic line and other Cu emission lines resulting from the different excitation mechanisms of the respective emission lines. Collisions of the second kind and electron-ion recombinations were found to be one of the major excitation mechanisms of Cu in Ar LP-LIP. 相似文献
80.
A novel emission excitation source comprising a high repetition rate diode-pumped Q-switched Nd:YAG laser and a Grimm-style glow-discharge lamp is described. Laser-ablated atoms are introduced into the He glow discharge plasma, which then give emission signals. By using phase-sensitive detection with a lock-in amplifier, the emission signal modulated by the pulsed laser can be detected selectively. It is possible to estimate only the emission intensity of sample atoms ablated by laser irradiation with little interference from the other species in the plasma. 相似文献