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951.
T. Nozaki Y. Itoh Z. L. Peng N. Nakanishi A. Goto Y. Ito H. Yoshida 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):175-178
Fluorine-18 produced by the18O(p,n)18F reaction on18O-water has proved to be highly useful as a source for a slow positron beam. About 70 GBq of18F is produced routinely by an ultra-compact cyclotron. The18F formed in H2
18O target is sent through a fine pipe to the site of positron slowing-down, fixed on a small spot by adsorption or drying,
and then placed close to the moderator foil. An automatic apparatus has been set up for the entire process including the recovery
of H2
18O. 相似文献
952.
Idehara T. Ogawa I. Mitsudo S. Pereyaslavets M. Nishida N. Yoshida K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(2):340-354
High frequency, medium power gyrotrons (Gyrotron FU series) have been developed at Fukui University as radiation sources covering a broad band from millimeter to submillimeter wave region. They have already been applied to high frequency electron spin resonance and to submillimeter wave scattering in plasma. Many parameters of the gyrotron series could be useful for applications in several new areas. The development and some applications of the Gyrotron FU series are summarized in this paper 相似文献
953.
Pereyaslavets M. Idehara T. Nishida N. Yoshida K. Ogawa I. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(2):363-367
Frequency modulation of the gyrotron output has been numerically simulated employing the approximation of weakly relativistic, mono-velocity electron beam as well as a quasi-empirical approach. The simulation results are compared to a first experiment in the 300 GHz region performed with a submillimeter-wave gyrotron named “Gyrotron FU IV”. The modulation amplitude of 30 MHz has been achieved by a 120 V modulation of the accelerating voltage resulting in the variation of the relativistic electron mass and in the corresponding modulation of the electron cyclotron frequency. Calculated amplitudes of frequency modulation are in reasonable agreement with the experimental results 相似文献
954.
Matsuta K. Onishi T. Fukuda M. Minamisono T. Mihara M. Sasaki M. Yamaguchi T. Miyake T. Sato K. Minamisono K. Ohsumi F. Muramoto Y. Oui S. Ha C. Tanaka K. Kidera K. Morishita A. Tsubota T. Sumikama T. Kitagawa A. Torikoshi M. Kanazawa M. Nishio T. Koda S. Ohtsubo T. Fukuda S. Nojiri Y. Momota S. Ozawa A. Yoshida K. Suzuki T. Kobayashi T. Tanihata I. Hanna S.S. Alonso J.R. Krebs G.F. Symons T.J.M. 《Hyperfine Interactions》1999,120(1-8):713-717
The degrees of nuclear spin polarization of 8,12B, 9C, 12N, 13O, 20,21F, 23Mg, 27Si and 39Ca produced in the high energy 12,13C, 16O, 22Ne, 24Mg, 28Si and 40Ca ions on Be collisions have been measured systematically, for the technical developments of the nuclear moment studies as
well as the hyperfine interaction studies by means of β-NMR technique. The fragment momentum dependences were well reproduced
by the simple kinematical model. Incident energy dependence and the mass dependence as well as the reaction angle dependences
were qualitatively explained by the mixing of the near and far side collisions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
955.
Let G be a connected graph and let eb(G) and λ(G) denote the number of end‐blocks and the maximum number of disjoint 3‐vertex paths Λ in G. We prove the following theorems on claw‐free graphs: (t1) if G is claw‐free and eb(G) ≤ 2 (and in particular, G is 2‐connected) then λ(G) = ⌊| V(G)|/3⌋; (t2) if G is claw‐free and eb(G) ≥ 2 then λ(G) ≥ ⌊(| V(G) | − eb(G) + 2)/3 ⌋; and (t3) if G is claw‐free and Δ*‐free then λ(G) = ⌊| V(G) |/3⌋ (here Δ* is a graph obtained from a triangle Δ by attaching to each vertex a new dangling edge). We also give the following sufficient condition for a graph to have a Λ‐factor: Let n and p be integers, 1 ≤ p ≤ n − 2, G a 2‐connected graph, and |V(G)| = 3n. Suppose that G − S has a Λ‐factor for every S ⊆ V(G) such that |S| = 3p and both V(G) − S and S induce connected subgraphs in G. Then G has a Λ‐factor. © 2001 John Wiley & Sons, Inc. J Graph Theory 36: 175–197, 2001 相似文献
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