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41.
Gauge theories for extended SU(N) conformal supergravity are constructed which are invariant under local scale, chiral, proper conformal, supersymmetry and internal SU(N) transformations. The relation between intrinsic parity and symmetry properties of their generators of the internal vector mesons is established. These theories contain no cosmological constants, but technical problems inherent to higher derivative actions are pointed out. 相似文献
42.
43.
K. Miyazaki N. Maekawa W. Kobayashi M. Kaku N. Yasumaru J. Kiuchi 《Applied Physics A: Materials Science & Processing》2005,80(1):17-21
We report characteristic changes in reflectivity of diamond-like-carbon (DLC) films following irradiation of femtosecond laser pulses at laser fluence around the ablation threshold, where we have observed the formation of periodic nanostructure on the film surface and the modification of bonding structure from DLC to glassy carbon in our recent experiments. The experimental results have shown that the reflectivity change should be a reliable measure to monitor the experimental condition to produce the structural changes, being closely associated with the fundamental physical process to induce these phenomena. PACS 79.20.Ds; 81.40.Tv; 42.62.Cf 相似文献
44.
The first fluorescent sensor for HF2 ? anion, N1, N3-di(naphthalene-1-yl)isophthalamide (L) has been derived from α-Napthylamine and isopthaloyl chloride. In 1:1 (v/v) DMSO:H2O, L exhibits high selectivity towards HF2 ? anion with a 4-fold enhancement in fluorescent intensity. Very little enhancement in fluorescence intensity is observed for F?, Cl?, Br?, I?, SCN?, PO4 3?, SO4 2?, and CH3COO? anions. The stoichiometry interaction between L and HF2 ? is found to be 1:1 from fluorescence and UV/Visible spectral data. DFT calculation shows that binding between HF2 ? and L is 1:1 and increases the relative planarity between the two naphthyl rings causing fluorescence enhancement. A shift of 0.080 V in oxidation potential of L is observed on interaction with HF2 ? by cyclic voltammetry and square wave voltammetry. 相似文献
45.
(Cyanomethylene)trimethylphosphorane (CMMP) mediates Mitsunobu-type reactions, which are a versatile method for the alkylation of various nucleophiles (HA) with alcohols (ROH) to give RA. CMMP is quite effective for the reaction of carbon nucleophiles whose pK(a) value are higher than 13. CMMP, which is very sensitive to air and moisture, was synthesized in two steps starting from chloroacetonitrile. 相似文献
46.
Widhalm L Abe K Abe K Adachi I Aihara H Arinstein K Asano Y Aushev T Bakich AM Balagura V Barberio E Barbero M Bay A Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Browder TE Chang P Chen A Chen WT Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Gorisek A Ha H Haba J Hara T Hayasaka K Hayashii H Hazumi M Hokuue T Hoshi Y Hou S Hou WS Iijima T Ikado K Imoto A Inami K Ishikawa A Itoh R Iwasaki M 《Physical review letters》2006,97(6):061804
Using a 282 fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider, we study D0 decays to K-l+nu and pi-l+nu final states. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q2=(pl+pnu)2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be B(D0-->Klnu)=(3.45+/-0.07stat+/-0.20syst)% and B(D0-->pilnu)=(0.255+/-0.019stat+/-0.016syst)% and the semileptonic form factors (within the modified pole model) f+K(0)=0.695+/-0.007stat+/-0.022syst and f+pi(0)=0.624+/-0.020stat+/-0.030syst. 相似文献
47.
Hiroyuki Nishide Naoki Yoshioka Takahiko Kaku Takashi Kaneko Masanori Yamazaki Eishun Tsuchida 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11-12):1177-1187
Synthesis and magnetic properties of π-conjugated stable polyradicals bearing a polyacetylene backbone are described. 2,6-Di-tert-butyl-4-ethynylphenol (8) and 4-ethynylphenylhydrogalvinoxyl (9) are polymerized with W, Mo chloride or Rh complex to yield their polyacetylene derivatives with molecular weight of ca. 104, while 2-ethynylphenalenone (10) gives only its oligomer. The polymers are soluble in common solvents and converted to the corresponding conjugated polyradicals via heterogeneous chemical oxidation using PbO2 or alkaline K3Fe(CN)6. The polyradicals with extremely high spin concentration (up to 4.8 × 1023 spins/monomer mol) are obtained by regulating the oxidative conditions. The polyradicals are quite stable in solution and even in the solid state because of resonance stabilization and/or a steric effect of the substituents. Magnetic interactions between the unpaired spins in the conjugated stable polyradicals are discussed. 相似文献
48.
M. Kaku S. Suetake Y. Senba M. Katto S. Kubodera 《Applied physics. B, Lasers and optics》2008,93(2-3):361-364
We have demonstrated auto-cleaning of deposited tin debris produced in a laser-plasma extreme ultraviolet (EUV) source by using a liquid jet target containing tin chloride solution. The use of double laser pulse irradiation improved the EUV conversion efficiency of 1.1%, which was 3.3 times as large as that obtained with single laser pulse irradiation. At an appropriate concentration of tin chloride, the amount of deposited debris was balanced out with that of sputtered and/or etched debris, resulting in a thickness of deposited debris less than 1 nm after 40?000 laser pulse irradiations. 相似文献
49.
Michio Kaku 《Nuclear Physics B》1975,91(1):99-108
By choosing the light-cone gauge, we remove all redundant components of the metric tensor as well as all Faddeev-Popov ghosts from the Einstein Lagrangian, from which Feynman rules for two independent transverse components can be immediately formulated. The 2 + 2 decomposition of the metric tensor proves to be simpler than the usual canonical 1 + 3 decomposition, so that all spurious components can be explicitly eliminated from the spectrum. Because the Lagrangian is now only a function of independent components, it is possible to study the unresolved problem of the functional measure for quantum gravity. We are presently studying the measure problem. 相似文献
50.
Mitsuyo Horikawa Toshihiro Hashimoto Shigeru Takaoka Hiroto Kaku Kentaro Yamaguchi Masaki Kawase Masao Sato 《Tetrahedron》2006,62(38):9072-9076
Two novel red pigments, uroleuconaphins A1 (1) and B1 (2) were isolated from the aphid Uroleucon nigrotuberculatum (Olive). The structures and the absolute configurations of 1 and 2 were determined by single-crystal X-ray analysis of their derivatives. These structures were constituted as dimeric compounds of two molecules of quinone A (3), which were linked via a dihydrofuran ring system. 相似文献