排序方式: 共有11条查询结果,搜索用时 609 毫秒
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D. Bisello G. Busetto A. Castro M. Nigro M. Penzo L. Pescara M. Posocco P. Sartori L. Stanco Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret A. Antonelli R. Baldini A. Calcaterra G. Capon M. Schioppa J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier F. Manè C. Paulot R. Riskalla Ph. Roy G. Szklarz DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,39(1):13-19
Thee + e ?→K + K ? cross section has been measured from about 750 events in the energy interval \(1350 \leqq \sqrt s \leqq 2400 MeV\) with the DM2 detector at DCI. TheK ± form factor |F F ±| cannot be explained by the ρ, ω, ? and ρ′(1600). An additional resonant amplitude at 1650 MeV has to be added as suggested by a previous experiment. 相似文献
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J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda B. Grelaud G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier B. Louis F. Mané C. Paulot R. Riskalla Ph. Roy F. Rumpf G. Szklarz Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret R. Baldini S. Calcaterra G. Capon D. Bisello G. Busetto S. Limentani M. Nigro L. Pescara M. Posocco P. Sartori L. Stanco DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1987,36(3):369-376
The radiative decayJ/ψ → γ π+ π? has been studied using the 8.6 millionJ/ψ produced in the DM2 experiment at the DCIe +e? storage rings at Orsay. The π+ π? mass spectrum shows a cleanf 2 (1270) signal, and the possible presence of two other states at thef 2 (1720) andf 4 (2030) masses. For thef 2 (1270), the branching ratio BR(J/ψ →γf)xBR(f→π+ π?) is measured to be (7.50±0.30±1.12)×10?4, and the spin analysis prefers theJ=2 assignment, with helicity parametersx=0.83±0.06 andy=0.01±0.06. The existence of higher mass states is discussed. 相似文献
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The steady propagation of a thin smouldering front in a half-spacehas been considered. A suitable coordinate transformation hasallowed the region near the leading edge of the front to beexamined for both a maintained planar surface and with surfacecollapse due to material shrinkage. The change in the oxidizerconcentration for a small increment in the propagation speedfor large time and surface collapse has been determined. Theinfluence of two types of nonlinear diffusion on the shape ofthe smouldering front has been found; other cases can be dealtwith in a similar manner. 相似文献
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Ovenden SP Nielson JL Liptrot CH Willis RH Tapiolas DM Wright AD Motti CA 《Molecules (Basel, Switzerland)》2012,17(3):2929-2938
The methanol extract of an assemblage of Halimeda stuposa and a Dictyota sp., yielded three natural products characteristic of Dictyota sp., and one of Halimeda sp. These included the xenicane diterpene 4-hydroxydictyolactone (1), and the diterpenes dictyol E (2), 8a,11-dihydroxypachydictyol A (3) and indole-3-carboxaldehyde (4). A minor revision of 1 and new spectroscopic data for 1 and 2 are provided, along with associated anti-cancer activities of compounds. 相似文献
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D. Bisello G. Busetto A. Castro M. Nigro L. Pescara M. Posocco P. Sartori L. Stanco A. Antonelli M. E. Biagini R. Baldini A. Calcaterra M. Schioppa J. E. Augustin G. Cosme F. Couchot F. Fulda G. Grosdidier B. Jean-Marie V. Lepeltier G. Szklarz DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,48(1):23-28
Search for baryon pairs production ine + e ? annihilation at \(\sqrt s = 2386 MeV\) is reported. The data relate to a luminosity of 161 nb?1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe + e ? annihilation into \(\Lambda \bar \Lambda \) and ofe + e ?→ \(p\bar p\) at this energy are presented. First observation of a goode + e ?→ \(n\bar n\) candidate is reported and upper limits are given fore + e ?→ \(n\bar n, \Lambda \bar \sum ^0 + c.c.\) and \(\Sigma ^0 \bar \Sigma ^0 \) . 相似文献
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Studies of australian soft corals—XXXV : The terpenoid chemistry of soft corals and its implications
John C. Coll Bruce F. Bowden Dianne M. Tapiolas Richard H. Willis Peter Djura Margaret Streamer Lindsay Trott 《Tetrahedron》1985,41(6):1085-1092
The in vivo incorporation of mevalonolactone specifically into the terpene portion of a sesquiterpene hydroquinone is reported for the soft coral Sinularia capillosa Eudesma-4 , 7(11)-diene-8β-ol (20) and the corresponding 8-keto derivative (21) have been isolated from the soft coral Nephthea species for the first time The aeolid nudibranch Phyllodesmium longicirra was collected when feeding on the soft coral Sarcophyton trocheliophorum and the known diterpene trocheliophorol (25) was found to be concentrated in the cerata of the nudibranch. The absolute stereochemistry of trocheliophorol (25) has been rigorously determined, and shown to be that previously assigned on spectroscopic grounds 相似文献
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Comparison of the biological properties of several marine sponge-derived sesquiterpenoid quinones 总被引:1,自引:0,他引:1
Motti CA Bourguet-Kondracki ML Longeon A Doyle JR Llewellyn LE Tapiolas DM Yin P 《Molecules (Basel, Switzerland)》2007,12(7):1376-1388
Eight naturally occurring marine-sponge derived sesquiterpenoid quinones were evaluated as potential inhibitors of pyruvate phosphate dikinase (PPDK), a C4 plant regulatory enzyme. Of these, the hydroxyquinones ilimaquinone, ethylsmenoquinone and smenoquinone inhibited PPDK activity with IC50's (reported with 95% confidence intervals) of 285.4 (256.4-317.7), 316.2 (279.2-358.1) and 556.0 (505.9-611.0) microM, respectively, as well as being phytotoxic to the C4 plant Digitaria ciliaris. The potential anti-inflammatory activity of these compounds, using bee venom phospholipase A2 (PLA2), was also evaluated. Ethylsmenoquinone, smenospongiarine, smenospongidine and ilimaquinone inhibited PLA2 activity (% inhibition of 73.2 +/- 4.8 at 269 microM, 61.5 +/- 6.1 at 242 microM, 41.0 +/- 0.6 at 224 microM and 36.4 +/- 8.2 at 279 microM, respectively). SAR analyses indicate that a hydroxyquinone functionality and a short, hydroxide/alkoxide side-chain atC-20 is preferred for inhibition of PPDK activity, and that a larger amine side-chain at C-20 is tolerated for PLA2 inhibitory activity. 相似文献