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1.
E. Costa A. Emanuele A. Rubini E. Massaro G. Matt G. Medici G. C. Perola M. Salvati 《Il Nuovo Cimento C》1990,13(2):431-436
Summary We describe a high sensitivity X-ray Thomson polarimeter for astrophysical research, particularly designed for the XMM mission.
The efficiency, the modulation factor and the performances of this instrument have been estimated by means of a Monte Carlo
simulation. The predicted sensitivity for the high eccentricity Orbit of XMM should allow the detection of the Crab Nebula
polarization (3σ, (5÷11)keV) in 15 seconds only.
To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee. 相似文献
2.
Ph. Gavillet C. Dionisi A. Gurtu R.J. Hemingway M.J. Losty J.C. Marin M. Mazzucato L. Montanet E. Pagiola R. Blokzijl B. Jongejans J.C. Kluyver G.G.G. Massaro J.J. Engelen J.S.M. Vergeest M. Zralek B. Foster P. Grossmann J. Wells 《Physics letters. [Part B]》1978,78(1):158-161
The backward production of the B(1235) meson is studied in the reaction K?p→Σ?π+ω. This reaction is observed in the final state Σ?π+π+π?π0. A π+ω mass enhancement is visible in the region of the B meson for events with small |u|K? →Σ?) squared four-momentum transfer. The properties of the enhancement agree with those of the B meson. The cross section for K?p→Σ?B+ at incident K? momentum is (3.2 ± 0.5) μb. The backward production of the B meson is compared with similar baryon exchange productions of the A1 and C(Q1) axial vector mesons observed in the same experiment. 相似文献
3.
R.J. Hemingway R. Armenteros C. Dionisi Ph. Gavillet A. Gurtu S.O. Holmgren M.J. Losty J.C. Marin M. Mazzucato L. Montanet M. Banting R. Blokzijl A.J. De Groot B. Jongejans J.C. Kluyver W.M. Van Leeuwen G.G.G. Massaro J. Wells 《Nuclear Physics B》1978,142(3):205-219
Forty events have been observed in a large (133 events/βb) experiment at 4.2 GeV/c incident K? momentum. Thirty nine of the events come from the three-body reaction . The is mainly produced in the forward hemisphere (direction of the incident K?). The lifetime is measured to be τ = (0.75 +0.14?0.11 × 10?10 sec substantially less than the Particle Data Group value of (1.3 ?0.3+0.2) × 10?10 sec. The mass is determined to be 1671.7 ± 0.6 MeV, in good agreement with other determinations. The decay asymmetry parameter α (for the decay mode ) is found to be ?0.2 ± 0.4. 相似文献
4.
Many scientific papers deal with motorcycle stability (weave and wobble modes) but very seldom they take into account the passive response of rider??s body. This paper aims at studying the interaction of the rider??s arms and torso with the handlebar and the frame. First the rider??s steering impedance is identified from experimental tests on a motorcycle riding simulator, then this information is used on a motorcycle model and the effect on straight-motion stability is investigated by eigenvalues calculation. 相似文献
5.
The asymmetric organocatalyzed Michael addition of aldehydes to alpha,beta-gamma,delta-unsaturated nitro compounds has been accomplished using only 5 mol % of (S)-diphenylprolinol silyl ether and 2 equiv of aldehyde in a mixture of ethanol and water (5% v/v). The Michael adducts were obtained in good yields, diastereoselectivities up to 94/6, and ee's up to 99%. This process provides synthetically useful compounds which can easily lead to more complex molecules, as exemplified with substituted tetrahydropyran or cyclohexene. 相似文献
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7.
S.M. Flatte J.B. Gay R.J. Hemingway S.O. Holmgren M.J. Losty R. Blokzijl J.C. Kluyver G.G.G. Massaro W.J. Metzger J.J.M. Timmermans R.T. Van de Walle P.R. Lamb P. Grossmann 《Physics letters. [Part B]》1976,64(2):225-229
A πω enhancement at 1245 MeV is observed in the reaction K?p → Σ+π?ω. Its properties agree with those of a B meson produced by natural-parity exchange thus establishing a coupling of the B to a system. 相似文献
8.
S.O. Holmgren M. Aguilar-Benitez M. Cerrada R.J. Hemingway M.J. Losty R.P. Worden B. Jongejans G.G.G. Massaro G.F. Wolters J.J. Engelen D.J. Schotanus R.T. Van de Walle B. Foster L. Lyons J. Wells 《Physics letters. [Part B]》1977,66(2):191-196
π ? ω interference is studied in the reactions K? p → π+ π? (Λ0, ?) at 4.2 GeV/c using data from a high statistics experiments in the CERN 2m HBC. The phenomenon is analysed in terms of the conventional formalism as well as in terms of a new model for π ? ω interference proposed by Earles and Srivastava. Satisfactory agreement with the data is found for both models. The rate of ω → 2π obtained in the latter model is in agreement with the VMD (Vector Meson Dominance) prediction for ω → γ → ? → 2π. 相似文献
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10.
D. Montagnino E. Costa F. R. Massaro G. Artioli D. Aquilano 《Crystal Research and Technology》2011,46(10):1010-1018
Gypsum is the most abundant natural sulphate, and in industrial application it plays an important role in gypsum based binders. Furthermore, it plays a critical role in the hydration of Portland cement, and then gypsum is one of the most important cement additive. In this paper we investigated the role of two commercial polymeric additives in modifying the crystal habits and size of gypsum, growth in aqueous solution. These two additives belong to the categories of acrylic polymers and they are known only by their commercial names of SP1 and SP3. We found that these substances can act as shape modifiers mainly at concentration over 0.04% by weight, with a shortening in the elongation of gypsum crystal and some change in the characters of {001} form, from stepped to flat, due to a change in the growth mechanism. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献