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排序方式: 共有307条查询结果,搜索用时 78 毫秒
71.
We obtain existence results for some strongly nonlinear Cauchy problems posed in
and having merely locally integrable data. The equations we deal with have as principal part a bounded, coercive and pseudomonotone
operator of Leray-Lions type acting on
, they contain absorbing zero order terms and possibly include first order terms with natural growth. For any p > 1 and under
optimal growth conditions on the zero order terms, we derive suitable local a-priori estimates and consequent global existence
results. 相似文献
72.
73.
S. Leoni 《Physics of Atomic Nuclei》2001,64(6):1087-1092
The rotational motion in thermally excited nuclei and its damping at high excitation energy is discussed here with reference to the role of effects beyond mean-field approximation. The experimental results for different mass regions and deformations are presented and compared with a cranked-shell-model calculation including a two-body residual interaction of surface delta type. Altogether, it is found that the dependence of the mixing process on the nuclear mass and deformation is well reproduced by the data. 相似文献
74.
75.
Fortunelli A Leoni P Marchetti L Pasquali M Sbrana F Selmi M 《Inorganic chemistry》2001,40(13):3055-3060
The reaction of the Pt(I)Pt(I)Pt(II) triangulo cluster Pt(3)(micro-PBu(t)()(2))(3)(H)(CO)(2) (1) with TfOH (Tf = CF(3)SO(2)) affords the hydride-bridged cationic derivative [Pt(3)(mu-PBu(t)()(2))(2)(mu-H)(PBu(t)()(2)H)(CO)(2)]OTf (2). With TfOD the reaction gives selectively [Pt(3)(mu-PBu(t)(2))(2)(mu-D)(PBu(t)(2)H)(CO)(2)]OTf (2-D(1)), implying that the proton is transferred to a metal center while a P-H bond is formed by the reductive coupling of one of the bridging phosphides and the terminal hydride ligand of the reagent. The reaction proceeds through the formation of a thermally unstable kinetic intermediate which was characterized at low temperatures, and was suggested to be the CO-hydrogen-bonded (or protonated) [Pt(3)(mu-PBu(t)(2))(3)(H)(CO)(2)].HOTf (3). An ab initio theoretical study predicts a hydrogen-bonded complex or a proton-transfer tight ion pair as a possible candidate for the structure of the kinetic intermediate. 相似文献
76.
By the action of thionyl chloride on 3(5)-R-4-phenacylpyrazole-5(3)-carboxylic acid ( 3c,d ), 3-R-5-phenylpyrano[3,4-c]pyrazole-7-(1H)ones ( 4c,d ) were obtained. When 4c,d were treated with hydrazine hydrate followed by refluxing in ethanol containing acetic acid, 4,7-dihydro-3-R-5-phenylpyrazolo[3,4-d][1,2]-diazepin-8-(1H)ones ( 6c,d ) were formed. Compounds 6c,d , in turn, were refluxed in ethanol saturated with hydrochloric acid to yield 6-amino-1,6-dihydro-3-R-5-phenyl-7H-pyrazolo[3,4-c]pyridin-7-ones ( 7c,d ). Compounds 7c,d could be obtained directly from 5c,d. The starting materials 3c,d were prepared by hydrolysis of the oxime of 3(5)-R-4-phenacyl-5(3)carboalcoxypyrazoles ( 1a,b ). Structural assignments rested on correct elemental analysis, molecular weights determined by mass spectrometry, and spectroscopic evidence. 相似文献
77.
A. Formicola M. Aliotta G. Gyürky F. Raiola R. Bonetti C. Broggini L. Campajola P. Corvisiero H. Costantini A. D’Onofrio Z. Fülöp G. Gervino L. Gialanella A. Guglielmetti C. Gustavino G. Imbriani M. Junker A. Ordine P. Prati V. Roca D. Rogalla C. Rolfs M. Romano F. Schümann E. Somorjai O. Straniero F. Strieder F. Terrasi H. P. Trautvetter S. Zavatarelli 《The European Physical Journal A - Hadrons and Nuclei》2000,8(4):443-446
The energy loss of deuterons in 3He gas was measured at E d = 15 to 100 keV using the 3He pressure dependence of the 3He(d,p)4He cross-section at a given incident energy. At the highest energies, the observed energy loss is in good agreement with a standard compilation. However, with decreasing energy the experimental values drop steadily below the theoretical values and near E d = 18 keV they drop sharply (within 1 keV) reaching the domain of nuclear stopping power. This threshold behavior is due to the minimum 1s → 2s electron excitation of the He target atoms, i.e. it is a quantum effect. Some consequences are discussed. 相似文献
78.
M. Kmiecik A. Maj B. Herskind A. Bracco R.A. Bark M. Bergström F. Camera G. Hagemann N. Hashimoto A. Holm S. Leoni T. Saitoh T.S. Tveter 《The European Physical Journal A - Hadrons and Nuclei》1998,1(1):11-13
The decay of 170W* formed in reactions with two different projectile - target combinations was studied. The observed differences in the average
number of emitted neutrons suggest an entrance channel effect at the highest excitation energy and angular momentum. It may
be explained by different excitation energies of the equilibrated system, resulting from the emission of pre-equilibrium α-particles
during a longer fusion time, in the more symmetric reaction.
Received: 30 October 1997 相似文献
79.
Peter Leoni Bart Partoens Franois M. Peeters 《Physica E: Low-dimensional Systems and Nanostructures》2005,26(1-4):312
In InP/GaInP quantum discs it is shown that strain induces a type I to type II transition with increasing thickness of the disc. When an external electric field is applied along the cylindrical axis of the disc, the exciton energy exhibits a Stark effect, which for the light hole exciton becomes linear even for a small field value, while for the heavy hole it is more quadratic. 相似文献
80.
K. Behringer B. Leoni und H. S. Pruys 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1973,24(3):466
Ohne Zusammenfassung 相似文献