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排序方式: 共有586条查询结果,搜索用时 15 毫秒
161.
M. Abdel-Bary S. Abdel-Samad R. Bilger K.-Th. Brinkmann H. Clement S. Dshemuchadse E. Dorochkevitch H. Dutz W. Eyrich A. Erhardt D. Filges A. Filippi H. Freiesleben M. Fritsch R. Geyer A. Gillitzer D. Hesselbarth B. Jakob L. Karsch K. Kilian H. Koch J. Kreß E. Kuhlmann S. Marcello S. Marwinski S. Mauro W. Meyer P. Michel K. Möller H. P. Morsch L. Naumann N. Paul M. Richter E. Roderburg M. Rogge A. Schamlott M. Schmitz P. Schönmeier M. Schulte-Wissermann W. Schroeder T. Sefzick F. Stinzing G.Y. Sun G.J. Wagner M. Wagner A. Wilms P. Wintz S. Wirth P. Zupranski 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):127-137
The reaction pp → ppη was measured at excess energies of 15 and 41 MeV at an external target of the Jülich Cooler Synchrotron COSY with the time-of-flight
spectrometer. About 25000 events were measured for the excess energy of 15 MeV and about 8000 for 41 MeV. Both protons of
the process ppη were detected with an acceptance of nearly 100% and the η was reconstructed by the missing-mass technique. For both excess
energies the angular distributions are found to be nearly isotropic. In the invariant-mass distributions strong deviations
from the pure phase space distributions are seen.
Received: 24 May 2002 / Accepted: 20 September 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: e.roderburg@fz-juelich.de
Communicated by M. Gar?on 相似文献
162.
Bianco A Guiso M Nicoletti M Foddai S Piccin A Serafini M Ballero M Poli F 《Natural product research》2005,19(6):615-617
The phytochemical analysis of iridoidic fraction of the aerial parts of Vinca sardoa and Vinca difformis, gave the identification of loganic acid in V. difformis as unique iridoid glucoside, while loganin is also present in V. sardoa. The two taxa highly differ in alkaloids, so the chemotaxonomic classification in two different species is supported. 相似文献
163.
Marcello Bruni 《Annali di Matematica Pura ed Applicata》1966,72(1):59-77
Riassunto Identificati, in modo opportuno, gli spazi vettoriali Qn ed R4n, si esaminano varie proprietà che intercorrono tra la metrica hermitiana di Qn e la metrica euclidea di R4n. Si definisce poi, per ogni sottospazio Et di E
4n (t =1, 2, 3, 4) una nozione di deviazione caratteristica assoluta che estende l'analoga nozione nota nel caso di cn. Si riescono così a caratterizzare i sottospazi Et pseudocaratteristici (cioè contenuti in un E4 che si identifica ad una retta di Qn), ed i sottospazi Et a prodotto hermitiano reale.
Lavoro eseguito nell'ambito dell'attività dei Gruppi di Ricerca del Comitato per la Matematica del C. N. R. per l'anno accademico
1964–65. 相似文献
164.
Different calibration methods have been applied for the determination of the Hydroxyl Number in polyester resins, namely Partial Least Squares (PLS), Principal Component Regression (PCR), Ordinary Least Squares with selection of the variables by genetic algorithm (OLS-GEN) and back-propagation Artificial Neural Networks (BP-ANN). The predictive ability of the regression models was estimated by splitting the dataset in training and test sets by application of the Kohonen self-organising maps. The linear methods (OLS-GEN, PLS and PCR) showed comparable results while artificial neural networks provided the best results both in fitting and prediction. 相似文献
165.
We investigate collinear factorization in electroweak radiative corrections to hard inclusive processes at the TeV scale. Because of the uncanceled double logs found previously, we find a factorization pattern which is qualitatively different from the analogous one in QCD. New types of splitting functions emerge which are needed to describe the initial beam charges and are dependent on an infrared cutoff provided by the symmetry breaking scale. We derive such splitting functions at the one-loop level for broken SU(2) gauge theory, and we also discuss the structure functions' evolution equations, under the assumption that isospin breaking terms are sufficiently subleading at higher orders. 相似文献
166.
167.
Nefzi A Giulianotti M Truong L Rattan S Ostresh JM Houghten RA 《Journal of combinatorial chemistry》2002,4(2):175-178
An efficient method for the solid-phase synthesis of hydantoins and thiohydantoins tethered to ureas, starting from a resin-bound amino acid, is presented. Following reduction of the amide with borane-THF, a second amino acid was selectively coupled to the primary amine followed by treatment of the secondary amine by an isocyanate to generate the corresponding urea. Hydantoin and thiohydantoin formation was achieved through the use of carbonyldiimidazole and thiocarbonyldiimidazole, respectively. Cleavage from the solid support using hydrogen fluoride, followed by extraction and lyophilization, provided the desired urea-linked heterocyclic compounds in good yield and high purity. 相似文献
168.
Crack Initiation in Brittle Materials 总被引:1,自引:0,他引:1
Antonin Chambolle Alessandro Giacomini Marcello Ponsiglione 《Archive for Rational Mechanics and Analysis》2008,188(2):309-349
In this paper we study the crack initiation in a hyper-elastic body governed by a Griffith-type energy. We prove that, during
a load process through a time-dependent boundary datum of the type t → t
g(x) and in the absence of strong singularities (e.g., this is the case of homogeneous isotropic materials) the crack initiation
is brutal, that is, a big crack appears after a positive time t
i
> 0. Conversely, in the presence of a point x of strong singularity, a crack will depart from x at the initial time of loading and with zero velocity. We prove these facts for admissible cracks belonging to the large
class of closed one-dimensional sets with a finite number of connected components. The main tool we employ to address the
problem is a local minimality result for the functional where , k > 0 and f is a suitable Carathéodory function. We prove that if the uncracked configuration u of Ω relative to a boundary displacement ψ has at most uniformly weak singularities, then configurations (uΓ, Γ) with small enough are such that . 相似文献
169.
Nozzle flow separation 总被引:2,自引:0,他引:2
170.
Elsa Callini Zuleyha Özlem Kocabas Atakli Bjørn C. Hauback Shin-ichi Orimo Craig Jensen Martin Dornheim David Grant Young Whan Cho Ping Chen Bjørgvin Hjörvarsson Petra de Jongh Claudia Weidenthaler Marcello Baricco Mark Paskevicius Torben R. Jensen Mark E. Bowden Thomas S. Autrey Andreas Züttel 《Applied Physics A: Materials Science & Processing》2016,122(4):353