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W. Braunschweig G. Fischer H. Fischer H. Genzel G. von Holtey H. Kämpgen G. Knop P. Schulz R. Wedemeyer H. Wessels 《Zeitschrift für Physik A Hadrons and Nuclei》1971,245(3):225-252
At the Bonn 500 MeV electron synchrotron the differential cross section of the reaction γ+p → π0+p has been measured detecting the recoil proton by a magnetic spectrometer. Angular distributions between pion c.m. angles of 50 ° and 160 ° were taken at photon energies between 220 and 420 MeV. 相似文献
3.
U. Idschok P. Kobe F. Selonke B. Wessels V. Blobel H. Fesefeldt B. Hellwig D. Mönkemeyer P. Söding H. Franz J.W. Lamsa N. Schmitz W. Schrankel 《Nuclear Physics B》1973,53(2):282-288
A low-mass S-wave (ππ)0 enhancement is observed in the reaction pp → p (ππ)0 p at 12 and 24 GeV/c incident momentum. The mechanism for producing these low-mass pion pairs is investigated, and it is shown that double pomeron exchange can contribute at most 5% to their production cross section at 24 GeV/c. 相似文献
4.
U. Idschok P. Kobe F. Selonke B. Wessels V. Blobel H. Fesefeldt B. Hellwig D. Mönkemeyer J. Benecke P. Breitenlohner H. Franz W. Schrankel B.M. Schwarzschild L. Van Hove 《Nuclear Physics B》1973,67(1):93-124
Charge distributions for the secondaries from inelastic proton-proton collisions are studied by means of new data from an experiment at 12 and 24 GeV/c (2 m HBC at CERN). By comparison with π±p data at 16 GeV/c, the inclusive charge distributions for the fragments of an incident proton and pion, respectively, are analysed. In addition, the cross sections for charge exchange between cms hemispheres are presented for the various charged-particle multiplicities. For events with no more than one neutral particle, charge and baryon exchange between cms hemispheres are compared to those between clusters. For the inelastic two-prong reactions, the two-dimensional distributions in longitudinal phase space are presented. 相似文献
5.
J Wessels 《Journal of Mathematical Analysis and Applications》1977,58(2):326-335
Markovian decision processes are considered in the situation of discrete time, countable state space, and general decision space. By introducing a Banach space with a weighted supremum norm, conditions are derived, which guarantee convergence of successive approximations to the value function. These conditions are weaker then those required by the usual supnorm approach. Several properties of the successive approximations are derived. 相似文献
6.
Fluorine-19 NMR spectra have been recorded for both the phases (cholesteric and smectic C*) of the ferroelectric liquid crystal 2,3-difluoro-4-octyloxybiphenyl-4'(-4'-oxycarbonyl-(S)-1-chloro-3-methylbutyl)benzoate, using a conventional high-resolution NMR probe. The magnitude of the dipolar coupling constant, DFF0, was found to increase with decreasing temperature in the cholesteric phase with a sudden increase (of approximately 1 000 Hz) at the cholesteric-smectic C* transition, whereafter a more gradual change was observed. The order parameter, was SFF, subsequently calculated for each temperature. 相似文献
7.
The queueing problem with Poisson arrivals and two identical parallel Erlang servers is analyzed for the case of shortest expected delay routing. This problem may be represented as a random walk on the integer grid in the first quadrant of the plane. An important aspect of the random walk is that it is possible to make large jumps in the direction of the boundaries. This feature gives rise to complicated boundary behavior. Generating function approaches to analyze this type of random walk seem to be extremely complicated and have not been successful yet. The approach presented in this paper directly solves the equilibrium equations. It is shown that the equilibrium distribution of the random walk can be written as an infinite linear combination of products. This linear combination is constructed in a compensation procedure. The starting solutions for this procedure are found by solving the shortest expected delay problem with instantaneous jockeying. The results can be used for an efficient computation of performance criteria, such as the waiting time distribution and the moments of the waiting time and the queue lengths. 相似文献
8.
L.M.M. Veugen J. van der Wal J. Wessels 《European Journal of Operational Research》1985,20(2):248-254
In this paper the possibility is investigated of using aggregation in the action space for some Markov decision processes of inventory control type. For the standard (s, S) inventory control model the policy improvement procedure can be executed in a very efficient way, therefore, aggregation in the action space is not of much use. However, in situations where the decisions have some aftereffect and, hence, the old decision has to be incorporated in the state, it might be rewarding to aggregate actions. Some variants for aggregation and disaggregation are formulated and analyzed. Numerical evidence is presented. 相似文献
9.
An Ft n.m.r. experiment is described which may lead to a substantial increase in the peak height of n.m.r. signals. 相似文献
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