排序方式: 共有42条查询结果,搜索用时 15 毫秒
31.
H Machner M Betigeri J Bojowald A Budzanowski A Chatterjee J Ernst L Freindl D Frekers W Garske K Grewer A Hamacher J Ilieva L Jarczyk K Kilian S Kliczewski W Klimala D Kolev T Kutsarova J Lieb H Machner A Magiera H Nann L Pentchev HS Plendl D Protić B Razen P Von Rossen BJ Roy R Siudak J Smyrski RV Srikantiah A Strzałkowski R Tsenov K Zwoll 《Pramana》2001,57(2-3):399-416
Total and differential cross sections for the reactions p + d → 3He + m
0 with m=π, η and p + d → 3H+π+ were measured with the GEM detector at COSY for beam momenta between threshold and the maximum of the corresponding baryon
resonance. For both reactions a strong forward-backward asymmetry was found. The data were compared with model calculations.
The aspect of isospin symmetry breaking is studied.
Representing the GEM Collaboration 相似文献
32.
K H?kansson RA Zubarev RV Coorey VL Talrose P H?kansson 《Rapid communications in mass spectrometry : RCM》1999,13(12):1169-1174
An HMX/insulin two-layer system was chosen as a model for further investigation of the matrix properties of explosive materials for protein analytes in plasma desorption mass spectrometry. The dependencies of the molecular ion yield and average charge state as a function of the analyte thickness were studied. An increase in the charge state of multiply protonated molecular species was confirmed as the major matrix effect, with the average charge state z at the smallest thickness studied being higher than in matrix-assisted laser desorption/ionization and closer to the value obtained in electrospray ionization under standard acidic conditions. Observed charge state distributions are significantly narrower than the corresponding Poisson distributions, which suggests that the protonation of insulin is limited in plasma desorption by the number of basic sites in the molecule, similar to electrospray ionization. Both the curve displaying total molecular ion yield and the one showing the total charge (proton) yield as a function of the insulin thickness have maxima at a thickness different from an insulin monolayer. These observations diminish the significance of a matrix/analyte interface mechanism for the explosive matrix assistance. Instead, a mechanism related to the chemical energy release during conversion of the explosive after the ion impact is proposed. As additional mechanisms, enhanced protonation of the analyte through collisions with products of the explosive decay is considered, as well as electron scavenging by other products, which leads to a higher survival probability of positively charged protein molecular ions. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
33.
A general parton model is used to formulate W° effects in inclusive e+e? annihilation. These effects are of the order 1% in the case of inclusive pion production at CM energies of 10 GeV with the Weinberg W°. 相似文献
34.
R. Budny 《Physics letters. [Part B]》1973,45(4):340-344
General cross-sections are given for annihilation via one photon and W0 exchange. Effects of the W0 in the special cases e+e?→μ+μ? and at high energies are discussed. These effects are estimated to be comparable to the effects from one γ exchange at energies accesible in NAL and SPS. 相似文献
35.
Bernabei S Bell MG Budny RV Fredrickson ED Gorelenkov NN Hosea JC Majeski R Mazzucato E Phillips CK Schilling G Wilson JR 《Physical review letters》2000,84(6):1212-1215
A correlation is explored between the presence of energetic particle modes (EPM) and long-period sawtooth oscillations in tokamak plasmas heated by rf waves. The eventual crash of these sawteeth is explained in terms of the loss of the stabilizing fast particles due to the EPM. The absence of long-period sawteeth in high q(a) discharges is explained in terms of ion loss due to toroidal Alfven eigenmodes. 相似文献
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Budny A Novak F Plumeré N Schetter B Speiser B Straub D Mayer HA Reginek M 《Langmuir : the ACS journal of surfaces and colloids》2006,22(25):10605-10611
Nonporous spherical silica nanoparticles resulting from a controlled St?ber process are covalently surface modified with redox-active molecules. Ferrocene, a ruthenium(II) complex with an N2P2Cl2 ligand set, and a sterically hindered biphenylamine are used as modifiers. The resulting materials are characterized by physical, spectroscopic, electrochemical, and chemical methods. The cyclic voltammetric behavior is studied in detail and reveals effects of charge transport by electron hopping along the surface of particles adsorbed on a Pt electrode. The ruthenium(II) complex remains catalytically active with respect to hydrogenation upon immobilization on the particles. Thus, the respective material provides a heterogenized homogeneous hydrogenation catalyst on a solid support. 相似文献
39.
R. Budny 《Physics letters. [Part B]》1975,58(3):338-340
The prediction for the cross section of e±e± → e±e± is given, assuming one photon and Wo exchange. Pure Wo terms and transverse and longitudinal beam polarizations are included. 相似文献