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71.
T. C. Awes C. Barlag F. Berger M. A. Bloomer C. Blume D. Bock R. Bock E. -M. Bohne D. Bucher A. Claussen G. Clewing L. Dragon A. Eklund S. Garpman R. Glasow H. Gustafsson H. H. Gutbrod G. Hölker J. Idh P. Jacobs K. H. Kampert B. W. Kolb H. Löhner I. Lund F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann F. Plasil A. M. Poskanzer M. Purschke B. Roters S. Saini R. Santo H. R. Schmidt S. P. Sørensen K. Steffens P. Steinhaeuser E. Stenlund D. Stüken G. R. Young 《Zeitschrift fur Physik C Particles and Fields》1995,65(2):207-213
Correlations between protons are studied in the target fragmentation region of reactions of protons and16O with C, Cu, Ag, Au and of32S with Al and Au at 200A GeV. The emitted protons were measured with the Plastic Ball detector in the WA80 experiment at the CERN SPS. The comparison of the correlation function with calculations, assuming a spherical, gaussian shaped source with a lifetime τ=0 fm/c, allows the extraction of radius parameters. The values are very close to those expected from the geometry of the target nuclei and increase with the target mass as αA Target 1/3 . Even in proton induced reactions the whole target nucleus is involved. The dependence of the radii on centrality, polar angleθ lab, and energy, and their relation to measured proton yields are presented. 相似文献
72.
We formulate the conditions under which the dynamics of a continuously measured quantum system becomes indistinguishable from that of the corresponding classical system. In particular, we demonstrate that even in a classically chaotic system the quantum state vector conditioned by the measurement remains localized and, under these conditions, follows a trajectory characterized by the classical Lyapunov exponent. 相似文献
73.
We present the first results of a new search for a permanent electric dipole moment of the 199Hg atom using a UV laser. Our measurements give d(199Hg) = -(1.06+/-0.49+/-0.40)x10(-28)e cm. We interpret the result as an upper limit absolute value [d(199Hg)]<2.1x10(-28)e cm (95% C.L.), which sets new constraints on theta bar;(QCD), chromo-EDMs of the quarks, and CP violation in supersymmetric models. 相似文献
74.
The rotational distribution of OH(X
2,v=0) radicals was investigated by resonant laser-induced fluorescence (LIF) after photolysis of H2O2 at 193 nm. A microcomputer equipped LIF arrangement allowed special shot-by-shot normalization of the fluorescence signal for noise reduction. Using a least-squares procedure we were able to account for all measured line intensities including overlapping lines (blends) and obtain a complete rotational state distribution of the OH(X
2,v=0) state. The rotational excitation shows a Gaussian-like distribution with a maximum atK=12 and with 16% of the total available energy (17,400 cm–1) appearing in rotation. Only 1% of the available energy is converted into vibration, leaving over 83% for translational excitation. The measured rotational distribution appears to fit a semiclassical theory. 相似文献
75.
76.
77.
V.L. Jacobs J. Davis J.E. Rogerson M. Blaha 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,19(6):591-598
The results of calculations of the ionization equilibrium and radiative energy loss rates for C, N and O ions in low-density plasmas are presented for electron temperatures in the range 104–107 °K (~1–103 eV). The ionization structure is determined using the steady-state corona model, in which electron impact ionization from the ground states is balanced by direct radiative and dielectronic recombination. Using an improved theory, detailed calculations are carried out for the dielectronic recombination rates in which account is taken of all radiative and autoionization processes involving a single-electron electricdipole transition of the recombining ion. The radiative energy loss processes considered are electron-impact excitation of resonance line emission, direct radiative recombination, dielectronic recombination, and electron-ion bremsstrahlung. For all three elements, resonance line emission resulting from 2s?2p transitions produces a broad maximum in the energy loss rate near 105°K(~ 10 eV). 相似文献
78.
Numerical and experimental techniques are used to model the flow and pressure distribution around the forebody of the HYFLEX
hypersonic flight vehicle. We compare numerical simulation results with modified Newtonian theory and flight data to determine
the accuracy of the computational fluid dynamics (CFD) technique used. The numerical simulations closely match the trends
in flight data, and show that real gas effects have a small but significant influence on the nose pressure distribution. We
also present pressure results from a scale-model tested in a shock tunnel, and compare them with simulation results. For the
shock tunnel experiment, the model was placed such that part of the upper surface was in a region of the test flow where nonuniformities
were significant, and it was shown that the numerical simulation could adequately capture these experimental flow features.
The binary scaling parameter (describing the similarity in species dissociation between flight and model) was used to design
the scale-model tests in the shock tunnel, and its effectiveness is discussed. We find that matching the flight Mach number
in the shock tunnel experiment is not critical for reproducing flight pressure data, so long as flight velocity is matched,
and binary scaling is maintained.
Received 11 June 1998 / Accepted 1 September 1998 相似文献
79.
80.
Results of the benchmark test are presented of comparing numerical schemes solving shock wave of Ms = 2.38 in nitrogen and argon interacting with a 43∘ semi-apex angle cone and corresponding experiments. The benchmark test
was announced in Shock Waves Vol. 12, No. 4, in which we tried to clarify the effects of viscosity and heat conductivity on
shock reflection in conical flows. This paper summarizes results of ten numerical and two experimental applications. State
of the art in studies regarding the shock/cone interaction is clarified.
PACS 01.50.Kw, 47.15.Pn
Communicated by K. Takayama 相似文献