共查询到20条相似文献,搜索用时 31 毫秒
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A. Ermolieff 《Solid State Communications》1975,17(8):1013-1016
The elastic constants c11, c33, c44 for ordinary ice and c11 for D2O ice between 12 and 250°K are deduced from light scattering Brillouin measurements for sound waves of wavevector q = 2.35 × 105cm?1. A range of temperature is found between 70 and 130°K where the elastic constants display an abnormal behaviour. 相似文献
3.
The total reaction cross section for 16O + 16O has been measured at six energies between Ec.m. = 6.8 and 11.9 MeV. Cross sections for the production of protons, alphas, neutrons, deuterons, 31S, 30P, 12C(g.s.) + 20Ne(g.s.) and the relative γ-yield were obtained with a variety of experimental methods. No 3H or 3He were found. All cross sections are normalized to 16O + 16O elastic scattering at θc.m. = 90°, which was measured separately with high precision between Ec.m. = 7.3 and 14.4 MeV. The elastic scattering and relative γ-yield of 12C + 12C were measured between Ec.m. = 3.9 and 7.5 MeV. The elastic scattering and neutron yield of 12C + 16O were measured between Ec.m. = 5.4 and 10.1 MeV. 相似文献
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5.
S. Haussühl 《Solid State Communications》1973,13(2):147-151
The temperature dependence of all elastic constants of cubic potassium cyanide has been measured by ultrasonic methods in the range from -105.4 to 181°C. Until about 180°C all elastic wave velocities increase with higher temperatures. The behaviour of the shear constant c44 is given by c44 = a · logT/T0 with a = 0.219 · 1011dyn.cm?2 and T0 = 153.7°K with a good approximation. These unusual effects are assigned to the librational vibrations and orientational jumping processes of the CN-ions. The phase transition at -105.5°C is a consequence of the low c44 value. 相似文献
6.
O. V. Miklukho G. M. Amalsky V. A. Andreev S. L. Belostotsky D. O. Veretennikov Yu. V. Elkin A. A. Zhdanov A. A. Izotov A. Yu. Kiselev A. I. Kovalev L. M. Kochenda M. P. Levchenko T. Noro A. N. Prokofiev D. A. Prokofiev H. Sakaguchi V. Yu. Trautman V. A. Trofimov S. I. Trush O. Ya. Fedorov K. Hatanaka A. V. Shvedchikov 《Physics of Atomic Nuclei》2006,69(3):452-459
The polarization of secondary protons from the (p, 2p) reaction induced by 1-GeV protons incident to a 4He nucleus was measured in a kinematically complete experiment. By using a two-arm magnetic spectrometer, two secondary protons from this reaction were recorded in coincidence at unequal scattering angles of Θ1 = 18°?24.21° and Θ2 = 53.22° over a broad range of the recoil-nucleus momentum K B between 0 and 150 MeV/c. It was found that the measured polarization of either secondary proton is less than that observed in free elastic proton-proton scattering. The magnitude of this difference is determined by the mean binding energy of s-shell protons rather than by the effective nuclear density. The polarizations measured in inclusive quasielastic and elastic scattering of 1-GeV protons on 4He nuclei are presented for scattering angles in the range Θ1 = 18° ? 24.21°. 相似文献
7.
Differential cross-section and analysing-power excitation functions were measured for elastic proton scattering from Ep = 3.6–6.4 MeV at θc.m. = 90°, 115.8°, 129.8° and 155.3°. Differential cross-section angular distributions were measured at 3.56, 3.94, 5.78 and 8.98 MeV and analysing-power angular distributions at 5.78 and 8.98 MeV. Optical-model parameters were deduced from these distributions. Resonance parameters were determined for eight analogue resonances in 71Ga and neutron spectroscopic factors were calculated. These were compared with the results of previous (p, p) cross-section analyses and the results of (d, p) reactions leading to states in 71Zn. 相似文献
8.
A small peak of specific heat has been observed in CaPd(CN)4·5H2O at - 70°C by differential thermal analysis indicating the possibility of a phase transition at this temperature. This hypothesis seems to be confirmed by a Brillouin scattering investigation which shows that the six elastic stiffnesses cii, i = 1, …, 6 are affected near the same temperature. The results are compared to those which are available in other compounds containing the planar groups M(CN)42?. 相似文献
9.
A new TOF facility has been built for measurements of differential (γ, n) cross sections to discrete final states of light nuclei in the photon energy range between giant resonance and pion threshold. The observed neutron angle θn can continuously be varied between 0° and 150°, and additionally measurements at 175° and 180° are possible. Differential cross sections for the reaction 16O(γ, n0)15O are presented for Eγ = 60 MeV (40° ? θn ? 149°) and for θn = 90° (60 MeV ? Eγ ? 160 MeV). The results, combined with the corresponding (γ, p0) cross sections, indicate an absorption mechanism of high energy photons by neutron-proton pairs. 相似文献
10.
The reaction channels of the system 16O + 16O with outgoing heavy particles from lithium to magnesium have been measured using a ΔE-E telescope. Excitation functions from 49 to 65 MeV at θLab = 30° and angular distributions from θLab = 10° (20°) to 50° at ELab = 51.5 MeV are presented for the strong transitions. The excitation function of the 12C-20Ne (4.25 MeV) channel shows a pronounced regular cross structure with peaks at 52 and 60 MeV. A selective excitation of certain states in the inelastic scattering and the 12C-20Ne channel is observed; the yields of the other heavy-ion channels being weaker by at least one order of magnitude. An explanation of this phenomenon is given by considering the angular momentum matching between entrance and exit channels. Furthermore it is shown that no strong dependence of the cross sections on the transferred angular momentum or on the nuclear structure of the final states is observed. Possible implications of these results on the reaction mechanism are discussed. 相似文献
11.
The microwave spectrum of the reactive species sulfine (CH2SO) has been studied. Assignments of 86 transitions of the ground vibrational state normal isotopic species, with J up to 60, have allowed a thorough centrifugal distortion analysis. With planarity implied by the Ic-Ia-Ib value of 0.1333 amu , spectral assignments of seven other isotopic modifications have resulted in the following substitution bond lengths and angles: CHsyn = 1.085 Å, CHanti = 1.077 Å, CS = 1.610 Å, SO = 1.469 Å, ?HCH = 121.86°, ?SCHsyn = 122.51°, ?SCHanti = 115.63°, and ?CSO = 122.51°. From Stark effect measurements of the normal and d2 species, the dipole moment has been determined to be 2.994 D, oriented 25.50° relative to the SO bond and 9.61° relative to the normal species “a” axis. At an initial pressure of 30 mTorr in a clean brass waveguide, the lifetime of sulfine at 25°C is ~30 min. 相似文献
12.
Gerald M. Lerner 《Nuclear Physics A》1973,205(2):385-397
An analysis of 65 MeV elastic proton scattering by 16,17,18O has been made in terms of a reformulated optical model. Matter distributions for 17O and 18O have been obtained relative to 16O. The results for the rms matter radii are R17?R16 = 0.04±0.03 fm and R18?R16 = 0.35± 0.07 fm. 相似文献
13.
Prasad Varanasi Sunil Sarangi 《Journal of Quantitative Spectroscopy & Radiative Transfer》1975,15(6):473-482
Intensities and nitrogen-broadened half-widths of lines R(0), R(8) and R(16) in the fundamental band of 12C16O have been measured at 83°K, 100°K, 150°K, 200°K and 298°K. The intensities of several other lines in the P- and R-branches of the band have also been measured at 298°K. The absolute intensity derived from the line intensity data using the Herman-Wallis formula is S°v = 273 ± 10 cm-2atm-1 at S.T.P. A separate measurement employing the Wilson-Wells-Penner-Weber method has yielded S°v = 277 ± 4 cm-2 atm-1 at S.T.P. Both of these values are within 6 per cent of most of the previously published direct measurements of this parameter. The values for the line intensities reported earlier by other authors are lower by nearly 16 per cent. 相似文献
14.
Gert Ziebarth 《Zeitschrift für Physik A Hadrons and Nuclei》1968,212(4):330-346
Using Mößbauer effect measurements in the temperature range between 3 °K and 310 °K the magnetic fields at the nucleus in iron-stilbene, FeCl2·H2O and FeCl3 are determined to beH T=0=(250±10) kOe, (252±18) kOe and (468±10) kOe; a Néel-temperature ofT N=(23±1) °K is measured for iron-stilbene. The electric quadrupole splittings atT=0 °K for iron-stilbene and FeCl2 ·H 2 O, ΔE=(+2.52±0.02) mm/sec and (+2.50±0.05) mm/sec, yield electric field gradients at the iron nucleus ofq z=+9.7·1017 V/cm2 and +9.6·1017 V/cm2, whereq z⊥H; Debyetemperatures of θ=162 °K and 188 °K are obtained. The energy of the excited 3d-electron levels in iron-stilbene is estimated to Δ1=309 cm?1 and Δ2=618cm?1 as deduced from the temperature dependence ofΔE. In contrast to the suggestion ofEuler andWillstaedt bivalence of the iron in ironstilbene is found; its composition is shown to be 4(FeCl2 ·H 2O)·stilbene. 相似文献
15.
The elastic differential scattering cross section from 55Mn has been measured at θ = 140° with Eγ = 5.5–11.4 MeV photons. Evidence for destructive interference between nuclear resonance (NR) scattering and nuclear Thomson (NT) scattering has been obtained. 相似文献
16.
The static quadrupole moment Q2+ and the B(E2; 0+ → 2+) value of the first excited state of 18O at ex = 1.982 MeV have been determined using the reorientation effect in Coulomb excitation. Surface-barrier detectors at laboratory angles of 90° and 174° were used to detect 18O ions elastically and inelastically scattered from 208Pb. At both angles, we determined experimentally the maximum bombarding energies at which nuclear interference effects were negligible. It is found that Q+ = ?0.023 ± 0.021 e · b (?0.052 ± 0.021 e · b) for destructive (constructive) interference from higher states. This result is in good agreement with theoretical expectation. For the transition moment we find B(E2; 0+ → 2+) = 0.00390 ± 0.00018 e2 · b2 (0.00371 ± 0.00018 e2 · b2) for destructive (constructive) interference. 相似文献
17.
N. Marquardt D. Sprengel H. v. Buttlar W. Hoppe 《Zeitschrift für Physik A Hadrons and Nuclei》1978,285(1):89-92
Excitation functions of the10B+10B elastic scattering at 80° (c.m.) and of the10B(10B,α)16O reaction at 5° (cm.) and 175° (c.m.) have been measured simultaneously for c.m. energies between 3 and 10 MeV. Whereas the elastic scattering is varying smoothly with energy, large resonant structures of intermediate width of about 600 keV have been found for the first time near 40 MeV excitation of20Ne in most reaction channels to16O. 相似文献
18.
D. Konnerth W. Trombik K.G. Bernhardt K.A. Eberhard R. Singh A. Strzalkowski W. Trautmann 《Nuclear Physics A》1985,436(3):538-560
We have studied elastic scattering, inelastic scattering and several transfer channels of the systems 14C + 14C and 14C + 12C over a wide range of energies up to Ec.m. = 35 eMeV and 32 MeV, respectively. The reaction channels were identified by means of kinematic coincidences between solid-state detectors, γγ coincidences were measured to determine cross sections for mutual inelastic scattering of 14C + 14C.Pronounced regular gross structures, similar to those found for 16O + 16O, are observed in the elastic excitation function of 14C + 14C at θc.m. = 90°, The angular distributions measured at the energies of the maxima and an optical-model analysis suggest that one or a few surface partial waves dominate the scattering behaviour. Correlated structure of narrower width is found in the inelastic channels and, to a lesser degree, in the transfer channels which appear with rather small cross sections.In 14C + 12C elastic scattering the gross structures are strongly fragmented, in contrast to 14C + 14C but similar to 12C + 12C. While the 12C(2+) excitation is very weak, the observed strengths of the 14C(3?) excitation and of neutron transfer point to a substantial role of these channels as coupling partners to the elastic configuration and to their influence on the elastic scattering behaviour. A correlated intermediate structure is observed near 23.5 MeV, where a dominance of l = 18 is suggested by the elastic scattering angular distribution. This unexpectedly high l-value exceeds lgraz at this energy by at least two units of ?. 相似文献
19.
《Nuclear Physics A》1988,483(2):406-428
The 13C+13C total fusion cross section has been determined in the range 3.26⩽Ec.m.⩽8.0 MeV using Ge(Li) detector measurements of low-lying transitions in the residual nuclei and a statistical model calculation of excited state populations. The six most abundantly produced residual nuclei have been observed and their yields are given. To constrain the parameters in fusion models for these reactions, we have also taken elastic scattering data at θc.m.=60°, 70°, 80°, and 90° for 4.5⩽Ec.m.⩽8.5 MeV, as well as angular distributions at Ec.m.=7.0 and 8.0 MeV. The IWBC model and an optical model with a “shallow” potential have been used for parametrizing the nucleus-nucleus interaction. 相似文献
20.
The elastic and inelastic scattering of 12C, 12C, 24Mg, 24Mg, 28Si, 28Si was studied at bombarding energies Ec.m. = 5–18.8, 20–33, 29–36 MeV, respectively. The experimental arrangement includes two position sensitive detectors covering the angular ranges from O124 = 20°–70°. The results are compared to calculations within the framework of the diffraction and optical model. A phase shift analysis is performed for the elastic scattering data of the 12C+12C system. It is shown that a shallow nuclei potential in needed to reproduce the 28Si+28Si results and that the 12C, 12C scattering shows evidence of resonance formation in the elastic channel. 相似文献