共查询到20条相似文献,搜索用时 31 毫秒
1.
S. M. Frolov N. M. Kuznetsov C. Krueger 《Russian Journal of Physical Chemistry B, Focus on Physics》2009,3(8):1191-1252
The objective of the research outlined in this paper was to develop the analytical approximations for calculating real-gas
properties (p-v-T data, thermodynamic functions: internal energy, enthalpy, and entropy, and specific heats) of vapor-phase n-alkanes from C1 (methane) to C14 (normal tetradecane), O2, N2, H2O, CO, CO2, and H2 within the range of pressure 0.05 MPa ≤ p ≤ 20 MPa and temperature 280 K ≤ T ≤ 3000 K aimed for implementation into computational fluid dynamics (CFD)-codes simulating the operation process in modern
Diesel engines. The analytical approximations have been developed based on available literature data and on the new equation
of state for moderately dense gases. The approximations reported are rather simple and therefore can be used directly in CFD
codes. Approximations for mixing rules are also provided. 相似文献
2.
3.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 3, pp. 455–465, March, 1990. 相似文献
4.
This paper reports on a self-consistent, full-potential LMTO calculation of the band structure of the medium-T c superconductor MgB2 and of the isostructural hexagonal phases of CaGa2, ZrBe2, HfBe2, AgB2, and AuB2. The factors responsible for the superconducting properties of magnesium diboride are considered. The results obtained are compared with previous calculations and available experimental data. 相似文献
5.
Thomas A. Carlson G.E. McGuire 《Journal of Electron Spectroscopy and Related Phenomena》1973,1(3):209-217
The photoelectron spectra of the triatomic molecules CO2, COS, CS2, N2O, H2O, and H2S have been measured as a function of the angle θ between the direction of the incoming photon and outgoing photoelectron. The photoelectron spectra have been measured with a double-focusing electrostatic electron spectrometer to which has been attached a chamber containing a gas discharge lamp that can be freely rotated. (The photon source used was the 21.22 eV He I resonance line). From the dependence of intensity as a function of θ the angular parameter β was determined for each ionization band observed in the photoelectron spectra. A correlation was noted between the values of β and the molecular orbitals relative to the contributions of oxygen and sulfur atomic orbitals. Individual β values were also obtained for most of the vibrational bands seen in the photoelectron spectra. In most cases the vibrational structure showed little or no change in the angular parameter for a given electronic state. In certain cases, however, such as the fourth ionization band in CS2, CO2, and COS, rather sizeable changes in β were observed for the different vibrational bands. 相似文献
6.
S. Carusotto E. Iacopini E. Polacco F. Scuri G. Stefanini E. Zavattini 《Il Nuovo Cimento D》1985,5(4):328-338
Summary The Kerr electro-optic constant of helium, argon and of molecular oxygen, nitrogen, hydrogen and deuterium have been measured
at room temperature and low pressure, by using a low-frequency-modulated electric field.
In this paper the density is given in amagat,i.e. in moles per molar volume. 相似文献
7.
We have applied the pseudopotential theory to the calculation of exciton states and binding energies for the ionic crystals CaF2, SrF2, and BaF2, using a transfer model. Because of the satisfying agreement between our results and the experimental data in each case, we assume this pseudopotential formalism will describe transfer exciton states and energies in other ionic crystals. 相似文献
8.
Total ionization cross-sections for C2, C3, Si2, Si3, SiC, SiC2 and Si2C molecules have been calculated by electron impact. Spherical complex optical potential formalism has been employed for obtaining the inelastic cross-sections for these molecules. Then by applying complex scattering potential-ionization contribution method, total ionization cross-sections are derived. These cross-sections are calculated in the energy range from ionization threshold to 2?keV. There are no measurements available in the literature to the best of our knowledge with which our results can be compared. The results show a linear relationship between maximum ionization cross-section and square root of the ratio of polarizability to ionization potential, depending on its atomicity. This gives a confirmation for the consistency of the data reported here. Present work is a maiden attempt to find electron impact ionization cross-section for these molecules, except for C2 and C3. 相似文献
9.
10.
Calculated structural properties of CrSi2, MoSi2, and WSi2 总被引:1,自引:0,他引:1
Mattheiss LF 《Physical review. B, Condensed matter》1992,45(7):3252-3259
11.
Raul A. Abreu 《Physics letters. A》1984,100(7):375-378
The results of electron energy loss measurements on polycrystalline films of PbF2, PbC12, PbBr2 and PbI2 are present and the calculated dielectric functions are discussed in relation to their band structures and optical data. 相似文献
12.
The band structure and Fermi surface parameters of ZrB2, VB2, NbB2, and TaB2 hexagonal diborides are considered in the framework of the self-consistent full-potential LMTO method in comparison with the relevant parameters of a MgB2 isostructural superconductor. The factors responsible for the superconducting properties of AlB2-like diborides are analyzed, and the results obtained are compared with previous calculations and available experimental data. 相似文献
13.
14.
The pseudopotential method is used to calculate the energy band structures of four
-type semiconductors including the effect of the displacement of anions from face-centered sites in the sublattices. It was established that CuAlSe2, CuInS2, and CuInSe2 are direct gap semiconductors and that CuAlS2 has a pseudodirect energy gap. Experimental data derived from studies of the optical properties of these crystals in the U V region are also discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 7–12, June, 1976. 相似文献
15.
《Journal of Molecular Spectroscopy》1987,121(2):401-419
Spontaneous Raman spectroscopy is used to determine line positions of the six isotopomers of molecular hydrogen: H2, HD, HT, D2, DT, and T2. State populations as low as 1.3 × 108 are detected with the present experimental apparatus. This sensitivity makes possible measurement of the first overtone Q-branch line positions for H2 and D2 and of higher rotational transitions than previous investigations. The line positions for D2, DT, and T2 indicate that literature values for molecular parameters do not predict accurately line positions of transitions at J values above the observed transitions from which they were determined. The results for the six molecular isotopomers show that ab initio energy levels restricted to the adiabatic approximation do not yield line positions within the experimental uncertainty whereas recent nonadiabatic calculations reproduce the present observations. Reexamination of literature results at high energies indicates discrepancies between the theoretical calculations and experimental vibrational band origins for all vibrational levels in HT, DT, and T2. No experimental measurements are currently available that test the accuracy of nonadiabatic ab initio rotational levels at high energies. 相似文献
16.
Klaus Baberschke 《Zeitschrift für Physik A Hadrons and Nuclei》1972,252(1):65-73
ENDOR measurements of the hyperfine and transferred hyperfine interaction of Eu2+ in CdF2, SrF2, and BaF2 were performed. Compared with measurements on CaF2, there is a radial shifting of the next fluorine ligands in CdF2∶ +5.4%, CaF2∶ + 3.5%, and BaF2∶ ?3.9%. Since the SrF2 and EuF2 lattice constants are approximately equal, a shifting in SrF2 was not assumed. In both europium isotopes (151 and 153) a change of hyperfine fields at the nucleus was observed. This can be explained qualitatively by the difference in radial distribution of the different europium orbitals. Also noticed was a small change of the hyperfine anomaly, which indicates contributions of the zero-point vibration. 相似文献
17.
L.C. Lee R.W. Carlson D.L. Judge M. Ogawa 《Journal of Quantitative Spectroscopy & Radiative Transfer》1973,13(10):1023-1031
The absorption cross sections of N2, O2, CO, NO, CO2, N2O, CH4, C2H4, C2H6, C4H10 have been measured photoelectrically in the 180–700 Å region using synchrotron radiation. The absorption cross sections in the region λ ≥ 500 Å was found to be structureless and to increase monotonically with wavelength for all gases. The positions of the structure observed in the 520–720 Å region for N2, O2, CO2 and N2O are consistent with the various Rydberg series reported by previous authors. 相似文献
18.
Neutron diffraction study of polycrystalline HoRu2Si2, HoRh2Si2, TbRh2Si2, and TbIr2Si2 was performed in the temperature range between 4.2 and 300 K. For HoRu2Si2 the magnetic spin alignment of a linear transverse wave mode below the Néel temperature 19 K is observed. This static moment wave is propagating along the b-axis with k=(0, 0.2, 0) and is polarized in the c-axis. The root-mean-square and maximum saturation moments per Ho atom are 9.26 and 13.09μB, respectively. HoRh2Si2, TbRh2Si2 an TbIr2Si2 are simple collinear antiferromagnets of +-+- type with Néel temperatures of (27±1), (98±2) and (72±3) K, respectively. For TbRh2Si2 and TbIr2Si2 magnetic moments are localized on RE ions only and are aligned along the tetragonal axis, while for HoRh2Si2 they form an angle ø = (28±3)°. 相似文献
19.
In BaF2 crystals, the linewidth of certain core band-conduction band excitons shows strong temperature dependence, while the corresponding linewidths in CaF2 and SrF2 do not. Calculations of the broadening due to the temperature-independent Auger effect are in good agreement with experimental data. 相似文献