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1.
Brief surveys are given of the Mayants-Averbukh Raman intensity theory, and of the polar tensor Raman intensity theory recently presented by Bogaard and Haines. It was found that these intensity theories in essence are equivalent. In addition, the appearances of the symmetry invariant parameter matrices Fn0 of the Mayants-Averbukh theory were derived and tabulated for various symmetries of bond n. These matrices, and a single bond coordinate system, can be used as a convenient alternative to the Mayants-Averbukh treatment of bonds which have some kind of symmetry with respect to the midpoint of the bond. A modification of the Mayants-Averbukh treatment is also suggested. The rotational mode equations of the Mayants-Averbukh theory have been investigated to elecudate the constraints which they impose on Raman intensity theories based on the bond polarizability model. It was found that the valenceoptical theory is in conformity with the rotational modes only if all electrooptical parameters ii(n)p are neglected, where αii(n) (i = 1, 2, 3) are the diagonal components of the polarizability α(n) of bond n, and γp is the pth internal angular coordinate. Furthermore, the valence-optical theory was found to be strictly applicable only for cylindrical bond symmetry, Cmv (m ≥ 4). A generalized valence-optical Raman intensity theory, allowing also for non-zero off-diagonal components αij(n), was found to be incompatible with the rotational mode equations of the Mayants-Averbukh theory. However, its basic polarizability equation was useful for suggesting a unique interpretation of a set of f parameters (elements of Fn0) in terms of components of the anisotropic part of a symmetric bond polarizability.  相似文献   

2.
From a comparison with the valence-optical theory of infrared intensity in the zeroth approximation, it is suggested that the d-parameters (elements of the effective charge tensor Dn0 of a bond) occurring in the Mayants-Averbukh theory can be expressed in terms of bond dipole moment components and their derivatives with respect to components of the Cartesian bond displacement vector. With this interpretation, which may be suitable for practical application, the Mayants-Averbukh theory formally appears as a combination of the “special” and the generalized valence-optical theory. In particular, it is found that for linear molecules the Mayants-Averbukh theory is equivalent to the “special” valence-optical theory in the zeroth approximation. For planar molecules the Mayants-Averbukh theory is equivalent to the generalized valence-optical theory (zeroth approximation) for in-plane modes and to the “special” valence-optical theory for out-of-plane modes.  相似文献   

3.
A quasiclassical formulation for mobility in extrinsic semiconductors is presented based on scattering from ionized impurity atoms. Quantum theory enters the otherwise classical Chapman-Enskog expansion of the Boltzmann equation through incorporation of the Thomas-Fermi interaction potential together with the Bom approximation for evaluation of scattering integrals. The following expression results for mobility μi, (cgs):
μi32?2nse3m122kBT321f(γ)
,
f(γ)=[(1+γ)eγE1(γ)?1]
, where ns is impurity concentration, m1 is effective mass, E1(γ) is the exponential integral, ? is dielectric constant and γ is dimensionless Thomas-Fermi energy. The structure of the dimensional factor in the preceding expression for μi agrees with previous expressions for this parameter.  相似文献   

4.
High dispersion rotational analysis of a red CuO band system has led to the identification of an A′ 2Σ+-X 2Πi transition. The anomalous appearance of the branches is due to a very large spin splitting of the 2Σ upper state. The influence of centrifugal distortion effects on this spin splitting (γD and γH parameters) is essential for explaining the band structure. A reassignment of electronic symmetries of all the 2Σ states of CuO is proposed.  相似文献   

5.
The ν1 bands of HO35Cl and HO37Cl have been recorded. Both the A- and B-type rotational transitions of these hybrid bands have been completely assigned, and spectroscopic constants have been obtained for both the ground and upper state. The ratio of the electric dipole moment derivatives (a?Q1)(b?Q1 has been found to be 0.985 ± 0.05 for ν1.  相似文献   

6.
The atomic beam magnetic resonance method combined with laser-induced state- and isotopeselective detection of metastable atoms has been used to investigate the hyperfine structure of the 2D ground multiplet in 175Lu and 176Lu. The analysis of the data yields not only accurate values for the hyperfine interaction constants, the nuclear magnetic dipole moment of 175Lu, and the electronic gJ, factors, but also the first directly measured value of the nuclear magnetic dipole moment of the low abundant isotope 176Lu: μI(176Lu) = 3.1692 (45)μN (corrected for diamagnetic shielding). The spectroscopic quadrupole moment of 176Lu was calculated from the ratio of the B-factors and the quadrupole moment of 175Lu: Qs(176Lu) = 4.92 (3) b. Moreover, the magnetic hyperfine anomalies for the isotopic chain 175,176,176m,177Lu were determined. A quadrupole hyperfine anomaly between 175Lu and 176Lu was not found when comparing the ratio of the B-factors in the states 2D32and2D52. From a comparison of the quadrupole moment of 175Lu obtained from the hyperfine structure data and the quadrupole moment measured in muonic lutetium atoms semi-empirical Sternheimer shielding factors could be estimated.  相似文献   

7.
The infrared intensity measurements and molecular beam electric resonance dipole moment measurements for HCl and DCl have been reviewed. A method not previously exploited is used to determine infrared matrix elements from the electric resonance dipole moment measurements. A ‘best’ set of matrix element values was selected for HCl and from these the Mi-coefficients of a polynomial dipole moment approximation were determined; M0 = 1.0935±0.0007 D, M1 = 0.947±0.023 D/A?, M2 = 0.015±0.041 D/A?2, M3 = -0.814± 0.116 D/A?3. Calculations using this dipole moment function for both HCl and DCl are shown to give good agreement with available band strength and vibration-rotation interaction factor measurements. RKR potentials are also calculated for both molecules.  相似文献   

8.
The discrepancies concerning the optical and microwave values of B0 and D0 for the X3Σg? state of O2 have been removed by a nonlinear least-squares fit to all of the lines of the O2, b 1Σg+-X 3Σg? Red Atmospheric bands recorded by Babcock and Herzberg (Astrophys. J., 108, 167, 1948). The resulting values for B0″ and D0″ are in excellent agreement with the Raman and microwave values. Improved values are determined for B1″, D1″, γ1″ (spin-rotation), and ?1″ (spin-spin). Both γv″ and ?v″ increase in magnitude from v″ = 0 to v″ = 1. Improved Dunham Yi0 and Yi1 expansion coefficients are determined for the b 1Σg+ state, from which the Rydberg-Klein-Rees potential is constructed.  相似文献   

9.
Several rotational bands in 163,165,167Yb are observed in (HI,xnγe?) experiments. The i132 and 32? [521] bands do not backbend, whereas the 52?[523] bands do, indicating additional processes besides the rotational alignment of one i132 neutron pair that are responsible for the backbending.  相似文献   

10.
The characteristics of allowed and forbidden transitions of Eu2+ ions in CaF2 single crystals have been investigated at room temperature. The Angular dependences of these transition intensities were theoretically calculated with the use of perturbation theory, and compared with the experimental values. The experimental results can be explained by taking into account crystal field effects (160) b4 [O04 + 5O44], and a hyper fine interaction AiS · Ii in the spin Hamiltonian.  相似文献   

11.
The irreducible components of the Raman scattering tensor operator α?γΓ(ΓksΓk′s′) under the symmetry of a general point group are calculated. The unitary transformations UγΓksΓks, ρσ) from the Cartesian α?ρσ and spherical α?QK components, respectively, to the irreducible components α?γΓ(ΓksΓk′s′) for the 32 crystallographic point groups are collected in tables. As an example the unitary transformation UγΓksΓks, ρσ) is used to discuss the behavior of the scattering tensor in a resonance Raman experiment. With the help of the general formalism the scattering tensor for electronic Raman transitions of transition metal ions is calculated. As an example the scattering tensors of electronic Raman transitions within the 5T2 state of the high-spin trigonal distorted octahedral Fe2+ are calculated and the refinement of the selection rules is discussed.  相似文献   

12.
The masses of composite leptons and quarks are discussed in a “dynamical subquark model of pregauge interactions”. In this model, the leptons and quarks are made of a spinor and scalar subquark with equal mass, M, and the gauge bosons and Higgs scalar of the SU(3)c×SU(2)L×U(1)Y model are made of a subquark-antisubquark pair. The SU(2)L×U(1)Y symmetry is spontaneously broken by the composite Higgs scalar and the (scalar) subquark mass parameter is in turn bounded as M > 5.4 TeV (=2π(2GF?1)12where GF is the Fermi coupling constant). The spontaneously generated mass of a lepton or quark, mi(n) (i = 1, 2; n = 1 ~ Ng), is calculated to be: mi(n) = ri(n) = ri(n) × (4+3Nge.m.(2GF?1)12/36 (=0.35ri(n) (4+3Ng)GeV), where ri(n) are the parameters satisfying that 0 ? ri(n) ? 1 and Σ (ri(n))2 = 1;Ng is the total number of generations of the leptons and quarks; αe.m. is the fine structure constant. The appearance of light composite fermions is related to a specific mechanism of generating global chiral symmetries of the leptons and quarks. Global symmetries of scalar subquarks yield chiral symmetries of the leptons and quarks. Our model turns out to satisfy 't Hooft's anomaly conditions on massless composite fermions.  相似文献   

13.
The rotational motion of the OH? ion was studied in cubic NaOH at 575 K with quasielastic incoherent neutron scattering. The data are compared to two simple models yielding values for the radius of rotation R, the translational mean square displacement 〈u2H, the rotational jump rate τ?1 and the rotational diffusion coefficient DR. The following parameter values are obtained: (a) rotational jump model: R = 0.95 A?, 〈u2H = 0.052 A?2, τ?1 = 2 meV, (b) rotational diffusion model: R = 0.99 A?, 〈u2H = 0.046 A?2, DR = 0.72 meV.  相似文献   

14.
The disagreement of Danyluk and King's (Chem. Phys.25, 343 (1977)) rotational constants for levels lying near the dissociation limit of B-state I2 with the mechanical behavior predicted by near-dissociation theory is investigated. The discrepancies are shown to be much too large to be explained by either the neglect of centrifugal distortion effects in the original analysis or by rotational or spin-rotation coupling to a nearby repulsive 1u state. These differences are therefore attributed to experimental error, a conclusion which is confirmed by more recent experimental results. A reanalysis of the best available data for levels near the dissociation limit of B-state I2 then yields improved values for the B-state dissociation limit D = 20 043.16 (±0.02) cm?1 of the vibrational index at dissociation vD = 87.32 (±0.04) and of the long-range potential constant C5 = 2.88 (±0.03) × 105cm?1A?5. This in turn implies a slightly improved ground-state dissociation energy of D0 = 12 440.18 (±0.02) cm?1.  相似文献   

15.
D.J. Gates 《Physica A》1975,81(1):47-71
The k-particle, infinite-volume distribution functions n?k (r1, …, rk?1, γ) and modified Ursell correlation functions U?k (r1, …, rk?1, γ) of a classical system of particles with the two-body potential q(r) + γνK(γr) are considered. The limiting values of the functions n?k (r1, …, rk?1, γ), n?k (S1/γ, …, Sk?1/γ, γ) and γ(1?kU?k (S1/γ, …, Sk?1/γ, γ) in the limit γ → 0 are calculated, under fairly weak conditions on q and K, by a method involving functional differentiation. These limiting functions are used to describe the molecular structure of the various states of the system both in the range of the potential q(r) and in the rage of the potential γνKr). The direct correlation function c? (r, γ) is also considered and it is shown that for S ≠ 0, limγ→0 γc? (Sγ, γ) = ?βK (S), for all one-phase states, where β is the reciprocal temperature. Special cases of our results confirm those of other authors, including the well-known results of Ornstein and Zernike.  相似文献   

16.
Based on the proper connected diagram expansion, we calculated cyclotron resonance widths Γn associated with neighboring Landau states (n, n +1) for free electrons in interaction with more than one kind of impurities. In 3D usual Matthiessen's rule Γn=Γ(1)n+Γ(2)n+…where Γ(i)n represent widths calculated separately for each kind, is obtained. In 2D a new rule: Γn=[Γ(1)2n(2)2n+…]12 is obtained.  相似文献   

17.
An extensive study of the microwave spectrum of cyanamide has been undertaken, the analysis being based in part on semirigidbender calculations by the methods of Bunker and Szalay. Inversion lines of NH2CN, K?1 = 2 aQ branches and a number of vibrational satellites of the J = 2?1 transition were observed. A two-vibrational-state Hamiltonian was used to fit simultaneously the 0+ and 0? microwave data and yielded rotational constants X, Y, Z, DJ, DJK, d1, HJK as well as the inversion splitting and the μyz-connecting matrix element. Vibrational satellite data of seven isotopic species and infrared frequencies of NH2CN were included in the semirigid bender calculations: The NCN spine is nonlinear by ca. 5° in the equilibrium structure of the molecule. Also, rNHA? = 0.9994 + 0.0144?2; <HNH/2 = 60.39° ? 0.1134?2; rNCA? = 1.3301 + 0.0327?2 (? is the inversion angle in rad); rCN = 1.1645 A? fixed. The inclusion of the NC bond flexing was necessary in order to reproduce the observed vibrational satellite patterns of NH2CN, NHDCN, and ND2CN. The barrier to inversion of the amino group is 510 ± 6 cm?1 with minima at ±45.0 ±0.2°. The inversion dipole moment is 0.91 ± 0.02 Debye.  相似文献   

18.
From its microwave spectrum, 1-aziridineethanol,
CH2CH2NCH2CH2OH
is found to have a gauche OCCN configuration, maintained by an OH?N-type hydrogen bond. The normal species rotational constants (MHz), A = 8528.87(25), B = 2069.74(2), and C = 2020.41(2), are consistent with a small (~6°) distortion from the “staggered” configuration about the central CN bond. Assuming a “normal” hydroxyl group, the hydroxy d1 data suggest a decrease in the O?N distance upon bridge deuteration of ~0.003 Å. The dipole moment is 2.77(5) D, with 2.34(3), 1.45(6), and 0.3(3) D “a,” “b,” and “c” components, respectively.  相似文献   

19.
Rotational energy levels in vibronic ground states of 2A, 2E, and 2F electronic states of open-shell XY4 molecules, as well as rotational line intensities for allowed transitions between such states, are discussed, including the effects of spin-orbit interaction and tetrahedral splittings. Jahn-Teller effects are assumed to be small, and are only taken into account implicitly, through their contributions to various parameters in the effective Hamiltonian. Qualitative information is obtained by considering several limiting-case coupling schemes among the electron spin angular momentum S, the electron orbital angular momentum L, and the pure rotational angular momentum R. These limiting cases are similar in spirit to Hund's coupling cases in diatomic molecules, but differ sufficiently from the latter to make detailed correspondences unhelpful. Quantitative information on rotational energy levels and line intensities is obtained numerically by diagonalizing a Hamiltonian matrix set up in a basis set characterized by uncoupled moleculefixed projections of S, L, and the total angular momentum J, and symmetrized so that all basis set functions belong to a definite species in the subgroup D2d of the true point group Td. Hamiltonian matrix elements are determined by ladder operator techniques. Three sample calculated spectra, corresponding to p(2F2)-s(2A1), d(2E)-p(2F2), and d(2F2)-p(2F2) are presented. As one might expect, when the spin-orbit constant A is set equal to zero, then both qualitative and quantitative aspects of the rotational-electronic problem in open-shell XY4 molecules can be mapped easily onto discussions of the rotation-vibration problem from the CH4 literature.  相似文献   

20.
We introduce the notion of uniform convergence of an operator sequence relative to a state operator, and we compare it with the notion of almost everywhere convergence, introduced by Gudder. We show that a sequence (Mn) of mean-value operators
Mn=1n∑ni=11?…?Ai?1?…,
defined on the infinite tensor product ?iHi, converges relative uniformly to x1 if and only if it converges almost everywhere to x1.  相似文献   

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