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1.
Concentration dependent diffusion coefficients for 45Ca2+ and 85Sr2+ in purified KCl were measured using a sectioning method. KCl was purified by an ion exchange — Cl2?HCl process and the crystals grown under atmosphere of HCl. The tracers were purified on small disposable ion exchange columns to remove precessor and daughter impurities prior to use in a diffusion anneal. Isothermal diffusion anneals were made in the temperature range from 451% to 669%C. At temperatures above 580%C (the lowest melting eutectic in this system) diffusion was from a vapor source: below 580%C surface depositied sources were used. The saturation diffusion coefficients. enthalpies and entropies of impurity-vacancy associations were calculated using the common ion model for simultaneous diffusion of divalent ions in alkali halides. In KCl the saturation diffusion coefficients DS(ca) and Ds(Sr) are given by (1) and (2) for calcium and strontium, respectively. The Gibbs free energy of association of the impurity vacancy complex in KCl for calcium can be represented by (3) and that for strontium by . (4) 相似文献
2.
The sound velocities in GeS2 glass have been measured by means of ultrasonic interferometry as a function of temperature or pressure up to 1.8 kbar. The bulk modulus Ks = 117.6 kbar and shear modulus G = 60.60 kbar were obtained for GeS2 glass at 15°C and 1 atm. The temperature derivatives of both sound velocities and elastic moduli are negative : p = °C, p = °C and p = , p = ?1.23 × 10?2 kbar/°C, p = ?2.93 × 10?2 their pressure derivatives are positive: T = 4.43× 10?2km/kbar, T = and (?Ks?P0)T=6.81, = 1.03, (?Y?TT= 3.57. The Grüneisen parameter, γth= 0.298, and the second Grüneisen parameter, δs = 3.27, have also been calculated from these data. The elastic behavior of GeS2 glass has proved to be normal despite the structural similarity among the tetrahedrally coordinated SiO2, GeO2 and GeS2 glasses. 相似文献
3.
Lary W. Pinkley K. Narahari Rao M. Dang-Nhu G. Tarrago G. Poussigue 《Journal of Molecular Spectroscopy》1976,63(3):402-444
The ν3 fundamental vibration-rotation band of carbon-13 enriched methane (13CH4) was recorded using a high-resolution vacuum infrared grating spectrograph. Forbidden transitions of this band are reported for the first time. Of the nearly 900 transitions identified, 560 are forbidden transitions and 347 of the forbidden transitions have 11 ≤ J ≤ 18. Pairs of forbidden and allowed transitions having the same upper-state energy levels were used to calculate 550 independent differences between ground-state term values. From these data, a least-squares analysis was used to calculate the following values for ground-state structure constants and their standard deviations (in cm?1): , , , . The 550 values for the ground-state combination differences retained for analysis can be reproduced with an overall standard deviation of 0.0155 using the stated values for the structure constants. The note added in proof refines the above constants by including the newly observed microwave data. 相似文献
4.
The lifetimes of the lowest levels in 103Rh, 107Ag and 109Ag have been measured with the Doppler-shift version of the recoil-distance technique. A beam of 35Cl ions of energy 64 MeV was used to Coulomb excite the target nuclei and eject them from the target. The following lifetimes were obtained: , , , , , . Of t correction factors taken into account the perturbation of the γ-ray angular distribution by the magnetic hyperfine interaction during recoil through vacuum was found to give the largest correction to the measured lifetimes. These lifetimes lead to reduced transition probabilities Bd(E2) for the silver nuclei in reasonable agreement with the predictions of the core-excitation theory. 相似文献
5.
The microwave spectrum of the molecular transient disulfur monoxide, S2O, has been reexamined and the microwave measurements have been extended into the millimeterwave region. From the present data, the following ground-state rotational constants and quartic distortion constants have been obtained (MHz): The centrifugal distortion constants obtained from the rotational spectrum are used to discuss the vibrational spectrum of disulfur monoxide. 相似文献
6.
The rotational spectrum of methylene cyanide has been measured up to J = 62 and a total of 82 b-type transitions have been obtained. These data have been analyzed with a semirigid rotor Hamiltonian to give accurate rotational and centrifugal distortion constants. The rotational constants are (in MHz) = 20882.7537 ≠ 0.017, = 2942.3003. ≠ 0.0031, = 2616.7225 ≠ 0.0031 The quartic centrifugal distortion constants are (in MHz) The uncertainties are twice the standard deviations in the constants obtained from the least squares analysis, and represent approximately 95% confidence limits. 相似文献
7.
A rotational analysis of the satellite bands of the β system of ZrO gives the splittings in the triplet states. For the lowest triplet state X′3Δ, these splittings are: 相似文献
8.
Jan T. łopuszański 《Reports on Mathematical Physics》1976,9(3):301-307
It is shown that for spinorial charges Q(L))α (α = 1, 2, L = 1, …, S) satisfying the commutation relations where Q is a scalar charge commuting with the spinor charges as well aswith the energy- momentum vector Pμ, there can exist several different multiplets for free massive scalar and spinor fields. 相似文献
9.
Optically detected magnetic resonance has been used to investigate exciton recombination in the layered semiconductor GaS. Five triplet exciton resonances have been observed all with the same g-value of gex6 = 2.006 ± 0.002 but with different zero field splittings: , . The resonances from the high energy wing are remarkably narrow and we believe that this may be the first observation of resonance from free indirect excitons. 相似文献
10.
A red-degraded band head, normally badly overlapped by the gamma system, , of zirconium oxide, appears in emission spectra of zirconium arcs and in absorption spectra of S-type stars and of frozen rare gas matrices containing zirconium. The emission band has been examined at high-resolution with the aid of separated zirconium isotopes. Identification of the band as 0-0 of a system of zirconium oxide is confirmed by rotational analysis where the following constants (cm?1) are obtained for 90Zr16O: The Λ-type doubling in the 1Π state and the question of whether or is the true ground state of ZrO are discussed. 相似文献
11.
J.C.D. Brand U.D. Deshpande A.R. Hoy S.M. Jaywant E.J. Woods 《Journal of Molecular Spectroscopy》1983,99(2):339-347
Molecular constants of the first E 0+ ion-pair state of IBr vapor have been determined using polarization-labeling spectroscopy applied to the sequential transitions E 0+ ← B′ 0+ ← X 0+, while the second f 0+ ion-pair state is reported and characterized for the first time. A least-squares, simultaneous analysis of data for the I79Br and I81Br isotopes gives the following constants (in cm?1) for I79Br: , , . , . Preliminary data for the first ion-pair state, accessed in the sequence , indicate that Te is ?30 cm?1 higher in energy than that of the E state. 相似文献
12.
The self-diffusion coefficient follows a relation of the form : D = (1,0?0.4+0.7)exp (?shape=case>34400RT±700) for b.c.c. europium D = (1,0?0.3+0.5) × 10?2 exp(? for β-b.c.c. gadolinium.Whereas europium has normal self-diffusion parameters, β-b.c.c. gadolinium must be set in the class of the anomalous b.c.c. rare-earth metals.From these results we conclude that there exists no evident connexion between the instability of the 4f shell and the activation energies anomalously low in the b.c.c. phases of the rare-earth metals. 相似文献
13.
14.
Jan T. Łopuszański 《Reports on Mathematical Physics》1978,13(1):37-55
It is shown that every spontaneous breaking of supersymmetry can be accomplished by means of a locally conserved supercurrent , where is a massless field satisfying the Weyl Equation. For a given supercurrent the necessary condition that it will break spontaneously the supersymmetry is It is shown that the anticommutation relations of the broken supercharges are not related to the energy-momentum vector.Similar procedure applied in case of a vector field is inconclusive.The extension of the Maisson and Reeh statement on the helicity of Goldstone fields is given. 相似文献
15.
The yrast spectroscopy of 209Rn has been investigated to an excitation energy of over 7 MeV and to a spin of . The existence of six isomers has been established: . Shell-model calcu are used to explain the observed structure. E3 and M2 transitions in 209Rn and neighbouring nuclei are discussed. 相似文献
16.
The ratio of the scale parameter Λ in massless QCD defined on a lattice to the one in the continuum theory is determined by performing one-loop renormalization of the coupling constant. Our calculation method on a lattice directly relates Λlattice to the continuum one in the minimal subtraction scheme. The effect of incorporation of massless quarks depends on a parameter λ which is introduced to avoid trouble with fermions on a lattice. For λ=1, which is Wilson's value, the ratio previously calculated by Hasenfratz in the pure gauge theory is changed as follows: Critical properties of the lattice QCD will also be discussed briefly. 相似文献
17.
Elastoresistances of TCNQ high conducting salts have been measured at room temperature by an original strain gauge technique. The effects, on the longitudinal and transverse resistivities ?, of an elementary uniaxial strain ? applied along one of the three axes, a, b or c1 respectively, have been estimated.For TTF-TCNQ, they are: ; ; (5% risk).So, in an hydrostatic pressure experiment, the fraction of piezoresistivity attributable to transverse effects is 43± 10% of the total value χb (Kba and Kbc effects accumulated).Low values have been found for the anisotropy (?a/?b) variations due to strains. So one may write: ; ; .The TTF-, HMTTF-, TSF-, HMTSF-TCNQ elastoresistance values are coherent with the previously measured hydrostatic pressure piezoresistivity values.All these experimental results are in good agreement with a model where the longitudinal but also the transverse elastoresistivities are essentially due to variations with strains of the longitudinal scattering time τν defined by σb = ne2τν/m1. 相似文献
18.
The third order elastic constants of RbCl, determined by measurements of the static stress dependence of ultrasonic waves, are found to be (in units of 1012) . The calculation of third order constants using a rigid ion Born model is briefly discussed, and results are compared to the measurements. The comparison qualitatively supports the model, but no quantitative evaluation of the repulsive interaction is possible. 相似文献
19.
G. Zech F. Dydak F.L. Navarria O.E. Overseth P. Steffen H. Wahl E.G.H. Williams C. Geweniger K. Kleinknecht H. Taureg 《Nuclear Physics B》1977,124(4):413-425
The mean lifetimes of the Λ and Ξ0 hyperons have been measured in a short neutral beam at the CERN Proton Synchrotron. Λ and Ξ0 decays have been identified by measuring their decay products in a magnetic spectrometer and in a lead glass hodoscope. The experimental results, based on 53 000 Λ decays and 6300 Ξ0 decays are From the result for τΞ0 together with existing data on τΞ? we obtain a violation of the rule in non-leptonic Ξ decays. 相似文献
20.
Single srystals of calcium tartrate doped with VO2+ are grown from silica gel. Its optical absorption spectrum is studied at laboratory and liquid air temperatures. The spectrum is analysed and ascribed to VO2+ ion in C4v symmetry. The following crystal field parameters are evaluated. 相似文献