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1.
John W. Tromp Robert J. Le Roy Simon Gerstenkorn Paul Luc 《Journal of Molecular Spectroscopy》1983,100(1):82-94
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 = 20 043.16 (±0.02) cm?1 of the vibrational index at dissociation v = 87.32 (±0.04) and of the long-range potential constant . This in turn implies a slightly improved ground-state dissociation energy of 0 = 12 440.18 (±0.02) cm?1. 相似文献
2.
We predict for M?+?M?0 the values -3.4 ± 0.8 MeV using the ?-ω mixing and the quark model, respectively. The extracted parameters indicate the necessity of a relativistic treatment of the old mesons. The problem of extrapolating these parameters to the charmed mesons is discussed. Under conservative assumptions, we predict 1.7 ? MD0 ? 2.2 MeV and . 相似文献
3.
The electromigration of cadmium in lead up to a concentration of 510 at ppm Cd was measured at constant temperatures between 250 and 290°C by the steady state method and also by a somewhat novel transient technique; the latter required shorter running time and also gave additional information, namely the chemical diffusion coefficient, Dch. From the steady state runs the observed effective charge number was Z1ss = + 2.5 ± 0.3 for the lowest concentration. The positive value was apparently the result of the counterflowing of the lead in a vacancy-interstitial pair mechanism. The temperature dependence of Z1 is described by and both the wind force and the electrostatic Zel appear to be small. The Z1ss, appeared to increase slightly with concentration. The transient measurements were in general less precise, but were consistent with the steady state results within their experimental accuracy. The values of appeared to be unity within the same accuracy for a range of composition up to 510 at ppm Cd. To a standard dissociation model for impurity mobility we have added a rather extended atomic exciton mechanism to help explain the diffusion kinetics. 相似文献
4.
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
5.
Marek Danielewski Jaeosław Da̧bek Stanisł;aw Mrowec Grażyna Siemińska 《Solid State Ionics》1985,17(4):331-335
Using the re-equilibration kinetic method the chemical diffusion coefficient in nonstoichiometric chromium sesquisulfide, Cr2+yS3, has been determined as a function of temperature (1073–1373 K) and sulphur vapour pressure (10?104 Pa). It has been found that this coefficient is independent of sulphur pressure and can be described by the following empirical equation: . It has been shown that the mobility of the point defects inCr2+yS3 is independent of their concentration and that the self-diffusion coefficient of chromium in this sulfide has the following function of temperature and sulphur pressure: . (cm2s?1). 相似文献
6.
The electroreflectance of Si under uniaxial stress has been measured in the 3.0–4.0 eV region at 77 K. The results indicate that the dominant structure in this energy region is attributed to Λv3 → Λc1 (or Lv3′ → Lc1 transition. The deformation potentials of these bands are determined to be . 相似文献
7.
H. Albrecht U. Binder G. Harder A. Philipp W. Schmidt-Parzefall H. Schröder H.D. Schulz R. Wurth A. Drescher B. Gräwe U. Matthiesen H. Scheck J. Spengler D. Wegener K.R. Schubert J. Stiewe R. Waldi H. Gennow 《Physics letters. [Part B]》1985,158(6):525-530
Using the ARGUS detector at DORIS II, we have observed a signal of 36.7±8.0 events in the decay channel D0→Ks0φ. In the same data sample, we have observed the well established decay D0→Ks0π+π?, and find the ratio, , to be 0.186±0.052. The substantial value of (0.99±0.32±0.17)% then derived for the branching ratio for gives direct evidence that W exchange contributes D0 decay. 相似文献
8.
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 〈u2〉H, the rotational jump rate τ?1 and the rotational diffusion coefficient DR. The following parameter values are obtained: (a) rotational jump model: , , (b) rotational diffusion model: . 相似文献
9.
The Raman active fundamentals ν1(A1g), ν2(Eg), ν5(F2g), and the overtone 2ν6 of SF6 have been investigated with a higher resolution and the band origins were estimated to be: ν1 = 774.53 cm?1, ν2 = 643.35 cm?1, ν5 = 523.5 cm?1, and 2ν6 = 693.8 cm?1. Raman and infrared data have been combined for estimation of several anharmonicity constants. The ν6 fundamental frequency is calculated as 347.0 cm?1. From the analysis of the ν2 Raman band, the following rotational constants of both the ground and upper states have been calculated: ; . 相似文献
10.
The parameter η̄ of muon decay has been measured in the radiative decay of unpolarized positive muons. The result (68% confidence) or with ρ fixed at yields an improvement of the previous value by more than a factor of two. An analysis of all data on muon decay that are presently available slightly improves the constraints on the weak coupling constants to: gs?0.29gv, gp?0.27gv, gT?0.23gv and 0.92gv?gA?1.2gv 相似文献
11.
Using a recent theoretical method, the ratio of nuclear matrix elements was determined to be either 20.50+0.35?0.55 or 25.22+0.28?0.17 in the second-forbidden nonunique decay of 8 × 104 y 59Ni. These values of R were obtained from a value of L3/K = 0.008 ± 0.002 found by subtracting the theoretical ratio = 0.113 (based on QPEC = 1070 ± 8 keV) from the total ratio L/K = 0.121 ± 0.002, which was measured with a reactor-produced, doubly-mass-separated 59Ni source introduced as gaseous nickel-ocene, (C5H5)2, into a wall-less, anticoincidence, multiwire proportional counter. The 854–1008 eV L and the 8.33 keV K peaks were measured simultaneously. 相似文献
12.
D.L. Albritton W.J. Harrop A.L. Schmeltekopf R.N. Zare 《Journal of Molecular Spectroscopy》1973,46(1):103-118
The discrepancies concerning the optical and microwave values of B0 and D0 for the X state of O2 have been removed by a nonlinear least-squares fit to all of the lines of the O2, 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 state, from which the Rydberg-Klein-Rees potential is constructed. 相似文献
13.
J.V. Mantese W.I. Goldburg D.H. Darling H.G. Craighead U.J. Gibson R.A. Buhrman W.W. Webb 《Solid State Communications》1981,37(4):353-357
Granular composites consisting of 25% nickel as 8 nm diameter particles dispersed in an aluminium oxide matrix display excess conduction noise. Co-deposited films with resistance per square about 105 ohms and negative temperature coefficient show a noise power spectral density where α ? 1.10 ± 0.03 over the accessible spectral range of 0.1 Hz ? ? ? 5000 Hz. The amplitude 3 × 10?15 ? Sv(1) ? 5 × 10?12 V2Hz?1, appears to increase approximately quadratically as the applied voltage Vs up to Vs ? 2.5 V and as the first power of Vs for 2.5 ? Vs < 35 V. 相似文献
14.
A. Honders J.M. der Kinderen A.H. van Heeren J.H.W. de Wit G.H.J. Broers 《Solid State Ionics》1985,15(4):265-276
Two electrochemical methods - involving the application of a long-time galvanostatic current pulse and a small potentiostatic voltage step to a M/MxSSE cell - are presented. From the overvoltage, respectively current response the chemical diffusion coefficient () and the thermodynamic factor (? ln a/? ln c) are obtained. The methods have been applied to the cells: Li/1M·LiClO4 in propylenecarbonate/LixTi1.03S2 0.05 < x < 0.95, T = 20°C; and LixCoO2 0.10 < × < 1, T = 20°C. From the application of the current pulse/voltage decay method it followed: , with a slight tendency to increase with decreasing x; , decreasing with decreasing x. These values are among the highest found for solid state Li+-ion diffusion, and will be closely evaluated and compared with data reported by other workers. The x-dependence of the thermodynamic factor, determined from kinetic data, for LixTi1.03S2 (x = 0.05-0.95) and LixCoO2 (x = 0.60-1.00) is in accordance with a simple thermodynamic model. Unlike for LixTi1.03S2, the thermodynamic factor for LixCoO2, determined from the EMF-x relation, cannot be accounted for by this model. Furthermore, a fast, but crude method to determine the average chemical diffusion coefficient in LixTi1.03S2 and LixCoO2 is discussed. 相似文献
15.
G.M. Lawrence S.C. Seitel 《Journal of Quantitative Spectroscopy & Radiative Transfer》1973,13(8):713-716
Relative oscillator strengths in the Cameron system of CO(a3Π ← X1Σ) have been observed in absorption for six bands (υ′ = 0–5, υ″ = 0) with the result, normalized to the absolute (0, 0) band measurement of Hasson and Nicholls, , , , , , . The density of CO was modulated with a motor-driven vacuum valve and synchronous fluctuations (?1 per cent) in the transmitted intensity detected with a lock-in amplifier. Peak pressure in the 21 cm absorption cell was approximately 10 torr. A curve of growth analysis was used to correct saturation effects by less than 3 per cent. 相似文献
16.
Atom transport in high-purity tin single crystals due to the influence of large direct currents has been measured by the “vacancy flux” technique. Cylindrical specimens were selected with c-axis oriented with 9° perpendicular or parallel to the direction of current flow. Rates of both longitudinal and transverse dimensional changes were used to calculate the anode-directed atom drift velocity. The results gave and , where Z1 is the effective charge number and ?6 = 0.89 and ?⊥ = 0.54 are the estimated correlation factors in the parallel and perpendicular directions. These values for Z1 are appreciably smaller than the results reported earlier for polycrystalline tin by Kuz'memko. The activation energies for agree within experimental error with those of self-diffusion. 相似文献
17.
A. Valentin A. Henry Ph. Cardinet M.F. Le Moal Da-Wun Chen K. Narahari Rao 《Journal of Molecular Spectroscopy》1978,70(1):9-17
The wavenumbers of the vibration rotation band lines of 14N16O are reported for the , and subbands of the 1-0 transition in the infrared. The full set of spectroscopic constants for this band has been determined by direct approach using the analysis of Zare, Schmeltekopf, Harrop, and Albritton. In addition to the band origin ν0 and the B, D, H constants for the lower and upper vibrational levels, the following spin-orbit coupling constants have been derived: and (in cm?1). Apparent centrifugal corrections to these constants have been determined and the values obtained for them are and . Λ-Type doubling constants evaluated by using both grating and tunable laser data are also reported. 相似文献
18.
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, , , . 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
19.
A weak emission spectrum of I2 near 2770 Å is reanalyzed and found to to minate on the A(1u3Π) state. The assigned bands span v″ levels 5–19 and v′ levels 0–8. The new assignment is corroborated by isotope shifts, band profile simulations, and Franck-Condon calculations. The excited state is an ion-pair state, probably the 1g state which tends toward . In combination with other results for the A state, the analysis yields the following spectroscopic constants: T″e = 10 907 cm?1, ″e = 1640 cm?1, ω″e = 95 cm?1, ; T′e = 47 559.1 cm?1, ω′e = 106.60 cm?1, . 相似文献
20.
The vibration-rotation transitions for v = 1 ← 0 of NO () have been studied by using the technique of laser magnetic resonance spectroscopy. Five magnetic resonance lines are observed with three CO laser lines in the range from 1859 to 1886 cm?1. From these, three zero-field transition frequencies, v = 1 ← 0; , , and are obtained with an accuracy of ±0.0007 cm?1. The molecular constants which have been determined by borrowing centrifugal constants from a previous infrared work are , , and . 相似文献