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981.
982.
K. A. Ashtiani J. L. Shohet F. S. B. Anderson D. T. Anderson J. B. Friedmann 《Plasma Chemistry and Plasma Processing》1992,12(2):161-175
The axial distribution of the electrostatic potentials ofan electron-cyclotron resonance (ECR) processing plasma confined in a do magnetic mirror geometry was characterized. The potential profiles far argon and helium at 8.0x 10–4 and 4.0 × 10–4 Torr were measured using electron emissive probes. The experimental measurements were then compared with the predictions of a one-dimensional, electrostatic, particle-in-cell computer code which runs on a personal computer. The potential profiles as predicted by the code showed good agreement with the experimental measurements. 相似文献
983.
The HREELS (high-resolution electron energy-loss spectroscopy) spectra from H2O and D2O chemisorbed on the clean Si(100)(2 × 1) surface have been investigated in the energy region between about 500 and 1400 meV. For the first time, second overtones have been observed for a chemisorbed species. This observation is believed to be due to the enhancement of the O-H stretching fundamental and overtone modes because of the temporary formation of a negative ion that occurs when the incident electron is briefly trapped in a shape resonance. Additional multiple and combination modes are observed involving the resonance enhanced overtones as well as the fundamental modes. Furthermore, the dissociation energy of the hydroxyl group has been determined and found to be much larger than the actual energy needed to dissociate hydroxyl groups on the surface, indicating that the driving force for the observed atomic rearrangements is probably Si-O bond formation rather than O-H dissociation. 相似文献
984.
985.
Oliver D. Anderson 《The Journal of the Operational Research Society》1986,37(4):423-427
We look at a statistical aspect of a recent case study. Although our discussion does not invalidate the general conclusions obtained there, it does suggest that the time series modelling may have been sub-optimal, and indicates how an alternative model specification could more probably have generated the sample statistics that were actually observed. The implication of our remarks is that discrimination between deterministic and stochastic non-stationarity, even if overlooked on preliminary inspection of the original data, will also be apparent from the raw sample autocorrelation plots. 相似文献
986.
H.E. Gillis Singbeil W.D. Anderson R.Wellington Davis M.C.L. Gerry E.A. Cohen H.M. Pickett F.J. Lovas R.D. Suenram 《Journal of Molecular Spectroscopy》1984,103(2):466-485
To permit atmospheric monitoring of the molecule, the microwave spectra of two isotopic species of hypochlorous acid, HOCl, have been measured in the frequency range 8–650 GHz. Three b-type branches and an a-type Q branch have all been measured for the first time; improved measurements have been made for the a-type R branches. The analysis has included combination differences of earlier high-resolution infrared spectra to give accurate values for all rotational constants, five quartic and five higher degree centrifugal distortion constants, as well as the chlorine nuclear quadrupole and spin-rotation coupling constants. From the Stark effect, accurate values have also been obtained for both components of the molecular dipole moment. A table of transition frequencies of potential use in atmospheric monitoring is presented. 相似文献
987.
J. Alnis B. Anderson M. Sjöholm G. Somesfalean S. Svanberg 《Applied physics. B, Lasers and optics》2003,77(6-7):691-695
The recently introduced Gas in Scattering Media Absorption Spectroscopy (GASMAS) technique is applied to the study of various wood samples. Molecular oxygen in the pores of the strongly scattering material is detected using diode laser spectroscopy around 760 nm. Diffuse light propagation in these media is studied by time-dispersion measurements. Furthermore, anisotropy related to the fibre structure of wood and gas diffusion properties are studied. Promising extensions of the experiments are discussed. PACS 42.55.Px; 42.62.Fi; 81.05.Rm; 81.70.Fy; 87.64.Cc 相似文献
988.
The innovations algorithm can be used to obtain parameter estimates for periodically stationary time series models. In this paper we compute the asymptotic distribution for these estimates in the case where the underlying noise sequence has infinite fourth moment but finite second moment. In this case, the sample covariances on which the innovations algorithm are based are known to be asymptotically stable. The asymptotic results developed here are useful to determine which model parameters are significant. In the process, we also compute the asymptotic distributions of least squares estimates of parameters in an autoregressive model. 相似文献
989.
Interval oscillation criteria are established for a second-order nonlinear dynamic equation on time scales by utilizing a generalized Riccati technique and an integral averaging technique. The theory can be applied to second-order dynamic equations regardless of the choice of delta or nabla derivatives. 相似文献
990.