[en] We show how to extract the energy- and coordinate dependence of dipole-moments for a neutral-to-ionic molecular transition from time-resolved photoelectron spectra. The procedure needs the potential surfaces of the neutral and the cationic state which are involved in the ionization process as an input. Given these potentials and the laser parameters it is possible to determine the functional form of the transition dipole moment from the measured time- and energy-resolved transient signals. (authors)

[en] Published in summary form only

No abstract available

[en] We present velocity map imaging measurements of photoelectrons in coincidence with ions produced via strong field molecular ionization. Our measurements, in conjunction with electronic structure and Stark shift calculations, allow us to assign several features in the low energy portion of the photoelectron spectrum to different molecular electronic continua (ionic states). Furthermore, we are able to distinguish between direct and indirect ionization pathways, uncovering the role of both neutral and ionic resonances in the ionization dynamics. (paper)

[en] A background correction method based on wavelet transform was devised and applied to inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed approach separated background from analyte signal according to their different frequencies. Compared with the analyte signal, the background has a low frequency. By removal of the components attributed to the signal, the background over the spectral window of the analyte line can be fitted through wavelet reconstruction. The results showed that the wavelet transform technique could handle all kinds of background and low signal-to-background ratio spectra, and required no prior knowledge about the sample composition, no selection of suitable background correction points, and no mathematical assumption of the background distribution. This technique performed as well as the conventional three-point background correction method for linear backgrounds, and provided better results than the latter for curved backgrounds. The proposed procedure was illustrated, by processing real spectra, to be an effective and practical tool for background correction in ICP-AES

No abstract available

[en] We report Akebono observations of anisotropic electron velocity distributions in the sunlit polar wind, in which the averaged energy (temperature) of the thermal energy electrons is higher in the upward magnetic field direction than in the downward and perpendicular directions. In the 1500-4000 km altitude region, the observed upward to downward temperature ratio, T_eu/T_ed, was in the range of 1.5 to 2. The observed downward and perpendicular temperatures were similar; T_ed/T(e perpendicular)≅1. The heat flux associated with the observed thermal energy electron velocity distribution was upward and on the order of ∼10^-2 erg cm^-2s^-1, and was a factor of 5 larger than that of the atmospheric photoelectrons above 10 eV. In this altitude region, the higher-energy (> a few eV) photoelectrons are essentially collisionless. In contrast, the ambient and lower-energy photoelectrons remain collisional because of their larger Coulomb collision cross sections. In the steady state, an ambipolar electric field is required to maintain quasi-neutrality along the field line. It is suggested that the ambipolar electric field and the Coulomb collisions modify the velocity distributions of the thermal energy electrons and the photoelectrons, resulting in the observed temperature anisotropy. The upward heat flux associated with the observed temperature anisotropy dominates any downward heat flux due to electron temperature gradients that may be present in the polar wind plasma and demonstrates the important role of the photoelectrons in the dynamics of the polar wind. 49 refs., 6 figs

[en] After recalling the general principles, experimental techniques are described: analyzers, detection methods, techniques of imaging and practical problems. In conclusion applications are reviewed including qualitative and quantitative analysis, concentration profiles and industrial applications

[en] The X ray photoelectron intensity issued from a thin film sample attached below an anode (in a sheet form) is calculated and the principles and expected performances of photoelectron microanalysis are deduced. In scanning electron microscopy, using the proposed operating conditions, it will be possible to obtain a final electronic image not only characteristic of a given element but also of its oxydation degree with a spatial resolution of about 1μ. A.E.S. and X.P.S. are compared and the schematic drawing of a versatile apparatus allowing electron induced A.E.S., X ray induced A.E.S. and X.P.S. is pointed out

[en] CdS 'Q-state' particles, with average diameters varying from 2 nm to 10 nm, grown in arachidic acid Langmuir-Blodgett (LB) films, deposited onto optically transparent glass electrodes (OTES), were exposed to H₂ Se(g) to form the corresponding Q-state Cd S_x Se_(1-x) particles. Those particles are considered to be made up of a core of CdS and coated with a monolayer of Cd Se. Q-state Cd S-x Se_(1-x) particle formation was verified by X-ray photoelectron spectroscopy (XPS) and by monitoring a red shift in the UV-visible absorbance spectra relative to that of Cds. XPS results on 5 nm diameter CdS particles that had been grown in an LB film and then extensively exposed to H₂ S (g) revealed a stable average composition of Cd S₀.₄ Se₀₆. A study of the photoelectrochemical behaviour of these systems was conducted through current the open-circuit voltage and a marked increase in the short-circuit current was observed when LB films with Q-state CdS particles were exposed to H₂ Se(g). (author)