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[en] Using a relatively simple semiclassical model, it is shown that transient, induced molecular negative ions (TIMNI), are produced through a potential barrier interaction between cold electron collisions and polarizable molecules in plasma. Such new negative ions lead to radio-frequency absorption in such discharges. The calculated radio-frequency absorption frequencies are consistent with earlier experimental measurements. (authors)
[en] The establishment of a mass mobility correlation for ions of the series H+ (H2O)sub(n) obtained by means of a device whereby a reaction chamber operating under atmospheric pressure is coupled with a mass spectrometer, has enabled to observe the transition between discrete mobilities of ions H+ (H2O)4 and H+ (H2O)5 and a mean mobility corresponding to the equilibrium
[fr]L'etablissement d'une correlation masse-mobilite pour les ions de la serie H+ (H2O)sub(n) realisee a l'aide d'un dispositif couplant une chambre de reaction fonctionnant a pression atmospherique et un spectrometre de masse, a permis de mettre en evidence la transition entre les mobilites discretes des ions H+ (H2O)4 et H+ (H2O)5 et une mobilite moyenne correspondant a l'equilibre
[en] Rate coefficients and product distributions for the reactions of CO+2 and CO2 x CO+2 with C2H4 were determined in a drift chamber filled with CO2 at 0.3 torr. The rate coefficients are k3 = 0.9 x 10-9 cm3 s-1 for CO+2 and k5 = 1.0 x 10-9 cm3 s-1 for CO2 x CO+2. The products from the first reactionare C2H+4 (17%), C2H+2 (56%) and C2H+3 (27%). The fragmentation pattern is in good agreement with the breakdown diagram of ethylene. The second reaction yields only C2H+4 as a product. It is concluded that the ion-electron recombination energy of CO2 x CO+2 is smaller than the appearance potential of C2H+2 from ethylene, 13.13 eV. From this result and the previous observation that CO2 x CO+2 reacts with N2O by charge transfer we derive the dissociation energy of CO2 x CO+2 as 75.3 +- 11.6 kJ mol-1 and its heat of formation as 468.6 +- 11.6 kJ mol-1. (orig.)
[en] Mass-analyzed threshold ionization (MATI) technique is optimized to generate substantial amount of state-selected molecular ions sufficient for dynamics study. The main strategy is to stabilize intermediate (n= 100-200) Rydberg states by l,m-mixing induced by AC field. Electrical jitter inherent in high voltage switching is utilized for this purpose. A related technique to locate the MATI onset is also described
[en] The solubility problems raised by some components of the polymeric residue of irradiated polyphenolic coolants, which make it necessary to operate with very small samples, have been solved by means of a differential cryoscopic technique using a thermoelectric thermometer (thermal) as sensitive element. The method is based on the direct measurement of the difference between the freezing points of the investigated solution and of a reference solution whose concentration may be changed at will. The change of Δ V (mV) versus c(molal) is linear, the equivalent point being determined either analytically or graphically depending on the required accuracy. The method has been tested by measurements on pure polyphenyls, using diphenyl ether as solvent. It has been also applied to the main prospective coolants for the DON reactor. Working with 102 molal solutions the accuracy is better than ± 2 per cent. (Author) 2 refs
[en] In this work, it was so particularly interested in exploring cultivable bacteria isolated from a digested sludge of an anaerobic digester. The characterization of the bacteria is determined by: The classic microbiology and molecular biology, with a study of radio-resistance profile of these bacteria.
[en] Dense cores are the final place where turbulence is dissipated. It has been proposed from theoretical arguments that the nonthermal velocity dispersion should be narrower both for molecular ions (compared to neutrals) and for transitions with higher critical densities. To test these hypotheses, we compare the velocity dispersion of (1–0) ( = 6 × 104 ) and ( = 2 × 103 ), in the dense core Barnard 5. We analyze well-resolved and high signal-to-noise observations of (1,1) and (2,2) obtained with combining Robert C. Byrd Green Bank Telescope (GBT) and Very Large Array (VLA) data, and (1–0) obtained with GBT Argus, which present a similar morphology. Surprisingly, the nonthermal velocity dispersion of the ion is systematically higher than that of the neutral by 20%. The derived sonic Mach number, , has peak values and for and , respectively. This observed difference may indicate that the magnetic field even deep within the dense core is still oscillating, as it is in the turbulent region outside the core. The ions should be more strongly dynamically coupled to this oscillating field than the neutrals, thus accounting for their broader line width. If corroborated by further observations, this finding would shed additional light on the transition to quiescence in dense cores.