Recoil intermediates

Since Ra and " Ra are both produced by recoil from the host mineral, it might be assumed that the production rates are equal. However, the relative recoil rates can be adjusted by considering that the parent nuclides near the mineral surface may not be in secular equilibrium due to ejection losses i.e., the activity of Th may be lower than that of Th due to recoil into groundwater of the intermediate nuclide Ra. Krisnaswami et al. (1982) calculated that the recoil rate of " Ra is 70% that of Ra if radionuclides are depleted along the decay chain in this way. 

This review illustrates the complementary nature of recoil-ion momentum spectroscopy, projectile scattering measurements, and conventional electron emission spectroscopy in ion-atom ionizing collisions. We have examined recent applications of both the CDW and CDW-EIS approximations from this perspective. We have shown that both models provide a flexible and quite accurate theory of ionization in ion-atom collisions at intermediate and high energies and also allows simple physical analysis of the ionization process from the perspective of these different experimental techniques. 

Howitzer (How). See Ref 44, p B27-L, under CANNON and Ref 40a, p 89. In Ref 45f, pp 2-1 2-3 it is defined as a complete weapon conforming to the general cannon definition including the attached or closely related units necesssry for operation as intended (recoil mechanism, mount, sighting system, accessories, etc, but not ammunition), and designed for performance characterized by velocity, range, and trajectory curvature intermediate between those of a gun and a mortar... 

When these heavy recoil nuclei are the result of a complete fusion of the projectile and target nuclei, they are usually called evaporation residues because they result from a deexcitation of the primary complete fusion product by particle evaporation (emission). In intermediate energy and relativistic nuclear collisions, the momentum transfer to the target nucleus is much less, and the energy of the recoiling nucleus is 5-100 keV/nucleon. Such recoils are usually called heavy residues ... 

Reactions of the recoil C1] with several olefins have been studied, including ethylene, propylene, cyclopentene, and cfs-butene-2, as well as with several paraffins. The type of products observed indicated the existence of several general modes of interaction, such as CH bond insertion, interactions with CC double bonds, formation of methylene-C11. The most important single product in all systems is acetylene, presumably formed by CH insertion and subsequent decomposition of the intermediate. Direct interaction with double bonds is shown by the fact that, for example, in the case of propylene, yields of stable carbon atom addition products were significantly higher than in the case of propane. The same was true for ethylene and ethane. 

Whereas several transient species have been observed for dioxygen activation by MMOH, no intermediates were found by rapid-mixing spectroscopic methods for the actual methane hydroxylation step. Mechanistic probes, i.e. certain non-natural substrates that are transformed into rearranged products only if the reaction proceeds via a specific intermediate such as a radical or a cation, give ambivalent results Some studies show that products according to a pathway via cationic intermediates are obtained in sMMO hydroxylations and at least one study suggests the presence of a radical intermediate [40]. Computational analyses of the reaction of MMOHq with methane suggest a so-called radical recoil/rebound mechanism in which MMOHq... 

In order to explain the behavior of recoil chlorine atoms in liquid hydrocarbon media. Miller and Dodson (56) proposed that every recoil atom forms an excited intermediate complex with the hydrocarbon diluent, and that this complex then decomposes by a number of different paths, leading to the various radioactive products. They also showed that the concept of elastic atom-atom collisions could be entirely relinquished... 

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