Fragmentation of methyl chloride studied by partial positive and negative ion-yield spectroscopy.

POSITIVE AND NEGATIVE ION MASS SPECTRA OF RING - SUBSTITUTED NITROBENZENES

The 70 ev positive and negative ion mass spectra of ring-substituted nitrobenzenes were studied. The influence of the substituent group on the fragmentation modes of the molecular ions is discussed. The effect of pressure in the formation of negative ions was also studied. As expected, the ratio of fragment ions to negative molecular ions decreased with increasing pressure in ion source.

Photofragmentation of SiF4 upon Si 2p and F 1s core excitation: cation and anion yield spectroscopy.

We have studied the fragmentation dynamics of core-excited SiF4 by means of soft-x-ray photoexcitation and partial positive and negative ion yield measurements around the Si L2,3-shell and F K-shell ionization thresholds. All detectable ionic fragments are reported and we observe significant differences between the various partial ion yields near the Si 2p threshold. The differences are similar...

Upper limits for the circular dichroism for the C 1s and O 1s core excitation of methyl oxirane

The circular dichroism in the total and partial ion yields of methyl-oxirane C3H6O was measured at the C 1s and O 1s edges. The difference of the response of the chiral molecule to circularly polarized light with opposite handedness was found to be less than 0.2% for the total ion yield and less than 0.5% for the partial ion yield. Additionally we tried to find a dipole allowed molecular orient...

Sources of Betaine as Methyl Group Donors in Broiler Diets

Betaine is donor of methyl groups and can partially replace methionine in diets for this purpose. The objective of this study was to evaluate three sources of betaine in partial substitution of methionine supplement in broiler diets. The Cobb-500 broiler chickens were allocated in a completely randomized experimental design with 5 treatments and 7 replicates of 49 birds each. The positive contr...

Fragmentation processes following core excitation in acetylene and ethylene by partial ion yield spectroscopy