Secondary module

As can be noted, all the iodides studied so far (circles) are almost equivalently reactive on silver, while exhibit on GC a secondary modulation effect chained to the organic moiety structure. On Ag, to appreciate the influence of bulky molecular structures (as in the case of haloadamantanes), or poorly activated C-X bonds (as in the case of long linear alkyl chain halides), it is necessary to consider the less reactive bromide (squares) and chloride (full triangles) derivatives. The difference between the reduction potentials on Ag and on GC ranges from 0.3 to 1.4 V, thus implying a substantial saving in the specific energy consumption. The remarkable... 

The first SMS experiments in 1989 utilized either of two powerful doublemodulation FM absorption techniques, laser frequency-modulation with Stark secondary modulation (FM-Stark) or frequency-modulation with ultrasonic strain secondary modulation (FM-US) [3,26]. The secondary modulation was required in order to remove the effects of residual amplitude modulation produced by the imperfect phase modulator. In contrast to fluorescence methods, Rayleigh and Raman scattering were unimportant. Figure 2.3B (specifically trace d) shows examples of the optical absorption spectrum from a single molecule of pentacene in p-terphenyl using the FM-Stark method. 

Thus x(vq, m) is proportional to dT/dt>o> the derivative of the normal transmission curve. The amplitude of the secondary modulation must be much less than the width of the Mossbauer line so that dr/dvo is nearly constant over the amplitude. 

Direct absorption (frequency-modulation spectroscopy with secondary modulation)... 

T Vegetative secondary module (determinate) Pleurocarpous perichaetial module with... 

Terms such as stolon, primary and secondary stem, and branch, have often been used without careful attention to the role of the apical cell in formation of each of these features. Consequently, a primary stem in one taxon may equate to a stolon in a second, and a branch in a third, while a secondary stem may be the continuation of the primary stan but with a different orientation, a new primary module, or a secondary module (a branch ). This lack of clarity reduces the information content of these terms and makes structural comparisons between taxa difficult or meaningless, especially for determination of homology in cladistic analysis. 

FIGURE 14.5 Architecture of pleurocarpous mosses characters 11 to 12 (perichaetial module origin and sub-perichaetial innovations). (A) Perichaetial modnles formed distaUy on primary modnles and on secondary modules, subperichaetial innovations absent (Pireella) (B) perichaetial modnles basal on primary modules, subperichaetial innovations present, fertile only (Pyrrhobryum) (C) perichaetial modules formed distaUy on primary module, subperichaetial innovations present, fertile only (Cryphaea) (D) perichaetial modnles formed nonspecificaUy on primary module, subperichaetial innovations present, both fertile and vegetative (Amblystegium). 

Other features that can be used to distinguish between primary and secondary modules are the relative diameter of the axis, the point on the subtending module at which the module originates, and whether or not it appears to be determinate or indeterminate. However, in some cases there may be no obvious difference between modules, and no objective alterion that can be used, in which case all vegetative modules have to be regarded as primary. 

FIGURE 14.6 Origin of primary modules in tufted pleurocarps Hypnodendron subspininervium ssp. arborescens, EUis 380). Note that only one frond has been drawn (of the other three, two were moribund t and the third robust >K) and the majority of secondary modules have been omitted. The branching points are expanded for clarity, and would normally be obscured by dense growth of rhizoids. 

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