Differential extinction spectra

Dust Dust has three major effects on the H II region spectrum. First, dust grains mixed with the ionized gas absorb Lyman-continuum radiation. Second, obscuration by dust is typically patchy differential extinction between stars and gas can affect the emission line equivalent widths. Third, dust can affect the heating and cooling by emitting and recombining with photoelectrons. 

The extinction spectrum of Ag core/poly(ADA)-shell hybridized NCs dispersion liquid is shown in Fig. 6 [50]. The main peak at ca. 450 nm is assigned to ESP of Ag core [108], and was red-shifted and broadened because of the large size and its distribution of Ag core [109-111]. The small shoulder peak at 540 nm may come from the EAP of poly(ADA) shell [112], and the inset in Fig. 6 also displays the differential spectrum before and after solid-state polymerization. The obtained extinction spectrum could be reproduced by spectrum simulation on the basis of Mie scattering theory [113], assuming spherical Ag core (radius = 45 nm)/poly(ADA) shell (thickness = 5 nm) type hybridized NC. In Fig. 7, both main peaks around 450-500nm is attribute to ESP (Frohlich mode) of Ag core, and the two sharp peaks at 380 and 400 nm are the quadrupole mode of ESP [108]. 

The negative band at 275 nm and the positive bands in the 320-450 nm region of the difference spectrum reflect reduction of ubiquinone. In addition, the difference spectrum also consists of several band shifts the red shift of the absorption bands of BO at 535 and 760 nm, and small blue shift of the 800- and 865-nm bands ofP870. These band shifts are attributed to the influence of local electric fields produced by photochemical charge separation. They are ascribed neither to ubiquinone reduction itself nor to redox changes of the pigment molecules. Note that the ordinate is expressed in differential molar extinction coefficient. As, in mM em", as it is readily obtainable since P870 and Qa are present in equimolar quantities. 

The UV spectrum in methylene chloride exhibits Amax at 440, 323, 260 and 232 nm with extinction coefficients of 109, 4960, 6660, and 6460, respectively. The IR in KBr exhibits bands at 3095, 2860-2990, 1360, 1218, 1103, 1038, 1020, 997, and 670 cm and resembled spectra for monoalkyl ferrocenes. The glass transition temperature was estimated to be 190°C from the broad curves obtained from differential-scanning calorimetry (DSC). 

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