Maxima shifting

The TPR profiles of the zirconia and silica series are shown in Fig 1 The silica series showed that the sulfated Ni catalysts are more difficult to reduce than the unsulfated ones The position of the maxima shifted 30-50°C to higher temperatures as sulfate was added As opposed to the silica series (see sample 6SSi), the zirconia series exhibited H2 consumption... 

Fig. 4 (a) Excitation (dashed) and emission (solid) spectra of different Au nanoclusters. Excitation and emission maxima shift to longer wavelength with increasing nanocluster size, (b) Emission from the three shortest wavelength-emitting Au-nanocluster solutions (from left to right) under UV irradiation (366 nm) [1]... 

Each cross section has a maximum around 13-16 eV, and the observed maxima shift to the higher energies with increasing the number of carbon atoms, i.e., from CH4 to -C4Hio, while the first ionization potentials shift to the lower energies as shown in Fig. 5. This shift of the maxima seems to be amenable to the trends in the ionization potentials of the deepest outer-valence orbitals of each molecule. 

Some of the data analysed using the approach of the present treatment have related to solute chemical shift or uv peak maxima shifts measurements at finite solute concentrations. In order to assume that ion-ion interactions do not in-... 

Figure 23. Effect of solute concentration on the derivation of K from chemical shift or peak maxima shift data, upper full line m = 0 (infinite dilution), K = 5 (assumed) — m = 1 . m = 2 lower full line m = 3 (the apparent value of K falls...

Photolysis of 1 and the J/MCM-41 complex provides evidence of cluster condensation in the pores of MCM-41. A darkening of the sample and a bathochromic maxima shift are observed for both samples. This parallels the solution chemistry of I whereby the photochemical reaction of leads to the nanocluster [Cu5o(TePh)2oTei7(PEtPh2) ]4 [6]. Although it is unlikely the same reaction path is followed in our (solid) studies, the UV data are consistent with the formation of higher nuclearity species. 

Figs. 25 to 28 show that the metal deposition in CoMo/A1203 hydrotreating catalysts is a function of the radial position within the catalyst and the axial location of the catalyst sample within the fixed-bed reactor. Nickel and vanadium both exhibit radial profiles with internal maxima, termed M-shaped profiles, at the reactor entrance. These maxima shift to the pellets edge at the reactor outlet, generating the classic U-shaped profile. 

Polycylic aromatic hydrocarbons with both angular and linear types of ring fusion show absorption curves of a similar profile to that of benzene but with the absorption maxima shifted to longer wavelengths the greater the number of rings the more pronounced the shift. 

Intercalators associate with dsDNA by insertion between the stacked base pairs of DNA [52], EtBr binds to dsDNA with little to no sequence specificity, with one dye molecule inserting for every 4-5 base pairs [53]. It also binds weakly via a non-intercalative binding mechanism only after the intercalative sites have been saturated [54], Propidium iodide (PRO) is structurally similar to ethidium bromide, and both dyes show a fluorescence enhancement of approximately 20-30 fold upon binding to dsDNA [41]. As well, their excitation maxima shift 30-40 nm upon binding due to the environment change associated with intercalation into the more rigid and hydrophobic interior of the double-stranded nucleic acid structure relative to aqueous solution [41]. 

It is interesting to observe the influence of the electronic systems of the substituents on the Si-Si bond. The Si-Si bond is a chromophor. With increasing chain length the UV maxima shift to longer wavelengths. In polymeric forms, the absorption maxima reach the visible region and the compounds become yellow (see Chapter 10 Polymeric Compounds). An electron delocalization seems to exist between the Si-Si bonds. 

The fluorescence maxima shift toward longer wavelengths when the number of the substituents is increased. We have carried out investigations with substituents like halides, OR, NHR etc. having free electron pairs. 

Quantum-chemical studies showed that the ability to form complexes with Lewis bases decreases on going from silylenes to stannylenes and increases in the following series of n-donor agents amines < phosphines < arsines < stibines189. This series somewhat differs from that proposed based on experimental data188. Calculations were successfully used to predict the absorption maxima shifts on complexation of silylenes with amines190. 

Beer s law is obeyed at both maxima up to 0.04 per cent. However, they note the free acid begins to decompose in aqueous solution after only a few. hours. Chloroform solutions of penicillin V have a similar spectrum to those in water with the maxima shifted slightly to 270 and 276 nm. 

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