Temperature-dependent resonance

Most recently, a C system was developed using tris(trimethylsilyl-methane), which can be added to any solution. The compound is stable under basic, acidic, oxidizing and reducing conditions, and can be removed chromatographically. The temperature-dependent resonances move across the... 

Fig. 13.5 Temperature-dependent resonance frequency of langasite, gallium phosphate, and quartz BAW resonators normalized using the resonance frequency at room temperature(Reprinted with permission from Fritze (2011). Copyright 2011 lOP)...

High-resolution proton NMR spectroscopy can be used to obtain an overview on the phase behavior. The hnewidth and the presence or absence of peaks provides information on the dynamic state of the chain molecules. As an example, the proton spectra of the different samples of SDS/CA/D2O obtained at 30 and 70 °C, which are shown in Fig. 4, are discussed [19]. The signal of D2O, which has a temperature dependent resonance frequency, was used as lock signal and chemical shift reference. Therefore the other signals have temperature-dependent chemical shifts. The signal intensities of all spectra are scaled to obtain equal heights of the large CH2 peaks, which occur at about 1.3 and 1.7 ppm in the spectra at 30 and 70 °C, respectively. 

Stephenson J C and Moore C B 1972 Temperature dependence of nearly resonant vibration-vibration energy transfer in COj mixtures J. Chem. Phys. 56 1295-308... 

A resonant Orbach process occurs when the energy of the coupled vibrational modes is equal to the energy A of the first excited level of the paramagnetic center. This leads to the temperature dependence 1/Ti oc (exp(A/ BT) 1) expi- /ksT) when ksT < A. 

This favors a sample s contraction V is the volume). This attractive force, which will be temperature dependent, is balanced by the regular temperature-independent elastic energy of the lattice Fsiast/V = K/2) 6V/V). Calculating the equilibrium volume from this balance allows us to estimate the thermal expansion coefficient a. More specifically, the simplest Hamiltonian describing two local resonances that interact off-diagonally is... 

Another study of the temperature dependence of the 6.2 keV Mossbauer resonance of Ta has been carried out by Salomon et al. [197] for sources of WAV metal and W/Ta metal in the temperature range from 15 to 457 K. In more recent investigations, Salomon et al. [198] have extended such studies of the temperature behavior of the 6.2 keV Mossbauer transition of Ta in tantalum metal to temperatures up to 2,300 K which has been the highest temperature range for any Mossbauer study so far. 

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