Coupling distorted systems

Figure 14 demonstrates the sensitivity improvement that is obtained by the described co-addition in the spin system, and shows that the method is applicable without distortions to strongly coupled spin systems and to CIDNP multiplet effects. 

It is not difficult to understand why a chemically coupled oscillator system can display birhythmicity for some range of parameters. If the coupling is not too strong, it may distort the shape and location of the limit cycle and the range of... 

Fig. 42. (a) Single id electron levels for a transition metal atom in a cubic site with axial distortion, (b) Eneigy levels of the (3<0 coupled atomic system, (c) Splitting of the lowest atomic level by residual crystal field and in-orbit interactions, and the applied magnetic field B. 

In the TPPI method a single data set with 512 increments is collected. In each successive increment the phase of the 90° pulse at the end of the period is incremented by 90° with respect to the phase of the corresponding pulse in the previous increment. (An equivalent experiment can be performed in which the phases of the pulses before the ti period are shifted by 90°). This is equivalent to changing the reference frame in so that the transmitter in the dimension appears to be shifted to one edge of the spectrum. After performing a real Fourier transformation, all peaks will appear to be shifted to one side of the transmitter in /. The main disadvantage of this technique is that phase distortions can appear for resonances in strongly coupled spin systems. 

A simple pulse sequence using transverse relaxation is the spin-echo (90 - s-180°-rs-FID) and here the signal intensity is proportional to exp(—2rs/72). Unlike the inversion-recovery method, the spin-echo method can allow the spectra to be phased to give positive peaks for all spins, but phase distortion is expected for homonuclear coupled spin systems when longer spin-echo times are used or where larger coupling constants are present in this method. 

In his classical paper, Renner [7] first explained the physical background of the vibronic coupling in triatomic molecules. He concluded that the splitting of the bending potential curves at small distortions of linearity has to depend on p, being thus mostly pronounced in H electronic state. Renner developed the system of two coupled Schrbdinger equations and solved it for H states in the harmonic approximation by means of the perturbation theory. 

The temperature of the metal-to-insulator transition in TTF—TCNQ is 53 K. For systems with increased interchain coupling, the transition temperature for the onset of metallic conduction increases roughly as the square of the interaction between the chains. This behavior is tme as long as the coupling between chains remains relatively weak. For compounds with strong interactions between stacks, the material loses its quasi-ID behavior. Thus, the Peieds distortion does not occur even at low temperatures, and the materials remain conductive. 

Enough space must be available to properly service the flow meter and to install any straight lengths of upstream and downstream pipe recommended by the manufacturer for use with the meter. Close-coupled fittings such as elbows or reducers tend to distort the velocity profile and can cause errors in a manner similar to those introduced by laminar flow. The amount of straight pipe required depends on the flow meter type. For the typical case of an orifice plate, piping requirements are normally Hsted in terms of the P or orifice/pipe bore ratio as shown in Table 1 (1) (see Piping systems). 

Tliis is the prime cause of noise and distortion in an audio system. The capacitive coupling (conduction) between the power and the communication lines gives rise to such an effect. It is associated more with the voltage of the system and particularly when it is capacitor compensated. Even without the power capacitors, the leakage (coupling) capacitances between the HV or EHV power lines, particularly 132 kV and above, and the overhead communication lines play an important role and give rise to this phenomenon. Systems lower than 132 kV do not cause such a situation as a result of the insignificant capacitive effect. 

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