Pulse angle interval

Copolymer at 125° and 15% by Weight in 1,2,4-Trichlorobenzene after (a) a 90 Pulse Angle and 16 sec Pulse Interval and (b) a 30 Pulse Angle and 1 sec Pulse Interval... 

Figure 6. NMR spectra of aerobic E. coli at 25°C. The samples contained - 5 x 10 cells/ml The arrows indicate the frequencies of the low-power pulses used in B to saturate the py-NTP peak. The repetition time was 0.17 s and the pulse angle was 60°. The spectra consist of 4000 scans each, taken in alternate 30-s intervals. The peaks labeled Pj and Pj correspond to intracellular and extracellular inorganic phosphate, respectively. The peak identified as P -NTP consists of approximately 50% ATP and 50% nonadenine nucleotide triphosphates. The high-field shoulder on this peak is due to the p phosphates of the nucleoside diphosphates. The Pj -to-ATP ratio derived from these intensities is 20 + 5. From Brown et al (1977).

Fig. 7. A C-13 relaxation time measurement of solid state wetted cellulose acetate (6% by weight water) using the inversion recovery (IR) method at 50.1 MHz and spinning at 3.2 kHz at the magic angle (54.7 deg) with strong proton decoupling during the aquisition time (136.3 ms), (upper part of the Figure). Tau represents the intervals between the 180 deg (12.2 us) inverting and 90 deg (6.1 us) measuring pulse. 2200 scans were collected and the pulse delay time was 10 s, Cf. Table 3 and Ref.281...

Figure 1.45 Coherence transfer pathways in 2D NMR experiments. (A) Pathways in homonuclear 2D correlation spectroscopy. The first 90° pulse excites singlequantum coherence of order p= . The second mixing pulse of angle /3 converts the coherence into detectable magnetization (p= —1). (Bra) Coherence transfer pathways in NOESY/2D exchange spectroscopy (B b) relayed COSY (B c) doublequantum spectroscopy (B d) 2D COSY with double-quantum filter (t = 0). The pathways shown in (B a,b, and d) involve a fixed mixing interval (t ). (Reprinted from G. Bodenhausen et al, J. Magn. Resonance, 58, 370, copyright 1984, Rights and Permission Department, Academic Press Inc., 6277 Sea Harbor Drive, Orlando, Florida 32887.)...

The second method uses pulsed lasers and the laser-induced fluorescence is detected by telescope. If the telescope and the laser source have a definite base distance, the crossing of laser beam and the acceptance angle of the telescope define the height of the atmospheric layer at which fluorescence is detected. There is also the technique of delayed coincidence, where the time interval between laser pulse and detected fluorescence pulse determines the distance of the observed molecules from the observer (Lidar)... 

The Al magic angle spinning nuclear magnetic resonance (MASNMR) spectra were acquired using a 30 pulse at 0.1 sec. intervals. About 5000 to 7000 scans were acquired on a Bruker AM-400. The chemical shift is relative to aluminum nitrate in water solution which contains A1(H20)6. ... 

When the simple one-pulse experiment is again considered, there is only one time factor (or variable) that affects the spectrum, namely the acquisition time, f2. We now consider a multiple-pulse sequence in which the equilibration period is followed by two pulses with an intervening time interval, the final pulse being the irll acquisition pulse. Thus, we have inserted an evolution period between the pulses. If we now vary this evolution time interval (f3) over many different experiments and collect the resulting FIDs into one overall experiment, we have the basis of a 2-D experiment. Sequential Fourier transformation of these FIDs yields a set of spectra whose peak intensities vary sinusoidally. This first series of Fourier transformations result in the second frequency axis, v2, derived from the acquisition time, r2, of each FID. The data are now turned by 90°, and a second Fourier transformation is carried out at right angles to the first series of transformations. This second series of Fourier transformations result in the first frequency axis, iq, a function of the evolution time, f1 which you recall was changed (i.e., incremented) in the pulse sequence for each successive FID. 

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