Understanding NMR Spectroscopy phần 10 pdf

... sufficient?] E9 -10. Use the formula given in section 9.6.2 for the overall decay of magnetization during a gradient 2 γ Gtr max to calculate how long a gradient is needed to dephase magnetization to (a) 10% and ... 10% and (b) 1% of its initial value assuming that: G = 0.1 T m –1 (10 G cm –1 ), r max = 0.005 m (0.5 cm) and γ = 2.8 × 10 8 rad s –1 . [Put all the quantities in SI u...

Ngày tải lên: 14/08/2014, 09:21

... 236–7 Musharakah contract 345–6 Salam contract 262–3 acronyms, list of 481–3 Ahd/W’adah (promise) 103 –5 conditions in commercial dealings 115 rationale 114 token money 116–17 Al’Arb ¯ un sale (downpayment ... (Sale of Debt) 146–7 AmBank Bank Berhad Al-Taslif Card 382 American national debt 5 Aqd (Contract) 103 –5 Arb ¯ un 116 Bai  al Istijrar (supply contract) 355 Bai  or exchange of val...

Ngày tải lên: 14/08/2014, 05:20

... represented as the corresponding operator, I z . Likewise for the S-spin magnetization Snnnn z =−+− 1234 [10] A third combination of populations will be needed, which is represented by the operator 2I z S z 2 132 ... difference in population differences across the two I-spin transitions; likewise, comparison with Eq. [10] shows that the same operator also represents the difference in popula...

Ngày tải lên: 14/08/2014, 09:21

... uses coherence transfer pathways to specify the desired outcome of the experiment. 9.2 Phase in NMR In NMR we have control over both the phase of the pulses and the receiver phase. The effect of ... Coherence Selection: Phase Cycling and Gradient Pulses † 9.1 Introduction The pulse sequence used in an NMR experiment is carefully designed to produce a particular outcome. For example, we...

Ngày tải lên: 14/08/2014, 09:21

... the 180° pulse. 9.2.8 Difference spectroscopy Often a simple two step sequence suffices to cancel unwanted magnetization; essentially this is a form of difference spectroscopy. The idea is well ... pulse phase phase shift experienced by transfer with ∆p = –3 equivalent phase 10 0 0 2 90 270 270 3 180 540 180 4 270 810 90 The fourth column, labelled "equivalent phase", is just...

Ngày tải lên: 14/08/2014, 09:21

... for water, which is 2.1 × 10 –9 m 2 s –1 at ambient temperatures. c Diffusion constant taken as 0.46 × 10 –9 m 2 s –1 . d Diffusion constant taken as 0.12 × 10 –9 m 2 s –1 . 9.6.6.1 ... gradient pulse pair of 2 ms duration and of strength 10 G cm –1 for a small, medium and large sized molecule; data is given for ∆ = 2 ms and ∆ = 100 ms. It is seen that even for the mo...

Ngày tải lên: 14/08/2014, 09:21