Understanding NMR Spectroscopy phần 1 ppt

... α 1 2 + 1 2 ν 0 ,1 − 1 2 ν 0,2 + 1 2 ν 0,3 − 1 4 J 12 + 1 4 J 13 − 1 4 J 23 3 βαα 1 2 − 1 2 ν 0 ,1 + 1 2 ν 0,2 + 1 2 ν 0,3 − 1 4 J 12 − 1 4 J 13 + 1 4 J 23 4 ββα − 1 2 − 1 2 ν 0 ,1 − 1 2 ν 0,2 + 1 2 ν 0,3 + 1 4 J 12 − 1 4 J 13 − 1 4 J 23 5 ... − 1 2 − 1 2 ν 0 ,1 − 1 2 ν 0,2 + 1 2 ν 0,3 + 1 4 J 12 − 1 4 J 13 − 1 4 J 23...

Ngày tải lên: 14/08/2014, 09:21

... effects and soft pulses 3 17 (a) (b) (c) -20 -10 10 20 -1 -0.5 0.5 1 -20 -10 0 10 20 0.5 1 -20 -10 10 20 -1 -0.5 0.5 1 M x M y M abs Ω / ω 1 Ω / ω 1 Ω / ω 1 Fig. 3.26 Plots of the magnetization produced ... the pulse duration so that the on-resonance flip angle is 18 0 ◦ . M z M z Ω / ω 1 Ω / ω 1 -20 -10 10 - 55 20 0.5 0.5 - 0.5 - 0.5 - 1 - 1 11 (a) (b) Fig. 3...

Ngày tải lên: 14/08/2014, 09:21

... the pulse flip angle to 270 ◦ about x? E 4–3 The gyromagnetic ratio of phosphorus- 31 is 1. 08 × 10 8 rad s 1 T 1 .This nucleus shows a wide range of shifts, covering some 700 ppm. Suppose that ... For a carbon -13 spectrum recorded at a Larmor frequency of 12 5 MHz, the max- imum offset is about 10 0 ppm which translates to 12 500 Hz. Let us suppose that the 90 ◦ pulse width is 15...

Ngày tải lên: 14/08/2014, 09:21

... ππ Jt 12 2= i.e. a delay of 1/ (2J 12 ). A delay of 1/ J 12 causes in- phase magnetization to change its sign: IIIII x JtII t J yz y JtII t J y zz zz 1 212 12 2 21 2 12 1 2 12 12 1 2 12 2 ππ == → ... immaterial) I I I x Ht x tI tI x tI tI zz zz 1 1 1 11 2 2 11 2 2 free → → → → + ΩΩ ΩΩ The first "arrow" is a rotation about z ItItI x t...

Ngày tải lên: 14/08/2014, 09:21

... zz 13 3 1 22 13 3 1 12 23 1 13 3 1 12 23 1 2 13 12 1 1 2 23 1 2 3 2 cos DQ cos cos DQ cos sin DQ 1 13 1 13 1 13 ΩΩ ΩΩ ΩΩ + () → + () + () −+ () + () − () + () () ππ π π sin ΩΩΩ ΩΩ ΩΩ 1 13 1 13 1 13 DQ cos ... DQ 1 13 1 13 1 13 ΩΩ ΩΩ ΩΩ + () → + () + () −+ () + () − () + () () ππ π π sin ΩΩΩ ΩΩ ΩΩ 1 13 1 13 1 13 DQ cos DQ DQ + () →...

Ngày tải lên: 14/08/2014, 09:21

... () = −       − () −− () [] +− − () +− () 0 12 12 1 exp exp exp exp where RR RRR RRR RRR IISSIS IS IS =− ++ =++ [] =+− [] 222 1 1 2 2 1 2 24 σ λλ These definitions ensure that λ 1 > λ 2 . If R I and ... F 1 (t+ τ ) will be very little different from F 1 (t). As a result, the product FtF t 11 () + () * τ will be positive. This is illustrated in the figure below,...

Ngày tải lên: 14/08/2014, 09:21

... 0 90 18 0 18 0 18 0 6 90 –90 90 18 0 90 90 7 18 0 18 0 90 18 0 0 0 8 270 –270 90 18 0 –90 270 9 0 0 18 0 360 360 0 10 90 –90 18 0 360 270 270 11 18 0 18 0 18 0 360 18 0 18 0 12 270 –270 18 0 360 90 90 13 0 ... i 12 1 4 11 1222 , exp exp exp () = () +− () [] − () + [] ΩΩ Fourier transformation with respect to t 1 gives, in the real part of the spectrum Re , – – – SFF AA...

Ngày tải lên: 14/08/2014, 09:21

... + 2 present during τ 1 evolves according to II II i II zz 12 12 1 2 1 111 212 ++ + ++ →+ () () ΩΩ ΩΩ ττ τ exp – , where Ω 1 and Ω 2 are the offsets of spins 1 and 2, respectively. ... types of nucleus. 9.6.7.2 Double-quantum Filtered COSY g RF (a) (b) t 1 G 1 G 2 1 τ 2 τ 2 1 0 1 –2 g RF t 1 G 1 G 2 1 τ 2 1 0 1 –2 This experiment has already been disc...

Ngày tải lên: 14/08/2014, 09:21

... I zx JtII zz z yyy yyy zz 2 12 2 12 3 2 12 2 11 2 2 33 12 3 12 3 12 1 2 2 2 2 ΩΩ Ω → → → → → → () ++ () () ++ () π π π 22 4 12 2 12 3 2 1 2 2 23 2 3 23 2 3 12 1 2 13 1 3 II II I I zx JtI ... rotations I II II I I II x tI xz II xz I x tI tI x JtII zy JtII y yy y zz zz zz 1 12 2 12 1 1 2 12 2 11 12 2 11 2 2 12 1 2 12 1 2 2 2 2 ω π...

Ngày tải lên: 14/08/2014, 09:21

... sử dụng kháng thể đơn dòng - BWSD: âm tính khi kiểm tra bằng các kỹ thuật trên WSSV 474 bp MBV 2 61 bp IHHNV 389 bp HỘI CHỨNG ĐỐM HỘI CHỨNG ĐỐM TRẮNG TRẮNG VS WSSV BWSD

Ngày tải lên: 24/09/2012, 14:16