The relative signs of coupling constants in ABX system for isophytol were determined using two methods of double resonance:selective spin decoupling and spin tickling methods. Through this example a simple and clever method is illustrated by which the relationship between double resonance method, related diagram, a simple diagram about energy levels and relative signs of coupling constants in ABX system is linked up without precise calculation by means of intensities of all peaks. In this ABX system δ_A 5.0lppm, δ_B 5.04ppm, δ_x 5.85ppm,|J_AB|=1.5Hz,|J_AX=10.6Hz,|J_BX|=17.3Hz were determined. Signs of J_AB, J_AX,and J_BX are the same.

The ¹H and ¹³C NMR spectra of the reaction products of α-bromoacrylamide derivatives and alanine were recorded in the reacting solution without being isolated.From the assignment of the spectral lines through different NMR techniques, the structure of the reaction product has been proved.It was found that the product is a mixture of equal amounts of two diastereoisomers of aziridine. The ¹H and ¹³C NMR spectra of stereoisomeric aziridines were discussed in the light of stereochemistry.The ¹³C NMR spectra of diastereoisomeric aziridines discussed in this paper have never been reported in the literature before.

The autooxidation of gentisic acid in alkaline solution was studied by ESR, A novel free radical was found by calculating the spin density and hyperfine coupling constants. The mechanism of autooxidation of gentisic acid was given. The ESR experimental condition and some influence factors have been investigated. The ESR method of studying gentisic acid in tussah silk was set up.

Some powder samples of molybdemum-copper-sulpher dimetal cluster containing=CuX form ligands, where X represents halogen, were studied by MASNMR method. The lines obtained were assigned and the effects of=CuX ligands on the positions of various lines were discussed. Comparisons between the ¹³C spectra of three crystalline powder, (t-BuNC)₄ Mo(t-BuS)₂, (t-BuNC)₄ Mo (μ-t-BuS)₂CuX and (t-BuNC)₄ Mo(μ-t-BuS) (μ-CO)CuX, were made. A simple but successful way to perform an inves tigation when the powder sample to be studied was not sufficient was also proposed.

While the composite pulise solid echo sequences reduce the effects of finite pulse width greatly, they do not eliminate them completely, and they introduce a new type of distortion into the powder lineshape, that is, the phase error. The present paper analyzed the composite pulse, and used it to construct the Magic Echo Sequence for I=1 spin systems for compensating the phase error. The theory was confirmed by computer simulations and experimental results. It is clear that the performance of the composite pulse Magic Echo Sequence is superior to that of the composite pulse solid echo sequences, and essentially solved the problems due to finite pulse width effects for ²D-NMR spectroscopy.

Lanthanide-induced shifts have been measured for ¹H and ¹³C nuclei of L-cy-steine in the presence of eight different lanthanide cations (La, Pr, Nd, Eu,Dy, Ho, Er, Tm).The complex formation shift and the pH dependance of lanthanide-induced shift indicate that L-cysteine is coordinated to lanthanide cations through its ionized carboxylic group.The complex stability constants show that sulfhydryl group is favorable for amino acid coodinating to lanthanide ions. The simulated calculation of the dipolar shift reveals that carboxylic and sulfhydryl groups are in gauche position in the complexes of L-cysteine and carboxylic group is coordinated to lanthanide cations through a single oxygen atom.

A method for describing strong coupling systems by weak coupling system method is suggested. Hamiltonian of strong coupling system was transfered into the form of weak coupling system by using unitary transformation, the same transformation was also applied to rf pulses. The multiple pulse experiments for strong coupling system were calculated in weak coupling space {φ}. As an example, COSY and 2D-J spectra in AB system were calculated.

The carbon-13 NMR of various 5-(α-naphthyl)-tetrazol (Ⅱ), methyl 5-(α-napht-hyl)-2H-tetrazolyl-2-acetate(Ⅲ), 5-(α-naphthyl) -2H-tetrazolyl-2-acetylhydrazine (Ⅳ), l-[5-(α-naphthyl]-2H-tetrazolyl-2-acetyl]-4-phenylthiosemicarbazide(Ⅴ)and 5-[α-naphthyl)-2H-tetrazol-2-ylmethylene]-4-phenyl-l,2,4-triazoline-5-thione(Ⅵ) were studied. The chemical shifts of variuts carbon resonances were assigned on the basis of chemical shift theory, signal intensity, APT techniques and comparison with the chemical shifts of the model compounds.

¹³C-NMR spectra of ten l-C-aryl-D-glucopyranoses, including four pairs of α,β anomers, were studied. Chemical shifts of the sugar moiety of β-anomers are larger than α-anomers (except C₄'), which could be used to distinguish the α and β-anomers of 1-C-aryl D-glucopyranoses. In addition, the effects of configuration of sugar on the chemical shift data of the aglycone has beeu discussed.

XRD and multinuclear liquid state NMR techniques were used to study the reaction mechanism of AlPO₄-5 molecular sieve (synthesized by using Et₃N as template) with NaF. It was shown that P and Al are strictly alternative in theframework of AlPO₄-5 molecular sieve; and that their ordering in AlPO₄-5 molecular sieve has nothing to do with the templates used.The mechanism of theabove reaction was proposed.

It is proposed that the resolution of 1D-NMR spectra can be improved by means of multiple quantum filter thereby the coupling information from the overlapped spectra can be obtained.It is proved theoretically that this method is in principle to observe the anti-phase magnetization instead of the normal magnetization and is generally independent on relaxation.

The ¹³C, ¹H-NMR, IR, MS spectra were measured for the seven N-methyl-3-alkyl-pyrrolidones.The NMR spectral lines were assigned, and the molecular structures were determined.The alkyl substituent empirical parameters for the calculation of pyrrolidone ¹³C chemical shifts and the pyrrolidone substituent empirical parameters for the alkyl ¹³C δ values were obtained.

The article describes a computer system. Combined with a JES-FE series ESR spectrometer, the computer system can carry out acquisition, processing and simulation of measured data The system consists of an IBM-PC microcomputer, an interface, consisting of the timing controller and A/D converter, and application software.The sampling and the signal average can be made by the system in very wide range of sweep time(lms-128 min).It improved greatly the ESR spectrometer in measuring the short life free radicals and the weak signal. The system is on a level with ES-PRIT23 in main functions and specifications, but it costs only one fifth of that of ES-PRIT23.

An electrochemical cell used for in situ electron spin resonance (ESR) measurements nnder electrochemical excitation in aqueous solution was designed and fabricated. Taking the in situ ESR investigation of methylene blue solution and polypyrrole film modified electrode as examples,the characteristics of the cell has been examined. The experiments performed in this cell not only provide new information for electrochemical processes of the two systems but also show that this cell is resonably arrangeed and has the outstanding advantages of precise potential control of the working electrode, rapid response and high sensitivity. This ESR cell is much useful for observing the intermediates or short lived species produced electrochemically in aqueous solution or other systems with large dielectric constant. Meanwhile, it can be applied for in situ preparing and studying film modified electrodes under different conditions with very convenient operation.

A new type of low-temperature and variable-temperature apparatus for ESR spectrometers is introduced in this paper. In the apparatus, an insert dewar joined directly to a coiled tube of liqeid nitrogen dewar. The dry nitrogen gas is pressed to the liquid nitrogen and the cooled nitrogen gas is jetted to the sample tube. The temperature of the sample is lowered.
The lowest temperature of the apparatus can reach 85K. It is lower than the temperature of usual variable-temperature apparatus.

The development of in Vivo NMR spectroscopic techniques is reviewed.The principles are also briefly introduced.The emphases are put on the spatial localization techniques which are classified according to their principles. The effect of chemical shift on the accuracy of spatial localization is discussed and experimental methods are introduced to improve the spatial localization. Finally, the applications of in Vivo NMR spectroscopy to living systems are summarized.