³¹P nuclear magnetic resonance (NMR) spectra of human lymphoma cell line Molt-4 were observed by using ³¹P NMR. The decrease in ATP levels and simultaneous increase in inorganic phosphate (Pi) levels occurred as the time of NMR experiment increased under temperatures of 37℃, 20℃ and 4℃.The changes in ³¹P spectra of cells slow down sequentially following the descent of NMR measurement temperature. Stable ³¹P spectrum of living cells was obtained when accumulation of data was started within 30min after the harvest of the cells and finished within 60 min at 4℃.Intracellular pH of Molt-4 cells was measured based on the chemical shift of Pi peak.

A series of N-alkyl iminodiacetato (diammine) Platinum (Ⅱ) complexes[Pt(NH₃)₂(R-N(CH₂COO)₂], R=Me, i-Pr, n-Pr, HO-Et] have been synthesized under different pH conditions.The results of ¹³C NMR study (20MHz) show that the iminodiacetate ligands are coordinated to platinum through N, O linkages, which doesn't change with pH value. Under soft acidity, these complexes exist in exchange equilibrium states. The equilibrium constant was calculated based on the ¹³C chemical shifts.

The relaxation of polystyrene (PS) chains with different molecular weights and concentrations and at different temperatures have been studied in detail. Cyclohexane and 1,4-dioxane were used as the theta solvent and as good solvent respectively. It was found that the topological and cohesional entanglements exist simultaniously in polystyrene solutions. The former depends strongly on molecular weight, concentration and temperature, and the latter depends mainly on concentration and temperature.The interlocking structure of the side chain-aromatic rings (i. e. cohesional entanglement) has a great effect on the dissolution process and main chain motion of polystyrene, thus it determines the solution property and even the property of PS bulk. In addtion, chain molecular weights in different ranges in values have quite dif ferent effects on the relaxation of PS. This behaviour is related to the formation of PS chain entanglements in solutions, and the number of entanglement points in a unit volume.

The defect for using Dante sequence as a band-pass selective excitation pulse is the strong remained side-bands,when a weak peak is excited in a spectrum with the other strong peaks.Sometimes,this remained part of the strong peak is still very large,which will lead to make a mistaken assignment for the coherence transference. In this report, we suggest to reduce the width of the first and last pulse in Dante sequence to a half.By means of this method,the remained peak can be suppressed to about 1/50.

To clarify the reason for the red solution of poly(aryl ether ketone), monomers in H₂SO₄, this paper had studied their chemical shifts and florine-ended dipolarity in solvents of CDCl₃, CDCl₃+DMSO-d₆ and H₂SO₄, results showed that, when the monomers in H₂SO₄, their carbonyl carbon relaxation time was shortened and their chemical shifts increased, While the chemical shift of the quarternary carbon attached to carbonyl group was reduced and relaxation time shortened. Based on the above, the polarization mechanism of H₂SO₄ on these monomers is presented for the first time,that is, the sulfo group made electrons in carbonyl group delocalized, which was further proved by ¹³C NMR under variation temperature.

We use the gauge invariant atomic orbitals(GIAO) approach,to carry out the ab initio-CHF ¹³C nuclear shielding calaulations for solid glycine and lysine,and found a better locally dense basis set which is applicable to larger amino acids. The ab initio shielding results are in agreement with the experimental ¹³C shieldings.

In this paper, the analytical solutions of Bloch equations under various physical conditions are given by means of Laplace transformation.Those solutions have clear physical pictures and are easy to be used.They have ban put in the use of the solvent peak suppression and Shaped pulse design.About solvent peak suppression,the approximate formulae of suppression efficiency's limit and optimum suppression time are given.In design of Shaped pulse,we think that all four kinds of solutions in Bloch equations have to be taken into account.It is also shown by simulation that if the same frequency function excited by pulses for different flip angles are required,the shape of pulses in time domain must be modified. A series of experimental results coincide well with the above conclusions.

Based upon thirteen kinds of 2,2,4-trimethylpentane-diol diester synthesized, the relationship between chemical shifts, coupling constants, spectral intensities, magnetic nonequivalences of methylene proton and molecular structures had been discussed.In order to decrease steric hindrance caused by mutual interaction of respective groups and to satisfy molecular stability,the diesters were arranged according to configuration Ⅱ.

A pulse gradient field instrument for pulse gradient-enhanced high-resolution NMR was developed on Bruker MSL 300 spectrometer. The system was composed of a modified ¹H liquid probe and a PC-controlled pulse gradient field generator whose waveform and amplitude can be arbitrarily set. The eddy-current effect caused by the gradient field was analyzed and a gradient-enhanced COSY experiment was also carried out to test this instrument.

The Magnetic Resonance Image(MRI) data,acquired on the BRUKER MSL 400 NMR spectrometer,are processed on general 486 personal computer.The data are compressed and converted to the normal raster image format-PC paintbrush format (PCX). With the converted PCX image data file,many image processing functions,such as grey correction, despeckle, edge enhancement,and sharpening, can be achieved and make the MRI data analysis easier and more effective. This method could be used for the similar spectrometer with some modifications in input data format convertion also.

A high resolution solid state DNP CP/MAS probe was designed.By using this probe,high resolution NMR spectra of solid state samples containing free radicals were obtained.Some typical results are shown in this paper. Technical problems in DNP NMR experiment are discussed and some methods are suggested to deal with these problems.

In this paper, a self-made X-band ESR imaging instrument and 1D and 2D ESR imaging results of some typical spin samples are reported.In the image reconstruction process, the algorithm of deconvolution and convolution filtering of analytic reconstruction were used to reconstruct the spatial distribution images.

We have used convolution difference method to enhace the resolution for EPR spectra of transition metal ions. It can be directly measured spectra parameter a_R、a_⊥、g_R and g_⊥ of different ions from superposed spectra of various kinds of transition metal ions. Particularly, the method can be used to increase the measurement accuracy of the g factors of anisotropic for wide EPR spectra of transition metal ions.

All the decoupling schemes of Varian have unique properties (especially in the width and perfection of decoupling). Each has attributes that suit different spectroscopic tasks. The Varian waveform generator incorporates the power and the flexibility, with a right design to meet your every of modulation need. Each and everychannel in a UNITY plus system has its own PROM controlled Phase Modulator.This PTOM contains a variety of decoupling schemes. It provides the user with GARP and WALTZ ("optional"), XY32, MLEV16, noise, cw, square wave, and sweptsquare wave, as well as access to the optional WFG customer -input text-file-driven decoupler schemes. More