The radical intermediates formed by photoinitiated crosslinking of low density polyethylene (LDPE) with benzophenone (BP) as photoinltiator have been investigated by spin-trapping ESR technique using 2,3,5,6-tetramethylnitrosodurene (ND). By the temperature change and determining the well-resolved ESR spectrum of the nitroxide spin-adducts at the melt, the following two radicals could be identified:one was the secondary carbon radical,CH₂-?H-CH₂-,another was the tertiary carbon radical,.Based on these results, the photocrosslinking reactions of LDPE initiated by BP mainly take place at the secondary and tertiary carbons.

This paper reports the results of the Electron Spin Resonance (ESR) experiment of the mixed ionic conductor Agl (Cr₂O₃). A kind of new stable ESR signal was observed, which might be assigned to certain defects (similar to F center) in the boundary layer between components Agl and Cr₂O₃.The existence of the defects may be an important factor for improving Ag⁺ ionic conductivity.

An analysis is made by Fourier Expansion method for the phase sensitive detection of magnetic resonance at the first and the second harmonics of modulation frequency. The effects of modulation amplitude on magnetic resonance linewidths, lineshapes and the first and the second derivative (or harmonics) signal intensities of single and overlap lines are examined. The related experimental results of LMR spectra of NO₂ agree with the calculation for Lorentzian and Gaussian lines. Suggestions for selecting the modulation parameters and searching for signal were proposed.

The average spectral density functions under MAS condition were derived from various models of jump motion and models of freely diffusive motion. The contents of crosslinking agent DVB were evaluated by using CP/MAS spectra. The rotational correlation times and diffusion coefficients of α-CH₃ in a series of poly (methyl methacrylates) crosslinked with DVB were calculated according to the measured T₁ values. The results showed that:(1) the correlation times increase and the diffusion coefficients decrease as the contents of DVB increase, (2) the rotation activation energy of the α-CH₃ is independent of the contents of DVB and less than that from dielectric and mechanical relaxations.

Spin diffuson is of great significance to many phenomena in solid state NMR. There have been several theoretical schemes for evaluating the diffusion coefficient. In fact, however, this kind of evaluation is not only unpractical but also unreliable. This paper presents a new scheme for determining spin diffusion rate by using the depolarization of the rare spins in CP MAS NMR, where the magnetization of rigid protonated rare spins decays in two-stages, and the slow second stage which is a single-exponential process offers a direct measurement of spin diffusion rate. Spin diffusion is actually a macroscopic manifestation of polarization transfer via flip-flop of successive pairs of spins, which can be reasonably described by a one-dimensional random walk model. The average flip-flop time can be deduced from the slope of the semilogarithm curve of depolarization, and the spin diffusion coefficient can thus be estimated. In some typical rigid organic solids and crystallized polymers, the average flip-flop time is found to be about 700μs, which is of an order of magnitude longer than the dipolar correlation time. It means that the spin diffusion time constant is quite different from the spin-spin relaxation time constant, although the two processes are closely related. Consequently, the estimation of spin diffusion coefficient from proton line width is quite questionable

¹H NMR spectra of benzene, cyclohexane and n-hexane and ²H NMR spectra of benzene-d₆ absorbed on four charcoals with different pore structures were measured at various temperatures in the range from 297 to 195 K. At room temperature ¹H NMR and ²H NMR spectra of each of the above mentioned compounds were singlets with different line widths(△γ_1/2) which increased with decreasing temperature. The Inγ_1/2 vs. reciprocal absolute temperature plots showed linear relationship with intersection. For C₆D₆ systems solid powder patterns were observed at temperatures where intersection occurred. Except for charcoal 2^# solid powder patterns appeared at almost identical temperatures for charcoal 3^#, 4^# and 5^#. The appearence of solid powder patterns suggests that the absorbed species in the 3D liquid state turned to 3D solid.

Spirasine Ⅲ, diterpene alkaloid, was isolated from the root of Spiraea japonica L. f. var. fortunei(phanchon) Rehd. Its structure was demonstrated by spectral and chemical methods. The assignment of proton and carbon in the structure as well as double signals in the oxazolidine ring were achieved on the basis of detailed 2D-NMR spectroscopic analyses.

We studied the complex process of Cu^2--Tyrosine of different ratio in different pH value aqueous solution by ESR at room temperature. The result reveals that the greater the ratio and pH value are, the easier the steady complexes are formed.

The plasma treatment of polytetrafluoroethylene (PTFE) film was carried out in a capacitively coupled reactor with external electrodes. The free radicals produced in the process of treatment were detected by ESR techniques. The effect of temperature on the ESR spectra was discussed in detail. Finally, the attenuation of the free radicals was investigated.

Soid complex of Gd^3- with 2, 3-dihydroxy-p-xylylenf diaminotetraacetic acid (DPTA) was synthesized. Studies have been performed in which the above-mentioned complex was utilized as water-soluble paramagnetic relaxation reagent for ¹³C NMR spectrometry. Model compounds with which the reagent is effective include threonine, cysteine, arginine, histidine, tryptophan and ascorbic acid. It was shown that the reagent investigated can not only enhance the singal intensities for carbons not attached to hydrogen, but also suppress the nuclear Overhauser effect (NOE) for protonated carbons. Carbons-13 spin-lattice relaxation times (T₁) of the arginine acid in the presence or absence of the relaxation reagents were measured. The results show that Gd-DPTA is more effective than Gd-DTPA as a carbon-13 relaxation reagent.

In this paper, the ¹³C NMR chemical shift data of ethylenc-propylenc copolymer are treated according to a method of substituent chemical shift (SCS). The SCS parameters of EP copolymer (CH₃) could be obtained in the first time. Based on it, ¹³C NMR spectrum of the copolymer is assignd and the signal rcpresentatin of sequence structure are discussed briefly. Then, the se-qucnce distribution of several copolymers could be calculated by using a set of universal formalu and compared with each other.

The method of determination of the phase cycle in PFT-NMR experiments from the desired coherence transfer pathway was introduced. A computer program PHASE. BAS used to assist design phase cycling procedure based on this method was proposed. The program has been used to design a 128 step phase cycling procedure for the one and two dimensional INADEQUATE experiments. The one and two dimensional INADEQUATE spectra of n-Butanol were recorded by using this 128 step phase cycling procedure and a 32 step one collected in the Bruker MSL Pulse Sequence Library-INADSYMQ. PC respectively. The experimental results show that the former is superior to the latter in suppressing the single quantum signals and eliminating the imperfection of the spectrometer. It seems that the program could be an useful tool in the designing of pulse sequences, especially for the pulse sequences in which huge phase cycle steps are required.

A few modified long-range C-H chemical shift correlation pulse sequences published recently have been experimentally compared with COLOC sequence in this paper. A new modified pulse sequence named by COLOCH has been proposed by synthesizing the advantages of every pulse sequences. The one bond suppression rate and success rate of long-range cross peak have been taken as evidence for judgement of the pulses. The results show that Martin pulses, COLOCS and COLOCH sequences are more successful and setting experimental parametcis is of great importance for success of experiments.

A method using KERMIT to realize the communication between dedicated computer on spectrometer Aspect-3000 and an universal microcomputer IBM-PC was introduced. Several application examples were presented. The IBM-PC microcomputer could be established as a NMR data station when it was implemented with a data processing software.

This paper presents the principle and data processing method for L-band ESR imaging reconstruction. Through outlining the whole system, the function of scanning field and gradient field and their relation with projection data are discussed. The flow diagram of reconstruction data processing emphasizing on convolution difference principle and method is given. The filtered back-projection method applied in our system is also described. Finally, some images reconstructed from ESR sígnals of DPPH and coal are given, and the results of experiments are also analysed and discussed.

In this paper, the loop-gap resonator's frequency and Q value were derived by using the equivalent circuit method. A critical oscillator with a loop-gap resorator was designed, and formed a set of ESR spectrometer.