Radical intermediates formed by UV-irradiation of low density polyethylene (LDPE) in the presence of benzophenone (BP) as a photoinitiator have been trapped by using 2,4,6-tri-t-butylnitrosobenzene (BNB) as a spin-trapping reagent. The resulting spin-adduct radicals have been characterized in situ by ESR spectroscopy. Two kinds of spin-adducts are detected and identified:a tertiary carbon radical and a secondary carbon radical which are formed by addition of the spin-trap (BNB) to two polymer radicals. These intermediates are produced by hydrogen abstraction of the BP excited triplet state from branch points and methylene groups of the LDPE chain, respectively. This is the evidence that the photocrosslinking of LDPE mainly takes place at both tertiary carbons (branch points) and secondary carbons along the chains and that H-shaped links dominate. Secondary bonded hydrogens are less reactive but occur in much larger number than tertiary bonded hydrogens in LDPE.

Electron spin resonance spectra of amorphous Li⁺ conductor B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃-0.1V₂O₅ (x=0.05 and 0.15) have been studied. It is found that (1) The ESR spectra is Gaussian type and the addition of V₂O₅ is suitable; (2) The hyperfine structure is due to the complex ions VO²⁺ which possess tetragonal symmetry and belong to group C_4v. Parallel and perpendicular principal components of the hyperfine-coupling tensor, A_//=0.0175cm^-1 and A_⊥=0.0063cm^-1. Calculation from g_// and g_⊥ shows that the energy difference between the gound state ²B_2g and the first excited state ²E_g, △₁=2.46×104cm^-1,the energy difference between ²B_2g and the second state ²B_1g,△₂=3.03×104cm^-1; (3) The ESR spectra from 295°to 440°K show that ESR intensity of the glass with less content of Al₂O₃ (0.05mol.) is 3-2 times higher than that of the glass with more content of Al₂O₃ (O.15mol.); The more the content of Al₂O₃, the less the drop of ESR intensity with increasing temparature.

Eight heterocyclic aryl n-butyltin (Ⅳ) compounds are synthesized. The general formula is R_n-SnBu_(4-n)(R=2-furyl or 2-thienyl, n=l,2,3; R=2-(N-methyl) pyrrolyl or 2-pyridyl, n=l). Four of them are novel compounds:dibutyl di(2-furyl) tin, butyltri (2-furyl)tin, dibutyl di(2-thienyl) tin and butyl tri(2-thicnyl) tin. Their structures are characterized by elementary analysis, IR and NMR etc. The spectral features are discussed.

Using VO²⁺ as spin probe, the micro-environment of VO²⁺ supported on zeolite was observed by ESR technique. Computer program was built for simulating ESR spectra with complicated and multi-centers. It was found that the dispersion character of VO²⁺ is dependent upon the preparation conditions employed and the carriers chosen. This may serve as a new method to get micro-environment information of carriers and can be used in the choice of carriers of coordination catalysts.

A method based on spectral editing is suggested to simplify the multidimensional nmr experiments. According to this method, a two dimension experiment that there are N resonance lines in F1 domain can be decomposed into N one dimension experiments with relevant evolution times, then these ǫne dimension data should be edited. The editing parameters are calculated from the resonance offsets of the lines in F1 domain and the different evolution times. The edited 1D spectra are 2D slices which contain 2D correlation informations. For demonstration, we have applied this method to simplify 2D inverse C-H correlation and 3D inverse C-H-H correlation experiments. The editing error due to the natural line width in F1 domain has been analyzed by numerical method, and it shows that the error can be ignored when T₂^*>>t₁.

Owing to the uncontinuously tunable property of CO laser, the frequency stability is very difficult to be determined by using direct molecular absorption spectrum. A new measurement method of laser frequency stability is proposed in this paper. The method is based on molecular spectrum of laser magnetic resonance (LMR). The variation of linewidth of molecular LMR spectrum were treated by Allan variance method. A series of CO laser frequency stabilities were obtained from 0.1s to 1000s. The frequency stabalities were fitted by power function in a computer. The expressions of frequency stabilities are found for stabilizing and free-running CO laser.

Two hydrogenated butadiene-styrene copolymer (HBS) samples are studied by ¹H NMR and ¹³C NMR by using JEOL-FX100 NMR and Varian UNITY-400 superconductive spectrometer. The SCS parameters of ethyl (-C₂H₅) and benzyl (-C₆H₅) are obtained by dealing with the ¹³C NMR data from references. The ¹³C NMR spectrum of HBS is reassigned by using the SCS method of ethylene-α-olefin copolymers and the DEPT NMR experiment. It is pointed out that the two methylenes of any ethylene unit in the main chain of HBS belong to dyad and triad respectively. The methine in the main chain is expressed by triad.
Finally the sequence distribution of dyad and triad is calculated. The molar composition of styrene, butene and ethylene unit in HBS calculated from ¹³C NMR spectrum is consistant with that calculated from ¹H NMR spectrum.

A new alkaloid, neuplatyphyllinc N-oxide, was isolated from the root of Caculia hupehensis Hand-Mazzi. Selective long-range DEPT ¹³C NMR new technique has been sucessfully used to identify ¹³C nuclei and to connect the spin system separated by quaternary carbons and heteroatoms in the compound. Total assignment of ¹H and ¹³C NMR spectra of the compound were achieved. Its structure has been elucidated as (1).

Gibberellins form an important group of plant growth hormone, which have many biological activities. Its structure was determined by X-ray single crystal diffraction, no complete assignment of ¹H and ¹³C NMR spectrum of the compounds have been reported. In this paper, all the ¹H and ¹³C NMR chemical shifts of methyl gibberellate (2), 13-acetoxygibberellin A₁ methyl ester (3) and its 3-epimer (4) were assigned by ¹H-¹H COSY, ¹³C-¹H COSY, NOESY and DEPT, and their relative configurations were discussed.

By combination of several NMR techniques (including ¹H-¹H、¹H-¹³C COSY、RELAY, and COLOC), the spin systems and sequences of amino acid residues of heterophyllin A and B, two new cyclopeptides which were isolated from Pseudostellaria heterophylla, have been successfully elucidated. The results indicated the sequences of amino acids with NH can be satisfactorily determined by COLOC when the ⁿJ_(XH) were 6Hz to 15Hz.

We have got various patterns of proton spectra of crystal violet in different solvents by the superconducting NMR spectrometer. The numbers of proton in the spectra are explained with the concept of "molecule hole" which affect on the protons in the molecule at resonance state. The action of protonation are studied by the Raman and UV/Vis spectra.

The characteristic and kinetics of free radical decay in irradiated starch from sweet potato have been investigated by ESR at room temperature. It is found that the relative concentration of free radical is related to the dose. The decay follows second order kinetics at room temperature. The constant of decav and half life of free radical have been obtained.

In this paper ¹H NMR spectra of fifty phosphonium and arsonium ylides were analysed. The relationship between the structure of phosphorus and arsenicylides and their ¹H NMR spectra was discussed.

An analysis has been made on the residual sidebands in TOSS spectra caused by the errors in π pulse widths and the resonance offset effects, from which it can be concluded that phase cycling can efficiently suppress these residual sidebands to the first order. In a large range of resonance offsets, the efficiency of the phase cycling method has been tested experimentally.

¹H and ¹³C NMR spectra of 3'(, 3")-(di)-formyl-(di)-benzo crown ethers (1~7) and 4'-formyl-benzo-15-crown-5(8) were recorded and assigned firstly by combination of ¹H-¹H COSY, ¹³C-¹H COSY and COLOC 2D NMR experiments. The structures of Crown 4 and Crown 5-the synthetic products were determined by ¹H-¹H NOESY spectra and rudimentary discussion was given for the conformational isomers of Crown 4. Referred to the ¹H, ¹³C chemical shifts of Crown 1~8a general rule is proposed for the assignment of ¹H, ¹³C chemical shifts of the methylenes of benzo crown ethers.