In this work, the structure of a poly(ethylene glycol) methyl ether-b- poly(L-alanine) copolymer (MPEG-b-PLA) in its solid- state was studied by ¹³C CP/MAS, DP/MAS and spin lattice relaxation time T₁ NMR experiments. The results revealed that the PEG blocks are crystallizable in the solid state of the diblock polymer, but the degree of crystallinity is considerably lower in the diblock polymer state than that in pure PEG. It was found that the PLA blocks is rigid not only because of the formation of a large number of α-helices and a small number of β-sheets as secondary structures, but also owing to PLA crystallinity in the solid state. The results also implied that Cβ is more mobile than Cα at room temperature, and the β-methyl group rotates freely around its axis.

By measuring ¹H and ¹³C NMR signals and 1H spin-lattice relaxation time T₁, we have studied the complexes formed between fluoroquinolone antimic
robials and metal ions Cr³⁺, Mn²⁺ and Fe³⁺. The complex sites of the metal ions with fluoroquinolone antimicrobials were measured.

Surfactants perfluoroheptanoic acid (PFHA) and perfluorooctanoic acid (PFOA) were studied in solvents 1,1,2-trifluorotrichloroethane (TFTCE) and n-pentanol (C₅-OH) by ¹⁹F NMR. The spectra of both compounds in both solvents displayed only one set of time-averaged spectral peaks, indicating that molecular exchange rate between micelle and monomer is faster than NMR timescale. All ¹⁹F resonance observed were assigned. Within the concentration range studied, all 19F nuclei in PFHA had lower chemical shifts (upfield shift) in TFTCE than in C₅-OH, indicating the existence of larger deshielding effects in C₅-OH. When PFHA dissolved in C₅-OH, the ¹⁹F nuclei in the α-CF₂ group had the largest chemical shift (δ), those in the ε-CF₂ and ω-CF₃ groups had
 the smallest δ; and the ¹⁹F nuclei in the β- and δ-CF₂ groups had chemical shifts in between. When dissolved in different solvents, the chemical shift differences (in TFTCE vs. in C₅-OH) of the ¹⁹F nuclei in the α-CF₂ and ω-CF₃ groups of PFHA, which locate at the ends of the fluorocarbon chain, were larger than those of the other ¹⁹F nuclei. By plotting chemical shift vs. the inverse of its concentration (1/C), the critical micellar concentrations (cmc) of PFHA was obtained, and is the concentration where the δ-1/C relationship starts to deviate from a linear relationship. cmc of PFHA in C₅-OH and in TFTCE calculated in this study were 0.0195 mol/L and 0.0406 mol/L, respectively. The cmc of PFOA in C₅-OH measured was 0.0547 mol/L. Using the chemical shift vs. 1/C relationship of different ¹⁹F nuclei to calculate cmc resulted in different values, and this might be an advantage for determining cmc using this method. By comparing the δ vs. 1/C relationship obtained experimentally with that calculated by stimulation, equilibrium constant (K) and aggregation number (n) for PFOA in C₅-OH were obtained, and were 21(mol/L)^-(n-1) and 3.9, respectively.

In this study, the coordination structure of Al³⁺ in CaO-Al₂O₃-SiO₂ aluminosilicate glasses (CAS) was studied using solid-state ²⁷Al and ²⁹Si magic-anglespinning NMR. The results showed that: 1). most Al³⁺ ions in CAS aluminosilicate glasses are present in the form of AlO₄ tetrahedra, and act as networkforming ions. A small part of Al³⁺ ions exist as network-modifying cations in the forms of six-, five- and other- coordinated aluminum. 2). O_nb/T is inversely proportional to η, where O_nb/T is the number of non-bridge oxygen atom per tetrahedra, and η is the ratio of the number of tetrahedral Al³⁺ to the total number of Al³⁺ in the region of interest (ROI). The slope of the O_nb/T vs.η relationship is influenced by γ, where γ is the ratio of the total number of Al³⁺ to the total number of Si⁴⁺ in the ROI.

Object  ]Severe spectral overlap often occurs in the ¹H and ¹³C NMR spectra of plant cyclopeptides because of the similarity in chemical shifts of different amino acid residuals.  This paper aims to look for suitable NMR techniques for structural elucidation of plant cyclopeptides. Methods 2D NMR techniques such as  HMQC, HMBC, ROESY, and HMQC-TOCSY were used to study the structure of Drymarin B, a cyclopeptide isolated from the plant Drymaria diandra B1 (Caryophyllaceae).  Results  The ¹H and ¹³C chemical shifts of the amino acid residuals (except for the quaternary carbons) can be assigned simultaneously using 2D HMQC-TOCSY  because this technique provides not only total proton correlation in the  F₂ dimension but also total carbon correlation (except for the quaternary carbons) in the F₁ dimension. The linkages among the anino acid residuals can be determined by  long range correlations from the HMBC spectra or NOEs from the ROESY or NOESY spectra. Conclusion   The 2D NMR techniques are  efficient tools for structural elucidation of plant cyclopeptides.

The basic principles of the software radio technique were introduced. The acquirements for designing a digital nuclear quadrupole resonance spectromet
er were analyzed. Some considerations on using the software radio technique in designing a spectrometer, and particularly a digital nuclear quadrupole resonance spectrometer, were discussed.

Based on a previous study on the absorption mechanisms of liquids in oil reservoir core, a method for determining the effective permeability of sandst
one was developed in this study, and the results obtained appeared relatively satisfactory. The effective permeability of sandstone determined by this method was closer to the real value than that obtained by the conventional method. The value of effective permeability derived can be used for evaluating the performance/cost ratio of using the water flooding method in an oil field, and for studying the distribution of surplus oil in an oil field. It is believed that this method will find many practical applications.

1D/2D ¹H and ¹³C NMR spectra of solid natural rubber, natural rubber latex and dissolved natural rubber in liquid phase were acquired using a BRUKER high-resolution magic angle spinning (HR/MAS) probe, a BRUKER solution broad bore (BBO) probe and a BRUKER solid CP/MAS probe. The results obtained from the three probes were compared. The results showed that high resolution 1H and 13C spectra could be obtained for solid nature rubber and rubber latex by using the HR/MAS probe, suggesting that the HR/MAS probe, in terms of signal-to-noise ratio and signal line width, is more advantageous than the CP/MAS probe for NMR studies on solid natural rubber.

¹³C NMR spectra were acquired for 5 new aryl α-naphthylacetylamides we synthesized, which can potentially be used as plant growth regulators, anti-tumor medicine and chemical picking agent for fruits. By analyzing the ¹³C NMR spectra, the structures of the compounds were determined. The effects of hemical structures on the ¹³C chemical shifts in aryl α-naphthylacetylamides were discussed.

Applications of NMR to the studies of DNA structures and dynamics are reviewed in aspects regarding NMR peak assignment, NMR constraints and structure calculation, main features of DNA NMR spectra, ring current effect on DNA chemical shifts, and DNA dynamics in solution. Unsolved problems in DNA NMR studies are also pointed out, which include: (1) The dihedral angle parameters in molecular modeling force field are not consistent with those in irregular DNA. (2) DNA structures simulated by molecular modeling usually do not have good consistency. (3) The ring current theory for explaining DNA chemical shifts is yet not ready for use. (4) The “modelfree” model has difficulties in interpreting steady-state NOE. Nonetheless, the structural and dynamical information provided by NMR is still important, and has greatly deepened our understanding of DNA.

The general situation, principles, experimental aspects and applications of time-resolved chemically induced dynamic polarization (CIDNP) is briefly reviewed.