A large body of conspicuous publications in recent years asserts that the high t emperature approximation (HTA), a mostly tested and most widely used assumption  in NMR spectroscopy and MRI technology, is invalid for concentrated samples in h igh magnetic fields such as for a proton COSY spectrum of water. A by-product o f  the alleged collapse of HTA, which is equally surprising, is the existence of i ntermolecular multi-quantum-coherences (MQC) in low viscosity liquids such as  wa ter. In this work, both HTA and intermolecular MQCs in liquids will be criticall y examined in light of our theoretical analysis and experimental results. Our co nclusions are: (1) There are no macroscopic quantum systems in conventional NMR samples such as water at room temperature. (2) At room temperature, high tempera ture approximation is still one of the most trustworthy approximations applicabl e to NMR and (3) The MQCs observed in proton COSY spectrum in, e.g., water, have  nothing to do with quantum mechanical intermolecular spin interactions.

Based on systematical induction and summarization of data  o f ¹⁷O-NMR chemical shifts of hydroxy-contained compounds already reported,  the article provides the equation(1):  δ_cal=δ_0n+Δα+Δβ+Δγ for primary, secondary, tertiary  alcohol and i-R—OH(em-R refers to substituents whose atom directly connected with hydroxy not telong ed to chain alkane) and equation(2):  δ_cal=δ₀+Δo+Δm+Δp for substituted hydroxybenzenes. 15 substituent parameters for calculating the ¹⁷O-NMR chemical shifts of alcoho ls  and carboxylic acids and 23 substituent parameters for substituted hydroxybenze nes are gained with regression analysis in connection with least square. Equatio n(1) is checked regressively by the ¹⁷O-NMR chemical shifts of 140  compounds of primary, secondary,  tertiary alcohol and i-R—OH,  and equati on(2) is checked regressively by ¹⁷O-NMR chemical shifts of 60 compounds of  substituted hydroxybenzenes. Consequently,  their confidence limits both are 99. 5% and calculating errors(4δ) for over 90% compounds are less than (relatio nerrors 0.5%).

Two new sesquiterpene polyols were obtained by basic hydrolysis of the  crude extract from the root-bark of Celastrus angulatus,  together with two kn ow n compounds. Their structures were established as 1β，2β，4α，6α，8β ，9α，15-heptol-β-dihydroagarofuran（2）and 1β，2β，4α ，6β，9α，15-he xol-β-dihydroagarofuran（3）on the basis of spectroscopic methods.

From the Inner Mongolia medicinal plant, Saussurea petrovii, which was coll ecte d in the suburb of Lanzhou city, Gansu province of China, a colourless gum compo und was isolated. The compound was identified as a new eudesmane type sesquiterp ene ester, petroviin, by MS and NMR. The structure of petroviin was determined b y two-dimensional NMR spectroscopy for the first time. All the ¹H and ¹³C NMR resonances   were assigned unambiguously. The relative configuration of petroviin was also  evaluated.

¹H NMR spectroscopy of amniotic fluid of chick embryo was reported for  the f irst time. 29 compounds, including amino acids, organic acids, carbohydrates and  lipids, were observed and their ¹H NMR resonances were assigned using one- and two-dimensional NMR methods.

Superparamagnetic iron oxides (SPIO) are known for their fast T₂ (T*₂) relaxation properties which result in a strong decrease in signal intensity (negative enhancement) of such reticuloendothelial system as the liver, the spleen, and et al where they accumulate. For its low solubility in water, SPIO usually  are colloidally coated and stabilized with a matrix such as dextran or liposomes . In this work, a series of micelle coated and stabilized SPIO colloids were pre pared and the T₂ values of these SPIO micells were measured, aiming to in vestig ate the effect of properties of different micelles on SPIO solution. The experim ental data showed that both different kind of charge which the micelle has and t he molecular weight of surfactant have distinct effect on the T₂ relaxation of SPIO colloid. The SPIO colloid coated by PEG-400 was selected for the acute toxi city and MR imaging contrast test. The results indicated that there was no obviou s toxicity for this polymeric micelle coated SPIO colloid, and mini dose (20 μm o l/kg) of SPIO exhibits the obvious negative enhanced MRI signal intensity in the  rat liver tissue.

NMR experiments at various temperature or with different solvents were  used to characterize the nature of hydrogen bonds and conformation of several c omplexes in solution, namely the trans(N, t-N) isomer of ［Co(tren)(DL-phen ylalaninato)］(ClO₄)₂(Ⅰ), Co(tren)(L-pro-linato)］I₂·H₂O(Ⅱ), ［Co(tren)(L-valinato)］I₂·1/3H₂O(Ⅲ), Co(tren)(L-isoleucinato)］I₂(Ⅳ), ［Co(tren)(L-leucinato)］I₂(Ⅴ). Compared with their crystal structures in  whi ch inte rmolecular double or single hydrogen bonds were observed. Intramolecular double  or single hydrogen bonds formed by the carbonyl oxygen of the amino acidato li gand and the amino hydrogen of the tren ligand were observed in Ⅲ, Ⅳ, Ⅴ. Whil e the situations in Ⅰand Ⅱ need more investigations. The ¹H and ¹³C NMR assignments were achieved by 2D NMR（COSY and HMQC ）.

Pulse programmer is an essential component in nuclear magnetic resona nce spectrometer. In this paper, a pulse programmer, developed using Delphi 5, i m plemented totally by software will be discussed in detail. It can generate pulse s with 12 ns resolution and 1.3 μs minimal width when the CPU clock is 333 MHz. Some experiments will be shown to demonstrate the features of this software pulse programmer.

Four compounds were isolated from water-soluble part of whole plant of Morina nepalensis var. alba Hand.-Mazz.by CC on Si gel, RP-8, Sephadex LH-20. Based on spectroscopic evidences,  their structures were elucidated as 3-O-caffeoyl-quinic acid (1), 3, 5-O-dicaffeoyl-quinic acid (2), 3,  4-O- dicaffeoyl-quinic acid (3] ) and 4, 5-O- dicaffeoyl-quinic acid (4), respectively. Complet e assignments of ¹H and ¹³C spectra of these four compounds were obtained by 2D NMR spe ctra. Furtherm ore, ¹H and ¹³C Chemical shifts of compound 1 and 2 were determined with both in CD₃OD and DMSO-d₆ solvent. All four compounds were firstly isolated from the Morin a plants. 

The ¹H and ¹³C NMR chemical shifts of Diazinon were assigned  by means of 1D and 2D NMR techniques.With the theory of orbitals hybridization, the differences of the chemical environment of the two ethoxies(OCH₂CH₃) in diazinon molecule and the characteristics of their spectra were discussed.

In this paper the process of synthesizing clindamycin has been observed by ³¹P NMR, especially, the hydrolyzing reaction form of clindamycin phosphate chl oride  was investigated. And some reaction mechanism has been discussed. The rational reaction condition was obtained by the study.

The photoreactions of 1-acetylindole-2,  3-didone (AID) with several hydrogen  don ors in benzene-d₆ and acetonitrile-d₃ at room temperature were investigate d by m easurement of the chemically induced dynamic nuclear polarization (CIDNP). The polarization pattern of AID indicates an intermediate with spin density distribut ion of a σ π radical, in this case, aneutral radical AIDH· was formed.; A hydrogen attraction interaction between 3AID+* and the donors result ed in the  formation of stable neutral radical pairs,  which have triplet multiplicity and can diffuse apart to make the pair loose enough for the nuclear polarization to b e developed. The radical pairs could undergo back hydrogen transfer or separate  and diffuse and meet again to lead to the observed products.

The magnetic properties of the complex MnLL′ (L: mnt^2-,  maleonitriledithiolate:  L′=phen-5, 6-dione, 1, 10-phenanthroline-5, 6-dio ne) were characterized by variable-temperature susceptibility and EPR of solid powder, EPR in DMSO, DMF and acetone solutions. The title complex MnLL′is hi gh spin tetracoordinate complex. The complex MnLL′possess remarkable paramagnet ism. Experiment fact of EPR of MnLL′is explained by theory.

This paper reviews the NMR methods to determine the absolute stereoche mistry of organic compounds.The methods are classified into two types in terms o f the principle in this paper. One applies magnetic anisotropy effect of phenyl orother aryl groups, such as Mosher method, methods utilizing MPA or other AM As chiral reagents. The other type applies glycosylation shift effects due to glyco sylate reactions, such as tetra-O-benzoyl glucosylation method and fucofurano side method. This review deals with the principle,  the determining process, the advantages and disadvantages of each mothod.