Experimental observation of disclinations of main一chain nematic polymers is re-viewed. The geometry of disclination structure is dicussed both from observations of schlieren texture and the theory of curvature elasticity for a two-dimensional case with equal splay and bend moduli. The effects of unequal elastic moduli, the nature of the disclination core and the observation of inversion walls are briefly mentioned. Examples of experimental observation of disclinations of high topological strengths up to s=4 are given. The main experimental methods to map the director field around disclinations are 1) lamellar decoration, 2 ) band-texture decora-tion and 3)surface microcrack decoration. The methods are discussed and compared. Examples illustrated by electron microrrraphs or photomicroeraphs are presented.

After a comparison between the contents of the Fifth National Congress on Quantum Chemistry and those of the last three Quantum Chemistry Sanibel Symposia, we tentatively discuss the present situation, progress and prospects of quantum chemistry.

Rotaxane is a special kind of complexes in which ringlike molecules surround the long chains of other molecules. In this paper, composition, synthesis, some properties and applications, as well as research methods of rotaxane complexes, esp. those with cyclodextrin as ringlike molecules are reviewed. Some research aspects that should pay attention to are rec-ommended .

This review dealt with the present situation of the study and commercialization of the various pathways for synthesizing L-Phenylalanine both at home and abroad. Emphasis was given to the pathway from traps-cinnamic acid and ammonia. Some suggestions were also proposed for further work in China.

The developments of asymmetric catalytic epoxidation systems were reviewed,with emphasis on the inspiring results and promising application of asymmetric epoxidation of unfunctionalized cis-olefins catalyzed by optical active(salen) Mn()complexes [salen=N'-ethylenebis( salicylideneaminato)]，as well as the merits, mechanism, new developments and applications of Sharpless-Katsuki asymmetric epoxidation.

The recent development of the 3D-QSAR research has been reviewed, includingCoMFA, APEX-3D, Ludi and Leapfrog. All these methods are 3D computer-aided melocular design commercial softwares. They are playing more and more important role in desinging new drugs and finding lead compounds.