Aims of research: Proposing some of measures to organize teaching practices in training Mathematics teachers at Teacher Training Institutions in Lao PDR, contribute to meet the human resource requirements of Laos in the new period.

Besides introduction and conclusion, this thesis consists of 3 chapters. Chapter 1. Overview of Bose-Einstein condensate. Theory of BECs.Chapter 2. Interfacial tension and wetting phase transition in the system of BECs limited by one hard wall. Chapter 3. Finite-size effects of interfacial tension in the system of BECs limited by two hard walls.