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In order to explore the comprehensive properties of heat convection in H-type finned tubes installed with small rectangular wings or triangular wings as the longitudinal vortex generators, the field synergy principle was adopted in analysis. At the same attack angle, the surface average and volume average synergy angles of the small triangular wings are bigger than those of the small rectangular wings; at the same time, the volume average synergy angles are bigger than the surface average ones. With the increase of the attack angle, both the surface average and volume average synergy angles decrease first but increase later, which reach their minimum values at the 60° attack angle for the rectangular wings but at the 45° attack angle for the triangular wings. At the same inlet velocity, both the surface average and volume average synergy angles of the 45°-attack-angle triangular wings are bigger than those of the 60°-attack-angle rectangular wings. With the increase of the inlet velocity, both the surface average and volume average synergy angles increase for the 60°-attack-angle rectangular wings and the 45°-attack-angle triangular wings as well. [ABSTRACT FROM AUTHOR]

Objective: To study the clinical effects and security of nanometer ceramics artificial bone transplantation to treat the bone defect., Methods: From March 2005 to November 2007, 32 patients (artificial bone group) with extremity bone defects applied nanometer ceramics artificial bone transplantations, included 19 males and 13 females, aged from 17 to 63 years old (averaged 31.4 years). The other 36 patients (internal fixation group) with extremity bone defects were treated by the internal fixation in the same period, included 21 males and 15 females, aged from 16 to 65 years old (averaged 32.6 years). Ca, P, B-ALP, IgG, IgA, IgM, CIC, C3, SL-2R and CD4+/CD8+ in the peripheral venous blood were measured in the 1st and 2th week and 1st, 3rd, 6th month after operation. All patients were followed up and the limb function was evaluated according to Enneking standard., Results: The wounds of all patients smoothly healed after operation. Every immunological indicators had no significant difference between two groups. Serum calcium and phosphorus content did not significantly increased. Serum B-ALP of all patients were increased after operation, fell to normal levels in the internal fixation group, but remained at a relatively high level in the artificial bone group. All patients were followed-up for from 9 to 24 months (averaged 15 months). All patients get the excellent physical function., Conclusion: The artificial bone has no immunogenicity, no rejection,does not affect the blood calcium and phosphorus content, and has higher osteogenic activity. It is affirmed that nanometer ceramics artificial bone is used to treat the smaller bone defect on clinical.