[1] [1] H. Zeng and W. R. Lacefield, Biomaterials 21, 23 (2000).

[2] [2] Y. Yang, C. Zhang, Y. Yang, and L. Chen, Chin. Opt. Lett. 3, 35 (2005).

[3] [3] Y. Zhang, J. Gao, J. Tan, and Z. Zhou, J. Mater. Res. (in Chinese) 8, 93 (1994).

[4] [4] Y. Zhang, J. Gao, and J. Wen, Mater. Sci. & Eng. (in Chinese) 17, 20 (1999).

[5] [5] J. Gao, Y. Zhang, J. Wen, and Y. Wang, Trans. Nonferrous Met. Soc. China 10, 477 (2000).

[6] [6] J. Gao and Y. Wang, Chin. J. Nonferrous Metals (in Chinese) 13, 675 (2003).

[7] [7] Y. Zhang, J. Gao, and J. Wen, Trans. Mater. and Heat Treatment (in Chinese) 56, 18 (1998).

[8] [8] J. Gao, Y. Zhang, and J. wen, Rare Metal Materials & Eng. (in Chinese) 26, 30 (1997).

[9] [9] L. Huang, H. Li, T. Fu, and K. Xu, Rare Metal Materials & Eng. (in Chinese) 28, 140 (1999).

[10] [10] J. Lee and H. Aoki, Biomed Mater Eng. 5, 49 (1995).

[11] [11] C. Deng, Y. Zhang, J. Gao, Y. Wang, and Y. Wang, Trans. Mater. and Heat Treatment (in Chinese) 25, 70 (2004).

[12] [12] C. Deng, Y. Zhang, J. Gao, Y. Wang, Y. Wang, and C. Dai, J. Mater. Sci. Eng. (in Chinese) 21, 503 (2003).

[13] [13] N. Liu, J. Chin. Rare Earth 15, 80 (1997).

[14] [14] M. Ogiso, Y. Yamashita, and T. Matsumoto, J. Biomed Mater. Res. 41, 296 (1998).