[Study on the Structural, Optical an Surface Plasmon Characteristics of Mo-Doped ZnO Thin Film].

Mo-doped zinc oxide (ZnO∶Mo) films were deposited with direct current magnetron sputtering on quartz substrates at room temperature. The effects of Mo doping content on the crystal structure, surface microstructure，optical properties and plasmon characteristics of the ZnO films were investigated with X-ray diffraction(XRD),atomic force microscopy (AFM),Spectrophotometer and Raman spectrometer. The XRD pattern reveals that pure ZnO film exhibits good crystallization and c-axis oriented while heavy doping leads to increasing film defects. That results decline the film crystalline quality. When Mo doping content exceeds 3.93 Wt%, the ZnO films transform c-axis oriented into amorphous. The AFM pattern indicates that the surface of amorphous MZO film is extraordinarily flat. The Rq is 498 pm. The transmittance spectra reveal that all samples have an average transmittance of 80% in the visible light range. The optical band gap energy (Eg) increases from 3.28 to 3.60 eV as the Mo doping content increase. The absorbance spectrum indicates that ZnO surface plasmon resonance absorbance perk moves to short-wavelength as the Mo doping content increase. The Raman spectrum suggests that heavy Mo doping make the Raman scattering intensity decrease significantly. This paper obtains amorphous ZnO thin film by Mo doping. That broadens the application field of ZnO thin film materials. Meanwhile, we study the effect of Mo doping concentration on ZnO thin films surface plasmon, which provides important reference value for the preparation of oxidized zinc base photonic devices.

[Analysis of complications of osteosarcoma around knee treated by resection and replacement of tumor-type prosthesis].

OBJECTIVE: To summarize the effects and complications of osteosarcoma around knee treated by wide resection and replacement by the tumor-type prosthesis. METHODS: Between July 1997 and July 2004, 117 patients with osteosarcoma around the knee had been treated with wide resection and reconstruction with prosthesis. Alcohol-devitalized tumor bone prosthetic composite were used for reconstruction in 13 patients, and allograft prosthetic composite (APC) were used in 25 patients. All patients accepted 2 cycles of chemotherapy before the surgery. RESULTS: The mean follow-up period was 3.5 years (1 - 8 years). Nine patients had failure of union at the graft-host junction. Fracture of the stem of the prosthesis occurred in 5 patients, late infection was found in 19 patients, and aseptic loosening occurred in 3 patients. Bone fracture occurred in 1 patient and prosthesis sinking occurred in 2 patients. CONCLUSIONS: The tumor-type prosthetic reconstruction offers the best knee function after resection of the tumor around the knee, and recurrence rate can be accepted. However, the tumor-type prosthesis needs further improvement because of the high complication rate.

[Extraction of heavy metals from contaminated soils with EDTA and their redistribution of fractions].

EDTA was used as extractant to leach Pb, Zn, Cu and Cd from tailing soils in soil columns. The redistributions of Pb, Zn, Cu and Cd were determined using the sequential extraction procedure of the optimized European Community Bureau of Reference (BCR) before and after extraction. The results indicated that EDTA was an effective extracting agent because of its strong chelating ability for different heavy metals. Percentage extractabilities of metal followed the sequence of Cd>Zn>Cu>Pb. The four fractions of metal could be extracted by EDTA and the proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA on the acid-extractable fraction was significant in shallow soil column, while in deeper soil column, a descent of the extraction efficiency on reduced, oxidizable and residual fractions was obtained. And heavy metals chelated by EDTA were more easily desorption by soil particles with the depth of the soil columns increased.