A NOVEL MODIFICATION TECHNIQUE FOR METAL SURFACE

A novel solution-are discharge surface modification technique has been introduced in this paper,ln this modification technique, the speed of mass transport in surface and diffusion Layer is much higher than that of other ways, such as ion implantation, PVD, CVD, PCVD, glow discharge plasma treatment, etc. The solution-arc discharge plasma belongs to a plasma in high air pressure. Its cathode electric field, electric charge density and current density are much larger than those of Low temperature plasma. The voltage-current characteristic has been measured. Mechanical and electrochemical properties of some steel treated with solution-arc discharge have been studied. As to the mechanism of this technique, an analysis has been given.

Study on the surface properties of surface modified silicone intraocular lenses

AIM: To prepare a new-type soft intraocular lens (IOL) that silicone intraocular lenses (IOLs) were modified by surface modification technique to assess IOLs biocompatibility. METHODS: With the technique of ion beam combined with low temperature and low pressure plasma, the surface characteristics of the IOLs including physical and optical properties were determined by the instruments of IOLs resolution, UV/VIS scanning spectrophotometer, contact angle measurement system, electron spectroscopy for chemical analysis (ESCA) and scanning electron microscope (SEM). RESULTS: The color of titanium (Ti) modified IOLs was light yellow and that of titanium nitride (TiN) modified IOLs was light brown. The absorptive degree of ultraviolet rays and the hydrophilicity of the surfaces of modified IOLs were increased, and appeared suitable chemical compositions. The resolution of unmodified and modified IOLs reached normal standard. The surfaces of unmodified and Ti-modified IOLs appeared uniform. The surfaces of TIN-modified IOLs presented fine porcelain structure. CONCLUSION: The optical properties of all IOLs and the surface morphology of the modified IOLs were not affected by modification processes. The surface properties of the modified IOLs were improved.

Application advances of catheter modification in difficult coronary artery Intervention

Background Judkins catheter is widely used in recent years, for clinical angiography and intervention of most normal coronary arteries, but still incapable to deal with the problems caused by difficult coronary artery （DCA）. DCA may influence the procedure of diagnosis and intervention of ischemic heart disease （IHD）. To cope with different subtypes of DCA, catheters like Amplatz, EBU, Leya, etc. were born at that moment, but these stan- dard catheters are used just in special cases and have so many sequences that a local hospital may not be able to keep all of them available routinely at any time. To overcome this problem, some centers perform angiography and intervention using modified catheters based on their own condition and have obtained some experiences. Catheter modification techniques used in these years are reviewed, and are stated respectively based on dealing with different subtypes of DCA to provide practical guidance for clinical diagnosis and intervention for IHD patients having DCA.

Effects of light exposure on the TL dating of pottery

Bleaching experiments on Chinese pottery fine grains were conducted under sunlight and laboratory light conditions. It is found that the thermoluminescence (TL) at high temperatures can be bleached significantly, but no effects were observed on TL signals used for the pre-dose dating technique. It is concluded that the pre-dose dating technique can be applied to samples even after light exposures. Pottery samples of Tang Dynasty and New Stone Age were studied. Modifications to routine pre-dose dating technique are proposed with adding preheat procedures and using saturation exponential fitting for the sensitivity change data. The modified technique can extend the dating range to New Stone Age.

Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis

Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, UV–Vis spectroscopy and scanning electron microscopy（SEM）. The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye,Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.