ZnO thin films were prepared by electrophoretic deposition on stainless steel wire sieve, using zinc acetate as a precursor. The film was sintered and characterised by Scanning Electron Microscopy （SEM）, X-Ray Diffr...ZnO thin films were prepared by electrophoretic deposition on stainless steel wire sieve, using zinc acetate as a precursor. The film was sintered and characterised by Scanning Electron Microscopy （SEM）, X-Ray Diffraction （XRD） and chemisorption of oxygen. A culture bacterial consortium composed by gram negative rod-shaped microbes was prepared in a liquid agar in a flask. It was transported by air through a reactor equipped with a UV lamp with 3 and 5 sieves of a stainless steel wire coated with ZnO film. It was exposed in continuous in five experiments to photocatalytic advanced oxidation. The experiments showed a total efficiency for colony forming unit reduction of a maximum of 99.66% for a residence time of 20 seconds with 5 stainless steel wire where exposed in continuous to UV. Also they were evaluated at 7.5 seconds, observing that the contribution of residence time and amount of catalytic for the CFU reduction was quite similar. Variance analysis showed that the efficiency was significant with the no parametric Kruskal-Wallis test with P 〈 0.05. This technology could be used to clean indoor air of closed environments such as hospitals, crowded buildings or public transportation systems where airborne bacteria has been documented.展开更多
The arc characteristics of submerged arc welding （SAW） with stainless steel wire were studied by using Analysator Hannover （AH）. The tests were carded out under the same preset arc voltage combined with different ...The arc characteristics of submerged arc welding （SAW） with stainless steel wire were studied by using Analysator Hannover （AH）. The tests were carded out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution （PDD） curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.展开更多
This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc...This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc physics and the alloy elements in the solid wire. The result shows that when the proportion of helium in the above-noted mixed gases excesses 45 percent, the mechanical properties and the intergranular corrosion tendency meet corresponding Chinese standards. Further, the alloy elements in the solid wire can react with oxygen during the period of high temperature boosted by helium arc ; this result in the formation of a bed of thin slag, which can avoid the oxidation of the backing weld and eliminate the need of backing gas.展开更多
文摘ZnO thin films were prepared by electrophoretic deposition on stainless steel wire sieve, using zinc acetate as a precursor. The film was sintered and characterised by Scanning Electron Microscopy （SEM）, X-Ray Diffraction （XRD） and chemisorption of oxygen. A culture bacterial consortium composed by gram negative rod-shaped microbes was prepared in a liquid agar in a flask. It was transported by air through a reactor equipped with a UV lamp with 3 and 5 sieves of a stainless steel wire coated with ZnO film. It was exposed in continuous in five experiments to photocatalytic advanced oxidation. The experiments showed a total efficiency for colony forming unit reduction of a maximum of 99.66% for a residence time of 20 seconds with 5 stainless steel wire where exposed in continuous to UV. Also they were evaluated at 7.5 seconds, observing that the contribution of residence time and amount of catalytic for the CFU reduction was quite similar. Variance analysis showed that the efficiency was significant with the no parametric Kruskal-Wallis test with P 〈 0.05. This technology could be used to clean indoor air of closed environments such as hospitals, crowded buildings or public transportation systems where airborne bacteria has been documented.
基金financially supported by the Shanxi Provincial Key Programs for Science and Technology Development (No. 20100321084)Taiyuan Special Foundation for Excellent Talents (No. 20111075)
文摘The arc characteristics of submerged arc welding （SAW） with stainless steel wire were studied by using Analysator Hannover （AH）. The tests were carded out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution （PDD） curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.
文摘This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc physics and the alloy elements in the solid wire. The result shows that when the proportion of helium in the above-noted mixed gases excesses 45 percent, the mechanical properties and the intergranular corrosion tendency meet corresponding Chinese standards. Further, the alloy elements in the solid wire can react with oxygen during the period of high temperature boosted by helium arc ; this result in the formation of a bed of thin slag, which can avoid the oxidation of the backing weld and eliminate the need of backing gas.
基金Project(52130509) supported by the National Natural Science Foundation,ChinaProject(BIPTACF-010) supported by the Cultivation Foundation from Beijing Institute of Petrochemical Technology,China。
