The effect of the ammonium molybdate concentration on the material removal rate（MRR） and surface quality in the preliminary chemical mechanical polishing（CMP） of a rough glass substrate was investigated using a si...The effect of the ammonium molybdate concentration on the material removal rate（MRR） and surface quality in the preliminary chemical mechanical polishing（CMP） of a rough glass substrate was investigated using a silica-based slurry.Experimental results reveal that the ammonium molybdate concentration has a strong influence on the CMP behaviors of glass substrates.When the ammonium molybdate was added to the baseline slurry,polishing rates increased,and then decreased with a transition at 2 wt.%,and the root mean square（RMS） roughness decreased with increasing ammonium molybdate concentration up to 2 wt.%,after which it increased linearly up to 4 wt.%.The improvement in MRR and RMS roughness may be attributed to the complexation of hydrolysis products of the glass substrate with the ammonium molybdate so as to prevent their redeposition onto the substrate surface.It was found that there exists an optimal ammonium molybdate concentration at 2 wt.%for obtaining the highest MRR and the lowest RMS roughness within a particular polishing time.展开更多
[ Objective] This study aimed to optimize the extraction conditions of high-activity phytase from triticale. [ Method] Food and forage triticale 209 was used as an experimental material to investigate the optimal extr...[ Objective] This study aimed to optimize the extraction conditions of high-activity phytase from triticale. [ Method] Food and forage triticale 209 was used as an experimental material to investigate the optimal extraction conditions, including pH, solid-liquid ratio, extraction duration and active agent concentra- tion. The extracted phytase was purified with salting-out concentration method for SDS-PAGE eIectrophoresis Total protein content was measured using Bradford method; phytase activity was measured using vanadium ammonium molybdate method in accordance with the national standard GB/T 18634 -2009. [ Result] Phytase activity reached the highest under extraction conditions of pH 5.0, solid-liquid ratio 10, room temperature, shaking speed 200 r/min and shaking duration 1 h, without addition of active agems. [ Condusion] This study improved the extraction technology of phytase from wheat plants and was suitable for practical ap- plication.展开更多
基金Project supported by the National Integrated Circuit Research Program of China(No.2009ZX02030-001)the Science and Technology Council of Shanghai,China(Nos.08111100300,08111100303,0952nm00200)+2 种基金the Shanghai Rising Star Program of China (No.07QH14017)the National Basic Research Program of China(Nos.2007CB935400,2010CB934300,2006CB302700)the National High Technology Research and Development Program of China(No.2008AA031402)
文摘The effect of the ammonium molybdate concentration on the material removal rate（MRR） and surface quality in the preliminary chemical mechanical polishing（CMP） of a rough glass substrate was investigated using a silica-based slurry.Experimental results reveal that the ammonium molybdate concentration has a strong influence on the CMP behaviors of glass substrates.When the ammonium molybdate was added to the baseline slurry,polishing rates increased,and then decreased with a transition at 2 wt.%,and the root mean square（RMS） roughness decreased with increasing ammonium molybdate concentration up to 2 wt.%,after which it increased linearly up to 4 wt.%.The improvement in MRR and RMS roughness may be attributed to the complexation of hydrolysis products of the glass substrate with the ammonium molybdate so as to prevent their redeposition onto the substrate surface.It was found that there exists an optimal ammonium molybdate concentration at 2 wt.%for obtaining the highest MRR and the lowest RMS roughness within a particular polishing time.
基金Supported by Doctoral Scientific Research Start-up Fund of Harbin Normal University "Molecular Genetic Research of Black-grain Wheat Pigment"(08XBSK87)
文摘[ Objective] This study aimed to optimize the extraction conditions of high-activity phytase from triticale. [ Method] Food and forage triticale 209 was used as an experimental material to investigate the optimal extraction conditions, including pH, solid-liquid ratio, extraction duration and active agent concentra- tion. The extracted phytase was purified with salting-out concentration method for SDS-PAGE eIectrophoresis Total protein content was measured using Bradford method; phytase activity was measured using vanadium ammonium molybdate method in accordance with the national standard GB/T 18634 -2009. [ Result] Phytase activity reached the highest under extraction conditions of pH 5.0, solid-liquid ratio 10, room temperature, shaking speed 200 r/min and shaking duration 1 h, without addition of active agems. [ Condusion] This study improved the extraction technology of phytase from wheat plants and was suitable for practical ap- plication.
