During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance, steel quality and environment of casting operation. The high temperature microscopy technique was used to inve...During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance, steel quality and environment of casting operation. The high temperature microscopy technique was used to investigate the melting behaviour of mold fluxes, and drip test method was used to determine their melting rate. The results showed that free carbon is a dominant factor in governing the melting behaviour of fluxes, and the melting rate is increased with increasing carbon reactivity and decreasing carbon content.展开更多
The solidification behavior of AISI DC 53 cold work tool steel was investigated by means of a cooling curve and its first derivative. Copper and sand wedge-shaped molds were used to obtain various solidification rates...The solidification behavior of AISI DC 53 cold work tool steel was investigated by means of a cooling curve and its first derivative. Copper and sand wedge-shaped molds were used to obtain various solidification rates.To reveal the cooling rate degree during solidification, the secondary dendrite arm spacing of the steel alloy was examined by scanning electron microscopy (SEM). The solidification rates of each section for both wedge steel samples were calculated by means of the secondary dendrite arm spacing using a research-based empirical relation from the literature. Experiment results revealed that at the tip region of the cast specimen in the copper wedgeshaped mold, the carbide size was 7?μm, where the solidification rate was approximately 4,830 ℃.s-1. The greatest carbide size obtained in the upper region of the sand cast wedge-shaped specimen was 250-70 μm.展开更多
In order to investigate antifungnl effect of medicinal plant extracts on Botrytis cinerea, the antifungal activity of ethanol extracts of 8 medicinal plants in- eluding Ginkgo biloba against Botrytis cinerea was deter...In order to investigate antifungnl effect of medicinal plant extracts on Botrytis cinerea, the antifungal activity of ethanol extracts of 8 medicinal plants in- eluding Ginkgo biloba against Botrytis cinerea was determined by growth rate method. The results showed that Ginkgo biloba and Ginnamomum cassia extracts had significant inhibition effects on B. cinema mycelium growth （P 〈 0.05）, with inhibition rates over 70% and ECho values of 0.027 mg/ml and 0.039 mg/ml, re- spectively, significantly different from the antifungal effects of other kinds of medicinal plants ; and P. ternata and A. tsaoko extracts showed the second highest in- hibition effects, with ECho values of 0. 011 9 and 0. 039 3 mg/ml, respectively. Further experimental application could be carried out.展开更多
The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding...The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding device, and then immersed into phosphate buffer saline （PBS） for in vitro degradation experiments. The mechanisms of degradation and the degradation rate were characterized by the change in molecular weight and reduction in specimen mass. In addition, the effects of processing temperature and the geometry of the formed PSADT tablets on the rate of degradation were studied. The surface morphology at different degradation times was observed by scanning electron microscopy （SEM）. The experimental results showed that PSADT exhibited sur^hce erosion due to the fact that near zero-order degradation kinetics was observed during its degradation process. Moreover, it is found that the geometry of tablets played an important role on the rate of degradation, while the processing temperature had no significant effect on the PSADT degradation rate.展开更多
文摘During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance, steel quality and environment of casting operation. The high temperature microscopy technique was used to investigate the melting behaviour of mold fluxes, and drip test method was used to determine their melting rate. The results showed that free carbon is a dominant factor in governing the melting behaviour of fluxes, and the melting rate is increased with increasing carbon reactivity and decreasing carbon content.
文摘The solidification behavior of AISI DC 53 cold work tool steel was investigated by means of a cooling curve and its first derivative. Copper and sand wedge-shaped molds were used to obtain various solidification rates.To reveal the cooling rate degree during solidification, the secondary dendrite arm spacing of the steel alloy was examined by scanning electron microscopy (SEM). The solidification rates of each section for both wedge steel samples were calculated by means of the secondary dendrite arm spacing using a research-based empirical relation from the literature. Experiment results revealed that at the tip region of the cast specimen in the copper wedgeshaped mold, the carbide size was 7?μm, where the solidification rate was approximately 4,830 ℃.s-1. The greatest carbide size obtained in the upper region of the sand cast wedge-shaped specimen was 250-70 μm.
基金Supported by Natural Science Foundation of China(31460491)Applied Basic Research Project for Youth Scientists of Science and Technology Department of Yunnan Province(2013FD040)+2 种基金Scientific Research Project of Education Department of Yunnan Province(2014Y390)Talent Introduction Project of Kunming University(YJL14005)Fund for Construction of Characteristic Key Discipline(Ecology)in Colleges and Universities in Yunnan Province
文摘In order to investigate antifungnl effect of medicinal plant extracts on Botrytis cinerea, the antifungal activity of ethanol extracts of 8 medicinal plants in- eluding Ginkgo biloba against Botrytis cinerea was determined by growth rate method. The results showed that Ginkgo biloba and Ginnamomum cassia extracts had significant inhibition effects on B. cinema mycelium growth （P 〈 0.05）, with inhibition rates over 70% and ECho values of 0.027 mg/ml and 0.039 mg/ml, re- spectively, significantly different from the antifungal effects of other kinds of medicinal plants ; and P. ternata and A. tsaoko extracts showed the second highest in- hibition effects, with ECho values of 0. 011 9 and 0. 039 3 mg/ml, respectively. Further experimental application could be carried out.
基金Funded by the China Scholarship Council and Wisconsin Institute for Discovery(WID)the Scientific Research Staring Foundation,Fujian University of Technology,China(No.GY-Z13028)+1 种基金the Programfor New Century Excellent Talents in Fujian Province University(NCETFJ-2010)the Research Fund for Fujian Provincial University(JK-2010038)
文摘The in vitro degradation rate of polyanhydride （poly（sebacic acid）, diacetoxy terminated）, also known as PSADT, was investigated. PSADT tablets with a circular cross-section were formed using a compression molding device, and then immersed into phosphate buffer saline （PBS） for in vitro degradation experiments. The mechanisms of degradation and the degradation rate were characterized by the change in molecular weight and reduction in specimen mass. In addition, the effects of processing temperature and the geometry of the formed PSADT tablets on the rate of degradation were studied. The surface morphology at different degradation times was observed by scanning electron microscopy （SEM）. The experimental results showed that PSADT exhibited sur^hce erosion due to the fact that near zero-order degradation kinetics was observed during its degradation process. Moreover, it is found that the geometry of tablets played an important role on the rate of degradation, while the processing temperature had no significant effect on the PSADT degradation rate.
