[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A st...[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A strain ZY-19-2 with strong inhibitory effect against P. parasitica were isolated and screened from tobacco rhizosphere soil samples, and identified according to its morphological characteristics. The chitinase production activity of the strain under different culture conditions was also studied. [Result] For stain ZY-19-2 Paecilomyces lilacinus, the optimal fermentation conditions were as follows： 1.2% colloidal chitin as carbon source, 1% peptone as nitrogen source, 0.1% Tween 80 as surfactant, initial pH of fermentation broth at 6.0, the fermentation time of 60 h, inoculum amount at 1%, shaker speed at 120 r/min. The highest enzyme activity reached 0.216 U/ml. [Conclusion]The optimization of fermentation condition of strain ZY-19-2 lay foundation for large-scale production of cheap and efficient chitinase and chitin oligosaccharides, as well as application of the strain for control of tobacco black shank.展开更多
In the pursuit of stable,high performance Ni-based oxygen evolution reaction(OER)electrocatalysts,modifying the local chemical compositions or fabricating hybrid nanostructures to generate abundant interfaces for impr...In the pursuit of stable,high performance Ni-based oxygen evolution reaction(OER)electrocatalysts,modifying the local chemical compositions or fabricating hybrid nanostructures to generate abundant interfaces for improving the water oxidation activity of electrocatalysts has emerged as an effective strategy.Herein,we report the facile development of a Ni_(3)S_(2)-CeO_(2)hybrid nanostructure via an electrodeposition method.Benefiting from the strong interfacial interaction between Ni_(3)S_(2)and CeO_(2),the electron transfer is notably improved and the water oxidation activity of Ni_(3)S_(2)nanosheets is significantly enhanced.In 1.0 M KOH,the Ni_(3)S_(2)-CeO_(2)electrocatalyst achieves a current density of 20 mA cm-2 at a low overpotential of 264 mV,which is 92 mV lower than that of Ni_(3)S_(2).Moreover,Ni_(3)S_(2)-CeO_(2)exhibits superior electrochemical stability.Density functional theory calculations demonstrate that the enhanced OER electrocatalytic performance of Ni_(3)S_(2)-CeO_(2)can be ascribed to an increase in the binding strength of the reaction intermediates at the Ni_(3)S_(2)-CeO_(2)interface.展开更多
The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water cont...The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.展开更多
基金Supported by Technology Development Project of Zhengzhou Tobacco Research Institute of CNTC"Isolation,Application and Research of Disease-resistant Endophyte"(122009CZ0420)~~
文摘[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A strain ZY-19-2 with strong inhibitory effect against P. parasitica were isolated and screened from tobacco rhizosphere soil samples, and identified according to its morphological characteristics. The chitinase production activity of the strain under different culture conditions was also studied. [Result] For stain ZY-19-2 Paecilomyces lilacinus, the optimal fermentation conditions were as follows： 1.2% colloidal chitin as carbon source, 1% peptone as nitrogen source, 0.1% Tween 80 as surfactant, initial pH of fermentation broth at 6.0, the fermentation time of 60 h, inoculum amount at 1%, shaker speed at 120 r/min. The highest enzyme activity reached 0.216 U/ml. [Conclusion]The optimization of fermentation condition of strain ZY-19-2 lay foundation for large-scale production of cheap and efficient chitinase and chitin oligosaccharides, as well as application of the strain for control of tobacco black shank.
文摘In the pursuit of stable,high performance Ni-based oxygen evolution reaction(OER)electrocatalysts,modifying the local chemical compositions or fabricating hybrid nanostructures to generate abundant interfaces for improving the water oxidation activity of electrocatalysts has emerged as an effective strategy.Herein,we report the facile development of a Ni_(3)S_(2)-CeO_(2)hybrid nanostructure via an electrodeposition method.Benefiting from the strong interfacial interaction between Ni_(3)S_(2)and CeO_(2),the electron transfer is notably improved and the water oxidation activity of Ni_(3)S_(2)nanosheets is significantly enhanced.In 1.0 M KOH,the Ni_(3)S_(2)-CeO_(2)electrocatalyst achieves a current density of 20 mA cm-2 at a low overpotential of 264 mV,which is 92 mV lower than that of Ni_(3)S_(2).Moreover,Ni_(3)S_(2)-CeO_(2)exhibits superior electrochemical stability.Density functional theory calculations demonstrate that the enhanced OER electrocatalytic performance of Ni_(3)S_(2)-CeO_(2)can be ascribed to an increase in the binding strength of the reaction intermediates at the Ni_(3)S_(2)-CeO_(2)interface.
基金Supported by Fundamental Research Funds for the Central Universities(ZXH2009D021)the Scientific Research Project Foundation of Civil Aviation University of China(09CAUC_S05)
基金supported by the National Natural Science Foundation of China (Grant No. 51108245)the National Basic Research Program of China ("973" Project) (Grant No. 2009CB623106)
文摘The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.
