The effects of 4 wt% rhenium （Re） addition on isothermal oxidation behavior of Tribaloy T-800 alloy have been studied at 800 °C and 1 000 °C in air. At 800 °C,T-800 shows nonuniform oxidation between ...The effects of 4 wt% rhenium （Re） addition on isothermal oxidation behavior of Tribaloy T-800 alloy have been studied at 800 °C and 1 000 °C in air. At 800 °C,T-800 shows nonuniform oxidation between dendritic and eutectic areas. Re addition clearly promotes the nonuniform oxidation,leading to considerably higher mass gains than that of T-800 at this temperature. At 1 000 °C exposure,the thickness of scale on T-800 increases significantly,accompanied by severe scale spallation during cooling to room temperature. On the contrary,T-800Re shows a marked decrease of oxide growth rate compared to the linear one of T-800 at 1 000 °C. The scale adhesion is also improved with Re addition at this higher temperature. Therefore,the role of Re depends on the exposure temperature. Re addition gives high oxidation rate at 800 °C,however,the excellent oxidation resistance is obtained by the addition of Re at a higher temperature of 1 000 °C.展开更多
介绍江苏某码头高桩墩台配套的2台800 t扒杆起重机在试车过程中,其所在高桩墩台的受力特征以及墩台变形,并通过数值仿真加以验证。试验与模拟结果表明:墩台顶板、底板及桩基的应变和墩台整体位移实测值能够反映出其在承载8.2 k N幅度45 ...介绍江苏某码头高桩墩台配套的2台800 t扒杆起重机在试车过程中,其所在高桩墩台的受力特征以及墩台变形,并通过数值仿真加以验证。试验与模拟结果表明:墩台顶板、底板及桩基的应变和墩台整体位移实测值能够反映出其在承载8.2 k N幅度45 m工况条件下的真实受力状态;通过数值模拟得到的墩台顶面、底面及桩基的应变及墩台整体位移与实测数据进行比对分析,两者基本吻合、相互验证,为高桩墩台三维设计方法提供重要依据。展开更多
Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） w...Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.展开更多
文摘The effects of 4 wt% rhenium （Re） addition on isothermal oxidation behavior of Tribaloy T-800 alloy have been studied at 800 °C and 1 000 °C in air. At 800 °C,T-800 shows nonuniform oxidation between dendritic and eutectic areas. Re addition clearly promotes the nonuniform oxidation,leading to considerably higher mass gains than that of T-800 at this temperature. At 1 000 °C exposure,the thickness of scale on T-800 increases significantly,accompanied by severe scale spallation during cooling to room temperature. On the contrary,T-800Re shows a marked decrease of oxide growth rate compared to the linear one of T-800 at 1 000 °C. The scale adhesion is also improved with Re addition at this higher temperature. Therefore,the role of Re depends on the exposure temperature. Re addition gives high oxidation rate at 800 °C,however,the excellent oxidation resistance is obtained by the addition of Re at a higher temperature of 1 000 °C.
文摘介绍江苏某码头高桩墩台配套的2台800 t扒杆起重机在试车过程中,其所在高桩墩台的受力特征以及墩台变形,并通过数值仿真加以验证。试验与模拟结果表明:墩台顶板、底板及桩基的应变和墩台整体位移实测值能够反映出其在承载8.2 k N幅度45 m工况条件下的真实受力状态;通过数值模拟得到的墩台顶面、底面及桩基的应变及墩台整体位移与实测数据进行比对分析,两者基本吻合、相互验证,为高桩墩台三维设计方法提供重要依据。
基金the Laboratory of Biotechnology and Environment as well as the Food and Nutrition Research Center(CRAN)of Institute for Medical Research and Study of Medicinal Plants in Cameroon for their support
文摘Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.
