Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast s...Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.展开更多
研究了铸态Cu-1.0Ni-0.2P合金在750、800、850、900、950℃,0.1、1.0、10.0 s-1应变率下的高温变形行为,获得其热压缩过程的流变应力-应变曲线,构建基于Arrhenius方程的本构模型和热加工图,阐明了变形温度和应变率对铸态Cu-1.0Ni-0.2P...研究了铸态Cu-1.0Ni-0.2P合金在750、800、850、900、950℃,0.1、1.0、10.0 s-1应变率下的高温变形行为,获得其热压缩过程的流变应力-应变曲线,构建基于Arrhenius方程的本构模型和热加工图,阐明了变形温度和应变率对铸态Cu-1.0Ni-0.2P合金显微组织的影响规律。结果表明:铸态Cu-1.0Ni-0.2P合金对温度、应变率较为敏感,其流变应力总体上随变形温度的升高而降低、随应变率的增大而增大,在真应变ε=0.2和ε=0.4对应的热变形激活能分别为359.102 k J/mol和498.313 k J/mol。同一温度下,当应变率为1、10 s-1时,长条变形晶粒更少或再结晶晶粒较小;随变形温度的升高,合金长条变形晶粒发生再结晶和晶粒长大,当热加工温度为900~950℃时,再结晶组织较为均匀。结合显微组织论证分析得到铸态Cu-1.0Ni-0.2P合金的最佳热加工工艺参数为900~950℃、1 s-1和900℃、10 s-1,为铸态Cu-1.0Ni-0.2P合金的热加工工艺提供理论指导。展开更多
为发展适宜中国区域农业种植特点的农业气象模式,基于国外作物生长模拟方法,通过模式机理过程改进或重构以及应用方式革新,建立了中国农业气象模式(Chinese AgroMeteorological Model version 1.0,CAMM1.0)。CAMM1.0利用平均温度和土壤...为发展适宜中国区域农业种植特点的农业气象模式,基于国外作物生长模拟方法,通过模式机理过程改进或重构以及应用方式革新,建立了中国农业气象模式(Chinese AgroMeteorological Model version 1.0,CAMM1.0)。CAMM1.0利用平均温度和土壤水分改进了作物发育进程模式,利用土壤水分改进了作物叶片光合作用、干物质分配和叶面积扩展过程模式,通过蒸发比法扩展了作物蒸散过程模式;自主建立了基于发育进程的冬小麦株高、基于遥感信息的作物灌溉、遥感数据同化、作物长势与灾害评价等模式。基于互联网技术构造了实时运转平台,主要功能包括作物生长过程实时常规模拟与用户个性化定制模拟。CAMM1.0的部分子模式采用多种方法构造,便于多模式集成。CAMM1.0对作物发育进程、光合过程、株高的模拟效果较好,但对土壤水分变化过程的拟合略差,模拟产量略偏低。CAMM1.0评价淮河流域夏玉米年际干旱减弱而涝渍增加的趋势与实际基本相符。展开更多
基金jointly supported by the National Natural Science Foundation of China (Grant Nos.42192562 and 42030605)。
文摘Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer.
文摘研究了铸态Cu-1.0Ni-0.2P合金在750、800、850、900、950℃,0.1、1.0、10.0 s-1应变率下的高温变形行为,获得其热压缩过程的流变应力-应变曲线,构建基于Arrhenius方程的本构模型和热加工图,阐明了变形温度和应变率对铸态Cu-1.0Ni-0.2P合金显微组织的影响规律。结果表明:铸态Cu-1.0Ni-0.2P合金对温度、应变率较为敏感,其流变应力总体上随变形温度的升高而降低、随应变率的增大而增大,在真应变ε=0.2和ε=0.4对应的热变形激活能分别为359.102 k J/mol和498.313 k J/mol。同一温度下,当应变率为1、10 s-1时,长条变形晶粒更少或再结晶晶粒较小;随变形温度的升高,合金长条变形晶粒发生再结晶和晶粒长大,当热加工温度为900~950℃时,再结晶组织较为均匀。结合显微组织论证分析得到铸态Cu-1.0Ni-0.2P合金的最佳热加工工艺参数为900~950℃、1 s-1和900℃、10 s-1,为铸态Cu-1.0Ni-0.2P合金的热加工工艺提供理论指导。
文摘为发展适宜中国区域农业种植特点的农业气象模式,基于国外作物生长模拟方法,通过模式机理过程改进或重构以及应用方式革新,建立了中国农业气象模式(Chinese AgroMeteorological Model version 1.0,CAMM1.0)。CAMM1.0利用平均温度和土壤水分改进了作物发育进程模式,利用土壤水分改进了作物叶片光合作用、干物质分配和叶面积扩展过程模式,通过蒸发比法扩展了作物蒸散过程模式;自主建立了基于发育进程的冬小麦株高、基于遥感信息的作物灌溉、遥感数据同化、作物长势与灾害评价等模式。基于互联网技术构造了实时运转平台,主要功能包括作物生长过程实时常规模拟与用户个性化定制模拟。CAMM1.0的部分子模式采用多种方法构造,便于多模式集成。CAMM1.0对作物发育进程、光合过程、株高的模拟效果较好,但对土壤水分变化过程的拟合略差,模拟产量略偏低。CAMM1.0评价淮河流域夏玉米年际干旱减弱而涝渍增加的趋势与实际基本相符。
