Future climate change is usually projected by coupled earth system models under specific emission scenarios designed by integrated assessment models(IAMs),and this offline approach means there is no interaction betwee...Future climate change is usually projected by coupled earth system models under specific emission scenarios designed by integrated assessment models(IAMs),and this offline approach means there is no interaction between the coupled earth system models and the IAMs.This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University(BNU-ESM). With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Integrated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4 °C warming by the end of the twenty-first century(2080–2099) compared with1980–1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 concentration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.展开更多
The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardeni...The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardening peak of the composite takes place at earlier time than that of the unreinforced alloy. Transmission electron microscopy(TEM) studies indicated that the major precipitation phases are Al_5Cu_2Mn_3 and θ′(Al_2Cu). Besides, Ω phase appeared in both specimens at peak hardening condition, which has been rarely observed previously in aluminum metal matrix composites without Ag. Accelerated aging kinetics and increased peak hardness may be attributed to the higher dislocation density resulted from the mismatch of coefficients of thermal expansion between n-SiC and 2014Al matrix. The results are beneficial to fabricating high performance composites for the application in automobile field such as pistons, driveshaft tubes, brake rotors, bicycle frames, railroad brakes.展开更多
基金supported by the National Natural Science Foundation of China (41605036 and 41305053)the National Key Research and Development Program of China (2016YFA0602703)+1 种基金the National-Level Major Cultivation Project of Guangdong Province (2014GKXM058)the Open Project of the State Key Laboratory of Cryospheric Science (SKLCS-OP-2016-09)
文摘Future climate change is usually projected by coupled earth system models under specific emission scenarios designed by integrated assessment models(IAMs),and this offline approach means there is no interaction between the coupled earth system models and the IAMs.This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University(BNU-ESM). With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Integrated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4 °C warming by the end of the twenty-first century(2080–2099) compared with1980–1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 concentration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.
基金Financial support by the National Basic Research Program of China(“973”Program,No.2012CB619600)the National Natural Science Foundation of China(No.51474111)+2 种基金the Science and Technology Development Project of Jilin Province(No.20160519002JH)support came from the Fundamental Research Funds for the Central Universities(JCKY-QKJC02)the Chang Bai Mountain Scholars Program(2013014)
文摘The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardening peak of the composite takes place at earlier time than that of the unreinforced alloy. Transmission electron microscopy(TEM) studies indicated that the major precipitation phases are Al_5Cu_2Mn_3 and θ′(Al_2Cu). Besides, Ω phase appeared in both specimens at peak hardening condition, which has been rarely observed previously in aluminum metal matrix composites without Ag. Accelerated aging kinetics and increased peak hardness may be attributed to the higher dislocation density resulted from the mismatch of coefficients of thermal expansion between n-SiC and 2014Al matrix. The results are beneficial to fabricating high performance composites for the application in automobile field such as pistons, driveshaft tubes, brake rotors, bicycle frames, railroad brakes.