Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction ...Future climate change is usually projected by coupled earth system models under specific emission sce- narios 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 Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration 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
Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natura...Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo.Here,we found that amphipol and digitonin stabilized the structure of natural silk fibroin(NSF)by a large-scale screening in vitro,and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen.Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm,rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules.Metal ions were required for NSF nanofibril formation.The successive p H decrease from posterior silk gland(PSG)to anterior silk gland(ASG)resulted in a gradual increase in NSF hydrophobicity,thus inducing the sol-gelation transition of NSF nanofibrils.NSF nanofibrils were randomly dispersed from PSG to ASG-1,and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning.Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and p H gradient,which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers.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 sce- narios 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 Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration 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supported by the National Key Research and Development Program of China(2022YFD1201600,2021YFA1300100,and 2018YFE0203300)the National Natural Science Foundation of China(31972622 and 32241029)+6 种基金the State Key Program of National Natural Science Foundation of China(32030103)the Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-LZX0302,CSTB2022NSCQ-MSX0761,and cstc2020jcyj-cxtt X0001)the Fundamental Research Funds for the Central Universities(XDJK2020TJ001)the Key Project of Science and Technology Research Program of Chongqing Municipal Education Commission,China(KJZD-K202200205)the Chinese Academy of Sciences(CAS)Strategic Priority Research Program(XDB37010100)the Shennong Youth Talent Program(Ministry of Agriculture and Rural Affairs,China)the Chongqing Innovation Supporting Program for Oversea Returned Talents(CX2023069)。
文摘Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo.Here,we found that amphipol and digitonin stabilized the structure of natural silk fibroin(NSF)by a large-scale screening in vitro,and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen.Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm,rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules.Metal ions were required for NSF nanofibril formation.The successive p H decrease from posterior silk gland(PSG)to anterior silk gland(ASG)resulted in a gradual increase in NSF hydrophobicity,thus inducing the sol-gelation transition of NSF nanofibrils.NSF nanofibrils were randomly dispersed from PSG to ASG-1,and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning.Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and p H gradient,which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers.
