Biomimetic materials that use natural wisdom to solve practical problems are developing rapidly.The trend for systematic biomimicry is towards in-situ characterization of naturalcreatures with high spatial resolutions...Biomimetic materials that use natural wisdom to solve practical problems are developing rapidly.The trend for systematic biomimicry is towards in-situ characterization of naturalcreatures with high spatial resolutions.Furthermore,rapid reconstruction of digital twin models with the same complex features as the prototype is indispensable.However,it faces bottlenecks and limits in fast characterization and fabrication,precise parameter optimization,geometricdeviations control,and quality prediction.To solve these challenges,here,we demonstrate astate-of-the-art method taking advantage of micro-computed tomography and three-dimensional printing for the fast characterization of the pitcher plant Nepenthes x ventrata and fabrication of its biomimetic model to obtain a superior drainage controller with multiscale structures withprecise surface morphology optimization and geometric deviation control.Thefilm-rupture-based drainage dynamic and mechanisms are characterized by x-ray and high-speed videography,which determines the crucial structures for unique directionaldrainage.Then the optimized artificial pitchers are further developed into sustained drainage devices with novel applications,such as detection,reaction,and smoke control.展开更多
The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still uncl...The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still unclear whether the boundary of the monsoon region changes according to monsoon variability. Investigations into the early Holocene environment in monsoon marginal zones are crucial for understanding the monsoon boundary changes. Zhuye Lake is located at the northwest edge of the Asian summer monsoon, the northern Qilian Mountains, which are less affected by modern summer monsoon water vapor. Previous studies have reached different conclusions regarding the early Holocene climatic and environmental changes based on different dating methods(^14C and OSL(optically stimulated luminescence)) and materials(shells, carbonate, pollen concentrates and bulk organic carbon). In this study, we synthesized 102 ^14C dates and 35 OSL dates from ten Holocene sedimentary sections and ten paleo-shorelines in the lake basin. A comparison between ages from different dating methods and materials generally shows that carbon reservoir effects are relatively slight in Zhuye Lake while the disordered chronologies are mainly related to the erosion processes and reworking effects. In addition, proxy data, including lithology, pollen, total organic carbon and carbonate, were collected from different sites of Zhuye Lake. According to the new synthesis, the early Holocene environment was relatively humid, associated with high runoff and lake water levels. The result indicates that the monsoon boundary moves to the north during the period of the intensified monsoon. A typical arid-area lake was formed during the mid-Holocene when carbonate accumulation and high organic matter contents were the main features of this period. The lake retreated strongly during the late Holocene, showing a drought trend. Overall, the lake evolution is generally consistent with the Holocene Asian summer monsoon change, showing the monsoon influence to monsoon marginal zones.展开更多
Hydrological circulation,as the most basic material cycle and active natural phenomenon on earth,exerts a significant in fluence on climate change.The mid-Holocene is an important period to better understand modern en...Hydrological circulation,as the most basic material cycle and active natural phenomenon on earth,exerts a significant in fluence on climate change.The mid-Holocene is an important period to better understand modern environmental change;however,little research has focused on its quantitative simulation of paleo-hydrological process.In this research,we first collected chronological evidence and sediment records from six Holocene sedimentary sections in the Shiyang River Ba sin to reconstruct the mid-Holocene environment and terminal paleo-lake area.Secondly,we comprehensively analyzed modern pollen combinations and their propagation characteristics in surface soil,air,river and lacustrine sediments in the Shiyang River Basin,and combined the pollen records,as well as quantitatively reconstructed the millennial-scale vegeta tion zones.Finally,based on the land-cover adjustment results during the mid-Holocene,we successfully used the Soil and Water Assessment Tool(SWAT)model,a modern distributed hydrological watershed model,to simulate mid-Holocene runoff in the basin.Results show that the reconstructed climate in the basin was warmer and moister than that in recent times.Vegetation types in the mid-Holocene mainly consisted of sub-alpine shrub distributed between 2,550 m and 2,750 m,forest at an elevation of 2,550 2,750 m,steppe at an elevation of 1,550 2,150 m and desert steppe below 1,550 m.The up stream,midstream,downstream and average annual runoff of the mid-Holocene in the basin were 16.76×10^8 m^3,22.86×10^8 m^3,9.00×10^8 m^3 and 16.20×10^8 m^3 respectively,compared to 15.61×10^8 m^3 of modern annual runoff.Also,the area of terminal paleo-lake in the mid-Holocene was 628 km^2.Thus,this study provides a new quantitative method for paleo-hy drological simulation.展开更多
This paper examines the relationship among organic geochemical proxies (TOC, C/N ratio and ~13C) and pollen assemblages in Zhuye Lake sediments since the Late Glacial. Results show that the reaction extent of organi...This paper examines the relationship among organic geochemical proxies (TOC, C/N ratio and ~13C) and pollen assemblages in Zhuye Lake sediments since the Late Glacial. Results show that the reaction extent of organic geochemical proxies and pollen as- semblages to environment changes are different. Organic geochemical proxies are sensitive to overall environmental change, while pollen assemblages indicate detailed information of environmental change. For the entire sedimentary section (except the sand layer fi'om the bottom of the section), when values of TOC, C/N ratio and total pollen concentrations are high, 813C values are low, and vice versa. The different responses of organic geochemical proxies and pollen records in Zhuye Lake are mainly due to their different sensitivity and diverse influencing factors in different environmental conditions.展开更多
基金provided by the National sKey R&D Program of China(2021YFA0716701)the National Natural Science Foundation of China(22005014,.22275007,22102204)+1 种基金Beihang University’s Young Talents(No.KG16164901)Open Foundation of the State Key Laboratory of Precision Measuring Technology and Instruments(No.pilab2106)。
文摘Biomimetic materials that use natural wisdom to solve practical problems are developing rapidly.The trend for systematic biomimicry is towards in-situ characterization of naturalcreatures with high spatial resolutions.Furthermore,rapid reconstruction of digital twin models with the same complex features as the prototype is indispensable.However,it faces bottlenecks and limits in fast characterization and fabrication,precise parameter optimization,geometricdeviations control,and quality prediction.To solve these challenges,here,we demonstrate astate-of-the-art method taking advantage of micro-computed tomography and three-dimensional printing for the fast characterization of the pitcher plant Nepenthes x ventrata and fabrication of its biomimetic model to obtain a superior drainage controller with multiscale structures withprecise surface morphology optimization and geometric deviation control.Thefilm-rupture-based drainage dynamic and mechanisms are characterized by x-ray and high-speed videography,which determines the crucial structures for unique directionaldrainage.Then the optimized artificial pitchers are further developed into sustained drainage devices with novel applications,such as detection,reaction,and smoke control.
基金supported by the National Natural Science Foundation of China (41371009)the Fundamental Research Fund for the Central Universities (lzujbky-2013-127)
文摘The intensified monsoon increases summer rainfall and creates wet conditions in the Asian summer monsoon region during the early Holocene. Along with millennial-scale changes of the monsoon intensity, it is still unclear whether the boundary of the monsoon region changes according to monsoon variability. Investigations into the early Holocene environment in monsoon marginal zones are crucial for understanding the monsoon boundary changes. Zhuye Lake is located at the northwest edge of the Asian summer monsoon, the northern Qilian Mountains, which are less affected by modern summer monsoon water vapor. Previous studies have reached different conclusions regarding the early Holocene climatic and environmental changes based on different dating methods(^14C and OSL(optically stimulated luminescence)) and materials(shells, carbonate, pollen concentrates and bulk organic carbon). In this study, we synthesized 102 ^14C dates and 35 OSL dates from ten Holocene sedimentary sections and ten paleo-shorelines in the lake basin. A comparison between ages from different dating methods and materials generally shows that carbon reservoir effects are relatively slight in Zhuye Lake while the disordered chronologies are mainly related to the erosion processes and reworking effects. In addition, proxy data, including lithology, pollen, total organic carbon and carbonate, were collected from different sites of Zhuye Lake. According to the new synthesis, the early Holocene environment was relatively humid, associated with high runoff and lake water levels. The result indicates that the monsoon boundary moves to the north during the period of the intensified monsoon. A typical arid-area lake was formed during the mid-Holocene when carbonate accumulation and high organic matter contents were the main features of this period. The lake retreated strongly during the late Holocene, showing a drought trend. Overall, the lake evolution is generally consistent with the Holocene Asian summer monsoon change, showing the monsoon influence to monsoon marginal zones.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41822708 and 41571178)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA20100102)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. lzujbky-2018k15)the Second Tibetan Plateau Scientific Expedition (STEP) program (Grant No. XDA20060700)
文摘Hydrological circulation,as the most basic material cycle and active natural phenomenon on earth,exerts a significant in fluence on climate change.The mid-Holocene is an important period to better understand modern environmental change;however,little research has focused on its quantitative simulation of paleo-hydrological process.In this research,we first collected chronological evidence and sediment records from six Holocene sedimentary sections in the Shiyang River Ba sin to reconstruct the mid-Holocene environment and terminal paleo-lake area.Secondly,we comprehensively analyzed modern pollen combinations and their propagation characteristics in surface soil,air,river and lacustrine sediments in the Shiyang River Basin,and combined the pollen records,as well as quantitatively reconstructed the millennial-scale vegeta tion zones.Finally,based on the land-cover adjustment results during the mid-Holocene,we successfully used the Soil and Water Assessment Tool(SWAT)model,a modern distributed hydrological watershed model,to simulate mid-Holocene runoff in the basin.Results show that the reconstructed climate in the basin was warmer and moister than that in recent times.Vegetation types in the mid-Holocene mainly consisted of sub-alpine shrub distributed between 2,550 m and 2,750 m,forest at an elevation of 2,550 2,750 m,steppe at an elevation of 1,550 2,150 m and desert steppe below 1,550 m.The up stream,midstream,downstream and average annual runoff of the mid-Holocene in the basin were 16.76×10^8 m^3,22.86×10^8 m^3,9.00×10^8 m^3 and 16.20×10^8 m^3 respectively,compared to 15.61×10^8 m^3 of modern annual runoff.Also,the area of terminal paleo-lake in the mid-Holocene was 628 km^2.Thus,this study provides a new quantitative method for paleo-hy drological simulation.
基金supported by the National Natural Science Foundation of China(Grant Nos.41371009 and 41001116)the Fundamental Research Fund for the Central Universities(Grant Nos.lzujbky-2013-127 and lzujbky-2013-129)
文摘This paper examines the relationship among organic geochemical proxies (TOC, C/N ratio and ~13C) and pollen assemblages in Zhuye Lake sediments since the Late Glacial. Results show that the reaction extent of organic geochemical proxies and pollen as- semblages to environment changes are different. Organic geochemical proxies are sensitive to overall environmental change, while pollen assemblages indicate detailed information of environmental change. For the entire sedimentary section (except the sand layer fi'om the bottom of the section), when values of TOC, C/N ratio and total pollen concentrations are high, 813C values are low, and vice versa. The different responses of organic geochemical proxies and pollen records in Zhuye Lake are mainly due to their different sensitivity and diverse influencing factors in different environmental conditions.