Slender chiral filaments are ubiquitous in both artificial and biological materials.Due to their chiral microstructures,chiral filaments usually exhibit favorable properties such as superior elasticity and unusual str...Slender chiral filaments are ubiquitous in both artificial and biological materials.Due to their chiral microstructures,chiral filaments usually exhibit favorable properties such as superior elasticity and unusual stretch-twist coupling deformation.However,how these chiral microstructures affect the elastic behavior of filaments remains unclear.In this paper,a refined Cosserat rod model with misfit or mismatching of chirality induced by inhomogeneous arrangement of chiral microstructures incorporated is developed.Using the refined rod model,the force-displacement relationships and variation of structural chirality during the tensile processes of two typical helical structures,i.e.,single-strand helix and double-strand helix,are investigated.The results show that the misfit of chirality can lead to a bend-twist deformation with a high coupling degree,which makes the rod much“soft”when stretched.The chiral filaments undergo an unusual twist when stretched,corresponding to an obviously nonlinear variation of structural chirality.The work suggests that the misfit of chirality can be used to tune the elastic behavior of chiral filaments,which is helpful in guiding the design of flexible actuators and soft devices.展开更多
Debris flow is a rapid flow which could lead to severe flooding with catastrophic consequences such as damage to properties and loss of human lives.It is important to study the movement of debris flow.Since during a d...Debris flow is a rapid flow which could lead to severe flooding with catastrophic consequences such as damage to properties and loss of human lives.It is important to study the movement of debris flow.Since during a debris flow process,the erosion and deposition processes are important,the no entrainment assumption is not acceptable.In this study,first we considered the debris flow as equivalent fluid and adopted the depth-averaged govern equations to simulate the movements and evolution of river bed.Secondly,the set of partial differential equations was solved numerically by means of explicit staggered leap-frog scheme that is accurate in space and time.The grid of difference scheme was derived from GIS raster data.Then the simulation results can be displayed by GIS and easily used to form the hazard maps.Finally,the numerical model coupled with GIS is applied to simulate the debris flow occurred on Oct.20th,2010,in Amamioshima City,Japan.The simulation reproduces the movement,erosion and deposition.The results are shown to be consistent with the field investigation.展开更多
In this study,a series of Na_(2)S-and S^(0)-decorated ZSM-5 adsorbents were prepared and their Hg^(0) adsorption performance was evaluated.Given that S^(0) and Na_(2)S were co-doped with the mass ratio of S^(0) to ZSM...In this study,a series of Na_(2)S-and S^(0)-decorated ZSM-5 adsorbents were prepared and their Hg^(0) adsorption performance was evaluated.Given that S^(0) and Na_(2)S were co-doped with the mass ratio of S^(0) to ZSM-5 fixed to 2:1,Hg^(0) removal efficiency quadruples compared with raw ZSM-5 and reached ca.100%at 300°C.Combined with the characterization results,it could be concluded that chemical properties,instead of physical structures,played an important role in Hg^(0) removal.Among the various gas components,O_(2),NO,and SO_(2) made negligible impacts on Hg^(0) capture over 2:1-S/ZSM-5 adsorbent surface.After recycling four times,Hg^(0) removal efficiency of 2:1-S/ZSM-5 adsorbent remained higher than 80%,which was indica-tive of a certain recyclability.Finally,XPS results illustrated that S^(0) and S^(2−)on 2:1-S/ZSM-5 surface functioned as the active sites for the transformation of Hg^(0) to HgS,which facilitated the chemisorption process and consequently led to an improved Hg^(0) capture performance.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12020101001,12021002,11890680,and 11872273)Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.19JCYBJC19300).
基金the National Natural Science Foundation of China(Grant Nos.12020101001,12021002,11872273,and 11890680)Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.19JCYBJC19300).
文摘Slender chiral filaments are ubiquitous in both artificial and biological materials.Due to their chiral microstructures,chiral filaments usually exhibit favorable properties such as superior elasticity and unusual stretch-twist coupling deformation.However,how these chiral microstructures affect the elastic behavior of filaments remains unclear.In this paper,a refined Cosserat rod model with misfit or mismatching of chirality induced by inhomogeneous arrangement of chiral microstructures incorporated is developed.Using the refined rod model,the force-displacement relationships and variation of structural chirality during the tensile processes of two typical helical structures,i.e.,single-strand helix and double-strand helix,are investigated.The results show that the misfit of chirality can lead to a bend-twist deformation with a high coupling degree,which makes the rod much“soft”when stretched.The chiral filaments undergo an unusual twist when stretched,corresponding to an obviously nonlinear variation of structural chirality.The work suggests that the misfit of chirality can be used to tune the elastic behavior of chiral filaments,which is helpful in guiding the design of flexible actuators and soft devices.
基金This study was supported by the Global Environment Research Found of Japan(S-8)and Grants-in-Aid for Scientific Research(Scientific Research(B),22310113,G.Chen)from Japan Society for the Promotion of ScienceAnd the first author acknowledges the support of China Scholarship Council.These financial supports are gratefully acknowledged.
文摘Debris flow is a rapid flow which could lead to severe flooding with catastrophic consequences such as damage to properties and loss of human lives.It is important to study the movement of debris flow.Since during a debris flow process,the erosion and deposition processes are important,the no entrainment assumption is not acceptable.In this study,first we considered the debris flow as equivalent fluid and adopted the depth-averaged govern equations to simulate the movements and evolution of river bed.Secondly,the set of partial differential equations was solved numerically by means of explicit staggered leap-frog scheme that is accurate in space and time.The grid of difference scheme was derived from GIS raster data.Then the simulation results can be displayed by GIS and easily used to form the hazard maps.Finally,the numerical model coupled with GIS is applied to simulate the debris flow occurred on Oct.20th,2010,in Amamioshima City,Japan.The simulation reproduces the movement,erosion and deposition.The results are shown to be consistent with the field investigation.
基金This work is supported by the National Natural Science Foundation of China(No.51568024).
文摘In this study,a series of Na_(2)S-and S^(0)-decorated ZSM-5 adsorbents were prepared and their Hg^(0) adsorption performance was evaluated.Given that S^(0) and Na_(2)S were co-doped with the mass ratio of S^(0) to ZSM-5 fixed to 2:1,Hg^(0) removal efficiency quadruples compared with raw ZSM-5 and reached ca.100%at 300°C.Combined with the characterization results,it could be concluded that chemical properties,instead of physical structures,played an important role in Hg^(0) removal.Among the various gas components,O_(2),NO,and SO_(2) made negligible impacts on Hg^(0) capture over 2:1-S/ZSM-5 adsorbent surface.After recycling four times,Hg^(0) removal efficiency of 2:1-S/ZSM-5 adsorbent remained higher than 80%,which was indica-tive of a certain recyclability.Finally,XPS results illustrated that S^(0) and S^(2−)on 2:1-S/ZSM-5 surface functioned as the active sites for the transformation of Hg^(0) to HgS,which facilitated the chemisorption process and consequently led to an improved Hg^(0) capture performance.
