How to achieve uniform mixing of highly viscous fluids with low energy consumption is a major industry demand and one of the hot spots of mixing research.A typical multistage rotor-stator mixer(MRSM)equipped with a di...How to achieve uniform mixing of highly viscous fluids with low energy consumption is a major industry demand and one of the hot spots of mixing research.A typical multistage rotor-stator mixer(MRSM)equipped with a distributor was investigated to disclose the effects on the mixing performance and power consumption for highly viscous fluids via numerical simulation,considering the influence factors associated with different geometric parameters of both MRSM and the distributor.The mixing index and power consumption are used to evaluate the performance of the mixers.The dimensionless correlations for the mixing index and the power consumption are established considering the factors including the flow rate,rotor speed,the number of mixing units.Adopting the optimized mixer with the distributor(X1-T1),the mixing index increases to 0.85(obviously higher than 0.46 for the mixer T1 without a distributor),meanwhile the corresponding power consumption is about 1/5 of that of T1 achieving the same mixing effect.It illustrates that the distributor can significantly improve the mixing of highly viscous fluids in the MRSM without the cost of large power consumption.These results would provide a guidance on the design and optimization of multistage rotor-stator mixers in industrial applications.展开更多
Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of...Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of the composite was characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM）. It was found that highly crystallined carbon composed of well-aligned graph℃ene layers with interlayer spacing of 0.34 nm can be formed by catalytic carbonization of biomass. However, the structure of the in-situ growing CNFs is lessaligned. Based on the results of the investigation, the formation mechanism of the crystallined hybrid carbon was discussed. Owning to synergistic effect of the highly crystallined carbon and the conductive network formed by CNFs, the crystallined hybrid carbon shows 32.6% lower electrical resistivity than biocarbon. When being used as anode material of lithium-ion batteries （LIBs）, the crystallined hybrid carbon and the biocarbon have nearly the same first coulombic efficiencies （CEs）, however, the former has a discharge capacity of 67% higher than the latter since the second cycle.展开更多
Twin–twin intersections are often observed in face-centered cubic(FCC)metallic nanostructures,which have important contributions to the plastic deformation and strengthening of FCC metals with low stacking fault ener...Twin–twin intersections are often observed in face-centered cubic(FCC)metallic nanostructures,which have important contributions to the plastic deformation and strengthening of FCC metals with low stacking fault energies.However,a deep insight into the underlying mechanism involved in the formation and evolution of twin–twin intersections remains largely lacking,especially in experiments.Here,by conducting the in situ straining experiments under high resolution transmission electron microscope(TEM),we directly visualize the dynamic evolution of a twin–twin intersection in Au nanowire at the nanoscale.It shows that dislocations in the incoming twin can either glide onto or transmit across the barrier twin via dislocation interaction with the twin boundary,resulting in the twin–twin intersection.Dynamic twinning and de-twinning of the twin–twin intersection govern the whole deformation of the nanowire.These findings reveal the dynamic behaviors of twin–twin intersection under mechanical loading,which benefits further exploration of FCC metals and engineering alloys with twin–twin intersection structures.展开更多
基金financially supported by the National Natural Science Foundation of China (22090034, 21776179)the Major Science and Technology Project of Xinjiang Bingtuan(2020AA004)the Major Project of Shihezi City(2020ZD002)
文摘How to achieve uniform mixing of highly viscous fluids with low energy consumption is a major industry demand and one of the hot spots of mixing research.A typical multistage rotor-stator mixer(MRSM)equipped with a distributor was investigated to disclose the effects on the mixing performance and power consumption for highly viscous fluids via numerical simulation,considering the influence factors associated with different geometric parameters of both MRSM and the distributor.The mixing index and power consumption are used to evaluate the performance of the mixers.The dimensionless correlations for the mixing index and the power consumption are established considering the factors including the flow rate,rotor speed,the number of mixing units.Adopting the optimized mixer with the distributor(X1-T1),the mixing index increases to 0.85(obviously higher than 0.46 for the mixer T1 without a distributor),meanwhile the corresponding power consumption is about 1/5 of that of T1 achieving the same mixing effect.It illustrates that the distributor can significantly improve the mixing of highly viscous fluids in the MRSM without the cost of large power consumption.These results would provide a guidance on the design and optimization of multistage rotor-stator mixers in industrial applications.
基金supported by the National Natural Science Foundation of China(No.51264016)the Natural Science Foundation of Yunnan Province of China(No.2009ZC006X)+1 种基金the Scientific Research Foundation of Kunming University of Science and Technology,China(No.2009-027)the Analysis and Testing Foundation of Kunming University of Science and Technology,China(No.2011458)
文摘Crystallined hybrid carbon was synthesized by the catalytic carbonization of biomass （Pinus kesiya sawdust） at 1100 ℃ and in-situ growth of carbon nanofibers （CNFs） at 750 ℃ from acetylene. The microstructure of the composite was characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM）. It was found that highly crystallined carbon composed of well-aligned graph℃ene layers with interlayer spacing of 0.34 nm can be formed by catalytic carbonization of biomass. However, the structure of the in-situ growing CNFs is lessaligned. Based on the results of the investigation, the formation mechanism of the crystallined hybrid carbon was discussed. Owning to synergistic effect of the highly crystallined carbon and the conductive network formed by CNFs, the crystallined hybrid carbon shows 32.6% lower electrical resistivity than biocarbon. When being used as anode material of lithium-ion batteries （LIBs）, the crystallined hybrid carbon and the biocarbon have nearly the same first coulombic efficiencies （CEs）, however, the former has a discharge capacity of 67% higher than the latter since the second cycle.
基金supported financially by the Basic Science Center Program for Multiphase Evolution in Hypergravity of the National Natural Science Foundation of China(No.51988101)the National Natural Science Foundation of China(Nos.51771172 and 51701179)+2 种基金the Innovation Fund of the Zhejiang Kechuang New Materials Research Institute(No.ZKN-18-Z02)the Australian Research Council(No.DE170100053)the Robinson Fellowship of the University of Sydney。
文摘Twin–twin intersections are often observed in face-centered cubic(FCC)metallic nanostructures,which have important contributions to the plastic deformation and strengthening of FCC metals with low stacking fault energies.However,a deep insight into the underlying mechanism involved in the formation and evolution of twin–twin intersections remains largely lacking,especially in experiments.Here,by conducting the in situ straining experiments under high resolution transmission electron microscope(TEM),we directly visualize the dynamic evolution of a twin–twin intersection in Au nanowire at the nanoscale.It shows that dislocations in the incoming twin can either glide onto or transmit across the barrier twin via dislocation interaction with the twin boundary,resulting in the twin–twin intersection.Dynamic twinning and de-twinning of the twin–twin intersection govern the whole deformation of the nanowire.These findings reveal the dynamic behaviors of twin–twin intersection under mechanical loading,which benefits further exploration of FCC metals and engineering alloys with twin–twin intersection structures.
