Microplastic wastes in ocean can include the harmful chemical material, and the harmful material is concentrated by marine species. The separation and collecting methods of microplastics in ocean are researched in the...Microplastic wastes in ocean can include the harmful chemical material, and the harmful material is concentrated by marine species. The separation and collecting methods of microplastics in ocean are researched in the world. The authors proposed the microplastics recovery device composed of the plates. Besides, the device consists of the tilted inlet/outlet and the horizontal part. In the water flow such as the tidal and ocean currents, the microplastics can be extracted from the main flow due to the vortex flow generated at the inner part of this device. In this research, the effects of the flow velocity and the inlet/outlet tilt angle on the capture performance were investigated experimentally and numerically. In the numerical simulations using the discrete phase model, the tilt angle was changed in a range between 30 degrees and 150 degrees in increments of 15 degrees, and the particle tracks of plastics were derived in steady condition. On the other hand, the capture performances in three cases of tilt angle 45 degrees, 120 degrees and 150 degrees were compared by circulation type water channel tests in which the plastics denser than the water were swept away 30 times every flow velocity. As the result, it seems that the tilt angle of 120 degrees is suitable for the wide range of the flow velocity in river and ocean.展开更多
Clinoptilolite(HEU)mineral is by far the most common natural zeolite;it has been described as an excellent adsorbent for heavy metal ions and radioactive^(137)Cs^(+).Heulandite,which possesses the same framework topol...Clinoptilolite(HEU)mineral is by far the most common natural zeolite;it has been described as an excellent adsorbent for heavy metal ions and radioactive^(137)Cs^(+).Heulandite,which possesses the same framework topology as clinoptilolite,has a lower Si/Al ratio than clinoptilolite.Thus,superior performance is expected for heulandite in harmful ion removal due to its higher cation exchange capacity.展开更多
The research on the hydrodynamics of blades is mainly focused on sea areas with high-speed current.However,the average velocity in most territorial waters of China is smaller than 1 m/s,and the lift type of airfoil bl...The research on the hydrodynamics of blades is mainly focused on sea areas with high-speed current.However,the average velocity in most territorial waters of China is smaller than 1 m/s,and the lift type of airfoil blades has limited application in most of these conditions.Therefore,it is of great significance to study the tidal current energy capture of blades in sub-low speed sea areas.The effect of flow impact resistance on the blade at sub-low current speed is considered and a new type of thin-walled blade based on the lift type of blade is proposed,and then the lift-impact combined hydrodynamic model of horizontal axis blade is established.Based on this model,and considering the characteristics of tidal current and velocity in the sea area of Yushan Islands,simulation and optimization of blade design are carried out.Additionally,the horizontal axis thin-walled blade and the NACA airfoil contrast blade under the same conditions are developed.By using a synthetical experimental test system,the power,torque,rotational speed and load characteristics of these two blades are tested.The performance of the thin-walled blade and the design theory are verified.It shows that this type of blade has much better energy capture efficiency in the sub-low speed sea area.This research will promote the study and development of turbines that can be used in low-speed current sea areas in the future.展开更多
It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of tr...It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of trinuclear indium cluster-based metal-organic frameworks(MOFs)for highly efficient CO_(2) capture and electrocatalytic conversion into C1 products.By adjusting the metal type and replacing the ligand,the mixed metal-based MOF InCo-ABDBC-HIN shows high CO_(2) capture performance(101.7 cm^(3) g^(-1) at 273 K under low pressure)and superior activity(a maximum FEC1 of 81.5% at -2.2 V vs.Ag/Ag^(+))for electrocatalytic CO_(2) reduction in organic electrolytes due to its modified electronic structure.Theoretical calculations suggest that the substitution of In by Co significantly modified the electronic structure of In-based clusters,which provides rich unpaired electrons for the CO_(2)RR and enhances the charge transfer efficiency.This work provides a specially coordinated trinuclear indium cluster-based MOF and sheds new light on the precise structural design of both CO_(2) adsorbents and electrocatalysts for efficient CO_(2) reduction.展开更多
Without assumptions made on motion states of missile and target, an extended differential geometric guidance law is derived. Through introducing a line of sight rotation coordinate system, the derivation is simplified...Without assumptions made on motion states of missile and target, an extended differential geometric guidance law is derived. Through introducing a line of sight rotation coordinate system, the derivation is simplified and has more explicit physical significances. The extended law is theoretically applicable to any engagement scenarios. Then, on basis of the extended law, a modified one is designed without the requirement of target acceleration and an approach is proposed to determining the applied direction of commanded missile acceleration. Qualitative analysis is carried out to study the capture performance and a criterion for capture is given. Simulation results indicate the two laws are effective and make up the deficiency that pure proportional navigation suitable for endoatmospheric interceptions cannot deal with high-speed maneuvering targets. Furthermore, the correctness of the criterion is validated.展开更多
Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magneti...Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magnetic confinement ECP under different working voltages was simulated,and the influence of magnetic flux intensity on the removal performance of submicron particles was explored.Results show that the number of particles escaped from the cyclone is greatly reduced after the introduction of magnetic field and electric field,indicating that charging effect and magnetic confinement are more conductive to trap submicron particles in the internal vortex ECP.The lower the working voltage is,the worse the charging lifting effect is,but the stronger the magnetic confinement characteristics are.Furthermore,the contributions of charging effect to collection efficiency and magnetic confinement characteristics are more obvious at a weaker magnetic flux density.The research results can provide a practical new idea for the innovative design of ECP.展开更多
文摘Microplastic wastes in ocean can include the harmful chemical material, and the harmful material is concentrated by marine species. The separation and collecting methods of microplastics in ocean are researched in the world. The authors proposed the microplastics recovery device composed of the plates. Besides, the device consists of the tilted inlet/outlet and the horizontal part. In the water flow such as the tidal and ocean currents, the microplastics can be extracted from the main flow due to the vortex flow generated at the inner part of this device. In this research, the effects of the flow velocity and the inlet/outlet tilt angle on the capture performance were investigated experimentally and numerically. In the numerical simulations using the discrete phase model, the tilt angle was changed in a range between 30 degrees and 150 degrees in increments of 15 degrees, and the particle tracks of plastics were derived in steady condition. On the other hand, the capture performances in three cases of tilt angle 45 degrees, 120 degrees and 150 degrees were compared by circulation type water channel tests in which the plastics denser than the water were swept away 30 times every flow velocity. As the result, it seems that the tilt angle of 120 degrees is suitable for the wide range of the flow velocity in river and ocean.
基金support from the National Natural Science Foundation of China(21571075,21621001,21835002)the 111 Project(B17020 and B12015)the Program for JLU Science and Technology Innovative Research Team.
文摘Clinoptilolite(HEU)mineral is by far the most common natural zeolite;it has been described as an excellent adsorbent for heavy metal ions and radioactive^(137)Cs^(+).Heulandite,which possesses the same framework topology as clinoptilolite,has a lower Si/Al ratio than clinoptilolite.Thus,superior performance is expected for heulandite in harmful ion removal due to its higher cation exchange capacity.
基金This work was financially supported by the Special Funds of the State Oceanic Administration(Grant No.NBME2011CL02)Ningbo Major Science and Technology Public Relations Project(Grant No.2015C110015)Ningbo Natural Science Foundation Project(Grant No.2014A610091).
文摘The research on the hydrodynamics of blades is mainly focused on sea areas with high-speed current.However,the average velocity in most territorial waters of China is smaller than 1 m/s,and the lift type of airfoil blades has limited application in most of these conditions.Therefore,it is of great significance to study the tidal current energy capture of blades in sub-low speed sea areas.The effect of flow impact resistance on the blade at sub-low current speed is considered and a new type of thin-walled blade based on the lift type of blade is proposed,and then the lift-impact combined hydrodynamic model of horizontal axis blade is established.Based on this model,and considering the characteristics of tidal current and velocity in the sea area of Yushan Islands,simulation and optimization of blade design are carried out.Additionally,the horizontal axis thin-walled blade and the NACA airfoil contrast blade under the same conditions are developed.By using a synthetical experimental test system,the power,torque,rotational speed and load characteristics of these two blades are tested.The performance of the thin-walled blade and the design theory are verified.It shows that this type of blade has much better energy capture efficiency in the sub-low speed sea area.This research will promote the study and development of turbines that can be used in low-speed current sea areas in the future.
基金supported by the National Natural Science Foundation of China(22071140 and 21901151)the Natural Science Foundation of Shaanxi Province(2021JLM-20)+1 种基金the China Postdoctoral Science Foundation(2022TQ0200)the Fundamental Research Funds for the Central Universities(GK202101002).
文摘It is crucial to design highly selective and cost-effective materials for efficient CO_(2) uptake and the desirable transformation of CO_(2) into fuels or high-value chemical products.Here,we synthesize a series of trinuclear indium cluster-based metal-organic frameworks(MOFs)for highly efficient CO_(2) capture and electrocatalytic conversion into C1 products.By adjusting the metal type and replacing the ligand,the mixed metal-based MOF InCo-ABDBC-HIN shows high CO_(2) capture performance(101.7 cm^(3) g^(-1) at 273 K under low pressure)and superior activity(a maximum FEC1 of 81.5% at -2.2 V vs.Ag/Ag^(+))for electrocatalytic CO_(2) reduction in organic electrolytes due to its modified electronic structure.Theoretical calculations suggest that the substitution of In by Co significantly modified the electronic structure of In-based clusters,which provides rich unpaired electrons for the CO_(2)RR and enhances the charge transfer efficiency.This work provides a specially coordinated trinuclear indium cluster-based MOF and sheds new light on the precise structural design of both CO_(2) adsorbents and electrocatalysts for efficient CO_(2) reduction.
文摘Without assumptions made on motion states of missile and target, an extended differential geometric guidance law is derived. Through introducing a line of sight rotation coordinate system, the derivation is simplified and has more explicit physical significances. The extended law is theoretically applicable to any engagement scenarios. Then, on basis of the extended law, a modified one is designed without the requirement of target acceleration and an approach is proposed to determining the applied direction of commanded missile acceleration. Qualitative analysis is carried out to study the capture performance and a criterion for capture is given. Simulation results indicate the two laws are effective and make up the deficiency that pure proportional navigation suitable for endoatmospheric interceptions cannot deal with high-speed maneuvering targets. Furthermore, the correctness of the criterion is validated.
基金sponsored by National Natural Science Foundation of China (Grant numbers 12172228,11572187)Natural Science Foundation of Shanghai (Grant number 22ZR1444400).
文摘Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator(ECP),a theoretical model with mechanics-electric-magnetic coupling was established,the collection efficiency of magnetic confinement ECP under different working voltages was simulated,and the influence of magnetic flux intensity on the removal performance of submicron particles was explored.Results show that the number of particles escaped from the cyclone is greatly reduced after the introduction of magnetic field and electric field,indicating that charging effect and magnetic confinement are more conductive to trap submicron particles in the internal vortex ECP.The lower the working voltage is,the worse the charging lifting effect is,but the stronger the magnetic confinement characteristics are.Furthermore,the contributions of charging effect to collection efficiency and magnetic confinement characteristics are more obvious at a weaker magnetic flux density.The research results can provide a practical new idea for the innovative design of ECP.
