The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visibl...The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu2O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO4 dosage 8 g, NaOH dosage 1.6 g, temperature 80℃, 60 min for Cu2+ absorption, and 60 min for reaction. Under the optimum conditions, the Cu2O deposition ratio approached 30% and the nano-Cu2O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu2O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu2O particles. Excellent antibacterial property of nano- Cu2O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu2O-loaded paper was proven to be hydrophobic.展开更多
In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform...In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform lateral load simulated using a gasbag.The investigation involved the performance of light frame wood structure after it experienced the repeated cyclic lateral wind load as well as the performance of the structure under the ultimate lateral load.Then,the study verified that light frame wood structure can resist repeated cyclic wind loads without observable degradation in stiffness during the anticipated serve life,and recommended shear wall percent drift restriction for lateral wind load design of wood structure in serviceability limit states is 1/400 drift,and in ultimate limit states is 1/80 drift.The conclusions of this paper can be benefit for the engineering practice of the light frame wood structures in high wind load regions.展开更多
随着双有源桥(Dual active bridge,DAB)变换器工作频率的不断提高,开关损耗对传输效率的影响也在不断增加。DAB变换器通过采用合适的软开关控制策略,来尽可能实现全开关器件的软开关,但轻载工况下的死区重叠现象使软开关条件产生了冲突...随着双有源桥(Dual active bridge,DAB)变换器工作频率的不断提高,开关损耗对传输效率的影响也在不断增加。DAB变换器通过采用合适的软开关控制策略,来尽可能实现全开关器件的软开关,但轻载工况下的死区重叠现象使软开关条件产生了冲突,这种现象在高频轻载条件下尤为突出。为了提高DAB变换器在高频轻载条件下的能量传输效率,对轻载条件下的死区重叠现象进行了分析,结合缓冲电容对死区过程的影响,提出了以电流应力为优化目标的三自由度控制策略。最后,通过试验验证了分析过程的正确性和所提控制策略的有效性。展开更多
A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in abov...A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in above rated operation. The pseudo-LIDAR measurement data are generated from a commercial software- Bladed using a designed sampling strategy. The nonlinear wind turbine model has been simplified and linearised at a set of equilibrium operating points. The feedforward controller is firstly developed based on a linearised model at an above rated wind speed, and then expanded to the full above rated operational envelope by employing gain scheduling strategy. The combined feedforward and baseline feedback control is simulated on a 5MW industrial wind turbine model. Simulation studies demonstrate that the proposed control strategy can improve the rotor and tower load reduction performance for large wind turbines.展开更多
基金financial support from the National Natural Science Foundation of China, with grant No. 31770620
文摘The removal of formaldehyde (HCHO) from indoor air is of great importance to reduce health risks and improve indoor air quality. In this study, nano-Cu2O-loaded paper with superior photocatalytic activity under visible light for the removal of HCHO was fabricated through a green, simple, and fast in situ synthesis method. The optimum preparation conditions for nano-Cu2O-loaded paper were as follows: 2 g (oven-dry basis) cellulose fibers, CuSO4 dosage 8 g, NaOH dosage 1.6 g, temperature 80℃, 60 min for Cu2+ absorption, and 60 min for reaction. Under the optimum conditions, the Cu2O deposition ratio approached 30% and the nano-Cu2O-loaded paper exhibited a catalytic efficiency of approximately 97% for HCHO removal. The photocatalytic capacity of nano-Cu2O-loaded paper for HCHO removal had a positive correlation with the deposition ratio of nano Cu2O particles. Excellent antibacterial property of nano- Cu2O-loaded paper against Staphylococcus aureus and Escherichia coli was also confirmed. Moreover, nano-Cu2O-loaded paper was proven to be hydrophobic.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 50508012)
文摘In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform lateral load simulated using a gasbag.The investigation involved the performance of light frame wood structure after it experienced the repeated cyclic lateral wind load as well as the performance of the structure under the ultimate lateral load.Then,the study verified that light frame wood structure can resist repeated cyclic wind loads without observable degradation in stiffness during the anticipated serve life,and recommended shear wall percent drift restriction for lateral wind load design of wood structure in serviceability limit states is 1/400 drift,and in ultimate limit states is 1/80 drift.The conclusions of this paper can be benefit for the engineering practice of the light frame wood structures in high wind load regions.
文摘随着双有源桥(Dual active bridge,DAB)变换器工作频率的不断提高,开关损耗对传输效率的影响也在不断增加。DAB变换器通过采用合适的软开关控制策略,来尽可能实现全开关器件的软开关,但轻载工况下的死区重叠现象使软开关条件产生了冲突,这种现象在高频轻载条件下尤为突出。为了提高DAB变换器在高频轻载条件下的能量传输效率,对轻载条件下的死区重叠现象进行了分析,结合缓冲电容对死区过程的影响,提出了以电流应力为优化目标的三自由度控制策略。最后,通过试验验证了分析过程的正确性和所提控制策略的有效性。
基金supported by UK Engineering and Physical Sciences Research Council(EPSRC)Supergen Wind project(No.EP/N006224/1)
文摘A gain-scheduled feedforward controller, based on pseudo-LIDAR （light detection and ranging） wind speed measurement, is designed to augment the baseline feedback controller for wind turbine＇s load reduction in above rated operation. The pseudo-LIDAR measurement data are generated from a commercial software- Bladed using a designed sampling strategy. The nonlinear wind turbine model has been simplified and linearised at a set of equilibrium operating points. The feedforward controller is firstly developed based on a linearised model at an above rated wind speed, and then expanded to the full above rated operational envelope by employing gain scheduling strategy. The combined feedforward and baseline feedback control is simulated on a 5MW industrial wind turbine model. Simulation studies demonstrate that the proposed control strategy can improve the rotor and tower load reduction performance for large wind turbines.
