为满足感应耦合电能传输(inductively coupled power transfer,ICPT)系统在实现电能正向无线传输的同时,对副边电路状态信息的采集与反向传输,基于ICPT系统电能耦合传输通道,提出了一种在负载变化情况下,电能与信号反向同步传输ICPT系统...为满足感应耦合电能传输(inductively coupled power transfer,ICPT)系统在实现电能正向无线传输的同时,对副边电路状态信息的采集与反向传输,基于ICPT系统电能耦合传输通道,提出了一种在负载变化情况下,电能与信号反向同步传输ICPT系统,并对其控制方法进行了深入研究。该系统在副边增加信号调制电容,检测负载大小以确定具体的信号调制方案,通过切入与切出该调制电容以改变原边电流波形包络,进而将数字信号调制到系统中,这样原边在发射电能的同时接收来自副边的状态信息,最后通过设计信号解调机构,复原信号。首先介绍了ICPT系统电能与信号同步传输原理,在此基础上,提出电能与信号反向同步传输ICPT系统;然后,通过对该系统进行建模分析得到负载变化情况下不同的信号调制策略,并对系统变负载情况下系统特性进行了分析和研究;最后,针对理论分析进行了仿真与实验验证,实验实现了ICPT系统在电能正向传输情况下的信号的反向低误码率传输。该研究结果可以为ICPT系统电能与信号反向同步传输系统的设计与研究提供参考。展开更多
The efficiency of advanced membranes towards removal of general and specific microbes from wastewater was investigated. The treatment included a subsequent system of activated sludge, ultrafiltration （hollow fibre me...The efficiency of advanced membranes towards removal of general and specific microbes from wastewater was investigated. The treatment included a subsequent system of activated sludge, ultrafiltration （hollow fibre membranes with 100 kDa cut-off, and spiral wound membranes with 20 kDa cut-off）, and RO （reverse osmosis）. The removal evaluation of screened microbes present in treated wastewater showed that hollow fibre membrane rejected only 1 log （90% rejection） of the TPC （total microbial count）, TC （total coliforms）, and FC （faecal coliforms）. A higher effectiveness was observed with spiral wound, removing 2-3 logs （99%-99.9%） of TPC and complete rejection of TC and FC. The RO system was successful in total rejection of all received bacteria. The removal evaluation of inoculated specific types of bacteria showed that the hollow membranes removed 2 logs （99%） of inoculated E. coli （10^7-10^8 cfu/mL inoculum）, 2-3 logs （99%-99.9%） of Enterococus spp. （10^7-10^10 cfu/mL inoculum）, 1-2 logs （90%-99%） of Salmonella （10^8-10^10 cfu/mL inoculum） and 1-2 logs （90%-99%） of Shigella （10^5-10^6 cfu/mL inoculum）. The spiral wound was significantly efficient in rejecting further 3 logs of E. coil, 5 logs of Enterococus spp., 4 logs of Salmonella, and a complete rejection of all received bacteria was accomplished by RO membrane. The results indicate that Gram positive bacteria were removed much more efficiently compared to the Gram negative ones, the rationale behind such behaviour is based on cell walls elasticity.展开更多
Stopping maneuver is an important research topic in ship maneuverability.The stopping ability of ship is not only related to the hydrodynamic characteristics of hull,rudder and propeller,but also related to the capaci...Stopping maneuver is an important research topic in ship maneuverability.The stopping ability of ship is not only related to the hydrodynamic characteristics of hull,rudder and propeller,but also related to the capacity of main engine.However,there are few researches on the capacity of main engine under reversed propulsion condition.In the paper,a numerical water tank is established to simulate the propeller loads using the computational fluid dynamics(CFD)software STAR CCM+.The numerical model is firstly validated by experimental data,and then is used to investigate the propeller loads on a full-scale model with different ship speed and propeller speed.By dimensionless,the relations between the advance coefficient and the load coefficients are shown as J-KT curves and J-KQ curves.Furtherly,the flow structures near the propeller and the pressure on the propeller with different J values are investigated.The simulations reveal that the flow velocities induced by the reversed propulsion of the propeller is similar to the wake flow by ship with J=-0.49.That is the reason for the minimum points of J-KT and J-KQ curve occurring in cases with J=-0.49.Subsequently,the capacity of the main engine and the output load of the propeller are considered comprehensively.The relations between the ship speeds and the maximum output loads on the propeller are discussed in details.展开更多
文摘为满足感应耦合电能传输(inductively coupled power transfer,ICPT)系统在实现电能正向无线传输的同时,对副边电路状态信息的采集与反向传输,基于ICPT系统电能耦合传输通道,提出了一种在负载变化情况下,电能与信号反向同步传输ICPT系统,并对其控制方法进行了深入研究。该系统在副边增加信号调制电容,检测负载大小以确定具体的信号调制方案,通过切入与切出该调制电容以改变原边电流波形包络,进而将数字信号调制到系统中,这样原边在发射电能的同时接收来自副边的状态信息,最后通过设计信号解调机构,复原信号。首先介绍了ICPT系统电能与信号同步传输原理,在此基础上,提出电能与信号反向同步传输ICPT系统;然后,通过对该系统进行建模分析得到负载变化情况下不同的信号调制策略,并对系统变负载情况下系统特性进行了分析和研究;最后,针对理论分析进行了仿真与实验验证,实验实现了ICPT系统在电能正向传输情况下的信号的反向低误码率传输。该研究结果可以为ICPT系统电能与信号反向同步传输系统的设计与研究提供参考。
文摘The efficiency of advanced membranes towards removal of general and specific microbes from wastewater was investigated. The treatment included a subsequent system of activated sludge, ultrafiltration （hollow fibre membranes with 100 kDa cut-off, and spiral wound membranes with 20 kDa cut-off）, and RO （reverse osmosis）. The removal evaluation of screened microbes present in treated wastewater showed that hollow fibre membrane rejected only 1 log （90% rejection） of the TPC （total microbial count）, TC （total coliforms）, and FC （faecal coliforms）. A higher effectiveness was observed with spiral wound, removing 2-3 logs （99%-99.9%） of TPC and complete rejection of TC and FC. The RO system was successful in total rejection of all received bacteria. The removal evaluation of inoculated specific types of bacteria showed that the hollow membranes removed 2 logs （99%） of inoculated E. coli （10^7-10^8 cfu/mL inoculum）, 2-3 logs （99%-99.9%） of Enterococus spp. （10^7-10^10 cfu/mL inoculum）, 1-2 logs （90%-99%） of Salmonella （10^8-10^10 cfu/mL inoculum） and 1-2 logs （90%-99%） of Shigella （10^5-10^6 cfu/mL inoculum）. The spiral wound was significantly efficient in rejecting further 3 logs of E. coil, 5 logs of Enterococus spp., 4 logs of Salmonella, and a complete rejection of all received bacteria was accomplished by RO membrane. The results indicate that Gram positive bacteria were removed much more efficiently compared to the Gram negative ones, the rationale behind such behaviour is based on cell walls elasticity.
基金the Development Project of Ship Situational Intelligent Awareness System(Grant No.MC-201920-X01)。
文摘Stopping maneuver is an important research topic in ship maneuverability.The stopping ability of ship is not only related to the hydrodynamic characteristics of hull,rudder and propeller,but also related to the capacity of main engine.However,there are few researches on the capacity of main engine under reversed propulsion condition.In the paper,a numerical water tank is established to simulate the propeller loads using the computational fluid dynamics(CFD)software STAR CCM+.The numerical model is firstly validated by experimental data,and then is used to investigate the propeller loads on a full-scale model with different ship speed and propeller speed.By dimensionless,the relations between the advance coefficient and the load coefficients are shown as J-KT curves and J-KQ curves.Furtherly,the flow structures near the propeller and the pressure on the propeller with different J values are investigated.The simulations reveal that the flow velocities induced by the reversed propulsion of the propeller is similar to the wake flow by ship with J=-0.49.That is the reason for the minimum points of J-KT and J-KQ curve occurring in cases with J=-0.49.Subsequently,the capacity of the main engine and the output load of the propeller are considered comprehensively.The relations between the ship speeds and the maximum output loads on the propeller are discussed in details.
