Wireless charging has played a crucial role in electric vehicle charging market presently.As electric vehicles will be important nodes access to the smart grid in the future,the security flow of energy and information...Wireless charging has played a crucial role in electric vehicle charging market presently.As electric vehicles will be important nodes access to the smart grid in the future,the security flow of energy and information between wireless charging infrastructure and the smart grid will directly affect the security of the smart grid.A novel secure wireless transfer method for energy and information transfer simultaneously has been represented in this paper by designing a reasonable dual-band coil for simultaneous transmission of energy and information,using improved chaotic modulation and a three times handshake protocol for encrypting energy and information between wireless charging infrastructure and the smart grid.Both the simulation and experiments show that the security of energy transmission can be effectively improved by this structure,in the premise of ensuring the power and efficiency of wireless energy transmission.展开更多
China has improved its social security system in recent decades,with the aim of achieving universal coverage and improving the equity of income distribution.Based on data from the five rounds of Chinese Household Inco...China has improved its social security system in recent decades,with the aim of achieving universal coverage and improving the equity of income distribution.Based on data from the five rounds of Chinese Household Income Project surveys from 1988 to 2018,this paper examines the long-term redistributive effects of social security programs in China.Our results show that social security programs have reduced income inequality consistently,and the positive redistributive effects have been improving for the past 30 years.Social security transfers have had an increasingly essential role in rural areas,especially after 2002 when China started to establish a comprehensive rural social safety net and expanded the coverage of the social security program.The redistributive efficiency of the social security system has also increased recently.展开更多
基金This work is supported by International Science&Technology Cooperation Program of China under contract No.2016YFE0102200.
文摘Wireless charging has played a crucial role in electric vehicle charging market presently.As electric vehicles will be important nodes access to the smart grid in the future,the security flow of energy and information between wireless charging infrastructure and the smart grid will directly affect the security of the smart grid.A novel secure wireless transfer method for energy and information transfer simultaneously has been represented in this paper by designing a reasonable dual-band coil for simultaneous transmission of energy and information,using improved chaotic modulation and a three times handshake protocol for encrypting energy and information between wireless charging infrastructure and the smart grid.Both the simulation and experiments show that the security of energy transmission can be effectively improved by this structure,in the premise of ensuring the power and efficiency of wireless energy transmission.
基金supported financially by the National Social Science Foundation of China(No.18ZDA080)Humanities and Social Sciences Project from the Ministry of Education of the People’s Republic of China(Nos.17JJD790023 and 20YJC790153)the National Natural Science Foundation of China(No.71703188).
文摘China has improved its social security system in recent decades,with the aim of achieving universal coverage and improving the equity of income distribution.Based on data from the five rounds of Chinese Household Income Project surveys from 1988 to 2018,this paper examines the long-term redistributive effects of social security programs in China.Our results show that social security programs have reduced income inequality consistently,and the positive redistributive effects have been improving for the past 30 years.Social security transfers have had an increasingly essential role in rural areas,especially after 2002 when China started to establish a comprehensive rural social safety net and expanded the coverage of the social security program.The redistributive efficiency of the social security system has also increased recently.
