Nanogenerators utilize nanomaterials to harvest mechanical or thermal energy at the micro-nano scale,thereby providing power for small self-sustaining devices.Compared to traditional generators,nanogenerators offer ad...Nanogenerators utilize nanomaterials to harvest mechanical or thermal energy at the micro-nano scale,thereby providing power for small self-sustaining devices.Compared to traditional generators,nanogenerators offer advantages such as compact size,high flexibility,and broad versatility.Triboelectric nanogenerators(TENGs),based on triboelectric theory,can collect energy from mechanical sources such as vibrations or sliding movements.TENGs hold promise for powering small electronics.However,the high pulse characteristics of their output voltage prevent them from directly charging electronic devices.To address the requirements of the internet of things(IoTs),this paper comprehensively reviews state-of-the-art power management systems used to enhance the current stability and output power of TENGs.First,the working principle and resistive load output characteristics of TENGs are elaborated.Power management circuits(PMCs)based on full-wave rectifiers,half-wave rectifiers,and Bennet's doublers are subsequently analyzed and compared.Mechanical and electronic switches proposed to further improve rectifier performance are also detailed.Mechanical switches are categorized as travel and voltagetriggered switches,while electronic switches include silicon-controlled rectifiers(SCRs),metal-oxide-semiconductor fieldeffect transistors(MOSFETs),and integrated circuits.In conclusion,the characteristics and applications of PMCs are summarized,along with the identification of existing limitations in their application.Subsequently,appropriate solutions and prospects for further development are explored.展开更多
To reveal the potential influence of styrene-butadiene-styrene(SBS)polymer modification on the anti-aging performance of asphalt,and its mechanism,we explored the aging characteristics of base asphalt and SBS-modified...To reveal the potential influence of styrene-butadiene-styrene(SBS)polymer modification on the anti-aging performance of asphalt,and its mechanism,we explored the aging characteristics of base asphalt and SBS-modified asphalt by reaction force field(ReaxFF)and classical molecular dynamics simulations.The results illustrate that the SBS asphalt is more susceptible to oxidative aging than the base asphalt under oxygen-deficient conditions due to the presence of unsaturated C=C bonds in the SBS polymer.In the case of sufficient oxygen,the SBS polymer inhibits the oxidation of asphalt by restraining the diffusion of asphalt molecules.Compared with the base asphalt,the SBS asphalt exhibits a higher degree of oxidation at the early stage of pavement service and a lower degree of oxidation in the long run.In addition,SBS polymer degrades into small blocks during aging,thus counteracting the hardening of aged asphalt and partially restoring its low-temperature cracking resistance.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62225308,62001281)Shanghai Science and Technology Committee(Grant No.22dz1204300)。
文摘Nanogenerators utilize nanomaterials to harvest mechanical or thermal energy at the micro-nano scale,thereby providing power for small self-sustaining devices.Compared to traditional generators,nanogenerators offer advantages such as compact size,high flexibility,and broad versatility.Triboelectric nanogenerators(TENGs),based on triboelectric theory,can collect energy from mechanical sources such as vibrations or sliding movements.TENGs hold promise for powering small electronics.However,the high pulse characteristics of their output voltage prevent them from directly charging electronic devices.To address the requirements of the internet of things(IoTs),this paper comprehensively reviews state-of-the-art power management systems used to enhance the current stability and output power of TENGs.First,the working principle and resistive load output characteristics of TENGs are elaborated.Power management circuits(PMCs)based on full-wave rectifiers,half-wave rectifiers,and Bennet's doublers are subsequently analyzed and compared.Mechanical and electronic switches proposed to further improve rectifier performance are also detailed.Mechanical switches are categorized as travel and voltagetriggered switches,while electronic switches include silicon-controlled rectifiers(SCRs),metal-oxide-semiconductor fieldeffect transistors(MOSFETs),and integrated circuits.In conclusion,the characteristics and applications of PMCs are summarized,along with the identification of existing limitations in their application.Subsequently,appropriate solutions and prospects for further development are explored.
基金the financial support of the National Natural Science Foundation of China(Grant No.51878162)the Scientific Research Foundation of Graduate School of South-east University(No.YBPY2043)the Innovation and Development Foundation of Tibet Tianlu Co.,Ltd.(No.XZ 2019 TL-G-01).
文摘To reveal the potential influence of styrene-butadiene-styrene(SBS)polymer modification on the anti-aging performance of asphalt,and its mechanism,we explored the aging characteristics of base asphalt and SBS-modified asphalt by reaction force field(ReaxFF)and classical molecular dynamics simulations.The results illustrate that the SBS asphalt is more susceptible to oxidative aging than the base asphalt under oxygen-deficient conditions due to the presence of unsaturated C=C bonds in the SBS polymer.In the case of sufficient oxygen,the SBS polymer inhibits the oxidation of asphalt by restraining the diffusion of asphalt molecules.Compared with the base asphalt,the SBS asphalt exhibits a higher degree of oxidation at the early stage of pavement service and a lower degree of oxidation in the long run.In addition,SBS polymer degrades into small blocks during aging,thus counteracting the hardening of aged asphalt and partially restoring its low-temperature cracking resistance.
