To improve the data transmission rate and use spectrum flexibly, a new spectrum allocation method for Multiband Impulse Radio UWB (MB-IR-UWB) is proposed in this paper based on the band-limited and orthogonal characte...To improve the data transmission rate and use spectrum flexibly, a new spectrum allocation method for Multiband Impulse Radio UWB (MB-IR-UWB) is proposed in this paper based on the band-limited and orthogonal characteristics of Prolate Spheroidal Wave Function (PSWF). The system model is built and the bit error rate (BER) formula is deprived by binary time hopping pulse position modulation under additive white Gaussian noise. Moreover, the system performance is analyzed via MATLB simulation. The results indicate that MB-IR-UWB system performance of BER is the same with single-band UWB. However, in the proposed scheme the data can be transmitted in multiple parallel bands, which enjoys much higher transmission rate. In addition, PSWF pulse duration affects the BER performance.展开更多
The development of infrared(IR)surveillance technology has led to a growing interest in thermal camouflage.However,the trade-off relationship between low IR-emissivity and thermal insulation hinders the advance of the...The development of infrared(IR)surveillance technology has led to a growing interest in thermal camouflage.However,the trade-off relationship between low IR-emissivity and thermal insulation hinders the advance of thermal camouflage materials.Herein,guided by multi-physics simulation,we show a design of asymmetric aramid nanofibers/MXene(ANF/MXene)aerogel film that realizes high-efficient thermal camouflage applications.The rationale is that the asymmetric structure contains a thermal-insulation three-dimensional(3D)network part to prevent effective heat transfer and a low IR-emissivity(~0.3)dense surface layer to suppress radiative heat emission.It is remarkable that the synergy mechanism in the topology structure contributes to over 40%reduction of target radiation temperature.Impressively,the tailored asymmetric ANF/MXene aerogel film also enables sound mechanical properties such as a Young’s modulus of 44.4 MPa and a tensile strength of 1.3 MPa,superior to most aerogel materials.It also exhibits great Joule heating performances including low driving voltage(4 V),fast thermal response(<10 s),and long-term stability,further enabling its versatile thermal camouflage applications.This work offers an innovative design concept to configure multifunctional structures for next-generation thermal management applications.展开更多
文摘To improve the data transmission rate and use spectrum flexibly, a new spectrum allocation method for Multiband Impulse Radio UWB (MB-IR-UWB) is proposed in this paper based on the band-limited and orthogonal characteristics of Prolate Spheroidal Wave Function (PSWF). The system model is built and the bit error rate (BER) formula is deprived by binary time hopping pulse position modulation under additive white Gaussian noise. Moreover, the system performance is analyzed via MATLB simulation. The results indicate that MB-IR-UWB system performance of BER is the same with single-band UWB. However, in the proposed scheme the data can be transmitted in multiple parallel bands, which enjoys much higher transmission rate. In addition, PSWF pulse duration affects the BER performance.
基金supported by the National Natural Science Foundation of China(Nos.51673156 and 52202301)the Fundamental Research Funds for the Central Universities(No.D5000210607)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(No.2022JQ-143)China Postdoctoral Science Foundation(Nos.2022M722587 and 2022TQ0256).
文摘The development of infrared(IR)surveillance technology has led to a growing interest in thermal camouflage.However,the trade-off relationship between low IR-emissivity and thermal insulation hinders the advance of thermal camouflage materials.Herein,guided by multi-physics simulation,we show a design of asymmetric aramid nanofibers/MXene(ANF/MXene)aerogel film that realizes high-efficient thermal camouflage applications.The rationale is that the asymmetric structure contains a thermal-insulation three-dimensional(3D)network part to prevent effective heat transfer and a low IR-emissivity(~0.3)dense surface layer to suppress radiative heat emission.It is remarkable that the synergy mechanism in the topology structure contributes to over 40%reduction of target radiation temperature.Impressively,the tailored asymmetric ANF/MXene aerogel film also enables sound mechanical properties such as a Young’s modulus of 44.4 MPa and a tensile strength of 1.3 MPa,superior to most aerogel materials.It also exhibits great Joule heating performances including low driving voltage(4 V),fast thermal response(<10 s),and long-term stability,further enabling its versatile thermal camouflage applications.This work offers an innovative design concept to configure multifunctional structures for next-generation thermal management applications.
