Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis tech...Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis technology still has a significant challenge.Herein,we have successfully designed and synthesized highly flexible MXene@cellulose lamellae/borate ion(MXCB)sheets with strong high‐temperature EM‐IR bi‐stealth through sequential bridging of hydrogen and covalent bonds.The resultant MXCB sheets display high conductivity and good mechanical features such as flexibility,stretchability,fatigue resistance,and ultrasonic damage.MXCB sheets have a high tensile strength of 795 MPa.Furthermore,MXCB sheets with different thicknesses indicate exceptional high‐temperature thermal‐camouflage characteristics.This reduces the radiation temperature of the target object(>300°C)to 100°C.The conductivity of MXCB sheet with 3μm thickness is 6108 S/cm and the EM interference(EMI)shielding value is 39.74 dB.The normalized surface‐specific EMI SE absolute shielding effectiveness(SSE/t)is as high as 39312.78 dB·cm2/g,which remained 99.39%even after 10,000 times repeated folding.These multifunctional ultrathin MXCB sheets can be arranged by vacuum‐assisted induction to develop EM‐IR bi‐stealth sheet.展开更多
The attenuation of electromagnetic （EM） waves in unmagnetized plasma generated by an inductively coupled plasma （ICP） actuator has been investigated both theoretically and experimentally. A numerical study is cond...The attenuation of electromagnetic （EM） waves in unmagnetized plasma generated by an inductively coupled plasma （ICP） actuator has been investigated both theoretically and experimentally. A numerical study is conducted to investigate the propagation of EM waves in multilayer plasma structures which cover a square fiat plate. Experimentally, an ICP actuator with dimensions of 20 cm×20 cm×4 cm is designed to produce a steady plasma slab. The attenuation of EM waves in the plasma generated by the ICP actuator is measured by a reflectivity arch test method at incident waves of 2.3 GHz and 10.1 GHz, respectively. A contrastive analysis of calculated and measured results of these incident wave frequencies is presented, which suggests that the experiment accords well with our theory. As expected, the plasma slab generated by the ICP actuator can effectively attenuate the EM waves, which may have great potential application prospects in aircraft stealth.展开更多
基金supported by the Nanning Innovation and Entrepreneurship Leading Talents“Yongjiang Plan”Project of Guangxi Province,China(No.2021016)Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars of China(No.LR19C160001)the Scientific Research Foundation of Zhejiang A&F University(No.2019FR009).
文摘Combination of flexible multifunctional stealth technology properties such as electromagnetic(EM)and infrared(IR)stealth is crucial to the development of aerospace,military,and electronic fields,but the synthesis technology still has a significant challenge.Herein,we have successfully designed and synthesized highly flexible MXene@cellulose lamellae/borate ion(MXCB)sheets with strong high‐temperature EM‐IR bi‐stealth through sequential bridging of hydrogen and covalent bonds.The resultant MXCB sheets display high conductivity and good mechanical features such as flexibility,stretchability,fatigue resistance,and ultrasonic damage.MXCB sheets have a high tensile strength of 795 MPa.Furthermore,MXCB sheets with different thicknesses indicate exceptional high‐temperature thermal‐camouflage characteristics.This reduces the radiation temperature of the target object(>300°C)to 100°C.The conductivity of MXCB sheet with 3μm thickness is 6108 S/cm and the EM interference(EMI)shielding value is 39.74 dB.The normalized surface‐specific EMI SE absolute shielding effectiveness(SSE/t)is as high as 39312.78 dB·cm2/g,which remained 99.39%even after 10,000 times repeated folding.These multifunctional ultrathin MXCB sheets can be arranged by vacuum‐assisted induction to develop EM‐IR bi‐stealth sheet.
基金supported by National Natural Science Foundation of China(Nos.51276197,11472306 and 11402301)
文摘The attenuation of electromagnetic （EM） waves in unmagnetized plasma generated by an inductively coupled plasma （ICP） actuator has been investigated both theoretically and experimentally. A numerical study is conducted to investigate the propagation of EM waves in multilayer plasma structures which cover a square fiat plate. Experimentally, an ICP actuator with dimensions of 20 cm×20 cm×4 cm is designed to produce a steady plasma slab. The attenuation of EM waves in the plasma generated by the ICP actuator is measured by a reflectivity arch test method at incident waves of 2.3 GHz and 10.1 GHz, respectively. A contrastive analysis of calculated and measured results of these incident wave frequencies is presented, which suggests that the experiment accords well with our theory. As expected, the plasma slab generated by the ICP actuator can effectively attenuate the EM waves, which may have great potential application prospects in aircraft stealth.
