Two-dimensional(2D)transition metal chalcogenides(TMCs)hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric properties.However,overcoming the imp...Two-dimensional(2D)transition metal chalcogenides(TMCs)hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric properties.However,overcoming the impedance mismatch at the low loading is still a challenge for TMCs due to the restricted loss pathways caused by their high-density characteristic.Here,an interface engineering based on the heterostructure of 2D Cr_(5)Te_(8) and graphite is in situ constructed via a one-step chemical vapor deposit to modulate impedance matching and introduce multiple attenuation mechanisms.Intriguingly,the Cr_(5)Te_(8)@EG(ECT)heterostructure exhibits a minimum reflection loss of up to−57.6 dB at 15.4 GHz with a thin thickness of only 1.4 mm under a low filling rate of 10%.The density functional theory calculations confirm that the splendid performance of ECT heterostructure primarily derives from charge redistribution at the abundant intimate interfaces,thereby reinforcing interfacial polarization loss.Furthermore,the ECT coating displays a remarkable radar cross section reduction of 31.9 dB m^(2),demonstrating a great radar microwave scattering ability.This work sheds light on the interfacial coupled stimulus response mechanism of TMC-based heterogeneous structures and provides a feasible strategy to manipulate high-quality TMCs for excellent microwave absorbers.展开更多
Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is cha...Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.展开更多
Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR clo...Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration limitations.Here,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption layer.The top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass through.Meanwhile,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric synergy.Through theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ranges.Specifically,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of 0.35.Additionally,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.展开更多
This editorial comments on a study by Zuo et al.The focus is on the efficacy of he-patic arterial infusion chemotherapy combined with camrelizumab and apatinib(the TRIPLET regimen),alongside microwave ablation therapy...This editorial comments on a study by Zuo et al.The focus is on the efficacy of he-patic arterial infusion chemotherapy combined with camrelizumab and apatinib(the TRIPLET regimen),alongside microwave ablation therapy,in treating advanced hepatocellular carcinoma(HCC).The potential application of this combination therapy for patients with advanced HCC is evaluated.展开更多
In this study,a novel microwave-water cooling-assisted mechanical rock breakage method was proposed to address the issues of severe tool wear at elevated temperatures,poor rock microwave absorption,and excessive micro...In this study,a novel microwave-water cooling-assisted mechanical rock breakage method was proposed to address the issues of severe tool wear at elevated temperatures,poor rock microwave absorption,and excessive microwave energy consumption.The investigation object was sandstone,which was irradiated at 4 kW microwave power for 60 s,180 s,300 s,and 420 s,followed by air and water cooling.Subsequently,uniaxial compression,Brazilian tension,and fracture tests were conducted.The evolution of damage in sandstone was measured using active and passive nondestructive acoustic detection methods.The roughness of the fracture surfaces of the specimens was quantified using the box-counting method.The damage mechanisms of microwave heating and water cooling on sandstone were discussed from both macroscopic and microscopic perspectives.The experimental results demonstrated that as the duration of the microwave irradiation increased,the P-wave velocity,uniaxial compressive strength(UCS),elastic modulus(E),tensile strength,and fracture toughness of sandstone exhibited various degrees of weakness and were further weakened by water cooling.Furthermore,an increase in the microwave irradiation duration enhanced the damaging effect of water cooling.The P-wave velocity of the sandstone was proportional to the mechanical parameters.Microwave heating and water cooling weakened the brittleness of the sandstone to a certain extent.The fractal dimension of the fracture surface was correlated with the duration of microwave heating,and the water-cooling treatment resulted in a rougher fracture surface.An analysis of the instantaneous cutting rate revealed that water cooling can substantially enhance the efficiency of microwave-assisted rock breakage.展开更多
Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_...Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.展开更多
BACKGROUND Flat bone metastases are common in patients with advanced cancers,often resulting in severe pain,limited mobility,and reduced quality of life(QOL).Traditional treatment options,such as radiotherapy or syste...BACKGROUND Flat bone metastases are common in patients with advanced cancers,often resulting in severe pain,limited mobility,and reduced quality of life(QOL).Traditional treatment options,such as radiotherapy or systemic therapies,often fail to provide sufficient pain relief or improve functional outcomes in these patients.Microwave ablation(MWA)offers advantages,such as shorter pro-cedure times and larger ablation zones,while percutaneous osteoplasty(PO)enhances bone stability and prevents pathological fractures.Despite these be-nefits,the combination of these techniques for treating flat bone metastases re-mains underexplored.AIM To evaluate the efficacy and safety of C-arm computed tomography(CT)-guided MWA combined with PO for managing painful flat bone metastases,focusing on pain relief,functional improvement,and QOL enhancement.METHODS A total of 45 patients with refractory moderate-to-severe pain resulting from flat bone metastases who underwent C-arm CT-guided MWA combined with PO between January 2015 and January 2021 were included.The efficacy of the pro-cedure was assessed by changes in the visual analog scale(VAS),Oswestry disability index(ODI),and QOL,as well as the occurrence of complications.Tumor response was evaluated using RECIST v1.1 and mRECIST criteria,with overall response rate(ORR)and disease control rate(DCR)as the primary end-points.RESULTS No serious complications were observed in any of the patients.A significant reduction in VAS and ODI was noted at 1 week,1 month,and 3 months post-procedure.A marked improvement in QOL was observed at all follow-up points.Bone cement extravasation was observed in 10 patients;however,none exhibited significant clinical symptoms.Based on RECIST v1.1,the ORR was 26.7%and the DCR was 88.9%.The mRECIST evaluation revealed a higher ORR of 51.1%and DCR of 88.9%.CONCLUSION C-arm CT-guided MWA with PO provides a dependable and effective strategy for managing flat bone metastases.It demonstrates significant pain relief,improved functional outcomes,and enhanced QOL.This treatment combination also shows promising tumor response rates with a low complication profile.展开更多
Microwave discharge plasma in liquid(MDPL)is a new type of water purification technology with a high mass transfer efficiency.It is a kind of low-temperature plasma technology.The reactive species produced by the disc...Microwave discharge plasma in liquid(MDPL)is a new type of water purification technology with a high mass transfer efficiency.It is a kind of low-temperature plasma technology.The reactive species produced by the discharge can efficiently act on the pollutants.To clarify the application prospects of MDPL in water treatment,the discharge performance,practical application,and pollutant degradation mechanism of MDPL were studied in this work.The effects of power,conductivity,pH,and Fe^(2+)concentration on the amount of reactive species produced by the discharge were explored.The most common and refractory perfluorinated compounds(perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS)in water environments are degraded by MDPL technology.The highest defluorination of PFOA was 98.8% and the highest defluorination of PFOS was 92.7%.The energy consumption efficiency of 50% defluorination(G_(50-F))of PFOA degraded by MDPL is 78.43 mg/kWh,PFOS is 42.19 mg/kWh.The results show that the MDPL technology is more efficient and cleaner for the degradation of perfluorinated compounds.Finally,the reaction path and pollutant degradation mechanisms of MDPL production were analyzed.The results showed that MDPL technology can produce a variety of reactive species and has a good treatment effect for refractory perfluorinated pollutants.展开更多
The Doppler backscattering(DBS)diagnostic is widely used to measure the localized density fluctuations and the propagation velocity of turbulent structures.Microwave is launched at a frequency that approaches a cutoff...The Doppler backscattering(DBS)diagnostic is widely used to measure the localized density fluctuations and the propagation velocity of turbulent structures.Microwave is launched at a frequency that approaches a cutoff layer in the plasma at an angle oblique to the cutoff layer.A new Q-band multichannel DBS system based on a comb generator has been designed and tested for application on the HL-3 tokamak.With the comb generator and heterodyne scheme,the stability and flexibility of the new DBS system are improved.The new DBS diagnostic has a high output power(~10 dBm),good power flatness(<5 dB in Q-band),and frequency stability,and the inter-frequency separation is tunable remotely.This article introduces the system design,laboratory test results,and initial experimental results from the HL-3 tokamak.With the help of the newly developed multichannel DBS,the turbulence information can be studied with high temporal and spatial resolution.展开更多
Microwave ablation(MWA)is emerging as a highly effective treatment for colorectal liver metastases(CRLMs).This review explores the advantages of MWA compared to other ablative techniques such as radiofrequency ablatio...Microwave ablation(MWA)is emerging as a highly effective treatment for colorectal liver metastases(CRLMs).This review explores the advantages of MWA compared to other ablative techniques such as radiofrequency ablation and cryoablation and highlights its clinical efficacy,safety,and technical considerations.MWA offers significant benefits,including higher intratumoral temperatures,larger ablation zones,and reduced susceptibility to the heat-sink effect,which make it particularly suitable for tumors near large blood vessels.This review details the patient selection criteria,procedural approaches,and the use of advanced imaging techniques to improve the precision and effectiveness of MWA.Clinical outcomes indicate that MWA achieves high rates of complete tumor ablation and long-term survival with a favorable safety profile.This review is significant because it provides updated insights into the expanding role of MWA in treating unresectable CRLM and its potential as an alternative to surgical resection for resectable tumors.By summarizing recent studies and clinical trials,this review highlights the comparative effectiveness,safety,and integration with systemic therapies of MWA.In conclusion,MWA is a promising treatment option for CRLM and offers outcomes comparable to or better than those of other ablative techniques.Future research should focus on optimizing technical parameters,integrating MWA with systemic therapies,and conducting large-scale randomized controlled trials to establish standardized treatment protocols.Advancing our understanding of MWA will enhance its application and improve long-term survival and quality of life for patients with CRLM.展开更多
BACKGROUND Liver cancer is one of the most common malignant tumors of the digestive system,and early detection and effective treatment are crucial for improving the prognosis.Microwave ablation(MWA)has shown promising...BACKGROUND Liver cancer is one of the most common malignant tumors of the digestive system,and early detection and effective treatment are crucial for improving the prognosis.Microwave ablation(MWA)has shown promising results as a local therapeutic method for liver cancer;however,further improvement of its efficacy remains a key focus of current research.AIM To evaluate the clinical efficacy of Linggui Zhugan decoction combined with MWA for the treatment of primary liver cancer.METHODS Data were collected from 164 patients with primary liver cancer who underwent MWA at our hospital between March 2019 and April 2021.Among them,79 patients(control group)received routine treatments and 85 patients(research group)received Linggui Zhugan decoction in addition to routine treatment.The clinical efficacy,incidence of adverse reactions,and levels of serum alphafetoprotein(AFP),des-γ-carboxy prothrombin(DCP),AFP-L3,total bilirubin(TBil),alanine aminotransferase(ALT),CD4 cell count,CD8 cell count,and CD4/CD8 ratio were compared between the two groups,before and after treatment.The three-year recurrence rates between the two groups were compared,and independent prognostic factors for recurrence were identified.RESULTS The study results revealed that the objective response rate(ORR)in the research group was significantly higher than that in the control group(P=0.005).After treatment,the CD4 cell count and CD4/CD8 ratio significantly increased,whereas the CD8 cell count and TBil,ALT,AFP,DCP,and AFP-L3 Levels were significantly lower in the research group than in the control group(P<0.001).The Cox regression analysis revealed that the treatment regimen(P=0.003),presence of cirrhosis(P=0.019),tumor diameter(P=0.037),Child-Pugh score(P=0.003),pretreatment AFP level(P=0.006),and AFP-L3 Level(P=0.002)were independent prognostic factors for disease-free survival.CONCLUSION The combination of Linggui Zhugan decoction with MWA significantly improved the clinical efficacy and longterm prognosis of patients with primary liver cancer.展开更多
Recently,multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials.Nevertheless,excessive stack and agglomeration for low-dimension carbon nanomaterials inducing imped...Recently,multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials.Nevertheless,excessive stack and agglomeration for low-dimension carbon nanomaterials inducing impedance mismatch are significant challenges.Herein,the delicate“3D helix-2D sheet-1D fiber-0D dot”hierarchical aerogels have been successfully synthesized,for the first time,by sequential processes of hydrothermal self-assembly and in-situ chemical vapor deposition method.Particularly,the graphene sheets are uniformly intercalated by 3D helical carbon nanocoils,which give a feasible solution to the mentioned problem and endows the as-obtained aerogel with abundant porous structures and better dielectric properties.Moreover,by adjusting the content of 0D core-shell structured particles and the parameters for growth of the 1D carbon nanofibers,tunable electromagnetic properties and excellent impedance matching are achieved,which plays a vital role in the microwave absorption performance.As expected,the optimized aerogels harvest excellent performance,including broad effective bandwidth and strong reflection loss at low filling ratio and thin thickness.This work gives valuable guidance and inspiration for the design of hierarchical materials comprised of dimensional gradient structures,which holds great application potential for electromagnetic wave attenuation.展开更多
Currently,electromagnetic radiation and interference have a significant effect on the operation of electronic devices and human health systems.Thus,developing excellent microwave absorbers have a huge significance in ...Currently,electromagnetic radiation and interference have a significant effect on the operation of electronic devices and human health systems.Thus,developing excellent microwave absorbers have a huge significance in the material research field.Herein,a kind of ultrafine zinc oxide(ZnO)nanoparticles(NPs)supported on three-dimensional(3D)ordered mesoporous carbon spheres(ZnO/OMCS)is prepared from silica inverse opal by using phenolic resol precursor as carbon source.The prepared lightweight ZnO/OMCS nanocomposites exhibit 3D ordered carbon sphere array and highly dispersed ultrafine ZnO NPs on the mesoporous cell walls of carbon spheres.ZnO/OMCS-30 shows microwave absorbing ability with a strong absorption(−39.3 dB at 10.4 GHz with a small thickness of 2 mm)and a broad effective absorption bandwidth(9.1 GHz).The outstanding microwave absorbing ability benefits to the well-dispersed ultrafine ZnO NPs and the 3D ordered mesoporous carbon spheres structure.This work opened up a unique way for developing lightweight and high-efficient carbon-based microwave absorbing materials.展开更多
Plasma photonic crystals(PPCs)are emerging as a powerful instrument for the dynamical control of the electromagnetic properties of a propagating wave.Here we demonstrate several one-dimensional(1 D)PPCs with uniquely ...Plasma photonic crystals(PPCs)are emerging as a powerful instrument for the dynamical control of the electromagnetic properties of a propagating wave.Here we demonstrate several one-dimensional(1 D)PPCs with uniquely designed superlattice structures,annular structures or with incorporation of the third material into the primitive unit cell.The influences of the properties of the third material as well as the structural configurations of suplerlattices on the transmittance characteristics of PPCs have been investigated by use of the finite element method.The optimal design strategy for producing PPCs that have more and larger band gaps is provided.These new schemes can potentially be extended to 2 D or 3 D plasma crystals,which may find broad applications in the manipulation of microwaves and terahertz waves.展开更多
Due to the low spatial resolution of sea surface temperature(T_S)retrieval by real aperture microwave radiometers,in this study,an iterative retrieval method that minimizes the differences between brightness temperatu...Due to the low spatial resolution of sea surface temperature(T_S)retrieval by real aperture microwave radiometers,in this study,an iterative retrieval method that minimizes the differences between brightness temperature(T_B)measured and modeled was used to retrieve sea surface temperature with a one-dimensional synthetic aperture microwave radiometer,temporarily named 1 D-SAMR.Regarding the configuration of the radiometer,an angular resolution of 0.43°was reached by theoretical calculation.Experiments on sea surface temperature retrieval were carried out with ideal parameters;the results show that the main factors affecting the retrieval accuracy of sea surface temperature are the accuracy of radiometer calibration and the precision of auxiliary geophysical parameters.In the case of no auxiliary parameter errors,the greatest error in retrieved sea surface temperature is obtained at low T_S scene(i.e.,0.7106 K for the incidence angle of 35°under the radiometer calibration accuracy of0.5 K).While errors on auxiliary parameters are assumed to follow a Gaussian distribution,the greatest error on retrieved sea surface temperature was 1.3305 K at an incidence angle of 65°in poorly known sea surface wind speed(W)(the error on W of 1.0 m/s)over high W scene,for the radiometer calibration accuracy of 0.5 K.展开更多
In this study, the bidirectional reflectance distribution function (BRDF) of a one-dimensional conducting rough surface and a dielectric rough surface are calculated with different frequencies and roughness values i...In this study, the bidirectional reflectance distribution function (BRDF) of a one-dimensional conducting rough surface and a dielectric rough surface are calculated with different frequencies and roughness values in the microwave band by using the method of moments, and the relationship between the bistatic scattering coefficient and the BRDF of a rough surface is expressed. From the theory of the parameters of the rough surface BRDF, the parameters of the BRDF are obtained using a genetic algorithm. The BRDF of a rough surface is calculated using the obtained parameter values. Further, the fitting values and theoretical calculations of the BRDF are compared, and the optimization results are in agreement with the theoretical calculation results. Finally, a reference for BRDF modeling of a Gaussian rough surface in the microwave band is provided by the proposed method.展开更多
We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe_5 single crystals through contactless electron spin resonance(ESR)measurements with the magne...We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe_5 single crystals through contactless electron spin resonance(ESR)measurements with the magnetic field up to 1.4 T.The ESR signals manifest remarkably anisotropic characteristics with respect to the direction of the magnetic field,indicating an anisotropic Fermi surface in ZrTe_5.Further experiments demonstrate that the ZrTe_5 single crystals have the signature of massless Dirac fermions with nontrivialBerry phase,key evidence for 3D Dirac/Weyl fermions.Moreover,the onset of quantum oscillation of our ZrTe_5 crystals revealed by the ESR can be derived down to 0.2 T,much smaller than the onset of SdH oscillation determined by conventional magnetoresistance measurements.Therefore,ESR measurement is a powerful tool to study the topologically nontrivial electronic structure in Dirac/Weyl semimetals and other topological materials with low bulk carrier density.展开更多
Based on the particle-in-cell technology and the secondary electron emission theory, a three-dimensional simulation method for multipactor is presented in this paper. By combining the finite difference time domain met...Based on the particle-in-cell technology and the secondary electron emission theory, a three-dimensional simulation method for multipactor is presented in this paper. By combining the finite difference time domain method and the panicle tracing method, such an algorithm is self-consistent and accurate since the interaction between electromagnetic fields and particles is properly modeled. In the time domain aspect, the generation of multipactor can be easily visualized, which makes it possible to gain a deeper insight into the physical mechanism of this effect. In addition to the classic secondary electron emission model, the measured practical secondary electron yield is used, which increases the accuracy of the algorithm. In order to validate the method, the impedance transformer and ridge waveguide filter are studied. By analyzing the evolution of the secondaries obtained by our method, multipactor thresholds of these components are estimated, which show good agreement with the experimental results. Furthermore, the most sensitive positions where multipactor occurs are determined from the phase focusing phenomenon, which is very meaningful for multipactor analysis and design.展开更多
Considering the risk of a sudden degeneration caused by the oxidation of MXenes in dielectric and microwave absorption properties,to enhance the oxidation resistance of multilayer MXenes can make them more applicable ...Considering the risk of a sudden degeneration caused by the oxidation of MXenes in dielectric and microwave absorption properties,to enhance the oxidation resistance of multilayer MXenes can make them more applicable as microwave absorbers than those with few-layer.However,there remains disadvantage in optimizing the poor impedance matching and inherent aggregation of multilayer MXenes via rational assembling.In the present study,a facile self-assembly process is conducted to obtain 2D MXenes/1D MnO_(2)/0D NiCo_(2)S_(4) assembled lowdimensional aggregate with hierarchical structure and interlaminar electromagnetic synergy network.In addition to bridging adjacent MXenes lamellas for the enhancement of internal electron transport,high-density MnO2 can also combine with NiCo2S4 to form an electromagnetic synergy network between lamellas,thus improving microwave attenuation.Though the modulation of components and assembled structures,it is achievable to effectively adjust and optimize the performance in impedance matching and microwave absorption.Given the thickness of 2.17 mm,the optimal reflection loss of59.23 dB,and the effective absorption bandwidth of 5.8 GHz are achieved.Moreover,the RCS simulations is performed to demonstrate its excellent performance.Thus,the present work contributes a facile method to the development of multi-layer MXenes based-MAs via interlaminar electromagnetic network design.展开更多
Compared with traditional real aperture microwave radiometers,one-dimensional synthetic aperture microwave radiometers have higher spatial resolution.In this paper,we proposed to retrieve sea surface temperature using...Compared with traditional real aperture microwave radiometers,one-dimensional synthetic aperture microwave radiometers have higher spatial resolution.In this paper,we proposed to retrieve sea surface temperature using a one-dimensional synthetic aperture microwave radiometer that operates at frequencies of 6.9 GHz,10.65 GHz,18.7 GHz and 23.8 GHz at multiple incidence angles.We used the ERA5 reanalysis data provided by the European Centre for Medium-Range Weather Forecasts and a radiation transmission forward model to calculate the model brightness temperature.The brightness temperature measured by the spaceborne one-dimensional synthetic aperture microwave radiometer was simulated by adding Gaussian noise to the model brightness temperature.Then,a backpropagation(BP)neural network algorithm,a random forest(RF)algorithm and two multiple linear regression algorithms(RE1 and RE2)were developed to retrieve sea surface temperature from the measured brightness temperature within the incidence angle range of 0°-65°.The results show that the retrieval errors of the four algorithms increase with the increasing Gaussian noise.The BP achieves the lowest retrieval errors at all incidence angles.The retrieval error of the RE1 and RE2 decrease first and then increase with the incidence angle and the retrieval error of the RF is contrary to that of RE1 and RE2.展开更多
基金the National Natural Science Foundation of China(grant No.62174013,92265111)Central Government Guides Local Funds for Science and Technology Development(No.YDZJSX2022A021)the funding Program of BIT(grant No.3180012212214 and 3180023012204).
文摘Two-dimensional(2D)transition metal chalcogenides(TMCs)hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric properties.However,overcoming the impedance mismatch at the low loading is still a challenge for TMCs due to the restricted loss pathways caused by their high-density characteristic.Here,an interface engineering based on the heterostructure of 2D Cr_(5)Te_(8) and graphite is in situ constructed via a one-step chemical vapor deposit to modulate impedance matching and introduce multiple attenuation mechanisms.Intriguingly,the Cr_(5)Te_(8)@EG(ECT)heterostructure exhibits a minimum reflection loss of up to−57.6 dB at 15.4 GHz with a thin thickness of only 1.4 mm under a low filling rate of 10%.The density functional theory calculations confirm that the splendid performance of ECT heterostructure primarily derives from charge redistribution at the abundant intimate interfaces,thereby reinforcing interfacial polarization loss.Furthermore,the ECT coating displays a remarkable radar cross section reduction of 31.9 dB m^(2),demonstrating a great radar microwave scattering ability.This work sheds light on the interfacial coupled stimulus response mechanism of TMC-based heterogeneous structures and provides a feasible strategy to manipulate high-quality TMCs for excellent microwave absorbers.
基金supported by the National Natural Science Foundation of China(No.52373280,52177014,51977009,52273257)。
文摘Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.
基金financial support from the National Nature Science Foundation of China(No.52273247)the National Science and Technology Major Project of China(J2019-VI-0017-0132).
文摘Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration limitations.Here,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption layer.The top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass through.Meanwhile,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric synergy.Through theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ranges.Specifically,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of 0.35.Additionally,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.
文摘This editorial comments on a study by Zuo et al.The focus is on the efficacy of he-patic arterial infusion chemotherapy combined with camrelizumab and apatinib(the TRIPLET regimen),alongside microwave ablation therapy,in treating advanced hepatocellular carcinoma(HCC).The potential application of this combination therapy for patients with advanced HCC is evaluated.
基金the financial support provided by the National Natural Science Foundation of China(Grant No.52274105)the China Scholarship Council(Grant No.202306370184)。
文摘In this study,a novel microwave-water cooling-assisted mechanical rock breakage method was proposed to address the issues of severe tool wear at elevated temperatures,poor rock microwave absorption,and excessive microwave energy consumption.The investigation object was sandstone,which was irradiated at 4 kW microwave power for 60 s,180 s,300 s,and 420 s,followed by air and water cooling.Subsequently,uniaxial compression,Brazilian tension,and fracture tests were conducted.The evolution of damage in sandstone was measured using active and passive nondestructive acoustic detection methods.The roughness of the fracture surfaces of the specimens was quantified using the box-counting method.The damage mechanisms of microwave heating and water cooling on sandstone were discussed from both macroscopic and microscopic perspectives.The experimental results demonstrated that as the duration of the microwave irradiation increased,the P-wave velocity,uniaxial compressive strength(UCS),elastic modulus(E),tensile strength,and fracture toughness of sandstone exhibited various degrees of weakness and were further weakened by water cooling.Furthermore,an increase in the microwave irradiation duration enhanced the damaging effect of water cooling.The P-wave velocity of the sandstone was proportional to the mechanical parameters.Microwave heating and water cooling weakened the brittleness of the sandstone to a certain extent.The fractal dimension of the fracture surface was correlated with the duration of microwave heating,and the water-cooling treatment resulted in a rougher fracture surface.An analysis of the instantaneous cutting rate revealed that water cooling can substantially enhance the efficiency of microwave-assisted rock breakage.
基金financially supported by the Key Project of Natural Science Research in Colleges and Universities of Anhui Province,China(No.2022AH050816)the Open Research Grant of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining(Nos.EC2023013 and EC2022018)+1 种基金the National Natural Science Foundation of China(No.52200139)the Introduction of Talent in Anhui University of Science and Technology,China(Nos.2021yjrc18 and 2023yjrc79)。
文摘Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.
文摘BACKGROUND Flat bone metastases are common in patients with advanced cancers,often resulting in severe pain,limited mobility,and reduced quality of life(QOL).Traditional treatment options,such as radiotherapy or systemic therapies,often fail to provide sufficient pain relief or improve functional outcomes in these patients.Microwave ablation(MWA)offers advantages,such as shorter pro-cedure times and larger ablation zones,while percutaneous osteoplasty(PO)enhances bone stability and prevents pathological fractures.Despite these be-nefits,the combination of these techniques for treating flat bone metastases re-mains underexplored.AIM To evaluate the efficacy and safety of C-arm computed tomography(CT)-guided MWA combined with PO for managing painful flat bone metastases,focusing on pain relief,functional improvement,and QOL enhancement.METHODS A total of 45 patients with refractory moderate-to-severe pain resulting from flat bone metastases who underwent C-arm CT-guided MWA combined with PO between January 2015 and January 2021 were included.The efficacy of the pro-cedure was assessed by changes in the visual analog scale(VAS),Oswestry disability index(ODI),and QOL,as well as the occurrence of complications.Tumor response was evaluated using RECIST v1.1 and mRECIST criteria,with overall response rate(ORR)and disease control rate(DCR)as the primary end-points.RESULTS No serious complications were observed in any of the patients.A significant reduction in VAS and ODI was noted at 1 week,1 month,and 3 months post-procedure.A marked improvement in QOL was observed at all follow-up points.Bone cement extravasation was observed in 10 patients;however,none exhibited significant clinical symptoms.Based on RECIST v1.1,the ORR was 26.7%and the DCR was 88.9%.The mRECIST evaluation revealed a higher ORR of 51.1%and DCR of 88.9%.CONCLUSION C-arm CT-guided MWA with PO provides a dependable and effective strategy for managing flat bone metastases.It demonstrates significant pain relief,improved functional outcomes,and enhanced QOL.This treatment combination also shows promising tumor response rates with a low complication profile.
基金supported by National Natural Science Foundation of China(Nos.12475258,12111530008 and 11675031)Major Scientific Research Project of Hebei Transportation Investment Group in 2024([202]155)the support of the Fundamental Research Funds for the Central Universities(No.3132023503)。
文摘Microwave discharge plasma in liquid(MDPL)is a new type of water purification technology with a high mass transfer efficiency.It is a kind of low-temperature plasma technology.The reactive species produced by the discharge can efficiently act on the pollutants.To clarify the application prospects of MDPL in water treatment,the discharge performance,practical application,and pollutant degradation mechanism of MDPL were studied in this work.The effects of power,conductivity,pH,and Fe^(2+)concentration on the amount of reactive species produced by the discharge were explored.The most common and refractory perfluorinated compounds(perfluorooctanoic acid(PFOA)and perfluorooctane sulfonate(PFOS)in water environments are degraded by MDPL technology.The highest defluorination of PFOA was 98.8% and the highest defluorination of PFOS was 92.7%.The energy consumption efficiency of 50% defluorination(G_(50-F))of PFOA degraded by MDPL is 78.43 mg/kWh,PFOS is 42.19 mg/kWh.The results show that the MDPL technology is more efficient and cleaner for the degradation of perfluorinated compounds.Finally,the reaction path and pollutant degradation mechanisms of MDPL production were analyzed.The results showed that MDPL technology can produce a variety of reactive species and has a good treatment effect for refractory perfluorinated pollutants.
基金supported by National Natural Science Foundation of China(Nos.12105087,12275096,and 11922503)the Joint Funds of the National Natural Science Foundation of China(No.U21A20440)the Science and Technology Planning Project of Sichuan Province(No.2023YFG0139)。
文摘The Doppler backscattering(DBS)diagnostic is widely used to measure the localized density fluctuations and the propagation velocity of turbulent structures.Microwave is launched at a frequency that approaches a cutoff layer in the plasma at an angle oblique to the cutoff layer.A new Q-band multichannel DBS system based on a comb generator has been designed and tested for application on the HL-3 tokamak.With the comb generator and heterodyne scheme,the stability and flexibility of the new DBS system are improved.The new DBS diagnostic has a high output power(~10 dBm),good power flatness(<5 dB in Q-band),and frequency stability,and the inter-frequency separation is tunable remotely.This article introduces the system design,laboratory test results,and initial experimental results from the HL-3 tokamak.With the help of the newly developed multichannel DBS,the turbulence information can be studied with high temporal and spatial resolution.
基金Supported by the Joint Medical Scientific Research Project of Chongqing Science and Technology Committee and Chongqing Health Committee,No.2021MSXM308.
文摘Microwave ablation(MWA)is emerging as a highly effective treatment for colorectal liver metastases(CRLMs).This review explores the advantages of MWA compared to other ablative techniques such as radiofrequency ablation and cryoablation and highlights its clinical efficacy,safety,and technical considerations.MWA offers significant benefits,including higher intratumoral temperatures,larger ablation zones,and reduced susceptibility to the heat-sink effect,which make it particularly suitable for tumors near large blood vessels.This review details the patient selection criteria,procedural approaches,and the use of advanced imaging techniques to improve the precision and effectiveness of MWA.Clinical outcomes indicate that MWA achieves high rates of complete tumor ablation and long-term survival with a favorable safety profile.This review is significant because it provides updated insights into the expanding role of MWA in treating unresectable CRLM and its potential as an alternative to surgical resection for resectable tumors.By summarizing recent studies and clinical trials,this review highlights the comparative effectiveness,safety,and integration with systemic therapies of MWA.In conclusion,MWA is a promising treatment option for CRLM and offers outcomes comparable to or better than those of other ablative techniques.Future research should focus on optimizing technical parameters,integrating MWA with systemic therapies,and conducting large-scale randomized controlled trials to establish standardized treatment protocols.Advancing our understanding of MWA will enhance its application and improve long-term survival and quality of life for patients with CRLM.
文摘BACKGROUND Liver cancer is one of the most common malignant tumors of the digestive system,and early detection and effective treatment are crucial for improving the prognosis.Microwave ablation(MWA)has shown promising results as a local therapeutic method for liver cancer;however,further improvement of its efficacy remains a key focus of current research.AIM To evaluate the clinical efficacy of Linggui Zhugan decoction combined with MWA for the treatment of primary liver cancer.METHODS Data were collected from 164 patients with primary liver cancer who underwent MWA at our hospital between March 2019 and April 2021.Among them,79 patients(control group)received routine treatments and 85 patients(research group)received Linggui Zhugan decoction in addition to routine treatment.The clinical efficacy,incidence of adverse reactions,and levels of serum alphafetoprotein(AFP),des-γ-carboxy prothrombin(DCP),AFP-L3,total bilirubin(TBil),alanine aminotransferase(ALT),CD4 cell count,CD8 cell count,and CD4/CD8 ratio were compared between the two groups,before and after treatment.The three-year recurrence rates between the two groups were compared,and independent prognostic factors for recurrence were identified.RESULTS The study results revealed that the objective response rate(ORR)in the research group was significantly higher than that in the control group(P=0.005).After treatment,the CD4 cell count and CD4/CD8 ratio significantly increased,whereas the CD8 cell count and TBil,ALT,AFP,DCP,and AFP-L3 Levels were significantly lower in the research group than in the control group(P<0.001).The Cox regression analysis revealed that the treatment regimen(P=0.003),presence of cirrhosis(P=0.019),tumor diameter(P=0.037),Child-Pugh score(P=0.003),pretreatment AFP level(P=0.006),and AFP-L3 Level(P=0.002)were independent prognostic factors for disease-free survival.CONCLUSION The combination of Linggui Zhugan decoction with MWA significantly improved the clinical efficacy and longterm prognosis of patients with primary liver cancer.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51972039,51803018,and 51661145025)LiaoNing Revitalization Talents Program(No.XLYC1902122).
文摘Recently,multilevel structural carbon aerogels are deemed as attractive candidates for microwave absorbing materials.Nevertheless,excessive stack and agglomeration for low-dimension carbon nanomaterials inducing impedance mismatch are significant challenges.Herein,the delicate“3D helix-2D sheet-1D fiber-0D dot”hierarchical aerogels have been successfully synthesized,for the first time,by sequential processes of hydrothermal self-assembly and in-situ chemical vapor deposition method.Particularly,the graphene sheets are uniformly intercalated by 3D helical carbon nanocoils,which give a feasible solution to the mentioned problem and endows the as-obtained aerogel with abundant porous structures and better dielectric properties.Moreover,by adjusting the content of 0D core-shell structured particles and the parameters for growth of the 1D carbon nanofibers,tunable electromagnetic properties and excellent impedance matching are achieved,which plays a vital role in the microwave absorption performance.As expected,the optimized aerogels harvest excellent performance,including broad effective bandwidth and strong reflection loss at low filling ratio and thin thickness.This work gives valuable guidance and inspiration for the design of hierarchical materials comprised of dimensional gradient structures,which holds great application potential for electromagnetic wave attenuation.
基金The authors are grateful of the financial support by the National Natural Science Foundation of China(51902083 and 21606068)the Foundation Strengthening Program(2019-JCJQ-142-00)the Higher Education Science and Technology Research Project of Hebei Province(ZD2019087).
文摘Currently,electromagnetic radiation and interference have a significant effect on the operation of electronic devices and human health systems.Thus,developing excellent microwave absorbers have a huge significance in the material research field.Herein,a kind of ultrafine zinc oxide(ZnO)nanoparticles(NPs)supported on three-dimensional(3D)ordered mesoporous carbon spheres(ZnO/OMCS)is prepared from silica inverse opal by using phenolic resol precursor as carbon source.The prepared lightweight ZnO/OMCS nanocomposites exhibit 3D ordered carbon sphere array and highly dispersed ultrafine ZnO NPs on the mesoporous cell walls of carbon spheres.ZnO/OMCS-30 shows microwave absorbing ability with a strong absorption(−39.3 dB at 10.4 GHz with a small thickness of 2 mm)and a broad effective absorption bandwidth(9.1 GHz).The outstanding microwave absorbing ability benefits to the well-dispersed ultrafine ZnO NPs and the 3D ordered mesoporous carbon spheres structure.This work opened up a unique way for developing lightweight and high-efficient carbon-based microwave absorbing materials.
基金supported by National Natural Science Foundation of China(No.11875014)the Natural Science Foundation of Hebei Province(A2017201099)。
文摘Plasma photonic crystals(PPCs)are emerging as a powerful instrument for the dynamical control of the electromagnetic properties of a propagating wave.Here we demonstrate several one-dimensional(1 D)PPCs with uniquely designed superlattice structures,annular structures or with incorporation of the third material into the primitive unit cell.The influences of the properties of the third material as well as the structural configurations of suplerlattices on the transmittance characteristics of PPCs have been investigated by use of the finite element method.The optimal design strategy for producing PPCs that have more and larger band gaps is provided.These new schemes can potentially be extended to 2 D or 3 D plasma crystals,which may find broad applications in the manipulation of microwaves and terahertz waves.
基金The National Natural Science Foundation of China under contract Nos 41475019,41575028,41705007,41605016,and 41505016。
文摘Due to the low spatial resolution of sea surface temperature(T_S)retrieval by real aperture microwave radiometers,in this study,an iterative retrieval method that minimizes the differences between brightness temperature(T_B)measured and modeled was used to retrieve sea surface temperature with a one-dimensional synthetic aperture microwave radiometer,temporarily named 1 D-SAMR.Regarding the configuration of the radiometer,an angular resolution of 0.43°was reached by theoretical calculation.Experiments on sea surface temperature retrieval were carried out with ideal parameters;the results show that the main factors affecting the retrieval accuracy of sea surface temperature are the accuracy of radiometer calibration and the precision of auxiliary geophysical parameters.In the case of no auxiliary parameter errors,the greatest error in retrieved sea surface temperature is obtained at low T_S scene(i.e.,0.7106 K for the incidence angle of 35°under the radiometer calibration accuracy of0.5 K).While errors on auxiliary parameters are assumed to follow a Gaussian distribution,the greatest error on retrieved sea surface temperature was 1.3305 K at an incidence angle of 65°in poorly known sea surface wind speed(W)(the error on W of 1.0 m/s)over high W scene,for the radiometer calibration accuracy of 0.5 K.
基金Project supported by the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 61225002), the Aeronautical Science Fund and Aviation Key Laboratory of Science and Technology on Avionics Integrated Sensor System Simulation, China (Grant No. 20132081015), and the Fundamental Research Funds for the Central Universities, China (Grant No. SPSZ031403)
文摘In this study, the bidirectional reflectance distribution function (BRDF) of a one-dimensional conducting rough surface and a dielectric rough surface are calculated with different frequencies and roughness values in the microwave band by using the method of moments, and the relationship between the bistatic scattering coefficient and the BRDF of a rough surface is expressed. From the theory of the parameters of the rough surface BRDF, the parameters of the BRDF are obtained using a genetic algorithm. The BRDF of a rough surface is calculated using the obtained parameter values. Further, the fitting values and theoretical calculations of the BRDF are compared, and the optimization results are in agreement with the theoretical calculation results. Finally, a reference for BRDF modeling of a Gaussian rough surface in the microwave band is provided by the proposed method.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0401003the National Natural Science Foundation of China under Grant Nos 11774353,11574320,11374302,11804340,U1432251,U1732274+1 种基金the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology under Grant No 2018CXFX002the China Postdoctoral Science Foundation under Grant No 2018M630718
文摘We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe_5 single crystals through contactless electron spin resonance(ESR)measurements with the magnetic field up to 1.4 T.The ESR signals manifest remarkably anisotropic characteristics with respect to the direction of the magnetic field,indicating an anisotropic Fermi surface in ZrTe_5.Further experiments demonstrate that the ZrTe_5 single crystals have the signature of massless Dirac fermions with nontrivialBerry phase,key evidence for 3D Dirac/Weyl fermions.Moreover,the onset of quantum oscillation of our ZrTe_5 crystals revealed by the ESR can be derived down to 0.2 T,much smaller than the onset of SdH oscillation determined by conventional magnetoresistance measurements.Therefore,ESR measurement is a powerful tool to study the topologically nontrivial electronic structure in Dirac/Weyl semimetals and other topological materials with low bulk carrier density.
基金Project supported by the National Key Laboratory Foundation,China(Grant No.9140C530103110C5301)
文摘Based on the particle-in-cell technology and the secondary electron emission theory, a three-dimensional simulation method for multipactor is presented in this paper. By combining the finite difference time domain method and the panicle tracing method, such an algorithm is self-consistent and accurate since the interaction between electromagnetic fields and particles is properly modeled. In the time domain aspect, the generation of multipactor can be easily visualized, which makes it possible to gain a deeper insight into the physical mechanism of this effect. In addition to the classic secondary electron emission model, the measured practical secondary electron yield is used, which increases the accuracy of the algorithm. In order to validate the method, the impedance transformer and ridge waveguide filter are studied. By analyzing the evolution of the secondaries obtained by our method, multipactor thresholds of these components are estimated, which show good agreement with the experimental results. Furthermore, the most sensitive positions where multipactor occurs are determined from the phase focusing phenomenon, which is very meaningful for multipactor analysis and design.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFE0122900)the National Natural Science Foundation of China(No 22165032,51971162,U1933112,51671146)China Postdoctoral Science Foundation(Grant No.2020M671208).
文摘Considering the risk of a sudden degeneration caused by the oxidation of MXenes in dielectric and microwave absorption properties,to enhance the oxidation resistance of multilayer MXenes can make them more applicable as microwave absorbers than those with few-layer.However,there remains disadvantage in optimizing the poor impedance matching and inherent aggregation of multilayer MXenes via rational assembling.In the present study,a facile self-assembly process is conducted to obtain 2D MXenes/1D MnO_(2)/0D NiCo_(2)S_(4) assembled lowdimensional aggregate with hierarchical structure and interlaminar electromagnetic synergy network.In addition to bridging adjacent MXenes lamellas for the enhancement of internal electron transport,high-density MnO2 can also combine with NiCo2S4 to form an electromagnetic synergy network between lamellas,thus improving microwave attenuation.Though the modulation of components and assembled structures,it is achievable to effectively adjust and optimize the performance in impedance matching and microwave absorption.Given the thickness of 2.17 mm,the optimal reflection loss of59.23 dB,and the effective absorption bandwidth of 5.8 GHz are achieved.Moreover,the RCS simulations is performed to demonstrate its excellent performance.Thus,the present work contributes a facile method to the development of multi-layer MXenes based-MAs via interlaminar electromagnetic network design.
基金The National Natural Science Foundation of China under contract Nos 41475019 and 41705007.
文摘Compared with traditional real aperture microwave radiometers,one-dimensional synthetic aperture microwave radiometers have higher spatial resolution.In this paper,we proposed to retrieve sea surface temperature using a one-dimensional synthetic aperture microwave radiometer that operates at frequencies of 6.9 GHz,10.65 GHz,18.7 GHz and 23.8 GHz at multiple incidence angles.We used the ERA5 reanalysis data provided by the European Centre for Medium-Range Weather Forecasts and a radiation transmission forward model to calculate the model brightness temperature.The brightness temperature measured by the spaceborne one-dimensional synthetic aperture microwave radiometer was simulated by adding Gaussian noise to the model brightness temperature.Then,a backpropagation(BP)neural network algorithm,a random forest(RF)algorithm and two multiple linear regression algorithms(RE1 and RE2)were developed to retrieve sea surface temperature from the measured brightness temperature within the incidence angle range of 0°-65°.The results show that the retrieval errors of the four algorithms increase with the increasing Gaussian noise.The BP achieves the lowest retrieval errors at all incidence angles.The retrieval error of the RE1 and RE2 decrease first and then increase with the incidence angle and the retrieval error of the RF is contrary to that of RE1 and RE2.