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101.
102.
High dielectric loss materials have an important application in electromagnetic (EM) absorption fields. In this paper, the ternary nanocomposites: 1T/2H-MoS2/Mo2S3 with heterogeneous interfaces are synthesized by hydrothermal method. XRD, XPS, FTIR, SEM, and TEM measurements are applied to study the structure, morphology, and composition. The frequency spectra of complex permittivity (εr-f) are measured in 2–18 GHz by vector network analyzer. The results show that the nanocomposites have higher dielectric loss angle tangents than the reported 2H-MoS2 absorbers. Based on the εr-f spectra, the reflection loss-frequency curves () are simulated at given thicknesses. An effective absorption bandwidth of 5.2 GHz (12.8–18 GHz) and a peak of −29.49 dB are achieved in a thin thickness of 1.62 mm, which are comparable to the reported 2H-MoS2 absorbers with complex composition, showing that the 1T/2H-MoS2/Mo2S3 nanocomposites have great application potential as an EM wave absorber in the Ku band. 相似文献
103.
An electromagnetic interference (EMI) shielding composite based on ultrahigh molecular weight polyethylene (UHMWPE) loaded with economical graphite-carbon black (CB) hybrid fillers was prepared via a green and facile methodology, i.e., high-speed mechanical mixing combined with hot compression thus avoiding the assistance of the intensive ultrasound dispersion in volatile organic solvents. In this composite, the graphite-CB hybrid fillers were selectively distributed in the interfacial regions of UHMWPE domains resulting a typical segregated structure. Thanks to the specific morphology of segregated conductive networks along with the synergetic effect of large-sized graphite flakes and small-sized CB nanoparticles, a low filler loading of 7.7 vol% (15 wt%) yielded the graphite-CB/UHMWPE composites with a satisfactory electrical conductivity of 33.9 S/m and a superior shielding effectiveness of 40.2 dB, manifesting the comparable value of the pricey large-aspect-ratio carbon nanofillers (e.g., carbon nanotubes and graphene nanosheets) based polymer composites. More interestingly, with the addition of 15 wt% graphite-CB (1/3, W/W) hybrid fillers, the tensile strength and elongation at break of the composite reached 25.3 MPa and 126%, respectively; with a remarkable increase of 58.1% and 2420% over the conventional segregated graphite/UHMWPE composites. The mechanical reinforcement could be attributed to the favor of the small-sized CB particles in the polymer molecular diffusion between UHMWPE domains which in turn provided a stronger interfacial adhesion. This work provides a facile, green and affordable strategy to obtain the polymer composites with high electrical conductivity, efficient EMI shielding, and balanced mechanical performance. 相似文献
104.
介绍了EAST装置上的384道(极向24道径向16道)的外差混频式电子回旋辐射成像诊断系统及其在EAST及其复杂的电磁环境中的运行情况。在低杂波电流驱动期间,高灵敏度的电子回旋辐射成像系统受到严重干扰以至于无法提供正确的实验数据。通过优化系统各模块的接地、外加多层铜网屏蔽等措施,使得ECEI系统屏蔽效能与改善之前相比提高了40dB,基本保障了EAST装置上电子回旋辐射成像诊断的正常工作。 相似文献
105.
Nonlinear Dynamics of Circularly Polarized Laser Pulse Propagating in a Magnetized Plasma with q ‐Nonextensive Velocity Distributions 下载免费PDF全文
The nonlinear dynamics of a circularly polarized laser pulse propagating in magnetized plasma contains hot nonextensive q ‐distributed electrons and ions is studied theoretically. A nonlinear equation which describes the dynamics of the slowly varying amplitude electromagnetic wave is obtained using the relativistic two‐fluids model. Some nonlinear phenomena include modulational instability, self‐focusing, soliton formation, and longitudinal and transversal evolutions of laser pulse in nonextensive plasma medium are investigated. Results show that the nonextensivity of particles can substantially change the nonlinearity of medium. The external magnetic field enhances the modulation instability growth rate of right‐hand polarization wave but for the left‐hand polarization the growth rate decreases. The spot size of the laser pulse is strongly affected by the plasma nonextensivity. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
106.
将化学共沉淀法合成的Co掺杂的Fe_3O_4(Co-Fe_3O_4)磁性粒子和化学氧化法合成的聚苯乙烯磺酸钠(PSS)掺杂的聚(3,4-乙撑二氧噻吩)(PEDOT-PSS)与聚乙烯醇(PVA)混合制备复合纺丝原液,然后经过湿法纺丝得到具有电、磁性能的PEDOT-PSS/Co-Fe_3O_4/PVA复合纤维.通过SEM、FTIR、XRD、TG、VSM以及电导率和机械性能的测试研究了不同牵伸倍率对复合纤维的结构和性能的影响.结果表明,随着牵伸倍率的增加,复合纤维的结晶性能、热稳定性能和机械性能都有所提升,其电导率则成倍增加,而其饱和磁化强度(M_s)则变化不大,约为1.7 A·m~2/kg.当牵伸倍数为4倍时,复合纤维的电导率可达到2.3 S/cm. 相似文献
107.
Y. Toh T. Czosnyka M. Oshima T. Hayakawa H. Kusakari M. Sugawara Y. Hatsukawa J. Katakura N. Shinohara M. Matsuda 《The European Physical Journal A - Hadrons and Nuclei》2000,9(3):353-356
74Ge beam was Coulomb-excited on a natPb target. Ten E2 matrix elements including diagonal matrix elements for 5 low-lying states have been determined using the least-squares search
code GOSIA. The expectation values of the rotational invariants 〈Q
2〉 and 〈cos3δ〉 show the small and triaxial deformation of the two lowest members of the ground-state band , while the 02
+ and 22
+ states are found to be almost spherical.
Received: 31 August 2000 / Accepted: 4 December 2000 相似文献
108.
本文推导了在低空核爆炸的条件下,瞬发γ光子在源区中产生的电流和电场的近似解析公式,从这些解析公式给出的计算结果可看出,电场的前沿、陡度、峰值数值和半宽度的大小主要取决于弹体释放的瞬发γ光子的强度和时间特性。 相似文献
109.
M. Sandoli A. Boiano L. Campajola A. De Rosa A. D'Onofrio G. Inglima M. La Commara A. Ordine D. Pierroutsakou V. Roca M. Romano M. Romoli M. Trotta F. Rizzo F. Amorini S. Tudisco 《The European Physical Journal A - Hadrons and Nuclei》1999,6(3):275-288
We report on the results obtained from the study of the 32S +74Ge deep inelastic reaction at incident energy E= 320 MeV. High-energy γ-rays were detected in an array of 6 seven-pack BaF2 clusters. Coincidence with complex fragments detected in 12 three-stage telescopes ensured the selection of peripheral reaction
events. In order to investigate the pre-equilibrium dipole strength excitation two independent analyses were performed. In
the first analysis the energy spectra of the γ-rays were evaluated in the statistical model framework while in the second
one the γ-ray fragment angular correlation with respect to the nuclear spin vector of the composite system was studied. Both
methods indicate the excitation of dipole strength in the highly deformed dinucleus and provide dipole resonance parameter
sets that are in good agreement with each other.
Received: 24 March 1999 / Revised version: 17 May 1999 相似文献
110.
Y.B. DongOn leave from Institute of High Energy Physics Academia Sinica Beijing P. R. China--> A. Faessler K. Shimizu 《The European Physical Journal A - Hadrons and Nuclei》1999,6(2):203-210
Electromagnetic form factors of protons and neutrons are investigated based on a relativistic quark model with the inclusion
of a pion cloud. Pseudo-scalar π-quark interaction is employed to study the coupling between the nucleon and the π. The results
show the important role of the pion cloud for the neutron charge form factor. Moreover, our numerical analysis indicates a
difference between the relativistic and the nonrelativistic treatments.
Received: 10 March 1999 / Revised version: 14 June 1999 相似文献