The concept of temperature in nonequilibrium thermodynamics is an outstanding theoretical issue. We propose an energy repartition principle that leads to a spectral (mode-dependent) temperature in steady-state nonequi...
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The concept of temperature in nonequilibrium thermodynamics is an outstanding theoretical issue. We propose an energy repartition principle that leads to a spectral (mode-dependent) temperature in steady-state nonequilibrium systems. The general concepts are illustrated by analytic solutions of the classical Heisenberg spin chain connected to Langevin heat reservoirs with arbitrary temperature profiles. Gradients of external magnetic fields are shown to localize spin waves in a Wannier-Zeemann fashion, while magnon interactions renormalize the spectral temperature. Our generic results are applicable to other thermodynamic systems such as Newtonian liquids, elastic solids, and Josephson junctions.
We theoretically investigate the spin injection in different FM/I/n-Si tunnel contacts by using the lattice NEGF method. We find that the tunnel contacts with low barrier materials such as TiO2 and Ta2O5, have much lo...
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We introduced a PC61BM layer between the compact TiO2 layer and the perovskite absorber, which forms a porous precursor film, and thus promotes uniform perovskite films with large grain size and improves the device ef...
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This work presents theoretical demonstration of Aharonov-Bohm (AB) effect in monolayer phosphorene nanorings (PNR). Atomistic quantum transport simulations of PNR are employed to investigate the impact of multiple mod...
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The 100-nm T-gate InP-based InA1As/InGaAs high electron mobility transistors （HEMTs） with the width of 2×50 μm and source-drain space of 2.4 μm are systematically investigated. High indium （In） composition ...
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The 100-nm T-gate InP-based InA1As/InGaAs high electron mobility transistors （HEMTs） with the width of 2×50 μm and source-drain space of 2.4 μm are systematically investigated. High indium （In） composition of InGaAs layer was adopted to acquire the higher mobility of the channel layer. A sandwich structure was adopted to optimize the cap layers and produce a very low contact resistance. The fabricated devices exhibit extrinsic maximum transconductance *** = 1441 mS/mm, cutoff frequency fT = 260 GHz, and maximum oscillation frequency fmax=607 GHz. A semi-empirical model has been developed to precisely fit the low-frequency region of scattering parameters （S parameters） for InP-based HEMTs. Excellent agreement between measured and simulated S parameters demonstrates the validity of this approach.
Progresses in thermoelectric(TE)materials will contribute to solving the world's demands for energy and global climate *** also calls for higher ZT to achieve ideal commercial conversion *** an effective way,nanos...
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Progresses in thermoelectric(TE)materials will contribute to solving the world's demands for energy and global climate *** also calls for higher ZT to achieve ideal commercial conversion *** an effective way,nanostructuring can reduce the thermal conductivity by the selective scattering of phonons or enhance Seebeck coefficient via modification of the density of the states,resulting in good ZT ***,TE properties of nanostructured materials should depend on the size and morphology of the microstructure *** review emphasizes the developments in the TE bulk materials at the nanoscale in the past several years and summarizes the understanding in this active field.
This paper presents a novel design of a tunable tri-band bandpass filter using varactor-tuned stub-loaded resonators. The first and the third passband center frequencies of the proposed tri-band filter can be independ...
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ISBN:
(纸本)9781509060948
This paper presents a novel design of a tunable tri-band bandpass filter using varactor-tuned stub-loaded resonators. The first and the third passband center frequencies of the proposed tri-band filter can be independently tuned by controlling the different values of the capacitances and different varactor diodes, whereas the second passband center frequency is fixed. A prototype tri-band filter is fabricated and measured. From the experimental results, the first passband center frequency tunable range is from 1.24 GHz to 1.50 GHz, and the third passband center frequency tunable range is from 2.26 GHz to 2.80 GHz, while the second passband center frequency is fixed at 1.80 GHz. Both theory and experiment are provided to validate the proposed filter.
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