3,036 research outputs found
Radiative thermal switch via metamaterials made of vanadium dioxide-coated nanoparticles
In this work, a thermal switch is proposed based on the phase-change material
vanadium dioxide (VO2) within the framework of near-field radiative heat
transfer (NFRHT). The radiative thermal switch consists of two metamaterials
filled with core-shell nanoparticles, with the shell made of VO2. Compared to
traditional VO2 slabs, the proposed switch exhibits a more than 2-times
increase in the switching ratio, reaching as high as 90.29% with a 100 nm
vacuum gap. The improved switching effect is attributed to the capability of
the VO2 shell to couple with the core, greatly enhancing heat transfer with the
insulating VO2, while blocking the motivation of the core in the metallic state
of VO2. As a result, this efficiently enlarges the difference in photonic
characteristics between the insulating and metallic states of the structure,
thereby improving the ability to rectify the NFRHT. The proposed switch opens
pathways for active control of NFRHT and holds practical significance for
developing thermal photon-based logic circuits
Investigation of ultra-thin AlâOâ film as Cu diffusion barrier on low-k (k=2.5) dielectrics
Ultrathin Al(2)O(3) films were deposited by PEALD as Cu diffusion barrier on low-k (k=2.5) material. The thermal stability and electrical properties of the Cu/low k system with Al(2)O(3) layers with different thickness were studied after annealing. The AES, TEM and EDX results revealed that the ultrathin Al(2)O(3) films are thermally stable and have excellent Cu diffusion barrier performance. The electrical measurements of dielectric breakdown and TDDB tests further confirmed that the ultrathin Al(2)O(3) film is a potential Cu diffusion barrier in the Cu/low-k interconnects system
Supplementation with probiotics modifies gut flora and attenuates liver fat accumulation in rat nonalcoholic fatty liver disease model
This study aimed to evaluate the relationship between gut probiotic flora and nonalcoholic fatty liver disease in a diet-induced rat model, and to compare the effects of two different probiotic strains on nonalcoholic fatty liver disease. Forty male Sprague-Dawley rats were randomized into 4 groups for 12 weeks: control (standard rat chow), model (fat-rich diet), Lactobacillus (fat-rich diet plus Lactobacillus acidophilus), and Bifidobacterium (fat-rich diet plus Bifidobacterium longum) groups. Probiotics were provided to rats in drinking water (1010/ml). Gut bifidobacteria and lactobacilli were obviously lower at weeks 8 and 10, respectively, in the model group compared with the control group. Supplementation with Bifidobacterium significantly attenuated hepatic fat accumulation (0.10 ± 0.03 g/g liver tissue) compared with the model group (0.16 ± 0.03 g/g liver tissue). However, there was no improvement in intestinal permeability in either the Lactobacillus or the Bifidobacterium group compared with the model group. In all 40 rats, the hepatic total lipid content was negatively correlated with gut Lactobacillus (r = â0.623, p = 0.004) and Bifidobacterium (r = â0.591, p = 0.008). Oral supplementation with probiotics attenuates hepatic fat accumulation. Further, Bifidobacterium longum is superior in terms of attenuating liver fat accumulation than is Lactobacillus acidophilus
The linear and nonlinear Jaynes-Cummings model for the multiphoton transition
With the Jaynes-Cummings model, we have studied the atom and light field
quantum entanglement of multiphoton transition, and researched the effect of
initial state superposition coefficient , the transition photon number
, the quantum discord and the nonlinear coefficient on the
quantum entanglement degrees. We have given the quantum entanglement degrees
curves with time evolution, and obtained some results, which should have been
used in quantum computing and quantum information.Comment: arXiv admin note: text overlap with arXiv:1404.0821, arXiv:1205.0979
by other author
Response of cattle manure anaerobic digestion to zinc oxide nanoparticles: methane production, microbial community, and functions
Study on the Lowest Energy Density of Welding Heat Source Required by Fusion Welding Metal
AbstractWelding is a common metal-processing method, which uses heating or press or both, at the same time, uses or disuses filled composites to achieve the atomic binding of workpieces. The basic welding methods are usually divided into three classes according to the conjunct property of weld metal, namely fusion welding, press welding and braze welding[1,2]. Powder composite welding rod is constituted with powder and termites, which belongs to fusion welding[3]. In order to make sure that the energy of this welding rod can achieve the requirement of fusion welding, so the lowest energy density required by fusing melt should be determined firstly
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