243 research outputs found
VIRUS ENABLED 3D NANO-ARRAY ELECTRODES FOR INTEGRATED LI/NA-ION MICROBATTERIES
Multilayers of functional materials (carbon/electrode/nickel) were hierarchically architectured over tobacco mosaic virus (TMV) templates that were genetically modified to self-assemble in a vertical manner on current-collectors for battery applications. The spaces formed between individual rods effectively accommodated the volume expansion and contraction of electrodes during charge/discharge, while surface carbon coating engineered over these nanorods further enhance the electronic conductivity. The microbattery based on self aligned nanoforests with precise arrangement of various auxiliary material layers including a central nanometric metal core as direct electronic pathway to current collector, can deliver high energy density and stable cycling stability. C/LiFePO4/Ni/TMV nanoforest cathodes for Li-ion batteries and C/Sn/Ni/TMV nanoforest anodes for Na-ion batteries were assembled using physical sputtering deposition. Both 3D nanoforest electrodes show exceptional cycling stability and rate capability
Incompressible Limit of a Compressible Liquid Crystals System
This article is devoted to the study of the so-called incompressible limit
for solutions of the compressible liquid crystals system. We consider the
problem in the whole space and a bounded domain of
with Dirichlet boundary conditions. Here the number
of dimension or 3
The Environmental Impact of Plastic Waste
The pollution caused by disposable plastic products is becoming more and more serious, and “plastic limit” has become a global consensus. This article mainly discusses the pollution problem from the following aspects: Integrate all relevant important indicators to establish a multiple regression model of the maximum amount of disposable plastic waste to estimate the maximum amount of disposable waste in the future without causing further damage to the environment; Establish an environmental safety level evaluation model and analyze the impact of plastic waste on environmental safety; Try to set the lowest level target that can be achieved by global waste at this stage, and conduct correlation analysis on the impact of humans, enterprises, and the environment; Select several countries based on their comprehensive strengths, conduct a comparative analysis of their plastic production, economic strength, and environment, and try to explore their responsibilities
CBISI-LSTM Deep Learning Model for Short-term Cross-border Capital Flow Prediction
With the drastic fluctuation of the international financial market in recent years, the cross-border capital flow between Shanghai and Hong Kong has become increasingly active. The lack of effective and timely tracking monitoring and scientific management of cross-border capital flow in the capital market will seriously affect the overall financial security of China\u27s economy. This paper constructs the cross-border investor sentiment index CBISI based on principal component analysis and analyzes the impact of cross-border investor sentiment and cross-border capital flows by constructing the VAR model. In addition, CBISI is used as part of the input variable of LSTM to forecast the cross-border capital flow (NF). The findings of the study indicate that changes in cross-border investor sentiment will have a significant short-term impact on cross-border capital flows, and the addition of CBISI will improve the accuracy of cross-border flow estimates
NB-IoT Uplink Synchronization by Change Point Detection of Phase Series in NTNs
Non-Terrestrial Networks (NTNs) are widely recognized as a potential solution
to achieve ubiquitous connections of Narrow Bandwidth Internet of Things
(NB-IoT). In order to adopt NTNs in NB-IoT, one of the main challenges is the
uplink synchronization of Narrowband Physical Random Access procedure which
refers to the estimation of time of arrival (ToA) and carrier frequency offset
(CFO). Due to the large propagation delay and Doppler shift in NTNs,
traditional estimation methods for Terrestrial Networks (TNs) can not be
applied in NTNs directly. In this context, we design a two stage ToA and CFO
estimation scheme including coarse estimation and fine estimation based on
abrupt change point detection (CPD) of phase series with machine learning. Our
method achieves high estimation accuracy of ToA and CFO under the low
signal-noise ratio (SNR) and large Doppler shift conditions and extends the
estimation range without enhancing Random Access preambles
Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions
Resonant tunneling can lead to inverse tunnel magnetoresistance when impurity
levels rather than direct tunneling dominate the transport process. We
fabricated hybrid magnetic tunnel junctions of CoFe/LiF/EuS/Ti, with an
epitaxial LiF energy barrier joined with a polycrystalline EuS spin-filter
bar-rier. Due to the water solubility of LiF, the devices were fully packaged
in situ. The devices showed sizeable positive TMR up to 16% at low bias
voltages but clearly inverted TMR at higher bias voltages. The TMR inversion
depends sensitively on the thickness of LiF, and the tendency of inversion
disap-pears when LiF gets thick enough and recovers its intrinsic properties
- …