3,185 research outputs found
All-solid flexible fiber-shaped lithium ion batteries
We propose fabrication of the fiber-shaped lithium ion batteries assembled by
twisting a cathode filament together with an anode filament. The cathode
filament is fabricated by depositing a LiFePO4 (LFP)-composite layer onto a
steel-filled polyester conductive thread (SPCT). As anode filaments, we propose
several scenarios including a Li4Ti5O12 (LTO)-composite coated SPCT
(dip-and-dry deposition), a tin-coated SPCT (PVD deposition) as well as a bare
tin wire. An electrolyte composite layer consisting of LiPF6 and polyethylene
oxide (PEO) is then deposited onto both the anode and cathode filament before
the battery assembly. By twisting the cathode filament and anode filament
together using a customized jig, the batteries are then assembled. The
open-circuit voltage is found to be ~ 2.3 V for the battery using the LTO@SPCT
anode, and ~3.3 V for the battery using the tin@SPCT anode and the tin wire
anode. Charge-discharge tests are carried out at different C rates for each
battery sample. Experimental results suggest that the LIBs using the LTO@SPCT
anode, the tin@SPCT anode and the bare tin wire anode could achieve a specific
capacity of ~64, ~67, and ~96 mAh/g, respectively, when charge-discharged at
0.5-C rate. The battery could retain well its capacity after 80
charge-discharge cycles. During operation of all the batteries reported in this
paper, their coulombic efficiency remained above 80%. Among the advantages of
the proposed LIB are light weight, ease of fabrication, high specific
capacitance, high energy density, and good durability. Finally, employing cheap
and commercially-available steel-filled polyester threads as a base material in
our batteries, makes them potentially suitable for integration into wearables
using various standard textile manufacturing techniques
A hierarchical statistical framework for emergent constraints: application to snow-albedo feedback
Emergent constraints use relationships between future and current climate
states to constrain projections of climate response. Here, we introduce a
statistical, hierarchical emergent constraint (HEC) framework in order to link
future and current climate with observations. Under Gaussian assumptions, the
mean and variance of the future state is shown analytically to be a function of
the signal-to-noise (SNR) ratio between data-model error and current-climate
uncertainty, and the correlation between future and current climate states. We
apply the HEC to the climate-change, snow-albedo feedback, which is related to
the seasonal cycle in the Northern Hemisphere. We obtain a snow-albedo-feedback
prediction interval of \%. The critical dependence on
SNR and correlation shows that neglecting these terms can lead to bias and
under-estimated uncertainty in constrained projections. The flexibility of
using HEC under general assumptions throughout the Earth System is discussed.Comment: 19 pages, 5 Figure
Interannual variability of the South China Sea throughflow inferred from wind data and an ocean data assimilation product
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 33 (2006): L14605, doi:10.1029/2006GL026316.The Luzon Strait transport, as an index for the South China Sea throughflow, has
attracted much attention. In this study the interannual variability of the Luzon Strait
transport is examined, using the Island Rule and results from an ocean general
circulation model. Transport variability obtained from these two approaches are
consistent with each other. Assessment of contribution from each integral segment
involved in the Island Rule indicates that wind stress in the western and central
equatorial Pacific is the key factor regulating the interannual variability of the Luzon
Strait transport, whereas the effect of local wind stress in the vicinity of the Luzon
Strait is secondary. Analysis also shows that when the westerly (easterly) wind
anomalies in the tropical Pacific break out, the Luzon Strait transport increases
(decreases), consistent with the variations in the North Equatorial Current during El
Niño (La Niña) events.This research was
supported by NSF of China (Grants Nos. 40136010 and 40406006). YD and TQ were
supported by the National Aeronautics and Space Administration through grant
NAG5-12756, and TQ also supported by Japan Agency for Marine-Earth Science and
Technology through its sponsorship of the International Pacific Research Center
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