13 research outputs found
LiMn<sub>2</sub>O<sub>4</sub> Nanotube as Cathode Material of Second-Level Charge Capability for Aqueous Rechargeable Batteries
LiMn<sub>2</sub>O<sub>4</sub> nanotube with a preferred orientation
of (400) planes is prepared by using multiwall carbon nanotubes as
a sacrificial template. Because of the nanostructure and preferred
orientation, it shows a superfast second-level charge capability as
a cathode for aqueous rechargeable lithium battery. At the charging
rate of 600C (6 s), 53.9% capacity could be obtained. Its reversible
capacity can be 110 mAh/g, and it also presents excellent cycling
behavior due to the porous tube structure to buffer the strain and
stress from JahnâTeller effects
Aqueous Rechargeable Zinc/Aluminum Ion Battery with Good Cycling Performance
Developing rechargeable batteries
with low cost is critically needed for the application in large-scale
stationary energy storage systems. Here, an aqueous rechargeable zinc//aluminum
ion battery is reported on the basis of zinc as the negative electrode
and ultrathin graphite nanosheets as the positive electrode in an
aqueous Al<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>/ZnÂ(CHCOO)<sub>2</sub> electrolyte. The positive electrode material was prepared through
a simple electrochemically expanded method in aqueous solution. The
cost for the aqueous electrolyte together with the Zn negative electrode
is low, and their raw materials are abundant. The average working
voltage of this aqueous rechargeable battery is 1.0 V, which is higher
than those of most rechargeable Al ion batteries in an ionic liquid
electrolyte. It could also be rapidly charged within 2 min while maintaining
a high capacity. Moreover, its cycling behavior is also very good,
with capacity retention of nearly 94% after 200 cycles
Successfully Engineering a Bacterial Sialyltransferase for Regioselective α2,6-sialylation
A ÎČ-galactoside
α2,6-sialyltransferase from <i>Photobacterium damselae</i> (Pd2,6ST) that is capable of sialylating
both terminal and internal galactose and <i>N</i>-acetylgalactosamine
was herein redesigned for regioselectively producing terminal α2,6-sialosides.
Guided by a recently developed bump-hole strategy, a series of mutations
at Ala200 and Ser232 sites were created for reshaping the acceptor
binding pocket. Finally, a Pd2,6ST double mutant A200Y/S232Y with
an altered L-shaped acceptor binding pocket was identified to be a
superior α2,6-sialyltransferase which can efficiently catalyze
the regioselective α2,6-sialylation of galactose or <i>N</i>-acetylgalactosamine at the nonreducing end of a series
of glycans. Meanwhile, A200Y/S232Y remains flexible donor substrate
specificity and is able to transfer Neu5Ac, Neu5Gc, and KDN
DonorâAcceptor Conjugated Polymers for Single-Component Near-Infrared II Organic Phototransistors with Ultrahigh Photoresponsivity
The design of donorâacceptor (DâA) conjugated
polymers
with narrow bandgaps remains a big challenge for achieving high-performance
near-infrared (NIR) phototransistors. Herein, we report a novel DâA
conjugated polymer (denoted as TBOPV-DT) based on a thiophene-fused
benzodifurandione-based oligo(p-phenylenevinylene)
(TBOPV) acceptor in conjugation with a 3,3âČ-dialkoxy-2,2âČ-dithiophene
(DT) donor. Benefiting from the alkoxylation of the donor units, the
TBOPV-DT conjugated polymer exhibits broad second NIR absorption and
a narrow bandgap of 0.65 eV. When being used as the channel material
in field-effect transistors, the TBOPV-DT conjugated polymer shows
p-type semiconducting behavior with a hole mobility of 0.16 cm2 Vâ1 sâ1. Besides, the
resulting single-component polymer phototransistor displays ultrahigh
sensitivity to a broad range of wavelengths (850â1450 nm) and
a record-high photoresponsivity of 1.9 Ă 105 A Wâ1. Moreover, the fast rise and decay response times
of 53 and 317 ms, respectively, are comparable to those of state-of-the-art
two-dimensional materials. This work sheds light on designing new
narrow-bandgap DâA conjugated polymers with molecular precision
and paves the way for the development of future high-performance optoelectronics
Persulfurated Coronene: A New Generation of âSulflowerâ
We report the first
synthesis of a persulfurated polycyclic aromatic
hydrocarbon (PAH) as a next-generation âsulflower.â
In this novel PAH, disulfide units establish an all-sulfur periphery
around a coronene core. The structure, electronic properties, and
redox behavior were investigated by microscopic, spectroscopic and
electrochemical methods and supported by density functional theory.
The sulfur-rich character of persulfurated coronene renders it a promising
cathode material for lithiumâsulfur batteries, displaying a
high capacity of 520 mAh g<sup>â1</sup> after 120 cycles at
0.6 C with a high-capacity retention of 90%
Behaviors and life events of Uyghur elderly (60 or older) in Xinjiang Uyghur Autonomous Region, China (Nâ=â1329), 2011.
<p>Behaviors and life events of Uyghur elderly (60 or older) in Xinjiang Uyghur Autonomous Region, China (Nâ=â1329), 2011.</p
Sociodemographic characteristics and prevalence of diseases among Uyghur elderly (60 or older) in Xinjiang Uyghur Autonomous Region, China (Nâ=â1329), 2011.
<p>Sociodemographic characteristics and prevalence of diseases among Uyghur elderly (60 or older) in Xinjiang Uyghur Autonomous Region, China (Nâ=â1329), 2011.</p
Behaviors, life events and satisfaction levels among recruited Uyghur elderly of Xinjiang, China (Nâ=â1329).
<p>Behaviors, life events and satisfaction levels among recruited Uyghur elderly of Xinjiang, China (Nâ=â1329).</p
Flow Chart of the recruitment of the elderly Uyghur in Xinjiang Uyghur Autonomous Religion, China (Nâ=â1329), 2011.
<p>Flow Chart of the recruitment of the elderly Uyghur in Xinjiang Uyghur Autonomous Religion, China (Nâ=â1329), 2011.</p
Disparity of geriatric depression between urban and rural Uyghur elderly in Xinjiang, China (Nâ=â1329).
<p>Disparity of geriatric depression between urban and rural Uyghur elderly in Xinjiang, China (Nâ=â1329).</p