16 research outputs found
Facile Synthesis of Novel Heterostructure Based on SnO<sub>2</sub> Nanorods Grown on Submicron Ni Walnut with Tunable Electromagnetic Wave Absorption Capabilities
In this work, the magnetic–dielectric
core-shell heterostructure composites with the core of Ni submicron
spheres and the shell of SnO<sub>2</sub> nanorods were prepared by
a facile two-step route. The crystal structure and morphology were
investigated by X-ray diffraction analysis, transmission electron
microscopy (TEM), and field emission scanning electron microscopy
(FESEM). FESEM and TEM measurements present that SnO<sub>2</sub> nanorods
were perpendicularly grown on the surfaces of Ni spheres and the density
of the SnO<sub>2</sub> nanorods could be tuned by simply varying the
addition amount of Sn<sup>2+</sup> in this process. The morphology
of Ni/SnO<sub>2</sub> composites were also determined by the concentration
of hydrochloric acid and a plausible formation mechanism of SnO<sub>2</sub> nanorods-coated Ni spheres was proposed based on hydrochloric
acid concentration dependent experiments. Ni/SnO<sub>2</sub> composites
exhibit better thermal stability than pristine Ni spheres based on
thermalgravimetric analysis (TGA). The measurement on the electromagnetic
(EM) parameters indicates that SnO<sub>2</sub> nanorods can improve
the impedance matching condition, which is beneficial for the improvement
of electromagnetic wave absorption. When the coverage density of SnO<sub>2</sub> nanorod is in an optimum state (diameter of 10 nm and length
of about 40–50 nm), the optimal reflection loss (RL) of electromagnetic
wave is −45.0 dB at 13.9 GHz and the effective bandwidth (RL
below −10 dB) could reach to 3.8 GHz (12.3–16.1 GHz)
with the absorber thickness of only 1.8 mm. By changing the loading
density of SnO<sub>2</sub> nanorods, the best microwave absorption
state could be tuned at 1–18 GHz band. These results pave an
efficient way for designing new types of high-performance electromagnetic
wave absorbing materials
Morphology-Control Synthesis of a Core–Shell Structured NiCu Alloy with Tunable Electromagnetic-Wave Absorption Capabilities
In this work, dendritelike and rodlike
NiCu alloys were prepared by a one-pot hydrothermal process at various
reaction temperatures (120, 140, and 160 °C). The structure and
morphology were analyzed by scanning electron microscopy, energy-dispersive
spectrometry, X-ray diffraction, and transmission electron microscopy,
which that demonstrate NiCu alloys have core–shell heterostructures
with Ni as the shell and Cu as the core. The formation mechanism of
the core–shell structures was also discussed. The uniform and
perfect dendritelike NiCu alloy obtained at 140 °C shows outstanding
electromagnetic-wave absorption properties. The lowest reflection
loss (RL) of −31.13 dB was observed at 14.3 GHz, and the effective
absorption (below −10 dB, 90% attenuation) bandwidth can be
adjusted between 4.4 and 18 GHz with a thin absorber thickness in
the range of 1.2–4.0 mm. The outstanding electromagnetic-wave-absorbing
properties are ascribed to space-charge polarization arising from
the heterogeneous structure of the NiCu alloy, interfacial polarization
between the alloy and paraffin, and continuous micronetworks and vibrating
microcurrent dissipation originating from the uniform and perfect
dendritelike shape of NiCu prepared at 140 °C
Solvent-Free Process for Blended PVDF-HFP/PEO and LLZTO Composite Solid Electrolytes with Enhanced Mechanical and Electrochemical Properties for Lithium Metal Batteries
All
solid-state lithium metal batteries are viewed as a potential
next-generation energy storage technology due to their high energy
density and better safety performance. The study on solid-state electrolytes
(SSE) is of crucial importance for the development of technology in
this field. Here, we develop a solvent-free preparation and matrix
modification process for all-solid-state composite electrolytes (CSEs)
based on the blended PVDF-HFP/PEO polymer matrix, and systematically
study the effects of the solvent-free process on their properties.
The results show that the solvent-free PVDF-HFP/PEO/10 wt % LLZTO
solid-state electrolytes (1:1 mass ratio blended polymer matrix) combine
the electrochemical and mechanical advantages of both polymers, thus-prepared
electrolytes perform excellent tensile strength and ductility (over
500% strain for polymer matrix as well as 170% strain and 4.78 MPa
strength for CSEs), and the ionic conductivity can reach ∼6.2
× 10–4 S·cm–1 at 80
°C. At the same time, the electrochemical stability and cycle
stability of the electrolytes are enhanced due to the optimized process.
The discoloration reaction of PVDF-HFP in composite electrolytes is
further studied in this work as well. In addition to excellent performance,
the simple process based on the solvent-free method also lays the
foundation for scale-up production
Preparation of Honeycomb SnO<sub>2</sub> Foams and Configuration-Dependent Microwave Absorption Features
Ordered honeycomb-like SnO<sub>2</sub> foams were successfully synthesized by means of a template method.
The honeycomb SnO<sub>2</sub> foams were analyzed by X-ray diffraction
(XRD), thermogravimetric and differential scanning calorimetry (TG-DSC),
laser Raman spectra, scanning electron microscopy (SEM), and Fourier
transform infrared (FT-IR). It can be found that the SnO<sub>2</sub> foam configurations were determined by the size of polystyrene templates.
The electromagnetic properties of ordered SnO<sub>2</sub> foams were
also investigated by a network analyzer. The results reveal that the
microwave absorption properties of SnO<sub>2</sub> foams were dependent
on their configuration. The microwave absorption capabilities of SnO<sub>2</sub> foams were increased by increasing the size of pores in the
foam configuration. Furthermore, the electromagnetic wave absorption
was also correlated with the pore contents in SnO<sub>2</sub> foams.
The large and high amounts pores can bring about more interfacial
polarization and corresponding relaxation. Thus, the perfect ordered
honeycomb-like SnO<sub>2</sub> foams obtained in the existence of
large amounts of 322 nm polystyrene spheres showed the outstanding
electromagnetic wave absorption properties. The minimal reflection
loss (RL) is −37.6 dB at 17.1 GHz, and RL less than −10
dB reaches 5.6 GHz (12.4–18.0 GHz) with thin thickness of 2.0
mm. The bandwidth (<−10 dB, 90% microwave dissipation) can
be monitored in the frequency regime of 4.0–18.0 GHz with absorber
thickness of 2.0–5.0 mm. The results indicate that these ordered
honeycomb SnO<sub>2</sub> foams show the superiorities of wide-band,
high-efficiency absorption, multiple reflection and scatting, high
antioxidation, lightweight, and thin thickness
Yolk–Shell Ni@SnO<sub>2</sub> Composites with a Designable Interspace To Improve the Electromagnetic Wave Absorption Properties
In
this study, yolk–shell Ni@SnO<sub>2</sub> composites
with a designable interspace were successfully prepared by the simple
acid etching hydrothermal method. The Ni@void@SnO<sub>2</sub> composites
were characterized by X-ray diffraction, Fourier transform infrared
spectroscopy, X-ray photoelectron spectroscopy, scanning electron
microscopy, and transmission electron microscopy. The results indicate
that interspaces exist between the Ni cores and SnO<sub>2</sub> shells.
Moreover, the void can be adjusted by controlling the hydrothermal
reaction time. The unique yolk–shell Ni@void@SnO<sub>2</sub> composites show outstanding electromagnetic wave absorption properties.
A minimum reflection loss (RL<sub>min</sub>) of −50.2 dB was
obtained at 17.4 GHz with absorber thickness of 1.5 mm. In addition,
considering the absorber thickness, minimal reflection loss, and effective
bandwidth, a novel method to judge the effective microwave absorption
properties is proposed. On the basis of this method, the best microwave
absorption properties were obtained with a 1.7 mm thick absorber layer
(RL<sub>min</sub>= −29.7 dB, bandwidth of 4.8 GHz). The outstanding
electromagnetic wave absorption properties stem from the unique yolk–shell
structure. These yolk–shell structures can tune the dielectric
properties of the Ni@air@SnO<sub>2</sub> composite to achieve good
impedance matching. Moreover, the designable interspace can induce
interfacial polarization, multiple reflections, and microwave plasma
[60]Fullerene-Fused Cyclopentanes: Mechanosynthesis and Photovoltaic Application
The mechanochemical cascade reaction of [60]fullerene
with 3-benzylidene
succinimides, diethyl 2-benzylidene succinate, or 2-benzylidene succinonitrile
in the presence of an inorganic base has been investigated under solvent-free
and ball-milling conditions. This protocol provides an expedient method
to afford various [60]fullerene-fused cyclopentanes, showing advantages
of good substrate scope, short reaction time, and solvent-free and
ambient reaction conditions. Furthermore, representative fullerene
products have been applied in inverted planar perovskite solar cells
as efficient cathode interlayers
Investigation of the Interaction between Perovskite Films with Moisture via in Situ Electrical Resistance Measurement
Organometal
halide perovskites have recently emerged as outstanding semiconductors
for solid-state optoelectronic devices. Their sensitivity to moisture
is one of the biggest barriers to commercialization. In order to identify
the effect of moisture in the degradation process, here we combined
the in situ electrical resistance measurement with time-resolved X-ray
diffraction analysis to investigate the interaction of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3−<i>x</i></sub>Cl<sub><i>x</i></sub> perovskite films with moisture. Upon short-time
exposure, the resistance of the perovskite films decreased and it
could be fully recovered, which were ascribed to a mere chemisorption
of water molecules, followed by the reversible hydration into CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3–<i>x</i></sub>Cl<sub><i>x</i></sub>·H<sub>2</sub>O. Upon long-time exposure,
however, the resistance became irreversible due to the decomposition
into PbI<sub>2</sub>. The results demonstrated the formation of monohydrated
intermediate phase when the perovskites interacted with moisture.
The role of moisture in accelerating the thermal degradation at 85
°C was also demonstrated. Furthermore, our study suggested that
the perovskite films with fewer defects may be more inherently resistant
to moisture
High-Performance Potassium-Ion Batteries with Robust Stability Based on N/S-Codoped Hollow Carbon Nanocubes
Currently, a big challenge for the
practical use of potassium-ion
batteries (PIBs) is their intrinsically poor cycling stability, due
to the relatively large radius of K+ and sluggish kinetics
for intercalation/deintercalation. Here we report the scalable fabrication
of N/S-codoped hollow carbon nanocubes (NSHCCs), which have the potential
as an electrode for advanced PIBs with robust stability. Their discharge
and charge specific capacities are ∼560 mA h g–1 and 310 mA h g–1 at a current density of 50 mA
g–1, respectively. Meanwhile, they exhibit 100%
specific capacity retention after 620 cycles over 9 months at a low
current density of 50 mA g–1, which is state-of-the-art
among carbon materials. Moreover, they demonstrate nearly no sacrifice
in specific capacities with 99.9% retention after 3000 cycles over
4 months under a high current density of 1000 mA g–1, superior to most carbon analogues for potassium storage previously
reported. The improved electrochemical performance of NSHCC can be
mainly attributed to the unique hollow carbon nanocubes with incorporated
N and S dopants, which can expand the carbon layer spacing, facilitate
K+ adsorption, and relieve the volume change during the
intercalation/deintercalation of K+ ions
Supplementary Figures 1 - 11 from A Clinically Relevant Androgen Receptor Mutation Confers Resistance to Second-Generation Antiandrogens Enzalutamide and ARN-509
PDF file - 401K, Supplementary Figure S1. Parental and 2nd generation anti-androgen resistant cell line proliferation. Supplementary Figure S2. AR levels in parental and 2nd generation anti-androgen resistant cell lines. Supplementary Figure S3. AR levels in transfection assays. Supplementary Figure S4. Transcriptional reporter assay of AR mutants. Supplementary Figure S5. Ligand binding domain of the AR bound to DHT (1T7T;(1)). Supplementary Figure S6. Competitive binding assay of wild-type AR vs. F876L AR. Supplementary Figure S7. AR levels in AR overexpressing cell lines. Supplementary Figure S8. LNCaP/AR(cs), LNCaP/SRF876L and LNCaP/pCDNAF876L cell proliferation. Supplementary Figure S9. Transcriptional activity of ARN-509 and enzalutamide in LNCaP/pCDNAF876L cells. Supplementary Figure S10. AR ChIP analysis of AR target genes. Supplementary Figure S11. PSA response for 3 patients with detectable AR F876L mutation.</p