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

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    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

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    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

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    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

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    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

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    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

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    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

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    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

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    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

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    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
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