<i>In Situ</i> Formation of Stable Interfacial Coating for High Performance Lithium Metal Anodes

Uncontrollable growth of Li dendrites is a big problem for Li metal batteries. In this work, we described a new universal strategy of <i>in situ</i> formation of interfacial coating with methyl viologen to achieve stable cycling of lithium metal anode. After treating the lithium metal layer with 0.5 wt % methyl viologen in the ether electrolyte, a highly uniform, stable, and ionically conductive interfacial coating can be formed on the surface because of the electrochemical reduction. The coating layer can generate better control of the lithium ion flow and suppress the lithium dendrite growth and therefore form a uniform and stable solid electrolyte interphase. Using this approach, a lifetime of 300 cycles with Columbic efficiency of 99.1% and 400 cycles with Columbic efficiency of 98.2% at a current density of 1 mA cm^–2 in ether-based electrolyte can be obtained. This lifetime is more than three times higher than the control ether electrolyte. In addition, this approach can enhance the performances of lithium metal anode in carbonate-based electrolyte. Compared with the previous approaches, our new strategy has many advantages such as low cost, easy manipulation, and compatibility with current lithium ion batteries

Binary System for MicroRNA-Targeted Imaging in Single Cells and Photothermal Cancer Therapy

Abnormal expression of microRNAs (miRNAs) is often associated with tumorigenesis, metastasis, and progression. Among them, miRNA-21 is found to be overexpressed in most of the cancer cells. Here, a binary system is designed for miRNA-21 targeted imaging and photothermal treatment in single cells. The binary system is composed by a pair of probes (probe-1 and probe-2), which are encapsulated in liposomes for cell delivery. Both of the two probes adopt gold nanoparticles (AuNPs) as the core material, and the AuNPs are functionalized with Cy5-marked molecular beacon (MB-1/MB-2 for probe-1/probe-2, respectively). The loop part of MBs are designed to be complementary with miRNA-21. Therefore, after the binary system enters into the cytoplasm, MBs can be opened upon miRNA-21 triggered hybridization, which turns “on” the fluorescence of Cy5 for the localization of miRNA-21. At the same time, a cross-linking between the probes occurs since the far ends of MB-1 and MB-2 are designed to be complementary with each other. The miRNA-induced aggregation shifts the absorption of AuNPs to near-infrared, which can be observed under dark-field microscopy (DFM) and used for the following photothermal therapy. Under near-infrared (NIR) irradiation, MCF-7 breast cancer cells are successfully killed. The proposed system can be further applied in tumor-bearing mice and shows significant therapeutic effect. This work provides a new tool for intracellular miRNA analysis and targeted treatment against cancer

Simultaneous NO Removal and Hg⁰ Oxidation over CuO Doped V₂O₅‑WO₃/TiO₂ Catalysts in Simulated Coal-Fired Flue Gas

A series of CuO doped V₂O₅-WO₃/TiO₂ based commercial selective catalytic reduction (SCR) catalysts were synthesized via the improved impregnation method for simultaneous NO removal and Hg⁰ oxidation under simulated coal-fired flue gas at a temperature range of 150–400 °C. Several characterization techniques, including Brunauer–Emmett–Teller analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction of H₂ (H₂-TPR), were used to characterize the catalysts. The results indicated that Cu₃-SCR catalyst exhibited the superior catalytic activity and a wide active temperature window for simultaneous NO removal and Hg⁰ oxidation. The effects of flue gas components on the catalytic activity were also investigated. The results indicated that Cu₃-SCR catalyst showed good performances on SO₂ tolerance and H₂O resistance. The effect of Hg⁰ on NO removal was almost negligible. However, the copresence of NO and NH₃ obviously inhibited the Hg⁰ oxidation activity. Further study revealed that this inhibiting effect was weakened as the consumption of NH₃. The BET and XRD results suggested that the highly dispersed Cu species was beneficial to the superior catalytic activity of the Cu₃-SCR catalyst. The XPS and H₂-TPR analyses indicated that the Cu₃-SCR catalyst possessed abundant chemisorbed oxygen and good redox ability, which was ascribed to the strong synergy between CuO and V₂O₅ on the catalyst. The redox cycle of V⁴⁺ + Cu²⁺ ↔ V⁵⁺ + Cu⁺ in Cu₃-SCR catalyst significantly improved the catalytic activity for simultaneous NO removal and Hg⁰ oxidation. The mechanism of Hg⁰ oxidation over the Cu₃-SCR catalyst was also investigated

Growth of SiC Whiskers onto Carbonizing Coir Fibers by Using Silicon Slurry Waste

To reduce environmental pollution and waste of resources, it is very important to recycle valuable materials in silicon slurry waste (SSW). We report a novel method for the rapid preparation of SiC nanowhiskers by spark plasma (SP) assisted thermal treatment using SSW as the silicon source. In the preparation process, coir fibers were used as the carbon source and whisker growth substrate. At 1100–1300 °C, carbon-rich tadpole-like 3C–SiC whiskers with Fe catalyst caps were prepared by the vapor–liquid–solid growth mechanism. At 1400–1600 °C, carbon-rich, stick-like 3C–SiC whiskers without Fe catalyst caps with aspect ratios of about 40, and diameters of about 50 nm were prepared by the vapor–solid growth mechanism. The SiC whiskers grew along the [111] direction on the (111) plane at different temperatures. At the optimum temperature of 1500 °C, the silicon in SSW reacted completely, and SiC whiskers with good morphology were prepared. Furthermore, the photoluminescence (PL) spectra of SiC whiskers showed strong blue-violet emission at 450 nm. Accordingly, this study provides an environmentally friendly method for preparing SiC whiskers

Preparation and Characterization of Perfluorosulfonic Acid Nanofiber Membranes for Pervaporation-Assisted Esterification

Multilayer membranes were prepared by the combination of perfluorosulfonic acid/SiO₂ nanofibers and a poly­(vinyl alcohol) (PVA) pervaporation layer and were used to enhance the esterification of acetic acid (HAc) and ethanol (EtOH). The esterification–pervaporation experiments were carried out in a continuous membrane contactor. The effects of the temperature, the ratio of HAc to EtOH, and the ratio of membrane area to reaction volume were investigated. The results demonstrated that the membranes had good catalytic activities even at low temperature because of the nanofibrous structure of the catalysis layer. The conversion of HAc at 60 °C after 10 h was 10–15% more than the equilibrium conversion and by improved about 45% with respect to the equilibrium conversion after 55 h. The yield of EtAc was higher than 90%, which demonstrates that the difunctional membrane could enhance the esterification process greatly through the in situ removal of water

Facile Synthesis of Surface-Modified Nanosized α‑Fe₂O₃ as Efficient Visible Photocatalysts and Mechanism Insight

In this study, α-Fe₂O₃ nanoparticles with high visible photocatalytic activity for degrading liquid-phase phenol and gas-phase acetaldehyde have been controllably synthesized by a simple one-pot water-organic two-phase separated hydrolysis-solvothermal (HST) method. Further, the visible photocatalytic activity is enhanced greatly after modification with a proper amount of phosphate. The enhanced activity is attributed to the increased charge separation by promoting photogenerated electrons captured by the adsorbed O₂ by means of the atmosphere-controlled surface photovoltage spectra, along with the photoelectrochemical I–V curves. On the basis of the O₂ temperature-programmed desorption measurements, it is suggested for the first time that the promotion effect results from the increase in the amount of O₂ adsorbed on the surfaces of Fe₂O₃ by the partial substitution of −Fe–OH with −Fe–O–P–OH surface ends. Expectedly, the positive strategy would be also applicable to other visible-response nanosized oxides as efficient photocatalysts. This work will provide us with a feasible route to synthesize oxide-based nanomaterials with good photocatalytic performance

Multivariate analyses assessing the effects of only-child on sex-related acknowledge, attitude and behavior.

a<p>Standardized regression coefficient and odds ratio with 95% confidence interval in parentheses was adjusted for age, major, grade, nationality, hometown area, and family economic status.</p>b<p>p<0.05 ^cp<0.01.</p

Risky sexual behaviors and risks among sexually active female students who were only-child and students with siblings.

a<p>Missed cases were excluded.</p>b<p>Significance tests was chi-squared tests for dichotomous variables.</p

Synthesis and Performances of UV-Curable Polysiloxane–Polyether Block Polyurethane Acrylates for PVC Leather Finishing Agents

A series of multifunctional UV-curable polysiloxane–polyether block polyurethane acrylates prepolymers (TSi¹E⁹PUA, TSi³E⁷PUA, TSi⁵E⁵PUA, TSi⁷E³PUA, and TSi⁹E¹PUA) used for polyvinyl chloride (PVC) leather finishing agents have been prepared and characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography (GPC). All five multifunctional prepolymers exhibited excellent photopolymerization efficiency and good yellowing resistance. And the content of polysiloxane in prepolymers obviously affected the viscosity, thermal stability, tensile strength, elongation at break, and surface hydrophobicity of the photopolymerization systems. The system with the prepolymer containing more polysiloxane segments presented a high viscosity, and UV-cured film had relatively good thermal stability, elongation at break, and surface hydrophobicity accordingly. The properties of the prepolymers well satisfied the application requirements for leather finishing agents. Furthermore, surface microstructures of UV-cured films were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). More importantly, the PVC leather finishing agents designed based on the multifunctional polysiloxane–polyether block polyurethane acrylates possessed excellent comprehensive performances

Systematic Investigation of Isoindigo-Based Polymeric Field-Effect Transistors: Design Strategy and Impact of Polymer Symmetry and Backbone Curvature

Ten isoindigo-based polymers were synthesized, and their photophysical and electrochemical properties and device performances were systematically investigated. The HOMO levels of the polymers were tuned by introducing different donor units, yet all polymers exhibited <i>p</i>-type semiconducting properties. The hole mobilities of these polymers with centrosymmetric donor units exceeded 0.3 cm² V^–1 s^–1, and the maximum reached 1.06 cm² V^–1 s^–1. Because of their low-lying HOMO levels, these copolymers also showed good stability upon moisture. AFM and GIXD analyses revealed that polymers with different symmetry and backbone curvature were distinct in lamellar packing and crystallinity. DFT calculations were employed to help us propose the possible packing model. Based on these results, we propose a design strategy, called “molecular docking”, to understand the interpolymer π–π stacking. We also found that polymer symmetry and backbone curvature affect interchain “molecular docking” of isoindigo-based polymers in film, ultimately leading to different device performance. Finally, our design strategy maybe applicable to other reported systems, thus representing a new concept to design conjugated polymers for field-effect transistors