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Metal phosphides are a new class of potential high‐capacity anodes for lithium ion batteries, but their short cycle life is the critical problem to hinder its practical application. A unique ball‐cactus‐like microsphere of carbon coated NiP2/Ni3Sn4 with deep‐rooted carbon nanotubes (Ni‐Sn‐P@C‐CNT) is demonstrated in this work to solve this problem. Bimetal‐organic‐frameworks (BMOFs, Ni‐Sn‐BTC, BTC refers to 1,3,5‐benzenetricarboxylic acid) are formed by a two‐step uniform microwave‐assisted irradiation approach and used as the precursor to grow Ni‐Sn@C‐CNT, Ni‐Sn‐P@C‐CNT, yolk–shell Ni‐Sn@C, and Ni‐Sn‐P@C. The uniform carbon overlayer is formed by the decomposition of organic ligands from MOFs and small CNTs are deeply rooted in Ni‐Sn‐P@C microsphere due to the in situ catalysis effect of Ni‐Sn. Among these potential anode materials, the Ni‐Sn‐P@C‐CNT is found to be a promising anode with best electrochemical properties. It exhibits a large reversible capacity of 704 mA h g?1 after 200 cycles at 100 mA g?1 and excellent high‐rate cycling performance (a stable capacity of 504 mA h g?1 retained after 800 cycles at 1 A g?1). These good electrochemical properties are mainly ascribed to the unique 3D mesoporous structure design along with dual active components showing synergistic electrochemical activity within different voltage windows.  相似文献   

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Organic–inorganic halide perovskites are promising photodetector materials due to their strong absorption, large carrier mobility, and easily tunable bandgap. Up to now, perovskite photodetectors are mainly based on polycrystalline thin films, which have some undesired properties such as large defective grain boundaries hindering the further improvement of the detector performance. Here, perovskite thin‐single‐crystal (TSC) photodetectors are fabricated with a vertical p–i–n structure. Due to the absence of grain‐boundaries, the trap densities of TSCs are 10–100 folds lower than that of polycrystalline thin films. The photodetectors based on CH3NH3PbBr3 and CH3NH3PbI3 TSCs show low noise of 1–2 fA Hz?1/2, yielding a high specific detectivity of 1.5 × 1013 cm Hz1/2 W?1. The absence of grain boundaries reduces charge recombination and enables a linear response under strong light, superior to polycrystalline photodetectors. The CH3NH3PbBr3 photodetectors show a linear response to green light from 0.35 pW cm?2 to 2.1 W cm?2, corresponding to a linear dynamic range of 256 dB.  相似文献   

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A fundamental understanding of structure‐morphology‐property relationships of proton exchange membranes (PEMs) is crucial in order to improve the cost, performance, and durability of PEM fuel cells (PEMFCs). In this context, there has been an explosion over the past five years in the volume of research carried out in the area of non‐perfluorinated, proton‐conducting polymer membranes, with a particular emphasis on exploiting phase behavior associated with block and graft copolymers. This progress report highlights a selection of interesting studies in the area that have appeared since 2005, which illustrate the effects of factors such as acid and water contents and morphology upon proton conduction. It concludes with an outlook on future directions.  相似文献   

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The separate co‐encapsulation and selective controlled release of multiple encapsulants in a predetermined sequence has potentially important applications for drug delivery and tissue engineering. However, the selective controlled release of distinct contents upon one triggering event for most existing microcarriers still remains challenging. Here, novel microfluidic fabrication of compound‐droplet‐pairs‐filled hydrogel microfibers (C‐Fibers) is presented for two‐step selective controlled release under AC electric field. The parallel arranged compound droplets enable the separate co‐encapsulation of distinct contents in a single microfiber, and the release sequence is guaranteed by the discrepancy of the shell thickness or core conductivity of the encapsulated droplets. This is demonstrated by using a high‐frequency electric field to trigger the first burst release of droplets with higher conductivity or thinner shell, followed by the second release of the other droplets under low‐frequency electric field. The reported C‐Fibers provide novel multidelivery system for a wide range of applications that require controlled release of multiple ingredients in a prescribed sequence.  相似文献   

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The continuous increasing of engineered nanomaterials (ENMs) in our environment, their combinatorial diversity, and the associated genotoxic risks, highlight the urgent need to better define the possible toxicological effects of ENMs. In this context, we present a new high‐throughput screening (HTS) platform based on the cytokinesis‐block micronucleus (CBMN) assay, lab‐on‐chip cell sorting, and automated image analysis. This HTS platform has been successfully applied to the evaluation of the cytotoxic and genotoxic effects of silver nanoparticles (AgNPs) and silica nanoparticles (SiO2NPs). In particular, our results demonstrate the high cyto‐ and genotoxicity induced by AgNPs and the biocompatibility of SiO2NPs, in primary human lymphocytes. Moreover, our data reveal that the toxic effects are also dependent on size, surface coating, and surface charge. Most importantly, our HTS platform shows that AgNP‐induced genotoxicity is lymphocyte sub‐type dependent and is particularly pronounced in CD2+ and CD4+ cells.  相似文献   

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Poor drug penetration into tumor cells and tissues is a worldwide difficulty in cancer therapy. A strategy is developed for virion‐like membrane‐breaking nanoparticles (MBNs) to smoothly accomplish tumor‐activated cell‐and‐tissue dual‐penetration for surmounting impermeable drug‐resistant cancer. Tailor‐made dendritic arginine‐rich peptide prodrugs are designed to mimic viral protein transduction domains and globular protein architectures. Attractively, these protein mimics self‐assemble into virion‐like nanoparticles in aqueous solution, having highly ordered secondary structure. Tumor‐specific acidity conditions would activate the membrane‐breaking ability of these virion‐like nanoparticles to perforate artificial and natural membrane systems. As expected, MBNs achieve highly efficient drug penetration into drug‐resistant human ovarian (SKOV3/R) cancer cells. Most importantly, the well‐organized MBNs can pass through endothelial/tumor cells and spread from one cell to another one. Intravenous injection of MBNs into nude mice bearing impermeable SKOV3/R tumors suggests that the MBNs can recognize the tumor tissue after prolonged blood circulation, evoke the membrane‐breaking function for robust transvascular extravasation, and penetrate into the deep tumor tissue. This work provides the first demonstration of sophisticated molecular and supramolecular engineering of virion‐like MBNs to realize the long‐awaited cell‐and‐tissue dual‐penetration, contributing to the development of a brand‐new avenue for dealing with incurable cancers.  相似文献   

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The micro‐supercapacitors are of great value for portable, flexible, and integrated electronic equipments. Here, the large‐scale and integrated asymmetrical micro‐supercapacitor (AMSC) array is fabricated in virtue of the laser direct writing and electrodeposition technology. The AMSC shows the ideal flexibility, high areal specific capacitance (21.8 mF cm?2), and good rate capability. Moreover, its energy density reaches 12.16 µW h cm?2, outperforming most micro‐supercapacitors reported previously. Meanwhile, large‐scale series‐connected AMSCs are integrated on the flexible substrates (e.g., indium tin oxide‐polyethylene terephthalate film), which can power a veriety of the commercial electronics. The combination of AMSCs array, solar cell, and electronic device proves the feasibility for practical application in the portable, flexible, and integrated electronic equipments.  相似文献   

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