Egholmmatzen8711

Conversion/alloying type anodes have shown great promise for sodium-ion batteries (SIBs) because of their high theoretical capacity. However, the poor structural stability derived from the large volume expansion and short lifetime impedes their further practical applications. Herein, we report a novel anode with a pomegranate-like nanostructure of SnP2O7 particles homogeneously dispersed in the robust N-doped carbon matrix. For the first time, we make use of in situ self-nanocrystallization to generate ultrafine SnP2O7 particles with a short pathway of ions and electrons to promote the reaction kinetics. Ex situ transmission electron microscope (TEM) shows that the average particle size of SnP2O7 decreases from 66 to 20 nm successfully based on this unique nanoscale-engineering method. Therefore, the nanoparticles together with the N-doped carbon contribute a high pseudocapacitance contribution. Moreover, the N-doped carbon matrix forms strong interaction with the self-nanocrystallization ultrafine SnP2O7 particles, leading to a stable nanostructure without any particle aggregation under a long-cycle operation. Benefiting from these synergistic merits, the SnP2O7@C anode shows a high specific capacity of 403 mAh g-1 at 200 mA g-1 and excellent cycling stability (185 mAh g-1 after 4000 cycles at 1000 mA g-1). This work presents a new route for the effective fabrication of advanced conversion/alloying anodes materials for SIBs.Fe-N-C-based electrocatalysts have been developed as an encouraging substitute compared to their expensive Pt-containing equivalents for the oxygen reduction reaction (ORR). However, they still face major durability challenges from the in- situ production of Fenton radicals. Therefore, the synthesis of Fe-free ORR catalysts is among the emerging concerns. Herein, we have precisely applied a multistep heating strategy to produce mesoporous N-doped carbon nanostructures with Mn-/Co-Nx dual moieties from mixed-metal zeolitic imidazolate frameworks (ZIFs). It is found that their unique structure, with dual-metallic active sites, not only offers a high electrochemical performance for the ORR (E1/2 = 0.83 V vs reversible hydrogen electrode (RHE) in acid media), but also enhances the operational durability of the catalyst after 20 000 cycles with 97% of retention and very low H2O2 production ( less then 5%) in 0.1 M HClO4. In addition, the catalyst performs well toward the ORR also in alkaline solution (exhibiting E1/2 = 0.90 V and 30 000 cyclic stability).A novel cell free protein synthesis (CFPS) system utilizing layer-by-layer (LbL) polymer assembly was developed to reduce the operational cost of conventional CFPS. This yielded an encapsulated cell system, dubbed "eCells", that successfully performs in vitro CFPS and allows cost-effective incorporation of noncanonical amino acids into proteins. The use of eCells in CFPS circumvents the need for traditional cell lysate preparation and purification of amino acyl-tRNA synthetases (aaRS) while still retaining the small scale of an in vitro reaction. eCells were found to be 55% as productive as standard dialysis CFPS at 13% of the cost. The reaction was shown to be scalable over a large range of reaction volumes, and the crowding environment in eCells confers a stabilizing effect on marginally stable proteins, such as the pyrrolysl tRNA synthetase (PylRS), providing a means for their application in in vitro protein expression. Photocaged-cysteine (PCC) and Nε-(tert-butoxycarbonyl)-l-lysine (Boc-lysine) were incorporated into Peptidyl-prolyl cis-trans isomerase B (PpiB) using small amounts of ncAA with an adequate yield of protein. Fluorescent activated cell sorting (FACS) was used to demonstrate the partition of the lysate within the eCells in contrast to standard one pot cell lysate-based methods.Water flow through two-dimensional nanopores has attracted significant attention owing to the promising water purification technology based on atomically thick membranes. However, the theoretical description of water flow in nanopores based on the classical continuum theory is very challenging owing to the pronounced entrance/exit effects. Here, we extend the classical Hagen-Poiseuille equation for describing the relationship between flow rate and pressure loss in laminar tube flow to two-dimensional nanopores. A totally theoretical model is established by appropriately considering the velocity slip on pore surfaces both in the friction pressure loss and entrance/exit pressure loss. Based on molecular dynamics simulations of water flow through graphene nanopores, it is shown that the model can not only well predict the overall flow rate but also give a good estimation of the velocity profiles. As the pore radius and length increase, the model can reduce to the equations applicable to the fluid flow in infinitely/finitely long nanotubes, thin orifices, and macroscale tubes, showing an accurate prediction of the existing experimental and simulation data of the water flow through nanotubes and nanopores in the literature. Namely, the presented model is a unified model that can uniformly describe the fluid flow from nanoscales to macroscales by modifying the classical continuum theory.Two-dimensional (2D) organic materials hold great promise for use in a multitude of contemporary applications due to their outstanding chemical and physical properties. Herein, 2D sheets of poly(3,4-ethylenedioxythiophene)poly(4-styrenesulfonate) (PEDOTPSS) are prepared from a commercially available PEDOTPSS suspension using ice as a template. The 2D PEDOTPSS sheets grow in the boundaries of ice crystals as the polymers are "squeezed" out of the suspension when the water solidifies. The mechanical robustness of the sheets can be enhanced by incorporating WO3 nanowires, and the PSS component can be conveniently removed with a concentrated solution of H2SO4 to afford stable suspensions of PEDOT or WO3@PEDOT sheets, either of which can be converted into flexible films with tunable thicknesses via filtration. Swagelok- or pouch-type supercapacitor devices prepared from the WO3@PEDOT films exhibit outstanding energy-storage characteristics, including high rate capability, thickness-independent energy storage (e.g., 701 mF cm-2 is achieved with a 1-mm-thick film), high resistance toward mechanical deformation, and good cycling stability. Additionally, a high energy density of 0.083 mWh cm-2 is measured for a device prepared using a 1-mm-thick film at a high power density of 10 mW cm-2. The methodology described establishes an efficient and readily scalable approach for accessing 2D organic sheets.Recent research has shown the almost barrierless cycloaddition reaction of the carboxylic acid with one SO3 to form products with group of -OSO3H, which can form stable clusters with the nucleation precursors through hydrogen bonds (Mackenzie et al., Science 2015, 349, 58). Oxalic acid (OA), the simplest and prevalent dicarboxylic acid, was selected as an example to clarify the possibility to react with two SO3 sequentially and the nucleation potential of products. The results indicate that OA can sequentially react with two SO3 through low reaction barriers to form the primary product (oxalic sulfuric anhydride (OSA)) and the secondary product (oxalic disulfuric anhydride (ODSA)). Interactions between atmospheric nucleation precursors and OSA, ODSA, or OA are in the order of ODSA > OSA > OA through evaluating the stability of generated clusters by the topological, thermodynamics, and kinetic analysis, which implies generated products could be nucleation stabilizers with nucleation potential positively correlating with the number of -OSO3H. This reaction mechanism contributes to a comprehensive understanding of the reactivity of dicarboxylic acid in the polluted environment as well as the role of products in organosulfur chemistry and, to some extent, help to explain the missing sources of new particle formation.Membraneless organelles (MLOs) are spatiotemporally regulated structures that concentrate multivalent proteins or RNA, often in response to stress. The proteins enriched within MLOs are often classified as high-valency "scaffolds" or low-valency "clients", with the former being associated with a phase-separation promoting role. In this study, we employ a minimal model for P-body components, with a defined protein-protein interaction network, to study their phase separation at biologically realistic low protein concentrations. Without RNA, multivalent proteins can assemble into solid-like clusters only in the regime of high concentration and stable interactions. RNA molecules promote cluster formation in an RNA-length-dependent manner, even in the regime of weak interactions and low protein volume fraction. Our simulations reveal that long RNA chains act as superscaffolds that stabilize large RNA-protein clusters by recruiting low-valency proteins within them while also ensuring functional "liquid-like" turnover of components. Our results suggest that RNA-mediated phase separation could be a plausible mechanism for spatiotemporally regulated phase separation in the cell.Manganese oxides are promising host materials in rechargeable aqueous batteries due to their low cost and high capacity; however, their practical applications have long been restricted by their sluggish reaction kinetics and poor cycling stability. Herein, the layered K0.36H0.26MnO2·0.28H2O (K36) with a proton and Zn2+ cointercalation mechanism leads to a progressive phase evolution from layer-type K36 to hybrid layer-type KxHyZnzMnO2·nH2O and spinel-type ZnMn2O4 nanocrystal after a long-term cycle. Accordingly, K36 shows a high specific capacity (∼329.8 mAh g-1 at 0.1C), a superior rate performance (∼100.1 mAh g-1 at 10C), and a remarkable cycling stability (capacity retention of ∼93.4% over 3000 cycles at 4C). selleck products This work provides a new viewpoint of enhancing electrode performance via generating hybrid phases under electrochemical driving and will be a benefit to developing the next-generation aqueous batteries.The possibility of actively controlling structural colors has recently attracted a lot of attention, in particular for new types of reflective displays (electronic paper). However, it has proven challenging to achieve good image quality in such devices, mainly because many subpixels are necessary and the semitransparent counter electrodes lower the total reflectance. Here we present an inorganic electrochromic nanostructure based on tungsten trioxide, gold, and a thin platinum mirror. The platinum reflector provides a wide color range and makes it possible to "reverse" the device design so that electrolyte and counter electrode can be placed behind the nanostructures with respect to the viewer. Importantly, this makes it possible to maintain high reflectance regardless of how the electrochemical cell is constructed. We show that our nanostructures clearly outperform the latest commercial color e-reader in terms of both color range and brightness.Layer-by-layer (LbL) assembly is a versatile platform for applying coatings and studying the properties of promising compounds for antifouling applications. Here, alginate-based LbL coatings were fabricated by alternating the deposition of alginic acid and chitosan or polyethylenimine to form multilayer coatings. Films were prepared with either odd or even bilayer numbers to investigate if the termination of the LbL coatings affects the physicochemical properties, resistance against the nonspecific adsorption (NSA) of proteins, and antifouling efficacy. The hydrophilic films, which were characterized using spectroscopic ellipsometry, water contact angle goniometry, ATR-FTIR spectroscopy, AFM, XPS, and SPR spectroscopy, revealed high swelling in water and strongly reduced the NSA of proteins compared to the hydrophobic reference. While the choice of the polycation was important for the protein resistance of the LbL coatings, the termination mattered less. The attachment of diatoms and settling of barnacle cypris larvae revealed good antifouling properties that were controlled by the termination and the charge density of the LbL films.