Significant Acceleration of Photocatalytic CO2 Reduction at the Gas-Liquid Interface of Microdroplets**

Solar-driven CO₂ reduction reaction (CO₂RR) is largely constrained by the sluggish mass transfer and fast combination of photogenerated charge carriers. Herein, we find that the photocatalytic CO₂RR efficiency at the abundant gas-liquid interface provided by microdroplets is two orders of magnitude higher than that of the corresponding bulk phase reaction. Even in the absence of sacrificial agents, the production rates of HCOOH over WO₃ ⋅ 0.33H₂O mediated by microdroplets reaches 2536 μmol h⁻¹ g⁻¹ (vs. 13 μmol h⁻¹ g⁻¹ in bulk phase), which is significantly superior to the previously reported photocatalytic CO₂RR in bulk phase reaction condition. Beyond the efficient delivery of CO₂ to photocatalyst surfaces within microdroplets, we reveal that the strong electric field at the gas-liquid interface of microdroplets essentially promotes the separation of photogenerated electron-hole pairs. This study provides a deep understanding of ultrafast reaction kinetics promoted by the gas-liquid interface of microdroplets and a novel way of addressing the low efficiency of photocatalytic CO₂ reduction to fuel.     

Contradictory effect of gold nanoparticle-decorated molybdenum sulfide nanocomposites on amyloid-β-40 aggregation

The effect of gold nanoparticle-decorated molybdenum sulfide (AuNP-MoS₂) nanocomposites on amyloid-β-40 (Aβ₄₀) aggregation was investigated. The interesting discovery was that the effect of AuNP-MoS₂ nanocomposites on Aβ₄₀ aggregation was contradictory. Low concentration of AuNP-MoS₂ nanocomposites could enhance the nucleus formation of Aβ₄₀ peptides and accelerate Aβ₄₀ fibrils aggregation. However, although high concentration of AuNP-MoS₂ nanocomposites could enhance the nucleus formation of Aβ₄₀ peptides, it eventually inhibited Aβ₄₀ aggregation process. It might be attributed to the interaction between AuNP-MoS₂ nanocomposites and Aβ₄₀ peptides. For low concentration of AuNP-MoS₂ nanocomposites, it was acted as nuclei, resulting in the acceleration of the nucleation process. However, the structural flexibility of Aβ₄₀ peptides was limited as the concentration of AuNP-MoS₂ nanocomposites was increased, resulting in the inhibition of Aβ₄₀ aggregation. These findings suggested that AuNP-MoS₂ nanocomposites might have a great potential to design new multifunctional material for future treatment of amyloid-related diseases.     

Lifting Surface in Subsonic Unsteady Regime

The paper refers to the solution of the integral equation for the acceleration (or pressure) potential for the study of subsonic linearized unsteady flow in view of aeroelastic applications. The case considered is relevant to a trapezoidal wing infinitely thin surface without discontinuities. As is well known [1, 2], the kernel of the integral equation exhibits three singularities, two of which are integrable in elementary form, whereas, for the third one integration in principal part according to Hadamard's rule is necessary. The kernel is therefore reworked in such a way that all the singularities are separated from the regular part, and eventually the discretization is performed in such a way that only the regular part is to be recalculated for each new value of the reduced frequency. Convergence tests, comparison with other methods of solution, and time saving associated with the technique of separation are also shown.Sommario. II lavoro tratta la risoluzione del problema relativo alla equazione integrale nel potenziale di accelerazione (o di pressione) per lo studio di una corrente subsonica linearizzata nonstazionaria, in vista di applicazioni aeroelastiche. Il caso considerato è quello di una superficie alare a pianta trapezoidale in assenza di discontinuità di spessore infinitesimo. Come è noto [1, 2], il nucleo della equazione integrale in parola presenta tre singolarità, due sole delle quali sono integrabili in forma elementare, (o riconducibili ad essa), mentre per la terza è necessario far ricorso alla integrazione in parte principale alla Hadamard. Il nucleo stesso viene quindi rielaborato in modo da isolare tutte le singolarità dalla componente regolare del nucleo; si procede così alla discretizzazione dell' equazione integrale, e, per ogni valore della frequenza ridotta, va ricalcolata solo la parte regolare della matrice risolvente. Vengono poi effettuati tests di convergenza, confronti con altri metodi di soluzione, analisi sui tempi di calcolo e risparmio di tempo di calcolo dovuto alla tecnica di separazione.     

地震作用下基于ADMF和系统参数组合的最优MTMD

多重调谐质量阻尼器 ( MTMD)是由许多频率成线性分布的调谐质量阻尼器组成。可能的系统参数组合形成 5种 MTMD,即 MTMD-1～MTMD-5。基于在基底加速度作用下具有一般 MTMD时结构的加速度传递函数 ,建立了 MTMD-1～ MTMD-5加速度动力放大系数 ( ADMF)的统一模式。利用 ADMF和数值寻优技术进行了详细的最优参数研究。最优参数包括 :最优频率间隔、最优阻尼比、最优调谐频率比。大量的数值比较表明 :在MTMD地震反应控制工程中 ,应优先选择 MTMD-1。     

Synthesis,surface property,micellization and pH responsivity of fluorinated gradient copolymers

In this work, fluorinated nonamphiphilic gradient copolymers of tert‐butyl acrylate (tBA) and 2,2,3,3,4,4,4‐heptafluorobutyl methacrylate (HFBMA) [poly(tBA‐grad‐HFBMA)] were first synthesized by semibatch atom transfer radical copolymerization of tBA and HFBMA. Their hydrolysis at acidic conditions led to amphiphilic poly(acrylic acid‐grad‐HFBMA). The chemical compositions and structures of these copolymers were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and gel permeation chromatography. Their surface properties were evaluated with water contact angle measurement and x‐ray photoelectron spectroscopy. The micellization behaviors of amphiphilic copolymer were also studied by transmission electron microscopy and dynamic light scattering. The results showed that the fluorinated and amphiphilic gradient copolymers could self‐assemble in a dilute solution to form aggregates of morphologies. Furthermore, the effect of pH on the aggregates was investigated to verify that the resulting gradient copolymers were to some extent pH sensitive. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

High‐Responsivity Photodetectors Based on Formamidinium Lead Halide Perovskite Quantum Dot–Graphene Hybrid

Highly performance photodetector requires a wide range of responses of the incident photons and converts them to electrical signals efficiently. Here, a photodetector based on formamidinium lead halide perovskite quantum dots (e.g., FAPbBr₃ QDs)–graphene hybrid, aiming to take the both advantages of the two constituents. The FAPbBr₃ QD–graphene layer not only benefits from the high mobility and wide spectral absorption of the graphene material but also from the long charge carrier lifetime and low dark carrier concentration of the FAPbBr₃ QDs. The photodetector based on FAPbBr₃ QD–graphene hybrid exhibits a broad spectral photoresponse ranging from 405 to 980 nm. A photoresponsivity of 1.15 × 10⁵AW⁻¹ and an external quantum efficiency as high as 3.42 × 10⁷% are obtained under an illumination power of 3 µW at 520 nm wavelength. In detail, a high responsivity is achieved in 405–538 nm, while a relatively low but fast response is observed in 538–980 nm. The photoelectric conversion mechanism of this hybrid photodetector is investigated in the view of built‐in electric field from the QD–graphene contact which improves the photoconductive gain.     

The Acceleration Severity Index in the impact of a vehicle against permanent road equipment support structures

The acceleration Severity Index (ASI), described in European Standard EN12767 (The passive safety of support structures for road equipment. Requirements, classification and the test method) is regarded as the most important indicator of impact on the occupants. The requirements for experiments are described, having in mind that the results depend on many factors. One of them is the selection of a vehicle to be used in the crash test. To perform numerical vehicle crash simulation, the finite-element models of permanent road equipment support structures were developed using the LS Dyna software available. To examine the response of the vehicle upon the impact, the acceleration severity index curves were calculated and visualised in Matlab.     

Jordan–Cattaneo waves: Analogues of compressible flow

We review work of Jordan on a hyperbolic variant of the Fisher–KPP equation, where a shock solution is found and the amplitude is calculated exactly. The Jordan procedure is extended to a hyperbolic variant of the Chafee–Infante equation. Extension of Jordan’s ideas to a model for traffic flow are also mentioned. We also examine a diffusive susceptible–infected (SI) model, and generalizations of diffusive Lotka–Volterra equations, including a Lotka–Volterra–Bass competition model with diffusion. For all cases we show how a Jordan–Cattaneo wave may be analysed and we indicate how to find the wavespeeds and the amplitudes. Finally we present details of a fully nonlinear analysis of acceleration waves in a Cattaneo–Christov poroacoustic model.