A Constraint‐based Maximum Entropy Sampling Method for Kriging Models in Fuel Cell Applications

A metamodel replaces the simulation model with an approximation model to make design optimization computationally achievable. The accuracy of a metamodel depends highly on the choice of sampling points. This article proposes a constraint‐based maximum entropy sampling method that locates most sampling points within a feasible constraint domain represented as a complex nonlinear function. As a robust measure of information, a maximum entropy criterion is used to select sampling points for constructing the Kriging model. The violation ratio from the feasible domain is incorporated into the covariance function in the Kriging model. The constraint‐based maximum entropy sampling method is applied to reduce the weight of a bipolar plate in a vanadium redox battery by optimizing its channel design. The proposed sampling method rapidly approximates the boundary of the feasible domain with a relatively small number of sampling points. Final optimal design results for the plate channel using the proposed method indicate a significant reduction in the plate weight compared with the existing bipolar plate design. Copyright © 2012 John Wiley & Sons, Ltd.     

Reactive Oxygen Species‐Regulating Polymersome as an Antiviral Agent against Influenza Virus

Reactive oxygen species (ROS) produced during mitochondrial oxidative phosphorylation play an important role as signal messengers in the immune system and also regulate signal transduction. ROS production, initiated as a consequence of microbial invasion, if generated at high levels, induces activation of the MEK (mitogen‐activated protein kinase kinase)/ERK (extracellular signal‐regulated kinase) pathway to promote cell survival and proliferation. However, viruses hijack the host cells' pathways, causing biphasic activation of the MEK/ERK cascade. Thus, regulation of ROS leads to concomitant inhibition of virus replication. In the present study, poly(aniline‐co‐pyrrole) polymerized nanoregulators (PASomes) to regulate intracellular ROS levels are synthesized, exploiting their oxidizing‐reducing characteristics. Poly(aniline‐co‐pyrrole) embedded within an amphiphilic methoxy polyethylene glycol‐block‐polyphenylalanine copolymer (mPEG‐b‐pPhe) are used. It is demonstrated that the PASomes are water soluble, biocompatible, and could control ROS levels successfully in vitro, inhibiting viral replication and cell death. Furthermore, the effects of homopolymerized nanoregulators (polypyrrole assembled with mPEG‐b‐pPhe or polyaniline assembled with mPEG‐b‐pPhe) are compared with those of the PASomes. Consequently, it is confirmed that the PASomes can regulate intracellular ROS levels successfully and suppress viral infection, thereby increasing the cell survival rate.     

Superfast Room‐Temperature Activation of SnO2 Thin Films via Atmospheric Plasma Oxidation and their Application in Planar Perovskite Photovoltaics

The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has now exceeded 20%; thus, research focus has shifted to establishing the foundations for commercialization. One of the pivotal themes is to curtail the overall fabrication time, to reduce unit cost, and mass‐produce PSCs. Additionally, energy dissipation during the thermal annealing (TA) stage must be minimized by realizing a genuine low‐temperature (LT) process. Here, tin oxide (SnO₂) thin films (TFs) are formulated at extremely high speed, within 5 min, under an almost room‐temperature environment (<50 °C), using atmospheric Ar/O₂ plasma energy (P‐SnO₂) and are applied as an electron transport layer of a “n–i–p”‐type planar PSC. Compared with a thermally annealed SnO₂ TF (T‐SnO₂), the P‐SnO₂ TF yields a more even surface but also outstanding electrical conductivity with higher electron mobility and a lower number of charge trap sites, consequently achieving a superior PCE of 19.56% in P‐SnO₂‐based PSCs. These findings motivate the use of a plasma strategy to fabricate various metal oxide TFs using the sol–gel route.     

Recent Advances in Doping of Molybdenum Disulfide: Industrial Applications and Future Prospects

Owing to their excellent physical properties, atomically thin layers of molybdenum disulfide (MoS₂) have recently attracted much attention due to their nonzero‐gap property, exceptionally high electrical conductivity, good thermal stability, and excellent mechanical strength, etc. MoS₂‐based devices exhibit great potential for applications in optoelectronics and energy harvesting. Here, a comprehensive review of various doping strategies is presented, including wet doping and dry doping of atomically crystalline MoS₂ thin layers, and the progress made so far for their doping‐based prospective applications is also discussed. Finally, several significant research issues for the prospects of doped‐MoS₂ in industry, as a guide for 2D material community, are also provided.     

Three-dimensional object feature extraction and classification with computational holographic imaging

We address three-dimensional (3D) object classification with computational holographic imaging. A 3D object can be reconstructed at different planes by use of a single hologram. We apply principal component and Fisher linear discriminant analyses based on Gabor-wavelet feature vectors to classify 3D objects measured by digital interferometry. Experimental and simulation results are presented for regional filtering concentrated at specific positions and for overall grid filtering. The proposed technique substantially reduces the dimensionality of the 3D classification problem. To the best of our knowledge, this is the first report on the use of the proposed technique for 3D object classification.     

Enhanced topical delivery of tacrolimus by a carbomer hydrogel formulation with transcutol P

Tacrolimus (TAC), a non-steroidal anti-inflammatory and immunosuppressive agent, is used for the treatment of atopic dermatitis (AD) and skin immune diseases. TAC-loaded topical hydrogel formulations composed of carbomer, carnosine, transcutol P (diethylene glycol monoethyl ether) and humectant were prepared. For comparison, TAC-loaded topical cream-type formulations were also prepared and commercially available TAC ointment was used as a reference. A drug release study in vitro revealed that the total amount of TAC released from hydrogels over 24?h was approximately 30 times greater than that for the reference formulation. Compared to the reference ointment and creams, carbomer gel formulations showed higher skin permeation and retention of TAC (significantly different at p?相似文献   

Wafer‐Scale and Low‐Temperature Growth of 1T‐WS2 Film for Efficient and Stable Hydrogen Evolution Reaction

The metallic 1T phase of WS₂ (1T‐WS₂), which boosts the charge transfer between the electron source and active edge sites, can be used as an efficient electrocatalyst for the hydrogen evolution reaction (HER). As the semiconductor 2H phase of WS₂ (2H‐WS₂) is inherently stable, methods for synthesizing 1T‐WS₂ are limited and complicated. Herein, a uniform wafer‐scale 1T‐WS₂ film is prepared using a plasma‐enhanced chemical vapor deposition (PE‐CVD) system. The growth temperature is maintained at 150 °C enabling the direct synthesis of 1T‐WS₂ films on both rigid dielectric and flexible polymer substrates. Both the crystallinity and number of layers of the as‐grown 1T‐WS₂ are verified by various spectroscopic and microscopic analyses. A distorted 1T structure with a 2a₀ × a₀ superlattice is observed using scanning transmission electron microscopy. An electrochemical analysis of the 1T‐WS₂ film demonstrates its similar catalytic activity and high durability as compared to those of previously reported untreated and planar 1T‐WS₂ films synthesized with CVD and hydrothermal methods. The 1T‐WS₂ does not transform to stable 2H‐WS₂, even after a 700 h exposure to harsh catalytic conditions and 1000 cycles of HERs. This synthetic strategy can provide a facile method to synthesize uniform 1T‐phase 2D materials for electrocatalysis applications.     

On the strain Assumption in a finite element model for plates and shells

Two different methods of assuming independent strain fields are examined for the nine node degenerate solid shell element. In the first case, the assumed strain field is chosen for the local orthogonal co-ordinate systems defined at the Gaussian integration points. In the second case, the independent strain is assumed for a local orthogonal co-ordinate system defined at the origin of the parent co-ordinates. The results of numerical tests involving simple example problems demonstrate that the second method is capable of exactly representing constant stress or moment states even when element geometries are distorted. In addition, both methods lead to a finite element model which is free of locking.     

Microbial adaptation in the degradation of phenol byAlcaligenes xylosoxidans Y234

Microbial adaptation was performed to enhance the biological degradation of phenol. WhenAlcaligenes xylosoxidans Y234 was adapted with benzene, it could degrade phenol of 1,000 ppm completely in 60 hours while phenoladapted cell could not. This phenomenon was discussed in terms of intracellular enzyme activity and applied to the degradation of phenol in a packed-bed bioreactor.