Effects of Transition Metal Oxides ZrO2, Y2O3, and Sc2O3 on Radiative Heat Transfer of Low-Reactive CaO-Al2O3-Based Mold Slag

Metallurgical and Materials Transactions B - To control heat transfer between the solidifying shell and the water-cooled mold during continuous casting, the transition metal oxides, ZrO2, Y2O3, and...     

Mathematical Modeling of Heat Transfer and Deformation of Bloom Tube Mold in Continuous Casting Process

Metallurgical and Materials Transactions B - The deformation of a bloom tube mold was investigated using an in-house-developed complex model considering the flow, heat transfer, and solidification...     

Vanadium Doping Enhanced Electrochemical Performance of Molybdenum Oxide in Lithium‐Ion Batteries

Molybdenum trioxide (MoO₃) suffers from poor conductivity, a low rate capability, and unsatisfactory cycling stability in lithium‐ion batteries. The aliovalent ion doping may present an effective way to improve the electrochemical performances of MoO₃. Here, it is shown, by first‐principle calculations, that doping MoO₃ with V by 12.5% can modulate significantly electronic structure and provide a small diffusion barrier for enhancing the electrochemical performance of MoO₃. The ultralong Mo_0.88V_0.12O_2.94 nanostructures, which retain the h‐MoO₃ structure and present an exceptionally high conductivity and fast ionic diffusion due to the substitution of V, facilitating lithiation/delithiation behavior, and induce a fine nanosized structure with a reduced volume change are prepared. As a result, the stress and strain are alleviated during the Li‐ion intercalation/deintercalation processes, improving the cycling stability and rate capability. Such a large improvement in the electrochemical properties can be ascribed to the stabilizing effect of V, the small migration energy barrier, and short diffusion path, which arise from the introduction of V into MoO₃. The unique engineering strategy and facile synthesis route open up a new avenue in modifying and developing other species of electrode materials.     

Utilizing a Spiro TADF Moiety as a Functional Electron Donor in TADF Molecular Design toward Efficient “Multichannel” Reverse Intersystem Crossing

Designing thermally activated delayed fluorescence (TADF) materials with an efficient reverse intersystem crossing (RISC) process is regarded as the key to actualize efficient organic light‐emitting diodes (OLEDs) with low efficiency roll‐off. Herein, a novel molecular design strategy is reported where a typical TADF material 10‐phenyl‐10H, 10′H‐spiro[acridine‐9, 9′‐anthracen]‐10′‐one (ACRSA) is utilized as a functional electron donor to design TADF materials of 2,4,6‐triphenyl‐1,3,5‐triazine(TRZ)‐p‐ACRSA and TRZ‐m‐ACRSA. It is unique that the intramolecular charge transfer of the ACRSA moiety and the intramolecular and through‐space intermolecular charge transfer between the TRZ and ACRSA moieties, provide a “multichannel” effect to enhance the rate of the reverse intersystem crossing process (k_risc) exceeding 10^?6 s^?1. TADF OLEDs based on TRZ‐p‐ACRSA as an emitter show a maximum external quantum efficiency (EQE) of 28% with reduced efficiency roll‐off (EQEs of 27.5% and 22.1% at 100 and 1000 cd m^?2, respectively). Yellow phosphorescent OLEDs utilizing TRZ‐p‐ACRSA as a host material show record‐high EQE of 25.5% and power efficiency of 115 lm W^?1, while phosphorescent OLEDs based on TRZ‐m‐ACRSA show further lower efficiency roll‐off with EQEs of 25.2%, 24.3%, and 21.5% at 100, 1000, and 10 000 cd m^?2, respectively.     

Ångstrom‐Scale Silver Particles as a Promising Agent for Low‐Toxicity Broad‐Spectrum Potent Anticancer Therapy

Cancer incidence is rising, and the efficacy of current available anticancer agents is limited by severe dose‐limiting toxicities and drug resistance problems. Nanoparticles are heralded as the next frontier in cancer treatment. Here, a pure physical method is used to efficiently fabricate very small silver particles even approaching the Ångstrom (Ång) dimension. Fructose is used as a dispersant and stabilizer to coat the Ång‐scale silver particles (AgÅPs). Functional and mechanistic studies demonstrate that fructose‐coated AgÅPs (F‐AgÅPs) can enter and accumulate in multiple cultured cancer cell lines to induce apoptotic death, whereas most normal cells are resistant to the efficacious dose of F‐AgÅPs; in vivo, intravenous administration of F‐AgÅPs potently inhibits the growth of pancreatic and lung cancer xenografts in nude mice, without inducing notable toxic effects on the healthy tissues. The results suggest the promising potential of F‐AgÅPs as a potent, safe, and broad‐spectrum agent for the cancer treatment.     

A novel image encryption scheme based on DNA sequence operations and chaotic systems

Neural Computing and Applications - In the paper, a novel image encryption algorithm based on DNA sequence operations and chaotic systems is proposed. The encryption architecture of permutation and...     

Fine‐Tuning Intrinsic Strain in Penta‐Twinned Pt–Cu–Mn Nanoframes Boosts Oxygen Reduction Catalysis

Tuning the intrinsic strain of Pt‐based nanomaterials has shown great promise for improving the oxygen reduction reaction (ORR) performance. Herein, reported is a tunable surface strain in penta‐twinned ternary Pt–Cu–Mn nanoframes (NFs). Pt–Cu–Mn ultrafine NFs (UNFs) exhibit ≈1.5% compressive strain compared to Pt–Cu–Mn pentagonal NFs (PNFs) and show the superior activity toward ORR in an alkaline environment. Specifically, the specific and mass activity of Pt–Cu–Mn UNFs are 3.38 mA cm^?2 and 1.45 A mg^?1, respectively, which is 1.45 and 1.71 times higher than that of Pt–Cu–Mn PNFs, demonstrating that compressive strain in NFs structure can effectively enhance the catalytic activity of ORR. Impressively, Pt–Cu–Mn UNFs exhibit 8.67 and 9.67 times enhanced specific and mass activity compared with commercial Pt/C. Theoretical calculations reveal that compression on the surface of Pt–Cu–Mn UNFs can weaken the bonding strengths and adsorption of oxygen‐containing intermediates, resulting in an optimal condition for ORR.     

All‐Natural,Degradable, Rolled‐Up Straws Based on Cellulose Micro‐ and Nano‐Hybrid Fibers

Among all the plastic pollution, straws have brought particularly intricate problems since they are single use, consumed in a large volume, cannot be recycled in most places, and can never be fully degraded. To solve this problem, replacements for plastic straws are being developed following with the global trend of plastic straw bans. Nevertheless, none of the available degradable alternatives are satisfactory due to drawbacks including poor natural degradability, high cost, low mechanical performance, and poor water stability. Here, all‐natural degradable straws are designed by hybridizing cellulose nanofibers and microfibers in a binder‐free manner. Straws are fabricated by rolling up the wet hybrid film and sealed by the internal hydrogen bonding formed among the cellulose fibers after drying. The cellulose hybrid straws show exceptional behaviors including 1) excellent mechanical performance (high tensile strength of ≈70 MPa and high ductility with a fracture strain of 12.7%), 2) sufficient hydrostability (10× wet mechanical strength compared to commercial paper straw), 3) low cost, and 4) high natural degradability. Given the low‐cost raw materials, the binder‐free hybrid design based on cellulose structure can potentially be a suitable solution to solve the environmental challenges brought by the enormous usage of plastics straws.     

移动互联网时代充值支付在新渠道快速上线的体系分析

随着网络的快速发展和手机功能的不断强大,互联网发生了用户习惯的大改变。为了更好地适应顾客消费习惯的改变,以服务赢得用户、跟随用户的步伐拓展渠道成为中国移动当前业务发展的新方向,秉持为客户提供最便利的服务的宗旨,开展建设互联网充值新渠道。文章以中国移动为例,介绍了其互联网时代充值支付在新渠道快速上线的体系,并结合当前形势进行简单的分析。     

Random selection-based adaptive saliency-weighted RXD anomaly detection for hyperspectral imagery

With recent advances in hyperspectral imaging sensors, subtle and concealed targets that cannot be detected by multispectral imagery can be identified. The most widely used anomaly detection method is based on the Reed–Xiaoli (RX) algorithm. This unsupervised technique is preferable to supervised methods because it requires no a priori information for target detection. However, two major problems limit the performance of the RX detector (RXD). First, the background covariance matrix cannot be properly modelled because the complex background contains anomalous pixels and the images contain noise. Second, most RX-like methods use spectral information provided by data samples but ignore the spatial information of local pixels. Based on this observation, this article extends the concept of the weighted RX to develop a new approach called an adaptive saliency-weighted RXD (ASW-RXD) approach that integrates spectral and spatial image information into an RXD to improve anomaly detection performance at the pixel level. We recast the background covariance matrix and the mean vector of the RX function by multiplying them by a joint weight that in fuses spectral and local spatial information into each pixel. To better estimate the purity of the background, pixels are randomly selected from the image to represent background statistics. Experiments on two hyperspectral images showed that the proposed random selection-based ASW RXD (RSASW-RXD) approach can detect anomalies of various sizes, ranging from a few pixels to the sub-pixel level. It also yielded good performance compared with other benchmark methods.