Targeted aspect based multimodal sentiment analysis:an attention capsule extraction and multi-head fusion network

Multimodal sentiment analysis has currently identified its significance in a variety of domains. For the purpose of sentiment analysis, different aspects of distinguishing modalities, which correspond to one target, are processed and analyzed. In this work, we propose the targeted aspect-based multimodal sentiment analysis (TABMSA) for the first time. Furthermore, an attention capsule extraction and multi-head fusion network (EF-Net) on the task of TABMSA is devised. The multi-head attention (MHA) based network and the ResNet-152 are employed to deal with texts and images, respectively. The integration of MHA and capsule network aims to capture the interaction among the multimodal inputs. In addition to the targeted aspect, the information from the context and the image is also incorporated for sentiment delivered. We evaluate the proposed model on two manually annotated datasets. the experimental results demonstrate the effectiveness of our proposed model for this new task

Large Eddy Simulation of Premixed Stratified Swirling Flame Using the Finite Rate Chemistry Approach

Large eddy simulations of a stratified swirling flow of a Cambridge swirl burner for both nonreacting and reacting cases are conducted using a finite rate chemistry approach represented by a partially stirred reactor model. The large eddy simulation predictions are compared with experimental measurements for velocity, temperature, and concentrations of major species. The agreement is found in overall trend of velocity prediction, but temperature and concentration of major species show slight discrepancies in the central region. Two reduced chemical mechanisms are examined in the present paper with the objective of assessing their capabilities in predicting swirling flame characteristics, and the distinct difference using two mechanisms is found in CO distribution profiles, which is considered the consequence of different kinetics of CO-CO2 equilibrium. Flow structures are qualitatively and quantitatively analyzed with numerical results. Large-scale vortex structures and precession motions are observed in both nonreacting and reacting cases. Frequency of vortex shedding is identified from the point data of instantaneous velocity in the discharging stream-induced shear layer. On this basis, the intensity and frequency of precession motion are shown to be enhanced in the presence of combustion. Large-scale wrinkling of the flame surface is resolved and characterized in the flame zone, and the effect of mixture stratification is then further discussed

Modeling of Spray Combustion with a Steady Laminar Flamelet Model in an Aeroengine Combustion Chamber Based on OpenFOAM

The development of high-performance aeroengine combustion chambers strongly depends on the accuracy and reliability of efficient numerical models. In the present work, a reacting solver with a steady laminar flamelet model and spray model has been developed in OpenFOAM and the solver details are presented. The solver is firstly validated by Sandia/ETH-Zurich flames. Furthermore, it is used to simulate nonpremixed kerosene/air spray combustion in an aeroengine combustion chamber with the RANS method. A comparison with available experimental data shows good agreement and validates the capability of the new developed solver in OpenFOAM

Removal of Tetracycline by Hydrous Ferric Oxide: Adsorption Kinetics, Isotherms, and Mechanism

The removal of tetracycline (TC) from solution is an important environmental issue. Here we prepared an adsorbent hydrous ferric oxide (HFO) by adjusting a FeCl3·6H2O solution to neutral pH. HFO was characterized by a surface area analyzer, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), and was used to remove TC from solution. The influence of pH, solid-to-liquid ratio, ionic type, and strength on TC removal was investigated. Adsorption kinetics and isotherms were also determined. HFO after adsorption of TC was analyzed by FTIR and XPS to investigate the adsorption mechanism. The results showed that the adsorption of TC increased from 88.3% to 95% with increasing pH (3.0–7.0) and then decreased. K+ ions had little effect on TC adsorption by HFO. However, Ca2+ and Mg2+ reduced the adsorption of TC on HFO. When the concentrations of Ca2+ and Mg2+ were increased, the inhibitory effect was more obvious. Pseudo-second-order kinetics and the Langmuir model fitted the adsorption process well. The maximum adsorption capacity of TC on HFO reached 99.49 mg·g−1. The adsorption process was spontaneous, endothermic, and increasingly disordered. Combination analysis with FTIR and XPS showed that the mechanism between TC and HFO involved electrostatic interactions, hydrogen interactions, and complexation. Therefore, the environmental behavior of TC could be affected by HFO

Boosting electrocatalytic hydrogen evolution with anodic oxidative upgrading of formaldehyde over trimetallic carbides

Coupling the electrochemical oxidative upgrading of organic molecules with hydrogen evolution reaction could enable the energy-efficient production of H2 from renewable electricity with simultaneous chemical production. This work shows that a trimetallic carbide (Co3Fe3W6C), derived from one-pot synthesis, could act as a robust electrocatalyst for formaldehyde upgrading reaction (FUR) to produce formate at a high faradaic efficiency (>98%), without any production of CO2 or O2. Compared to OER, the input voltages of Co3Fe3W6C-catalyzed FUR are 150 and 120 mV lower to achieve current densities of 10 and 50 mA cm-2, respectively, thereby facilitating a significant boost in the energy efficiency of electrochemical H2 production from water. Density functional theory calculations reveal that the trimetallic carbide system modulates the d band of the transition-metal active sites to achieve optimal adsorption toward the selective oxidation of formaldehyde, while suppressing the further formation of CO2. Co3Fe3W6C was also found to be highly stable under considerably high-throughput electrochemical conditions in an alkaline electrolyte. This work offers a new strategy of synergizing water electrolysis with the oxidative upgrading of organic molecules to simultaneously boost the cost competitiveness of green hydrogen production and the electrochemical upgrading of organic feedstocks.National Research Foundation (NRF)Submitted/Accepted versionThe authors are grateful to the financial support from the National Natural Science Foundation of China (nos. 21872123, 22172143, and 52102316). M.T. and W.L. acknowledge funding from National Research Foundation of Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE)