ABSTRACT
Entity alignment aims to construct a complete knowledge graph (KG) by matching the same entities in multi-source KGs. Existing researches on entity alignment mainly focuses on static multi-relational data in knowledge graphs. However, the relationships or attributes between entities often possess temporal characteristics as well. Neglecting these temporal characteristics can frequently lead to alignment errors. Compared to studying entity alignment in temporal knowledge graphs, there are relatively few efforts on entity alignment in cross-lingual temporal knowledge graphs. Therefore, in this paper, we put forward an entity alignment method for cross-lingual temporal knowledge graphs, namely CTEA. Based on GCN and TransE, CTEA combines entity embeddings, relation embeddings and attribute embeddings to design a joint embedding model, which is more conducive to generating transferable entity embedding. In the meantime, the distance calculation between elements and the similarity calculation of entity pairs are combined to enhance the reliability of cross-lingual entity alignment. Experiments shows that the proposed CTEA model improves Hits@m and MRR by about 0.8â¼2.4 percentage points compared with the latest methods.
Subject(s)
Knowledge , Pattern Recognition, Automated , Reproducibility of ResultsABSTRACT
Despite the growing interest in halide perovskite-based NH3 sensors, the NH3 sensing mechanism is still not well understood. Here, we report an anomalous behavior of resistance enhancement in CH3NH3PbI3(MAPbI3) perovskite films upon exposure to NH3 gas, which is contrary to a resistance drop trend in previously reported perovskites. We propose a NH3 sensing mechanism in which the anomalous resistance enhancement is dominated by grain boundaries of perovskites. It is demonstrated that NH3 molecules can substitute MA+ cations of MAPbI3 to form the insulating NH4PbI3·MA intermediate layers onto the surface of crystal grains, thereby resulting in an increase of resistance. Additionally, we construct the MAPbI3-based sensor, and achieve a gas response of 472% toward 30 ppm of NH3. This study suggests the potential of the perovskite-based NH3 sensors, and also provides guidance for developing high-performance sensing perovskite materials.
ABSTRACT
A novel polyaniline (PANI)/Eu3+ nanofiber sensing film was prepared in the presence of Eu(NO3)3 which serves as structure-directed agent. The morphological, component, crystallinity and electrochemical properties were carried out by using Scanning Electron Microscope (SEM), Energy-Dispersive X-ray (EDX), Fourier Transform Infrared spectroscopy (FT-IR), X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) techniques. The results indicated the nanofiber-like network with porous structure appeared in the PANI embedded by Eu3+ ions, thereby leading to large specific surface area. Furthermore, the PANI/Eu3+ nanofibers were grown onto the inner wall of capillary glass to form the tube sensor. By the sensing measurements, this tube sensor enabled the detection of low-volume (0.3â¯mL) NH3 for response 435% at concentration of 0.25â¯ppm with a short response time (5â¯s) and recovery time (5â¯s), and the performances of reproducibility and selectivity were also excellent. The above results demonstrated the potential application of PANI/Eu3+ tube sensor for low-volume NH3 gas.
ABSTRACT
A sodium citrate (SC) doped polypyrrole (PPy)/PS capillary sensor was prepared for ultra-small volume HCl gas detection. A PS film was formed in advance on the inner wall of a silica glass capillary tube, which enabled us to prepare a high-qualified PPy sensitive film inside the tube. The crystallinity, morphology, microstructure and carrier transport properties of the PPy film were characterized by XRD, SEM, FTIR and Hall effect system, respectively. The results indicated that the as-prepared tube sensor sample was able to detect 0.2 mL 30 ppm HCl gas while the plane-shaped PPy/PS sensor failed to probe. The improvement of sensing properties was attributed to the trend of crystallinity, pore (or gap) morphology and the long-narrow gas cell. The tube-like gas cell and the featured PPy/PS film of the tube sample contribute to sensing the small volume of HCl gas, which may be applied in breath analysis for potential nonintrusive disease diagnosis.
