Search

An ontology-based knowledge graph construction method for military terminology is proposed, which is used to obtain semantic information in military terminologycorpus and construct military terminology knowledge graph. Then the ontology of military terminology is built firstly based on the analysis of military terminologycorpus. In this method, the rule based method and the pre-trained model based method are used to extract the relation of military terminology and the knowledge of military terminology is stored in the graph database at last. This method can construct high quality knowledge graph of military terminology for intelligent applications such as semantic search, intelligent question and answer.

To improve the photodetction performance of MXene titanium carbide (Ti3C2), a MXene film assembled by two-dimensional (2D) MXene Ti3C2Tx nanosheets (NSs) via a layer-by-layer technique is employed to facilely pattern zero-dimensional (0D) bismuth nanoparticles (Bi NPs), abbreviated as patterned Bi NP@MXene Ti3C2Tx NS, for the construction of a prototypical photoelectrochemical (PEC)-type photodetector. Compared to individual 2D MXene Ti3C2Tx NSs and 0D Bi NPs, the patterned Bi NP@MXene Ti3C2Tx NS displays remarkably better PEC performance, including photocurrent density, photoresponsivity, and detectivity under the same conditions. A theoretical investigation demonstrates that monolayer Bi shows a semiconducting property on the MXene Ti3C2 that usually yields a strict bandgap match with an incident light, while multilayer (≥2) Bi tends to be conductive, which not only facilitates electron transport but also promotes the generation of photoinduced current by overcoming the work function. The intriguing experimental and theoretical results indicate that 2D MXene Ti3C2Tx NSs can be employed as building blocks to construct many promising hydrides for various photoelectronic devices, further greatly widening the application prospects of 2D MXenes. [ABSTRACT FROM AUTHOR]

MXene as a novel two-dimensional (2D) material exhibits a lot of advantages in nonlinear optics. However, the common MXene, Ti3C2Tx and Ti2CTx nanosheets, easily suffer from degradation under ambient conditions, greatly limiting their practical applications. Here, we demonstrated one of MXene compounds, V2CTx, which has a strong modulation depth (nearly 50%), can serve as an excellent saturable absorber (SA) in passively mode-locked (PML) fiber lasers. More importantly, 206th harmonic order has been successfully generated in Er-doped mode-locked fiber laser, exhibiting maximum repetition rate of 1.01 GHz and pulse duration of 940 fs, which to the best of our knowledge, is the highest harmonic mode-locked fiber laser from the MXene SA so far. In addition, the high harmonic order mode-locked operation can maintain at least 24 h without any noticeable change, suggesting MXene V2CTx nanosheets have excellent stability in this mode-locked fiber laser. It is anticipated that the present work can pave the way to new design for MXene-based heterostructures for high-performance harmonic mode-locked lasers.

MXene is a promising two-dimensional (2D) material that is widely used in electro-photonic devices due to its unique properties. In this contribution, V2CTx, a novel MXene, was employed as a saturable absorber (SA) for hybrid passively mode-locked fiber lasers. An ultra-stable and self-starting mode-locked laser system with low threshold can be achieved using V2CTx nanosheets and nonlinear polarization evolution (NPE). Signal to noise ratio increased 13 dB compared with using only NPE SA. A 72 fs pulse duration is easily achieved from this hybrid mode-locked fiber laser system. To the best of our knowledge, this is the shortest pulse duration generated from the Yb-doped mode-locked fiber lasers using a hybrid or 2D SAs. This study proves that MXene V2CTx nanosheets can be developed as suitable SAs and served as potential advanced ultrafast photonic devices in the future.

Members of the tristetraprolin (TTP) family of CCCH tandem zinc finger proteins bind to AU-rich regions in target mRNAs, leading to their deadenylation and decay. Family members in Saccharomyces cerevisiae influence iron metabolism, whereas the single protein expressed in Schizosaccharomyces pombe, Zfs1, regulates cell-cell interactions. In the human pathogen Candida albicans, deep sequencing of mutants lacking the orthologous protein, Zfs1, revealed significant increases (> 1.5-fold) in 156 transcripts. Of these, 113 (72%) contained at least one predicted TTP family member binding site in their 3'UTR, compared with only 3 of 56 (5%) down-regulated transcripts. The zfs1Δ/Δ mutant was resistant to 3-amino-1,2,4-triazole, perhaps because of increased expression of the potential target transcript encoded by HIS3. Sequences of the proteins encoded by the putative Zfs1 targets were highly conserved among other species within the fungal CTG clade, while the predicted Zfs1 binding sites in these mRNAs often 'disappeared' with increasing evolutionary distance from the parental species. C. albicans Zfs1 bound to the ideal mammalian TTP binding site with high affinity, and Zfs1 was associated with target transcripts after co-immunoprecipitation. Thus, the biochemical activities of these proteins in fungi are highly conserved, but Zfs1-like proteins may target different transcripts in each species.

Two-dimensional tin sulfide (SnS), as a black phosphorus-analogue binary semiconductor, has received considerable attention in photonics and optoelectronics. Herein, the third-order nonlinearity susceptibility Im χ3 is enhanced from −(6.88 ± 0.10) × 10−14 esu to −(15.90 ± 0.27) × 10−14 esu by the size-related quantum confinement in layered SnS nanosheets. Due to the energy level alignment, a phonon-bottleneck effect is observed, which leads to a prolonged carrier lifetime. These results provide a platform for actively tuning the linear and nonlinear optics, and pave the way for designing SnS-based tunable and anisotropic optoelectronic devices.

Herein, we present an efficient synthesis method utilizing Bi quantum dots (QDs) as catalysts for the photochemical oxidative coupling of thiols to disulfides under mild conditions. The protocol offers low catalyst loading, simplicity in reaction setup as well as high efficiency. Aromatic thiols and aliphatic thiols are successfully transformed into disulfides with good to quantitative yields, demonstrating tolerance to various substituents and heterocycles. Additionally, the protocol extends to the synthesis of asymmetric disulfides and allows for gram-scale synthesis. An efficient synthesis method utilizing Bi quantum dots (QDs) as catalysts for the photochemical oxidative coupling of thiols to disulfides under mild conditions is reported. The protocol offers low catalyst loading with high efficiency. Symmetric and asymmetric disulfides have been successfully obtained which allows for gram-scale synthesis. [ABSTRACT FROM AUTHOR]

In recent years, deep learning network models have been widely used in the aspect of text emotion classification and have achieved remarkable achievements. The traditional TextCNN network can only extract local spatial features of sentences, while the improved DPCNN model has the ability to capture long-distance dependence of the text by deepening the network depth. At the same time, bi-LSTM model is characterized by learning temporal information of text. Therefore, this paper combines the two models, which can not only obtain the spatial local information of the text, but also further strengthen the ability to understand and learn the semantic association information of the text. Experimental results show that the classification effect of the model used in this paper is better than the single model.