The consultation intention of emergency decision-makers in urban rail transit(URT)is input into the emergency knowledge base in the form of domain questions to obtain emergency decision support services.This approach ...The consultation intention of emergency decision-makers in urban rail transit(URT)is input into the emergency knowledge base in the form of domain questions to obtain emergency decision support services.This approach facilitates the rapid collection of complete knowledge and rules to form effective decisions.However,the current structured degree of the URT emergency knowledge base remains low,and the domain questions lack labeled datasets,resulting in a large deviation between the consultation outcomes and the intended objectives.To address this issue,this paper proposes a question intention recognition model for the URT emergency domain,leveraging knowledge graph(KG)and data enhancement technology.First,a structured storage of emergency cases and emergency plans is realized based on KG.Subsequently,a comprehensive question template is developed,and the labeled dataset of emergency domain questions in URT is generated through the KG.Lastly,data enhancement is applied by prompt learning and the NLP Chinese Data Augmentation(NLPCDA)tool,and the intention recognition model combining Generalized Auto-regression Pre-training for Language Understanding(XLNet)and Recurrent Convolutional Neural Network for Text Classification(TextRCNN)is constructed.Word embeddings are generated by XLNet,context information is further captured using Bidirectional Long Short-Term Memory Neural Network(BiLSTM),and salient features are extracted with Convolutional Neural Network(CNN).Experimental results demonstrate that the proposed model can enhance the clarity of classification and the identification of domain questions,thereby providing supportive knowledge for emergency decision-making in URT.展开更多
Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was propos...Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was proposed to prepare the target Al-Si-Mg aluminum alloy.Based on the synchronous deposition of AlSi_(12) wire and pure Mg powder,the deposition width of the WPAAMed thin-wall was increased by 61% compared with that of WAAMed thin-wall using AlSi_(12) wire,and the machining allowance was reduced by 81%.The added Mg powder benefited to form refined equiaxed grains,and reduced the average grain size of the WPAAMed thin-wall to 47.1μm,showing a decrease of 23.8% relatively to that of the WAAMed thin-wall.Besides,Mg reacted with Si to form Mg_(2)Si strengthening phases.The mechanical properties tests showed that the ultimate tensile strength and elongation of the WPAAMed thin-wall increased up to 174.5 MPa and 4.1%,reaching 92% and 60% those of the WAAMed thin-wall,respectively.展开更多
The structural design of n-i-p in antimony selenide(Sb_(2)Se_(3))thin film solar cells can effectively improve the low carrier collection efficiency caused by the lower doping concentration of Sb_(2)Se_(3).However,the...The structural design of n-i-p in antimony selenide(Sb_(2)Se_(3))thin film solar cells can effectively improve the low carrier collection efficiency caused by the lower doping concentration of Sb_(2)Se_(3).However,the unideal carrier transport ability of the intrinsic light-absorbing layer remains a major limitation for its power conversion efficiency improvement.Herein,it is discovered that the carrier transport in Sb_(2)Se_(3)thin films strongly depends on the film thickness of the absorber layer in n-i-p structure.By exploring the carrier transport mechanism under different thicknesses of light-absorbing layers,a suitable absorber layer with thickness of 550 nm is demonstrated can effectively separate,transport,and extract photogenerated carriers in Sb_(2)Se_(3)solar cells.Finally,the vapor transport deposition processed Sb_(2)Se_(3)solar cells achieve the highest PCE of 7.62%with a short-circuit current density of 30.71 mA·cm^(-2).This finding provides a constructive guidance for the future researches on Sb_(2)Se_(3)thin film solar cells with n-i-p structure.展开更多
基金supported in part by the National Natural Science Foundation of China.The funding numbers 62433005,62272036,62132003,and 62173167.
文摘The consultation intention of emergency decision-makers in urban rail transit(URT)is input into the emergency knowledge base in the form of domain questions to obtain emergency decision support services.This approach facilitates the rapid collection of complete knowledge and rules to form effective decisions.However,the current structured degree of the URT emergency knowledge base remains low,and the domain questions lack labeled datasets,resulting in a large deviation between the consultation outcomes and the intended objectives.To address this issue,this paper proposes a question intention recognition model for the URT emergency domain,leveraging knowledge graph(KG)and data enhancement technology.First,a structured storage of emergency cases and emergency plans is realized based on KG.Subsequently,a comprehensive question template is developed,and the labeled dataset of emergency domain questions in URT is generated through the KG.Lastly,data enhancement is applied by prompt learning and the NLP Chinese Data Augmentation(NLPCDA)tool,and the intention recognition model combining Generalized Auto-regression Pre-training for Language Understanding(XLNet)and Recurrent Convolutional Neural Network for Text Classification(TextRCNN)is constructed.Word embeddings are generated by XLNet,context information is further captured using Bidirectional Long Short-Term Memory Neural Network(BiLSTM),and salient features are extracted with Convolutional Neural Network(CNN).Experimental results demonstrate that the proposed model can enhance the clarity of classification and the identification of domain questions,thereby providing supportive knowledge for emergency decision-making in URT.
基金supported by the National Natural Science Foundation of China(No.52205360)。
文摘Owing to the lack of matching commercial welding wires,the development of wire arc additive manufacturing(WAAM)for most aluminum alloys is hindered.A wire-powder synchronous arc additive manufacturing(WPAAM)was proposed to prepare the target Al-Si-Mg aluminum alloy.Based on the synchronous deposition of AlSi_(12) wire and pure Mg powder,the deposition width of the WPAAMed thin-wall was increased by 61% compared with that of WAAMed thin-wall using AlSi_(12) wire,and the machining allowance was reduced by 81%.The added Mg powder benefited to form refined equiaxed grains,and reduced the average grain size of the WPAAMed thin-wall to 47.1μm,showing a decrease of 23.8% relatively to that of the WAAMed thin-wall.Besides,Mg reacted with Si to form Mg_(2)Si strengthening phases.The mechanical properties tests showed that the ultimate tensile strength and elongation of the WPAAMed thin-wall increased up to 174.5 MPa and 4.1%,reaching 92% and 60% those of the WAAMed thin-wall,respectively.
基金supported by the National Natural Science Foundation of China(No.62305064)the Beijing Nova Program from Beijing Municipal Science&Technology Commission(No.Z211100002121072).
文摘The structural design of n-i-p in antimony selenide(Sb_(2)Se_(3))thin film solar cells can effectively improve the low carrier collection efficiency caused by the lower doping concentration of Sb_(2)Se_(3).However,the unideal carrier transport ability of the intrinsic light-absorbing layer remains a major limitation for its power conversion efficiency improvement.Herein,it is discovered that the carrier transport in Sb_(2)Se_(3)thin films strongly depends on the film thickness of the absorber layer in n-i-p structure.By exploring the carrier transport mechanism under different thicknesses of light-absorbing layers,a suitable absorber layer with thickness of 550 nm is demonstrated can effectively separate,transport,and extract photogenerated carriers in Sb_(2)Se_(3)solar cells.Finally,the vapor transport deposition processed Sb_(2)Se_(3)solar cells achieve the highest PCE of 7.62%with a short-circuit current density of 30.71 mA·cm^(-2).This finding provides a constructive guidance for the future researches on Sb_(2)Se_(3)thin film solar cells with n-i-p structure.
