After three-body abrasion, the hardness re-distribution near the worn surface has a close relationship with the carbon content of martensite steel. It is considered that there is a competition between the work-hardeni...After three-body abrasion, the hardness re-distribution near the worn surface has a close relationship with the carbon content of martensite steel. It is considered that there is a competition between the work-hardening and the temper softening, which results from deformation and friction heat of material. When the carbon content of martensite steel is below about 0.6%, the subsurface hardness distribution of material is a softened layer sandwiched between two hardened layers, but above 0.6%C, no softened region appears on the hardness re-distribution curve.展开更多
The N_(b)-bromomethyl derivative (2) of gelsemine,a quaternary ammonium salt,was found to be recalcitrant toward Hofmann type alkaline degradation which has been successful in other cases.Instead,a re-distribution of ...The N_(b)-bromomethyl derivative (2) of gelsemine,a quaternary ammonium salt,was found to be recalcitrant toward Hofmann type alkaline degradation which has been successful in other cases.Instead,a re-distribution of the N-methyl group took place,giving rise to 3a,1,3b and 3c,in descending order of R_f values.展开更多
Automatically detecting learners’engagement levels helps to develop more effective online teaching and assessment programs,allowing teachers to provide timely feedback and make personalized adjustments based on stude...Automatically detecting learners’engagement levels helps to develop more effective online teaching and assessment programs,allowing teachers to provide timely feedback and make personalized adjustments based on students’needs to enhance teaching effectiveness.Traditional approaches mainly rely on single-frame multimodal facial spatial information,neglecting temporal emotional and behavioural features,with accuracy affected by significant pose variations.Additionally,convolutional padding can erode feature maps,affecting feature extraction’s representational capacity.To address these issues,we propose a hybrid neural network architecture,the redistributing facial features and temporal convolutional network(RefEIP).This network consists of three key components:first,utilizing the spatial attention mechanism large kernel attention(LKA)to automatically capture local patches and mitigate the effects of pose variations;second,employing the feature organization and weight distribution(FOWD)module to redistribute feature weights and eliminate the impact of white features and enhancing representation in facial feature maps.Finally,we analyse the temporal changes in video frames through the modern temporal convolutional network(ModernTCN)module to detect engagement levels.We constructed a near-infrared engagement video dataset(NEVD)to better validate the efficiency of the RefEIP network.Through extensive experiments and in-depth studies,we evaluated these methods on the NEVD and the Database for Affect in Situations of Elicitation(DAiSEE),achieving an accuracy of 90.8%on NEVD and 61.2%on DAiSEE in the fourclass classification task,indicating significant advantages in addressing engagement video analysis problems.展开更多
This statistics-based study shows that in China the urban-rural income gap is contributing more to general income inequality than regional income gaps are. The regional income disparity sets in an east-west plus centr...This statistics-based study shows that in China the urban-rural income gap is contributing more to general income inequality than regional income gaps are. The regional income disparity sets in an east-west plus central contrast while the urban-rural gap is most significantly present in the west and central areas between the cities and the countryside. Rural migrant laborers have helped shrink the urban-rural and regional income gaps. However, when the economy is hit by the global financial crisis to slow, a number of public actions are crucial and urgent to reduce income inequality and enhance social stability. The actions would include an immediate social bail-out and provisions for social security for rural-based migrants currently working in the cities, employment programs targeting low-income group as well as encouraging entrepreneurship.展开更多
Site measurements have shown that slab loads re-distribute, between the slabs during the concrete curing, while the external Ioadings and structural geometry remain the same. Some have assumed that this is caused by c...Site measurements have shown that slab loads re-distribute, between the slabs during the concrete curing, while the external Ioadings and structural geometry remain the same. Some have assumed that this is caused by concrete shrinkage and creep, but there have been no studies on how these factors exactly influence the load distributions and to what degree these influences exist. This paper analyzes the influences of concrete shrinkage, creep, and temperature on the load re-distributions among slabs. Although these factors may all lead to load re-distribution, the results show that the influence of concrete shrinkage can be neglected. Simulations indicate that shrinkage only reduces slab loads by a maximum of 1.1%. Creep, however, may reduce the maximum slab load by from 3% to 16% for common construction schemes. More importantly, temperature variations between day and night can cause load fluctuation as large as 31.6%. This analysis can, therefore, assist site engineers to more accurately estimate slab loads for construction planning.展开更多
文摘After three-body abrasion, the hardness re-distribution near the worn surface has a close relationship with the carbon content of martensite steel. It is considered that there is a competition between the work-hardening and the temper softening, which results from deformation and friction heat of material. When the carbon content of martensite steel is below about 0.6%, the subsurface hardness distribution of material is a softened layer sandwiched between two hardened layers, but above 0.6%C, no softened region appears on the hardness re-distribution curve.
文摘The N_(b)-bromomethyl derivative (2) of gelsemine,a quaternary ammonium salt,was found to be recalcitrant toward Hofmann type alkaline degradation which has been successful in other cases.Instead,a re-distribution of the N-methyl group took place,giving rise to 3a,1,3b and 3c,in descending order of R_f values.
基金supported by the National Natural Science Foundation of China(No.62367006)the Graduate Innovative Fund of Wuhan Institute of Technology(Grant No.CX2023551).
文摘Automatically detecting learners’engagement levels helps to develop more effective online teaching and assessment programs,allowing teachers to provide timely feedback and make personalized adjustments based on students’needs to enhance teaching effectiveness.Traditional approaches mainly rely on single-frame multimodal facial spatial information,neglecting temporal emotional and behavioural features,with accuracy affected by significant pose variations.Additionally,convolutional padding can erode feature maps,affecting feature extraction’s representational capacity.To address these issues,we propose a hybrid neural network architecture,the redistributing facial features and temporal convolutional network(RefEIP).This network consists of three key components:first,utilizing the spatial attention mechanism large kernel attention(LKA)to automatically capture local patches and mitigate the effects of pose variations;second,employing the feature organization and weight distribution(FOWD)module to redistribute feature weights and eliminate the impact of white features and enhancing representation in facial feature maps.Finally,we analyse the temporal changes in video frames through the modern temporal convolutional network(ModernTCN)module to detect engagement levels.We constructed a near-infrared engagement video dataset(NEVD)to better validate the efficiency of the RefEIP network.Through extensive experiments and in-depth studies,we evaluated these methods on the NEVD and the Database for Affect in Situations of Elicitation(DAiSEE),achieving an accuracy of 90.8%on NEVD and 61.2%on DAiSEE in the fourclass classification task,indicating significant advantages in addressing engagement video analysis problems.
基金adapted from the key research project titled "Harmonious Society and Social Equity Policy Options" conducted by the research team of the Institute of Economics of the Chinese Academy of Social Sciences(CASS)
文摘This statistics-based study shows that in China the urban-rural income gap is contributing more to general income inequality than regional income gaps are. The regional income disparity sets in an east-west plus central contrast while the urban-rural gap is most significantly present in the west and central areas between the cities and the countryside. Rural migrant laborers have helped shrink the urban-rural and regional income gaps. However, when the economy is hit by the global financial crisis to slow, a number of public actions are crucial and urgent to reduce income inequality and enhance social stability. The actions would include an immediate social bail-out and provisions for social security for rural-based migrants currently working in the cities, employment programs targeting low-income group as well as encouraging entrepreneurship.
基金Supported by the National Nature Science Foundation of China (Nos.50378051,70172005,and 70572007)Excellent Young Teacher Program of Ministry of Education of Chinathe National Science and Technology Planning Project (No.2006BAJ01B04-03)
文摘Site measurements have shown that slab loads re-distribute, between the slabs during the concrete curing, while the external Ioadings and structural geometry remain the same. Some have assumed that this is caused by concrete shrinkage and creep, but there have been no studies on how these factors exactly influence the load distributions and to what degree these influences exist. This paper analyzes the influences of concrete shrinkage, creep, and temperature on the load re-distributions among slabs. Although these factors may all lead to load re-distribution, the results show that the influence of concrete shrinkage can be neglected. Simulations indicate that shrinkage only reduces slab loads by a maximum of 1.1%. Creep, however, may reduce the maximum slab load by from 3% to 16% for common construction schemes. More importantly, temperature variations between day and night can cause load fluctuation as large as 31.6%. This analysis can, therefore, assist site engineers to more accurately estimate slab loads for construction planning.
