作者机构:
[Xu, Jun; Li, Xintao; Zheng, Kaihong; Pan, Fusheng; Kang, Yuehua; Zhou, Nan] Guangdong Acad Sci, Inst New Mat, Guangzhou 510650, Peoples R China.;[Zhao, Jun] Hunan City Univ, Sch Mech & Elect Engn, Yiyang 413002, Peoples R China.;[Yang, Hong; Jiang, Bin; Pan, Fusheng] Chongqing Univ, Coll Mat Sci & Engn, Natl Engn Res Ctr Magnesium Alloys, Chongqing 400044, Peoples R China.;[Yang, Hong; Jiang, Bin; Pan, Fusheng] Chongqing Inst Adv Light Met, Chongqing 400030, Peoples R China.;[Liu, Wenjun] Chongqing Univ Technol, Coll Mat Sci & Engn, Chongqing, Peoples R China.
通讯机构:
[Jun Xu] I;[Bin Jiang] N;Institute of New Materials, Guangdong Academy of Sciences, Guangzhou, China<&wdkj&>National Engineering Research Center for Magnesium Alloys, College of Materials Science and Engineering, Chongqing University, Chongqing, China<&wdkj&>Chongqing Institute for Advanced Light Metals, Chongqing, China
摘要:
Mg-3Al-1Zn (AZ31) sheets were produced by transverse gradient extrusion (TGE) process. The flow behavior and dynamic recrystallization during extrusion were systematically analyzed. The microstructures, textures, and mechanical behavior of extruded AZ31 sheet were also analyzed and compared with conventional extruded (CE) sheet. The results showed that fine grain structure and multi-type unique textures were formed in TGE sheet because of the generation of extra flow velocity along transverse direction (TD) and flow velocity gradient along extrusion direction (ED) during extrusion. The basal poles gradually deviated away normal direction (ND) from edge to center of the TGE sheet along TD, and the largest inclination angle at center region reached around 65 degrees. Furthermore, the basal poles inclined from ED to TD 40 degrees-63 degrees, except for the center region of TGE sheet. The TGE sheet presented higher ductility and strain hardening exponent (n-value), but lower yield strength and Lankford value (r-value) in comparison with the CE sheet. Both the basal <a> slip and tensile twins were easy to be activated during deformation, and the largest elongation of 41% and the lowest yield strength of 86.5 MPa were obtained for the ED-center sample in the TGE sheet.
摘要:
Super-hard abrasive grinding is considered to be the main approach to realize precision and ultra-precision machining of difficult-to-machine materials such as cemented carbide, engineering ceramics, titanium alloys and superalloy materials encountered. However, heavy grinding force, high grinding temperature and poor surface integrity are prone to be encountered in conventional negative rake angle grinding of difficult-to-machine materials. In response to these problems, a novel concept of positive rake angle grinding is first proposed and an abrasive grain regularly arranged binder-less polycrystalline diamond face grinding wheel with positive rake angle has been designed and fabricated by femtosecond laser ablation. To evaluate the grinding performance of the face grinding wheel with positive rake angle, grinding experiments of YG8 cemented carbide are conducted and compared with the traditional electroplated diamond grinding tool with equivalent abrasive grain dimension and distribution. The results show that compared with the conventional negative rake angle grinding, the normal and tangential forces in positive rake angle face grinding are reduced by 30.3 % similar to 36.4 % and 21.1 % similar to 29.3 %, respectively, and the ratio of normal to tangential force is reduced by 12.6 % similar to 20.3 %. The surface roughness and average depth of subsurface metamorphic layer are also significantly smaller. The laser fabricated polycrystalline diamond face grinding wheel also has better wear resistance in the grinding of cemented carbide. Therefore, it can be concluded that better ground surface quality is obtained by the novel grinding wheel with positive rake angle. The innovative grinding method can fill the research gap on the grinding mechanism of positive rake angle grinding and further enrich the grinding theory of difficult-to-machine materials.
摘要:
Background and objective: Traditional disease diagnosis is usually performed by experienced physicians, but misdiagnosis or missed diagnosis still exists. Exploring the relationship between changes in the cor-pus callosum and multiple brain infarcts requires extracting corpus callosum features from brain image data, which requires addressing three key issues. (1) automation, (2) completeness, and (3) accuracy. Residual learning can facilitate network training, Bi-Directional Convolutional L STM (BDC-L STM) can ex-ploit interlayer spatial dependencies, and HDC can expand the receptive domain without losing resolu-tion.Methods: In this paper, we propose a segmentation method by combining BDC-LSTM and U-Net to seg-ment the corpus callosum from multiple angles of brain images based on computed tomography (CT) and magnetic resonance imaging (MRI) in which two types of sequence, namely T2-weighted imaging as well as the Fluid Attenuated Inversion Recovery (Flair), were utilized. The two-dimensional slice sequences are segmented in the cross-sectional plane, and the segmentation results are combined to obtain the final re-sults. Encoding, BDC-LSTM, and decoding include convolutional neural networks. The coding part uses asymmetric convolutional layers of different sizes and dilated convolutions to get multi-slice information and extend the convolutional layers' perceptual field.Results: This paper uses BDC-LSTM between the encoding and decoding parts of the algorithm. On the image segmentation of the brain in multiple cerebral infarcts dataset, accuracy rates of 0.876, 0.881, 0.887, and 0.912 were attained for the intersection of union (IOU), dice similarity coefficient (DS), sensitivity (SE), and predictive positivity value (PPV). The experimental findings demonstrate that the algorithm out-performs its rivals in accuracy.Conclusion: This paper obtained segmentation results for three images using three models, ConvLSTM, Pyramid-L STM, and BDC-L STM, and compared them to verify that BDC-LSTM is the best method to per-form the segmentation task for faster and more accurate detection of 3D medical images. We improve the convolutional neural network segmentation method to obtain medical images with high segmenta-tion accuracy by solving the over-segmentation problem.& COPY; 2023 Elsevier B.V. All rights reserved.
作者:
Xiao, Jun;Gong, Yanping;Li, Jian;Javeed, Sohail Ahmad;Peng, Yao
期刊:
Heliyon,2023年9(8):e18347 ISSN:2405-8440
通讯作者:
Javeed, SA;Li, J
作者机构:
[Xiao, Jun; Gong, Yanping] Cent South Univ, Sch Business, Changsha 410083, Peoples R China.;[Xiao, Jun; Javeed, Sohail Ahmad] Hunan City Univ, Sch Management, Yiyang 413000, Peoples R China.;[Li, Jian] Anhui Univ, Sch Business, Hefei 230601, Peoples R China.;[Peng, Yao] CITIC Bank Credit Card Ctr, Shenzhen 518000, Peoples R China.
通讯机构:
[Li, J ] A;[Javeed, SA ] H;Hunan City Univ, Sch Management, Yiyang 413000, Peoples R China.;Anhui Univ, Sch Business, Hefei 230601, Peoples R China.
关键词:
Work-family conflict;Self-control;Hedonic products;Utilitarian products;Frugality;The strength model of self-control
摘要:
Despite the high incidence of work-family conflict, there has been a lack of research that investigates its impact on employee behavior, particularly concerning their consumption behavior, which has received inadequate attention. The present study draws on the strength model of self-control and investigates the influence of individuals' work-family conflict on their preferences for hedonic and utilitarian products via self-control, with frugality acting as a moderator of this relationship. This study gathered data from 502 full-time employees with families in China. Results from the moderated mediating model analysis conducted using the SPSS-PROCESS macro revealed that work-family conflict was positively associated with a preference for hedonic products and negatively associated with a preference for utilitarian products. Self-control was found to mediate the relationship between work-family conflict and product preferences, with a weaker mediating effect observed for individuals with higher levels of frugality in the case of utilitarian products. The findings of this study contribute to the literature on work-family conflict and have implications for organizations and merchants in understanding and addressing the impact of work-family conflict on employee consumption behavior. Specifically, this study provides insight into how organizations can better manage work-family conflict and how merchants can make more informed marketing decisions for hedonic and utilitarian products.
摘要:
The fatigue crack propagation behaviour of Q550E high-performance steel (HPS) is studied in this paper. Static tensile testing and fatigue crack propagation testing were carried out, and the results were compared with those of Q235. Finite element models were developed and verified against the experimental results. The impacts of the initial crack angle, crack depth ratio, stress ratio, thickness, and corrosion pitting on the fatigue crack propagation behaviour of the HPS were analysed. The results show that the fatigue life of Q550 was reduced by 18% due to the corrosion pitting, but it did not change the crack propagation path. When the stress intensity factor is higher than a certain value, the fatigue performance of Q235 is better than that of Q550E. The initial crack angle of 52.5 & DEG; is the critical angle of the crack stress intensity factor. The steel tends to fracture as the crack depth ratio increases, and more attention should be paid to the effective crack length in engineering practice. An increasing stress ratio leads to a smaller stress intensity factor, and the thickness affects the stress intensity factor in the later stage. The crack stress intensity factor around the corrosion pits gradually decreases along the thickness direction, and the crack tips around the corrosion pits tend to reach the yield state initially, accelerating the fatigue fracture of the specimen and ultimately leading to a decrease in fatigue life.
期刊:
Water Supply,2023年23(11):4682–4690. ISSN:1606-9749
通讯作者:
Du, LY
作者机构:
[Du, Linyuan; Du, LY] Hunan City Univ, Sch Humanities, Yiyang 413000, Hunan, Peoples R China.
通讯机构:
[Du, LY ] H;Hunan City Univ, Sch Humanities, Yiyang 413000, Hunan, Peoples R China.
关键词:
agricultural water management;drought;irrigation efficiency;water footprint
摘要:
The increasing use of water and the decrease in average rainfall along with climate change have caused the reduction of water resources in arid and semi-arid regions. In addition, despite the consumption of more than half of these resources in the agricultural sector, a rate between 0 and 15% of the price of the products has always been received from the farmers. Considering the concept of virtual water and the water content of products in the form of green water, blue water and gray water, the present research has calculated the economic value of virtual water of agricultural products with the approach of maximizing water use efficiency. The investigated sample includes eight cities (counties) of Sanmenxia, Jiaozuo, Nanyang, Shangqiu, Puyang, Luohe, Luoyang and Kaifeng and six agricultural products (wheat, barley, potato, rapeseed, tomato and corn). A fuzzy dynamic programming model has been used to evaluate the objective function. The results showed that the maximum and minimum economic value of water content (sum of surface and groundwater) of the products were estimated for Kaifeng and Shangqiu regions equal to 1.16 and 0.86 Yuan/m3, respectively.
作者机构:
[Li, Wanting; Huang, Zhiliang; Peng, Li; Yang, Jingyu; Yang, Tongguang] Hunan City Univ, Key Lab Smart City Energy Sensing & Edge Comp Huna, Yiyang 413000, Peoples R China.
通讯机构:
[Li, WT ] H;Hunan City Univ, Key Lab Smart City Energy Sensing & Edge Comp Huna, Yiyang 413000, Peoples R China.
摘要:
To improve the short-term wind power output prediction accuracy and overcome the model prediction instability problem, we propose a combined prediction model based on variational modal decomposition (VMD) combined with the improved whale algorithm (GSWOA) to optimize the long short-term memory network (LSTM) short-term wind power. First, VMD is utilized to decompose the wind power input sequence into modal components of different complexities, and the components are reconstructed into subcomponents with typical characteristics through approximate entropy, which reduces the computational scale of non-smooth sequence analysis. Second, the GSWOA is used to optimize the main influencing parameters of the LSTM model in order to obtain the weights and thresholds under the optimal LSTM model and to use the reconstructed individual subsequences. Finally, the actual data from two wind farms in Xinjiang and Northeast China are taken to verify the generalizability of the proposed model. The comparative analysis of the prediction results under different scenarios demonstrates that the improved model shows higher performance than the original model. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).