Introduction Aortic arch anomalies are congenital malformations of the position or branching of the aortic arch,or both.Double aortic arch(DAA)is a very rare malformation,affecting approximately 0.005%~0.007% of fetus...Introduction Aortic arch anomalies are congenital malformations of the position or branching of the aortic arch,or both.Double aortic arch(DAA)is a very rare malformation,affecting approximately 0.005%~0.007% of fetuses[1],and there has been no relevant literature mentioning the prenatal finding DAA in Macao till now.展开更多
Purpose–The wavelet neural network(WNN)has the drawbacks of slow convergence speed and easy falling into local optima in data prediction.Although the artificial bee colony(ABC)algorithm has strong global optimization...Purpose–The wavelet neural network(WNN)has the drawbacks of slow convergence speed and easy falling into local optima in data prediction.Although the artificial bee colony(ABC)algorithm has strong global optimization ability and fast convergence speed,it also has the drawbacks of slow speed while finding the optimal solution and weak optimization ability in the later stage.Design/methodology/approach–This article uses an ABC algorithm to optimize the WNN and establishes an ABC-WNN analysis model.Based on the example of the Jinan Yuhan underground tunnel project,the deformation of the surrounding rock of the double-arch tunnel crossing the fault fracture zone is predicted and analyzed,and the analysis results are compared with the actual detection amount.Findings–The comparison results show that the predicted values of the ABC-WNN model have a high degree of fitting with the actual engineering data,with a maximum relative error of only 4.73%.On this basis,the results show that the statistical features of ABC-WNN are the lowest,with the errors at 0.566 and 0.573,compared with the single back propagation(BP)neural network model and WNN model.Therefore,it can be derived that the ABC-WNN model has higher prediction accuracy,better computational stability and faster convergence speed for deformation.Originality/value–This article uses firstly the ABC-WNN for the deformation analysis of double-arch tunnels.This attempt laid the foundation for artificial intelligence prediction in deformation analysis of multiarch tunnels and small clearance tunnels.It can provide a new and effective way for deformation prediction in similar projects.展开更多
By the end of 1997, totally ten 300 MW grade W-flame double arch boilers, firing anthracite or meager coal, were operating in China. These W-flame boilers were designed and supplied separately by four different manufa...By the end of 1997, totally ten 300 MW grade W-flame double arch boilers, firing anthracite or meager coal, were operating in China. These W-flame boilers were designed and supplied separately by four different manufacturers in the world, using either their own technology or foreign patent. It is shown by a recent survey that all these boilers are having a normal operation. However, there is still some room to be improved, such as boiler furnace configuration. Also, for raising the burnout rate and avoiding local slagging, furnace volume and burner layout need to be deliberated. And the tineness of pulverized coal and the air / coal ratio need to be improved. Some suggestions are made in this paper for optimizing the boiler design, Test data for the minimum stable combustion load and NOx emission are given too.展开更多
Double aortic arch is a common form of complete vascular ring that encircles both the trachea and the esophagus, and presents with various respiratory and esophageal symptoms, usually in the pediatric population. We p...Double aortic arch is a common form of complete vascular ring that encircles both the trachea and the esophagus, and presents with various respiratory and esophageal symptoms, usually in the pediatric population. We present a case of double aortic arch in an adult patient that manifested as massive upper gastrointestinal bleeding after prolonged nasogastric intubation.展开更多
Introduction: Double aortic arch (DAA) is the most frequently encountered vascular ring malformation characterized by a complete encirclement of the trachea and esophagus by the aortic arch with a wide clinical spectr...Introduction: Double aortic arch (DAA) is the most frequently encountered vascular ring malformation characterized by a complete encirclement of the trachea and esophagus by the aortic arch with a wide clinical spectrum. Objective: The aim of this study is to describe a case of DAA in adolesecents. Case Presentation: An 11-year-old boy was admitted for chronic productive cough which initially was diagnosed with pulmonary arterial hypertension. The final diagnosis was DAA which was established after chest computed tomography (CT) scan. Conclusion: Establishing a diagnosis of DAA in adolescents requires thorough understanding and clinical skills in performing diagnostic steps. The management of heart failure symptoms and other comorbidities is essential while preparing for its definite therapy.展开更多
Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the mini...Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the minimally invasive surgical technique(MIST).Methods:We retrospectively reviewed 7 cases of DAA-LAAA that were treated from January 2017 to July 2021.All infant patients underwent surgical repair by minimally invasive surgical technique.Mean follow-up was 14.43 months(range,5–21 months).Results:There were seven patients with DAA-LAAA,including six males and one female.Median age was 19.29 months(range,9.0–29.0 months).Median weight was 11.30 kg(range,9.6–13.0 kg).Three patients were found severe tracheal compression by cardiac computed tomography angiography(cCTA).Six patients with isolated DAA-LAAA were performed operations through left subaxillary minithoracotomy,and one patient with ventricular septal defect(VSD)was performed operation concurrently under the cardiopulmonary bypass(CPB)through right subaxillary minithoracotomy.All patients had symptom improvement in the postoperative period and discharged successfully.Follow-up data showed good results in short-term.Conclusions:We introduce a new surgical pathway for DAA-LAAA treatment with good symptomatic relief in short-term.MIST is a safe,feasible and economical approach for infant patients.展开更多
Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam ...Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C＋＋ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.展开更多
文摘Introduction Aortic arch anomalies are congenital malformations of the position or branching of the aortic arch,or both.Double aortic arch(DAA)is a very rare malformation,affecting approximately 0.005%~0.007% of fetuses[1],and there has been no relevant literature mentioning the prenatal finding DAA in Macao till now.
基金funded by the Natural Science Foundation of Hebei Province(No:E2020210068)Project of Science and Technology Research and Development Program of China National Railway Group Co.,Ltd.(No:N2020G009).
文摘Purpose–The wavelet neural network(WNN)has the drawbacks of slow convergence speed and easy falling into local optima in data prediction.Although the artificial bee colony(ABC)algorithm has strong global optimization ability and fast convergence speed,it also has the drawbacks of slow speed while finding the optimal solution and weak optimization ability in the later stage.Design/methodology/approach–This article uses an ABC algorithm to optimize the WNN and establishes an ABC-WNN analysis model.Based on the example of the Jinan Yuhan underground tunnel project,the deformation of the surrounding rock of the double-arch tunnel crossing the fault fracture zone is predicted and analyzed,and the analysis results are compared with the actual detection amount.Findings–The comparison results show that the predicted values of the ABC-WNN model have a high degree of fitting with the actual engineering data,with a maximum relative error of only 4.73%.On this basis,the results show that the statistical features of ABC-WNN are the lowest,with the errors at 0.566 and 0.573,compared with the single back propagation(BP)neural network model and WNN model.Therefore,it can be derived that the ABC-WNN model has higher prediction accuracy,better computational stability and faster convergence speed for deformation.Originality/value–This article uses firstly the ABC-WNN for the deformation analysis of double-arch tunnels.This attempt laid the foundation for artificial intelligence prediction in deformation analysis of multiarch tunnels and small clearance tunnels.It can provide a new and effective way for deformation prediction in similar projects.
文摘By the end of 1997, totally ten 300 MW grade W-flame double arch boilers, firing anthracite or meager coal, were operating in China. These W-flame boilers were designed and supplied separately by four different manufacturers in the world, using either their own technology or foreign patent. It is shown by a recent survey that all these boilers are having a normal operation. However, there is still some room to be improved, such as boiler furnace configuration. Also, for raising the burnout rate and avoiding local slagging, furnace volume and burner layout need to be deliberated. And the tineness of pulverized coal and the air / coal ratio need to be improved. Some suggestions are made in this paper for optimizing the boiler design, Test data for the minimum stable combustion load and NOx emission are given too.
文摘Double aortic arch is a common form of complete vascular ring that encircles both the trachea and the esophagus, and presents with various respiratory and esophageal symptoms, usually in the pediatric population. We present a case of double aortic arch in an adult patient that manifested as massive upper gastrointestinal bleeding after prolonged nasogastric intubation.
文摘Introduction: Double aortic arch (DAA) is the most frequently encountered vascular ring malformation characterized by a complete encirclement of the trachea and esophagus by the aortic arch with a wide clinical spectrum. Objective: The aim of this study is to describe a case of DAA in adolesecents. Case Presentation: An 11-year-old boy was admitted for chronic productive cough which initially was diagnosed with pulmonary arterial hypertension. The final diagnosis was DAA which was established after chest computed tomography (CT) scan. Conclusion: Establishing a diagnosis of DAA in adolescents requires thorough understanding and clinical skills in performing diagnostic steps. The management of heart failure symptoms and other comorbidities is essential while preparing for its definite therapy.
基金This study was supported by the CAMS Innovation Fund for Medical Sciences(CIFMS)[2020-I2M-C&T-A-009]the National Key R&D Program of China[2017YFC1308100].
文摘Background:Double aortic arch(DAA)with distal left-sided aortic arch atresia(LAAA)can form complete vascular ring by ligamentum connection.We aimed to introduce an uncommon DAA-LAAA diagnosis and treatment by the minimally invasive surgical technique(MIST).Methods:We retrospectively reviewed 7 cases of DAA-LAAA that were treated from January 2017 to July 2021.All infant patients underwent surgical repair by minimally invasive surgical technique.Mean follow-up was 14.43 months(range,5–21 months).Results:There were seven patients with DAA-LAAA,including six males and one female.Median age was 19.29 months(range,9.0–29.0 months).Median weight was 11.30 kg(range,9.6–13.0 kg).Three patients were found severe tracheal compression by cardiac computed tomography angiography(cCTA).Six patients with isolated DAA-LAAA were performed operations through left subaxillary minithoracotomy,and one patient with ventricular septal defect(VSD)was performed operation concurrently under the cardiopulmonary bypass(CPB)through right subaxillary minithoracotomy.All patients had symptom improvement in the postoperative period and discharged successfully.Follow-up data showed good results in short-term.Conclusions:We introduce a new surgical pathway for DAA-LAAA treatment with good symptomatic relief in short-term.MIST is a safe,feasible and economical approach for infant patients.
基金Supported by Postgraduate education innovation fund of Chongqing Jiaotong University 2010
文摘Because of its good condition with mechanics, logarithmic spiral double curve arch bam has been widely used in the practical engineering. The introduction of a new method in how to divide transverse joint in arch dam will be given and the further research of its calculation has been done. The C＋＋ is used in electronic procedure and the 3D simulation has been finished with AutoCAD, which will provide the object model for computer simulation of the arch dam and the division of finite element mesh. Meanwhile, this method in dividing the transverse joint in arch dam also can be taken as the calculated basis for the design and calculation of arch dam, construction lofting and the calculation of the work amount.
