The selective catalytic reduction of NOV with NH3 (NH3-SCR) is a very effective technology to control the emission of NOA, and the thermal stability of NH3-SCR catalyst is very important for removal of NOV from diesel...The selective catalytic reduction of NOV with NH3 (NH3-SCR) is a very effective technology to control the emission of NOA, and the thermal stability of NH3-SCR catalyst is very important for removal of NOV from diesel engines. In this work, V2O5/WO3-TiO2 (VWT) and SiO2- doped V2O5/WO3-TiO2 (VWTSi10)) catalysts were prepared by impregnation method and characterized by Brunauer- Emmett-Teller (BET), X-ray diffraction (XRD), Raman, temperature programmed reduction by hydrogen (H2-TPR), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption by ammonia (NH3- TPD). The doping of SiO2 promotes the thermal stability of V2O5/WO3-TiO? for NH3-SCR significantly. After calcination at 650 °C for 50 h, the operation window of 10% SiO2-doped V2O5/WO3-TiO2 is 220-480 °C, while the maximum NOV conversion on V2O5/WO3-TiO2 is about 77%. The presenee of SiO2 obviously blocks the transformation of TiO2 from anatase to rutile and stabilizes the dispersion of VOv and WO3 on the surface. It is available for the existence of V44 and the amount of surface acid sites increases, which inhabits the NH3 oxidation at the high temperature range and promotes NH3-SCR activity.展开更多
Although concern has been recently expressed with regard to the solution to the non-convex problem, convex optimization is still important in machine learning, especially when the situation requires an interpretable m...Although concern has been recently expressed with regard to the solution to the non-convex problem, convex optimization is still important in machine learning, especially when the situation requires an interpretable model. Solution to the convex problem is a global minimum, and the final model can be explained mathematically. Typically, the convex problem is re-casted as a regularized risk minimization problem to prevent overfitting. The cutting plane method (CPM) is one of the best solvers for the convex problem, irrespective of whether the objective function is differentiable or not. However, CPM and its variants fail to adequately address large-scale data-intensive cases because these algorithms access the entire dataset in each iteration, which substantially increases the computational burden and memory cost. To alleviate this problem, we propose a novel algorithm named the mini-batch cutting plane method (MBCPM), which iterates with estimated cutting planes calculated on a small batch of sampled data and is capable of handling large-scale problems. Furthermore, the proposed MBCPM adopts a "sink" operation that detects and adjusts noisy estimations to guarantee convergence. Numerical experiments on extensive real-world datasets demonstrate the effectiveness of MBCPM, which is superior to the bundle methods for regularized risk minimization as well as popular stochastic gradient descent methods in terms of convergence speed.展开更多
Objective:To explore the relationship between acid reflux and esophageal motility in patients with gastroesophageal reflux disease.Methods:From January 2018 to December 2019,80 patients with typical gastroesophageal r...Objective:To explore the relationship between acid reflux and esophageal motility in patients with gastroesophageal reflux disease.Methods:From January 2018 to December 2019,80 patients with typical gastroesophageal reflux symptoms such as reflux and heartburn were randomly selected from the Department of Gastroenterology,First Affiliated Hospital of guangxi university of chinese medicine.The patients were divided into pathological group,sensitive group and physiological group based on the percentage of acid exposure time and reflux-symptom correlation.The GerdQ score,quality of life score,esophageal acid test and esophageal manometry related parameters of the three groups of patients were compared.Results:Compared with the sensitive group and the physiological group,the GerdQ score,DeMeester score,orthostatic acid reflux time,orthostatic acid reflux time,longest acid reflux time and acid reflux times in the pathological group were significantly higher.Sf-36 score,lower esophageal sphincter pressure and effective rate of deglutition were all significantly reduced,with statistically significant differences(P<0.05).Compared with the physiological group,the GerdQ score of the sensitive group was higher.The sf-36 score was low,and the differences were statistically significant(P<0.05).The acid indexes in the sensitive group were higher than those in the physiological group,but the differences were not statistically significant(P>0.05).Compared with the physiological group,the distal contraction integral and the amplitude of the lower esophageal sphincter 3cm above the pathological group and the sensitive group decreased significantly(P<0.05).There were no statistically significant differences in the length of the lower esophageal sphincter,the length of the lower esophageal sphincter in the abdominal segment,the amplitude of the upper esophageal sphincter at 7cm and 11cm and the peristaltic wave velocity of the esophageal body in the three groups(P>0.05).Conclusion:the decrease of lower esophageal sphincter pressure 展开更多
In this paper, an unbounded condition is presented, under which we are able to utilize the interior point homotopy method to solve the Brouwer fixed point problem on unbounded sets. Two numerical examples in R3 are pr...In this paper, an unbounded condition is presented, under which we are able to utilize the interior point homotopy method to solve the Brouwer fixed point problem on unbounded sets. Two numerical examples in R3 are presented to illustrate the results in this paper.展开更多
基金financially supported by the National Key Research and Development Program of China (No. 2016YFC0204300)the National High Technology Research and Development Program of China (No. 2015AA034603)+2 种基金the National Natural Science Foundation of China (Nos. 21333003 and 21571061)the "Shu Guang" Project of the Shanghai Municipal Education Commission (No. 12SG29)the Commission of Science and Technology of Shanghai Municipality (No. 15DZ1205305)
文摘The selective catalytic reduction of NOV with NH3 (NH3-SCR) is a very effective technology to control the emission of NOA, and the thermal stability of NH3-SCR catalyst is very important for removal of NOV from diesel engines. In this work, V2O5/WO3-TiO2 (VWT) and SiO2- doped V2O5/WO3-TiO2 (VWTSi10)) catalysts were prepared by impregnation method and characterized by Brunauer- Emmett-Teller (BET), X-ray diffraction (XRD), Raman, temperature programmed reduction by hydrogen (H2-TPR), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption by ammonia (NH3- TPD). The doping of SiO2 promotes the thermal stability of V2O5/WO3-TiO? for NH3-SCR significantly. After calcination at 650 °C for 50 h, the operation window of 10% SiO2-doped V2O5/WO3-TiO2 is 220-480 °C, while the maximum NOV conversion on V2O5/WO3-TiO2 is about 77%. The presenee of SiO2 obviously blocks the transformation of TiO2 from anatase to rutile and stabilizes the dispersion of VOv and WO3 on the surface. It is available for the existence of V44 and the amount of surface acid sites increases, which inhabits the NH3 oxidation at the high temperature range and promotes NH3-SCR activity.
基金Project supported by the National Key R&D Program of China(No.2018YFB0204300)the National Natural Science Foundation of China(Nos.61872376 and 61806216)。
文摘Although concern has been recently expressed with regard to the solution to the non-convex problem, convex optimization is still important in machine learning, especially when the situation requires an interpretable model. Solution to the convex problem is a global minimum, and the final model can be explained mathematically. Typically, the convex problem is re-casted as a regularized risk minimization problem to prevent overfitting. The cutting plane method (CPM) is one of the best solvers for the convex problem, irrespective of whether the objective function is differentiable or not. However, CPM and its variants fail to adequately address large-scale data-intensive cases because these algorithms access the entire dataset in each iteration, which substantially increases the computational burden and memory cost. To alleviate this problem, we propose a novel algorithm named the mini-batch cutting plane method (MBCPM), which iterates with estimated cutting planes calculated on a small batch of sampled data and is capable of handling large-scale problems. Furthermore, the proposed MBCPM adopts a "sink" operation that detects and adjusts noisy estimations to guarantee convergence. Numerical experiments on extensive real-world datasets demonstrate the effectiveness of MBCPM, which is superior to the bundle methods for regularized risk minimization as well as popular stochastic gradient descent methods in terms of convergence speed.
基金Medical Scientific Research Fund(No.YWJKJKHKYJJ-A308)
文摘Objective:To explore the relationship between acid reflux and esophageal motility in patients with gastroesophageal reflux disease.Methods:From January 2018 to December 2019,80 patients with typical gastroesophageal reflux symptoms such as reflux and heartburn were randomly selected from the Department of Gastroenterology,First Affiliated Hospital of guangxi university of chinese medicine.The patients were divided into pathological group,sensitive group and physiological group based on the percentage of acid exposure time and reflux-symptom correlation.The GerdQ score,quality of life score,esophageal acid test and esophageal manometry related parameters of the three groups of patients were compared.Results:Compared with the sensitive group and the physiological group,the GerdQ score,DeMeester score,orthostatic acid reflux time,orthostatic acid reflux time,longest acid reflux time and acid reflux times in the pathological group were significantly higher.Sf-36 score,lower esophageal sphincter pressure and effective rate of deglutition were all significantly reduced,with statistically significant differences(P<0.05).Compared with the physiological group,the GerdQ score of the sensitive group was higher.The sf-36 score was low,and the differences were statistically significant(P<0.05).The acid indexes in the sensitive group were higher than those in the physiological group,but the differences were not statistically significant(P>0.05).Compared with the physiological group,the distal contraction integral and the amplitude of the lower esophageal sphincter 3cm above the pathological group and the sensitive group decreased significantly(P<0.05).There were no statistically significant differences in the length of the lower esophageal sphincter,the length of the lower esophageal sphincter in the abdominal segment,the amplitude of the upper esophageal sphincter at 7cm and 11cm and the peristaltic wave velocity of the esophageal body in the three groups(P>0.05).Conclusion:the decrease of lower esophageal sphincter pressure
文摘In this paper, an unbounded condition is presented, under which we are able to utilize the interior point homotopy method to solve the Brouwer fixed point problem on unbounded sets. Two numerical examples in R3 are presented to illustrate the results in this paper.
