The optimization of the performance of a single-stage Linde-Hampson refrigerator （LHR） operating with six different binary refrigerants （R23/R134a, R23/R227ea, R23/R236ea, R170/R290, R170/R600a and R170/R600） with...The optimization of the performance of a single-stage Linde-Hampson refrigerator （LHR） operating with six different binary refrigerants （R23/R134a, R23/R227ea, R23/R236ea, R170/R290, R170/R600a and R170/R600） with ozone depletion potentials （ODPs） of zero was conducted using a new approach at the temperature level of-60℃. Among these binary refrig- erants, the 0.55 and the 0.6 mole fractions of R23 for R23/R236ea are the most prospective nonflammable ones for the medium and low suction pressure compressors, respectively. For these two kinds of compressors, the 0.6 and the 0.65 mole fractions of R170 for R 170/R600, respectively, are the most prospective binary refrigerants with low global warming potentials （GWPs）. The results of optimization of pressure levels indicate that the optimum low pressure value for coefficients of performance （COP） is achieved when the minimum temperature differences occur at both the hot and the cold ends of the recuperator at a specified composition and pressure ratio. Two useful new parameters, the entropy production per unit heat recuperated and the ratio of heat recuperating capacity to the power consumption of the compression, were introduced to analyze the exergy loss ratio in the recuperator. The new approach employed in this paper also suggests a promising application even to the optimization of the performance with multi-component refrigerants.展开更多
As an important index affecting the aerodynamic performance and the structural strength of hollow turbine blades, the wall-thickness precision of the blade is mainly inherited from the positional relationship between ...As an important index affecting the aerodynamic performance and the structural strength of hollow turbine blades, the wall-thickness precision of the blade is mainly inherited from the positional relationship between the corresponding wax pattern and the internal ceramic core.However, due to locating errors, the actual position of ceramic core is always deviated from the ideal position, which makes it difficult to guarantee the wall-thickness precision of the wax pattern.To solve this problem, a wall-thickness compensation strategy is proposed in this paper. Firstly,based on the industrial computed tomography(ICT) technique and curve matching algorithms, a model reconstruction method is developed, with which the 3D model of a trial wax pattern can be easily constructed. After that, focusing on eliminating the wall-thickness errors of the trial wax pattern, an optimization method for the pose of the ceramic core in the wax pattern is proposed. Then, by mapping the optimal pose of the ceramic core to length adjustments of the locating rods, the wall-thickness errors of the wax pattern can be greatly reduced. A case study is also given to illustrate the effectiveness of the proposed compensation strategy.展开更多
The deviation in wall thickness caused by core shift during the investment casting process significantly impacts the strength and service life of hollow turbine blades.To address this issue,a core shift limitation met...The deviation in wall thickness caused by core shift during the investment casting process significantly impacts the strength and service life of hollow turbine blades.To address this issue,a core shift limitation method is developed in this study.Firstly,a shift model is established based on computational fluid dynamics and motion simulation to predict the movement of the ceramic core in investment casting process.Subsequently,utilizing this model,an optimization method for fixturing layout inside the refractory ceramic shell is devised for the ceramic core.The casting experiment demonstrates that by utilizing the optimized fixture layout,not only can core shift during the investment casting pouring process be effectively controlled,but also the maximum wall thickness error of the blade can be reduced by 42.02%.In addition,the core shift prediction is also validated,with a prediction error of less than 26.9%.展开更多
Background:Esophageal cancer(EC)is the seventh most prevalent cancer and the sixth most common cause of cancer-related mortalities worldwide.Camrelizumab,a monoclonal antibody,has demonstrated moderate efficacy in eso...Background:Esophageal cancer(EC)is the seventh most prevalent cancer and the sixth most common cause of cancer-related mortalities worldwide.Camrelizumab,a monoclonal antibody,has demonstrated moderate efficacy in esophageal squamous cell carcinoma(ESCC).Lactobacillus paracasei,a probiotic bacterium,has a complementary effect in immunotherapy.This study aimed to evaluate the combination of camrelizumab and L.paracasei for advanced ESCC.Methods:This single-arm,single-center,exploratory trial was conducted at the First Affiliated Hospital of Zhengzhou University,Zhengzhou,China.Eligible patients received 200 mg camrelizumab biweekly and two bags of L.paracasei twice daily.The primary endpoint was progression-free survival(PFS),and the secondary endpoints were disease control rate(DCR),overall survival(OS),objective response rate(ORR),and adverse events(AEs).Results:From May 2020 to October 2022,ten patients with advanced ESCC who did not respond to first-line therapy were admitted.At the data cutoff date(August 9,2023),the median follow-up duration was 12 months.Two of 10(20%)achieved objective responses.The median survival was 7.5 months and the median OS was not reached.Grade 3 treatment-related AEs occurred in two of the 10 patients(20%).No serious treatmentrelated AEs or deaths occurred.Conclusions:Camrelizumab combined with L.paracasei showed favorable anticancer activity and may be a viable second-line treatment for patients with ESCC.展开更多
Abstract The shipbuilding industry plays a pivotal role in national strategic security and economic development,and one critical challenge is the pipeline layout design problem.It predominantly relies on designers’su...Abstract The shipbuilding industry plays a pivotal role in national strategic security and economic development,and one critical challenge is the pipeline layout design problem.It predominantly relies on designers’subjective experience,and it is marked by a lack of efficient knowledge sharing and the absence of smart pipe routing algorithms.This paper proposes an agile design system,which integrates ship pipeline design knowledge management,semi-automatic design that involves frequent interaction with human designers,and automatic rule checking.The framework is refined by digital twin concepts,facilitating close collaboration between physical and digital systems.The paradigm shift holds the potential to substantially enhance the efficiency of ship pipeline layout design,while concurrently reducing the reliance on manual labor.展开更多
基金Project (Nos.50876095 and 50890184) supported by the National Natural Science Foundation of China
文摘The optimization of the performance of a single-stage Linde-Hampson refrigerator （LHR） operating with six different binary refrigerants （R23/R134a, R23/R227ea, R23/R236ea, R170/R290, R170/R600a and R170/R600） with ozone depletion potentials （ODPs） of zero was conducted using a new approach at the temperature level of-60℃. Among these binary refrig- erants, the 0.55 and the 0.6 mole fractions of R23 for R23/R236ea are the most prospective nonflammable ones for the medium and low suction pressure compressors, respectively. For these two kinds of compressors, the 0.6 and the 0.65 mole fractions of R170 for R 170/R600, respectively, are the most prospective binary refrigerants with low global warming potentials （GWPs）. The results of optimization of pressure levels indicate that the optimum low pressure value for coefficients of performance （COP） is achieved when the minimum temperature differences occur at both the hot and the cold ends of the recuperator at a specified composition and pressure ratio. Two useful new parameters, the entropy production per unit heat recuperated and the ratio of heat recuperating capacity to the power consumption of the compression, were introduced to analyze the exergy loss ratio in the recuperator. The new approach employed in this paper also suggests a promising application even to the optimization of the performance with multi-component refrigerants.
基金co-supported by the National Natural Science Foundation of China (Nos. 51475374 and 51505387)the Fundamental Research Funds for the Central Universities (No. 3102015ZY087)
文摘As an important index affecting the aerodynamic performance and the structural strength of hollow turbine blades, the wall-thickness precision of the blade is mainly inherited from the positional relationship between the corresponding wax pattern and the internal ceramic core.However, due to locating errors, the actual position of ceramic core is always deviated from the ideal position, which makes it difficult to guarantee the wall-thickness precision of the wax pattern.To solve this problem, a wall-thickness compensation strategy is proposed in this paper. Firstly,based on the industrial computed tomography(ICT) technique and curve matching algorithms, a model reconstruction method is developed, with which the 3D model of a trial wax pattern can be easily constructed. After that, focusing on eliminating the wall-thickness errors of the trial wax pattern, an optimization method for the pose of the ceramic core in the wax pattern is proposed. Then, by mapping the optimal pose of the ceramic core to length adjustments of the locating rods, the wall-thickness errors of the wax pattern can be greatly reduced. A case study is also given to illustrate the effectiveness of the proposed compensation strategy.
基金the National Natural Science Foundation of China(Grant No.52005311)the Scientific and the National Science and Technology Major Project(Grant No.J2019-VII-0013-0153)Research Project Supported by Shanxi Scholarship Council of China(Grant No.2023-003).
文摘The deviation in wall thickness caused by core shift during the investment casting process significantly impacts the strength and service life of hollow turbine blades.To address this issue,a core shift limitation method is developed in this study.Firstly,a shift model is established based on computational fluid dynamics and motion simulation to predict the movement of the ceramic core in investment casting process.Subsequently,utilizing this model,an optimization method for fixturing layout inside the refractory ceramic shell is devised for the ceramic core.The casting experiment demonstrates that by utilizing the optimized fixture layout,not only can core shift during the investment casting pouring process be effectively controlled,but also the maximum wall thickness error of the blade can be reduced by 42.02%.In addition,the core shift prediction is also validated,with a prediction error of less than 26.9%.
基金supported by the Henan Provincial Health Commission Program for Young and Middle-aged Discipline Leaders(No.HNSWJW-2022026)the Outstanding Youth Talent Program of the Henan Provincial Health Commission(No.YXKC2022039).
文摘Background:Esophageal cancer(EC)is the seventh most prevalent cancer and the sixth most common cause of cancer-related mortalities worldwide.Camrelizumab,a monoclonal antibody,has demonstrated moderate efficacy in esophageal squamous cell carcinoma(ESCC).Lactobacillus paracasei,a probiotic bacterium,has a complementary effect in immunotherapy.This study aimed to evaluate the combination of camrelizumab and L.paracasei for advanced ESCC.Methods:This single-arm,single-center,exploratory trial was conducted at the First Affiliated Hospital of Zhengzhou University,Zhengzhou,China.Eligible patients received 200 mg camrelizumab biweekly and two bags of L.paracasei twice daily.The primary endpoint was progression-free survival(PFS),and the secondary endpoints were disease control rate(DCR),overall survival(OS),objective response rate(ORR),and adverse events(AEs).Results:From May 2020 to October 2022,ten patients with advanced ESCC who did not respond to first-line therapy were admitted.At the data cutoff date(August 9,2023),the median follow-up duration was 12 months.Two of 10(20%)achieved objective responses.The median survival was 7.5 months and the median OS was not reached.Grade 3 treatment-related AEs occurred in two of the 10 patients(20%).No serious treatmentrelated AEs or deaths occurred.Conclusions:Camrelizumab combined with L.paracasei showed favorable anticancer activity and may be a viable second-line treatment for patients with ESCC.
基金supported by Shanghai Pujiang Program(23PJ1405700)Defense Industrial Technology Development Program(JCKY2021206B049).
文摘Abstract The shipbuilding industry plays a pivotal role in national strategic security and economic development,and one critical challenge is the pipeline layout design problem.It predominantly relies on designers’subjective experience,and it is marked by a lack of efficient knowledge sharing and the absence of smart pipe routing algorithms.This paper proposes an agile design system,which integrates ship pipeline design knowledge management,semi-automatic design that involves frequent interaction with human designers,and automatic rule checking.The framework is refined by digital twin concepts,facilitating close collaboration between physical and digital systems.The paradigm shift holds the potential to substantially enhance the efficiency of ship pipeline layout design,while concurrently reducing the reliance on manual labor.
