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Uncertainty analysis of measured geometric variations in turbine blades and impact on aerodynamic performance

Chinese Journal of Aeronautics 2023年第6期36卷 140-160页

作者： Xiaojing WANG Pengcheng DU lichao yao Zhengping ZOU Fei ZENG School of Energy and Power Engineering Beihang UniversityBejing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBejing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Inevitable geometric variations significantly affect the performance of turbines or even that of entire engines;thus,it is necessary to determine their actual characteristics and accurately estimate their impact on *** this study,based on 1781 measured profiles of a typical turbine blade,the statistical characteristics of the geometric variations and the uncertainty impact are analyzed,and some commonly used uncertainty modelling methods based on Principal-Component Analysis(PCA)are *** geometric variations are found to be evident,asymmetric,and non-uniform,and the non-normality of the random distributions is *** performance is notably affected,which is manifested as an overall offset,a notable scattering,and significant deterioration in several extreme ***,it is demonstrated that the PCA reconstruction model is effective in characterizing major uncertainty characteristics of the geometric variations and their impact on the performance with almost the first 10 PCA *** on a reasonable profile error and mean geometric deviation,the Gaussian assumption and stochasticprocess-based model are also found to be effective in predicting the mean values and standard deviations of the performance ***,they fail to predict the probability of some extreme cases with high ***,a Chi-square-based correction model is proposed to compensate for this *** present work can provide a useful reference for uncertainty analysis of the impact of geometric variations,and the corresponding uncertainty design of turbine blades.

关键词： Aerodynamic performance Measured geometric variations Principal-component analysis Turbine blade Uncertainty analysis

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Insights into thermodynamic performance of a hypersonic precooled air-breathing engine with a complicated multi-branch closed cycle

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Chinese Journal of Aeronautics 2024年第8期37卷 106-123页

作者： Yifan WANG Zhengping ZOU Pengcheng DU lichao yao Huoxing LIU Yusen XU Research Institute of Aero-Engine Beihang UniversityBeijing 102206China National Key Laboratory of Science and Technology on Aero-Engine and Aero-Thermodynamics Beihang UniversityBeijing 102206China

An advanced precooled airbreathing engine with a closed Brayton cycle is a promising solution for high-speed propulsion,of which the Synergetic Air Breathing Rocket Engine(SABRE)is a representative *** performance of the latest SABRE-4 cycle was analyzed in this ***,a relatively complete engine performance model that considers the characteristics of turbomachinery and heat exchangers was ***,Sobol’global sensitivity analysis of key performance parameters was carried out to identify the most influential design *** specific impulses under different target specific thrusts were obtained by particle swarm optimization,of which the thermodynamic parameters corresponding to a specific thrust of 1.12 kN·s·kg^(-1)and a specific impulse of 3163 s were chosen as the design *** different control laws were analyzed in contrast,and the charge control method had the strongest ability of thrust regulation as well as maintaining a favorable specific impulse ***,working characteristics under the charge control and over a typical flight envelope were calculated,in which the average value of the maximum specific impulse was as high as 5315 *** study would help to deepen the understanding of SABRE-4 thermodynamic characteristics and other precooled airbreathing engine cycles with similar layouts.

关键词： Hypersonic Precooled airbreathing engine Thermodynamic cycle Control law Working characteristics

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Mitochondrial dysfunction: A promising therapeutic target for liver diseases

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Genes & Diseases 2024年第3期11卷 324-337页

作者： Ping Chen lichao yao Mengqin Yuan Zheng Wang Qiuling Zhang Yingan Jiang Lanjuan Li Department of Infectious Diseases Renmin Hospital of Wuhan UniversityWuhanHubei 430060China State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhouZhejiang 310003China

The liver is an important metabolic and detoxification organ and hence demands a large amount of energy,which is mainly produced by the *** tissues of pa-tients with alcohol-related or non-alcohol-related liver diseases contain ultrastructural mito-chondrial lesions,mitochondrial DNA damage,disturbed mitochondrial dynamics,and compromised ATP *** of mitochondrial reactive oxygen species in-duces oxidative damage to mitochondrial proteins and mitochondrial DNA,decreases mito-chondrial membrane potential,triggers hepatocyte inflammation,and promotes programmed cell death,all of which impair liver *** DNA may be a poten-tial novel non-invasive biomarker of the risk of progression to liver cirrhosis and hepatocellular carcinoma in patients infected with the hepatitis B *** herein present a review of the mechanisms of mitochondrial dysfunction in the development of acute liver injury and chronic liver diseases,such as hepatocellular carcinoma,viral hepatitis,drug-induced liver injury,alcoholic liver disease,and non-alcoholic fatty liver *** review also discusses mito-chondrion-centric therapies for treating liver diseases.

关键词： Chronic diseases Liverdamage Mesenchymalstem cell Mitochondrial dysfunction Oxidativestress

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IGF2-NR4A2 Signaling Regulates Macrophage Subtypes to Attenuate Liver Cirrhosis

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Journal of Clinical and Translational Hepatology 2023年第4期11卷 787-799页

作者： lichao yao Xue Hu Mengqin Yuan Qiuling Zhang Pingji Liu Lian Yang Kai Dai Yingan Jiang Department of Infectious Diseases Renmin Hospital of Wuhan UniversityWuhanHubeiChina Department of Obstetrics and Gynecology Renmin Hospital of Wuhan UniversityWuhanHubeiChina

Background and Aims:Liver cirrhosis can lead to liver failure and eventually *** are the main contributors to cirrhosis and have a bidirectional role in regulating matrix deposition and ***-based cell therapy has been developed as an alternative to liver ***,there is insufficient evidence regarding its safety and *** this study,we aimed to explore the effect of combining insulin-like growth factor 2(IGF2)with bone marrow-derived macrophages(BMDMs)to treat mice with liver ***:We assessed liver inflammation,fibrosis regression,liver function,and liver regeneration in mice with CCl4-induced cirrhosis and treated with BMDM only or IGF2+*** performed in vitro experiments in which activated hepatic stellate cells(HSCs)were co-cultured with macrophages in the presence or absence of *** polarity of macrophages and the degree of inhibition of HSCs were *** effect of IGF2 on macrophages was also verified by the overexpression of ***:Combining IGF2 with BMDM reduced liver inflammation and fibrosis and increased hepatocyte *** IGF2 with BMDM was more effective than using BMDM *** vitro experiments demonstrated that IGF2 inhibited HSCs activation by upregulating NR4A2 to promote the anti-inflammatory macrophages ***2 also increased the synthesis of matrix metalloproteinases(MMPs)by macrophages,which may explain why administering IGF2 combined with BMDM was more effective than administering BMDM ***:Our study provides a theoretical basis for the future use of BMDM-based cell therapy to treat liver cirrhosis.

关键词： Liver cirrhosis Macrophage IGF2 Cell therapy Hepatic stellate cell

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Causal Relationship Between Gut Microbiota and Liver Cirrhosis:16S rRNA Sequencing and Mendelian Randomization Analyses

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Journal of Clinical and Translational Hepatology 2024年第2期12卷 123-133页

作者： Mengqin Yuan Xue Hu lichao yao Ping Chen Zheng Wang Pingji Liu Zhiyu Xiong Yingan Jiang Lanjuan Li Department of Infectious Diseases Renmin Hospital of Wuhan UniversityWuhanHubeiChina State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Centre for Infectious DiseasesCollaborative Innovation Centre for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina

Background and Aims:Accumulating evidence highlights the association between the gut microbiota and liver ***,the role of the gut microbiota in liver cirrhosis remains ***:We first assessed the differences in the composition of the bacterial community between CCl4-induced liver cirrhosis and control mice using 16S rRNA *** then performed a two-sample Mendelian randomization(MR)analysis to reveal the underlying causal relationship between the gut microbiota and liver *** relationships were analyzed using primary inverse variance weighting(IVW)and other supplemental MR ***,fecal samples from liver cirrhosis patients and healthy controls were collected to validate the results of the MR ***:Analysis of 16S rRNA sequencing indicated significant differences in gut microbiota composition between the cirrhosis and control *** analyses suggested that Alphaproteobacteria,Bacillales,NB1n,Rhodospirillales,Dorea,Lachnospiraceae,and Rhodospirillaceae were positively correlated with the risk of liver cirrhosis,whereas Butyricicoccus,Hungatella,Marvinbryantia,and Lactobacillaceae displayed the opposite ***,the weighted median and MR-PRESSO estimates further showed that only Butyricicoccus and Marvinbryantia presented stable negative associations with liver *** significant heterogeneity or horizontal pleiotropy was observed in the sensitivity ***,the result of 16S rRNA sequencing also showed that healthy controls had a higher relative abundance of Butyricicoccus and Marvinbryantia than liver cirrhosis ***:Our study provides new causal evidence for the link between gut microbiota and liver cirrhosis,which may contribute to the discovery of novel strategies to prevent liver cirrhosis.

关键词： 16S rRNA gene sequencing Liver cirrhosis Gut microbiota Causality Two-sample Mendelian randomization study

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低压涡轮在工作剖面内的多学科耦合仿真

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工程热物理学报 2024年第5期45卷 1374-1384页

作者：张云达邹正平姚李超北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室北京100191 北京航空航天大学航空发动机研究院北京102206

在涡轮的典型工作剖面内,采用计算流体力学和两种多学科耦合求解方式对某二级低压涡轮部件进行仿真,比较不同求解方式所预测的涡轮气动热力参数之间的差异,分析工作剖面内局部几何的形变规律以及局部形变对流场的影响,结果表明:多学科... 详细信息

在涡轮的典型工作剖面内,采用计算流体力学和两种多学科耦合求解方式对某二级低压涡轮部件进行仿真,比较不同求解方式所预测的涡轮气动热力参数之间的差异,分析工作剖面内局部几何的形变规律以及局部形变对流场的影响,结果表明:多学科耦合作用对低叶高位置叶型负荷分布产生一定的影响,具体影响规律与不同工况密切相关。考虑固体域热传导和形变的多学科耦合求解方式所预测的效率值更高。随着涡轮功率的提升,级间轮缘间歇和封严篦齿间隙的改变会导致更多封严冷气聚集在前腔中,影响盘腔内的流动结构,削弱了燃气入侵现象,实现盘腔内更好的冷却和封严效果。

关键词：多学科耦合低压涡轮工作剖面

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Hypertension and NAFLD risk:Insights from the NHANES 2017-2018 and Mendelian randomization analyses

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Chinese Medical Journal 2024年第4期137卷 457-464页

作者： Mengqin Yuan Jian He Xue Hu lichao yao Ping Chen Zheng Wang Pingji Liu Zhiyu Xiong Yingan Jiang Lanjuan Li Department of Infectious Diseases Renmin Hospital of Wuhan UniversityWuhanHubei 430000China Department of Gastroenterology Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510010China State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Centre for Infectious DiseasesCollaborative Innovation Centre for Diagnosis and Treatment of Infectious DiseasesDepartment of Infectious DiseasesThe First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhouZhejiang 310000China

Background:Hypertension and non-alcoholic fatty liver disease(NAFLD)share several pathophysiologic risk factors,and the exact relationship between the two remains *** study aims to provide evidence concerning the relationship between hypertension and NAFLD by analyzing data from the National Health and Nutrition Examination Survey(NHANES)2017-2018 and Mendelian randomization(MR)***:Weighted multivariable-adjusted logistic regression was applied to assess the relationship between hypertension and NAFLD risk by using data from the NHANES ***,a two-sample MR study was performed using the genome-wide association study(GWAS)summary statistics to identify the causal association between hypertension,systolic blood pressure(SBP),diastolic blood pressure(DBP),and *** primary inverse variance weighted(IVW)and other supplementary MR approaches were conducted to verify the causal association between hypertension and *** analyses were adopted to confirm the robustness of the ***:A total of 3144 participants were enrolled for our observational study in *** multivariable-adjusted logistic regression analysis suggested that hypertension was positively related to NAFLD risk(odds ratio[OR]=1.677;95%confidence interval[CI],1.159-2.423).SBP≥130 mmHg and DBP≥80 mmHg were also significantly positively correlated with ***,hypertension was independently connected with liver steatosis(β=7.836[95%CI,2.334-13.338]).The results of MR analysis also supported a causal association between hypertension(OR=7.203[95%CI,2.297-22.587])and *** results were observed for the causal exploration between SBP(OR=1.024[95%CI,1.003-1.046]),DBP(OR=1.047[95%CI,1.005-1.090]),and *** sensitive analysis further confirmed the robustness and reliability of these findings(all P>0.05).Conclusion:Hypertension was associated with an increased risk of NAFLD.

关键词： Hypertension Non-alcoholic fatty liver disease National Health and Nutrition Examination Survey Mendelian randomization analysis Causality

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基于改进遗传算法的电厂粉尘监测节点覆盖控制研究

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中国安全科学学报 2024年第9期34卷 121-130页

作者：王博商宇航姚立超蒋永清哈尔滨理工大学测控技术与通信工程学院黑龙江哈尔滨150080

为有效降低粉尘环境监测中存在盲区和管控缺失的风险,优化火电厂粉尘环境监测系统的节点覆盖控制,延长无线传感器网络(WSN)寿命,提出一种基于改进遗传算法的节能优化方法。首先构建基于节点覆盖率、节点布设总能耗和节点通信传输总能耗... 详细信息

为有效降低粉尘环境监测中存在盲区和管控缺失的风险,优化火电厂粉尘环境监测系统的节点覆盖控制,延长无线传感器网络(WSN)寿命,提出一种基于改进遗传算法的节能优化方法。首先构建基于节点覆盖率、节点布设总能耗和节点通信传输总能耗的网络覆盖质量目标函数;然后针对传统遗传算法存在局部最优和编码重复的问题,提出整数编码的染色体组合方案、自适应调节交叉和变异概率的方法,以及精英保留策略;最后通过仿真对比分析,确定优化后的节点数量和分布方案。结果表明:改进的遗传算法显著提高了收敛速度,所需迭代次数减少至20次,适应度值优化52.18%;在节点部署和覆盖研究中,优化后的节点数量为42个,覆盖率达97.28%,节点休眠率为76.19%,有效提升了火电厂粉尘环境监测系统的节能效果。

关键词：改进遗传算法电厂粉尘环境监测节点覆盖控制无线传感器网络(WSN) 精英保留策略

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非定常来流压力下基于DMD方法的预冷器换热特性

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航空动力学报 2020年第10期35卷 2064-2077页

作者：姚李超付超张俊强李泽鹏邹正平北京航空航天大学能源与动力工程学院航空发动机气动热力国防重点实验室北京100191 北京航空航天大学航空发动机研究院北京100191

采用大涡模拟方法对非定常来流压力条件下叉排管束预冷器换热特性进行了研究,同时运用动力学模态分解方法对流场主控流动结构进行了识别,探讨了来流压力周期性变化频率对预冷器内部流动、换热性能和熵产的影响。结果表明:来流压力变化... 详细信息

采用大涡模拟方法对非定常来流压力条件下叉排管束预冷器换热特性进行了研究,同时运用动力学模态分解方法对流场主控流动结构进行了识别,探讨了来流压力周期性变化频率对预冷器内部流动、换热性能和熵产的影响。结果表明:来流压力变化频率对预冷器时均和瞬态换热性能影响均不显著,但当来流压力变化频率增大至流场固有频率950 Hz时,流场发生共振,换热性能发生剧烈振荡;管束壁面剪切层运动和绕流脱落涡结构为主控流动结构,其时空演化过程对瞬时换热性能起决定作用;当流场发生共振时,剪切层的生长和演化与来流速度的脉动密切相关,前排管束的绕流涡脱落周期与来流压力/速度变化周期一致,而壁面剪切层的生长周期则为来流压力/速度变化周期的两倍。此外,叉排管束流场的换热熵产决定于主控流动结构,其时空演化特征与主控流动结构演化规律完全一致。

关键词：叉排管束预冷器来流压力变化换热特性动力学模态分解主控流动结构

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SiBCN陶瓷先驱体合成、固化动力学及陶瓷化产物性能研究

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复合材料科学与工程 2024年第6期 15-21页

作者：彭喆姚利超柴笑笑李松北京玻钢院复合材料有限公司北京102101 特种纤维复合材料国家重点实验室北京102101

采用脱氢偶联聚合方法,以聚硅氮烷和环硼氮烷制备了四种低黏度SiBCN陶瓷先驱体,通过红外表征了SiBCN陶瓷先驱体的结构,通过非等温DSC研究了SiBCN陶瓷先驱体的固化动力学过程,通过超高温TG,XRD,XPS等手段表征了SiBCN陶瓷化产物的性能。... 详细信息

采用脱氢偶联聚合方法,以聚硅氮烷和环硼氮烷制备了四种低黏度SiBCN陶瓷先驱体,通过红外表征了SiBCN陶瓷先驱体的结构,通过非等温DSC研究了SiBCN陶瓷先驱体的固化动力学过程,通过超高温TG,XRD,XPS等手段表征了SiBCN陶瓷化产物的性能。结果表明:四种SiBCN陶瓷先驱体的室温黏度为198~275 mPa·S,固化温度范围为120~235℃。SiBCN陶瓷先驱体的固化过程为双放热峰,通过Kissinger, Ozawa, Crane方程对主放热峰进行分析得到SiBCN陶瓷先驱体P1、P2、P3、P4固化动力学参数,其中活化能Ea分别为96.9 kJ/mol、88.4 kJ/mol、119.5 kJ/mol、268.2 kJ/mol,反应级数n分别为0.933,0.930,0.940,0.943。SiBCN陶瓷先驱体P4经过1 300℃裂解后的SiBCN陶瓷结构为非晶态,其B含量为4.67%,分解温度高达1 651℃。四种SiBCN陶瓷先驱体裂解产物的分解温度与B含量表现出一定的关系:当B含量超过一定浓度时,陶瓷化产物的高温稳定性得到有效提高。

关键词： SiBCN先驱体 SiBCN陶瓷脱氢偶联固化动力学耐高温性复合材料

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