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Impact of acoustic wave propagation characteristics on aerodynamic damping of rotor blades in a transonic axial compressor

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Chinese Journal of Aeronautics 2024年第11期37卷 168-187页

作者： yongbo yu Yanrong WANG Le HAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center for Advanced Aero-Engine Beijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

The aeroelastic stability associated with the acoustic wave propagation characteristics of transonic rotor blades was numerically investigated in this *** influence of the vibration frequency on the aerodynamic damping of the first bending mode was primarily considered at different speeds,including both work and stall *** found that the state of acoustic wave propagation associated with aeroelastic instability is closely related to rotational *** low speeds near stall points,the risk of aeroelastic instability is confined to the upstream cut-off ***,at high speeds near stall points,aeroelastic instability may occur in both the downstream cut-off state and the acoustic wave propagation state of the upstream cut-off frequency,further expanding the range of the acoustic wave propagation state in which aeroelastic instability can *** research findings show that for suction surfaces,aerodynamic work is affected not only by acoustic wave propagation characteristics,but also by shock waves,radial flow,and reflux in the flow ***,for pressure surfaces,the acoustic wave propagation characteristics play a significant *** aeroelastic instability occurs,negative damping predominantly arises from the pressure *** investigate why lower-order modes are more prone to aeroelastic instability,specific simulations were conducted for the first bending and twisting modes under different operating conditions in the downstream cut-on *** the vibration frequency significantly exceeds the downstream cutoff frequency,the blade phase is minimally influenced by acoustic wave propagation characteristics,and the rotor is aeroelastically stable in these ***,there is an approximately linear increase in the unsteady pressure amplitude with increasing vibration frequency,and the aerodynamic work is predominantly influenced by the unsteady pressure amplitude.

关键词： Aeroelastic stability Nodal diameter Aerodynamic damping Acoustic wave propagation characteristic Vibration frequency

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A Time Series Short-Term Prediction Method Based on Multi-Granularity Event Matching and Alignment

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Computers, Materials & Continua 2024年第1期78卷 653-676页

作者： Haibo Li yongbo yu Zhenbo Zhao Xiaokang Tang College of Computer Science and Technology Huaqiao UniversityXiamen361021China

Accurate forecasting of time series is crucial across various *** prediction tasks rely on effectively segmenting,matching,and time series data *** instance,regardless of time series with the same granularity,segmenting them into different granularity events can effectively mitigate the impact of varying time scales on prediction ***,these events of varying granularity frequently intersect with each other,which may possess unequal *** minor differences can result in significant errors when matching time series with future ***,directly using matched events but unaligned events as state vectors in machine learning-based prediction models can lead to insufficient prediction ***,this paper proposes a short-term forecasting method for time series based on a multi-granularity event,MGE-SP(multi-granularity event-based short-termprediction).First,amethodological framework for MGE-SP established guides the implementation *** framework consists of three key steps,including multi-granularity event matching based on the LTF(latest time first)strategy,multi-granularity event alignment using a piecewise aggregate approximation based on the compression ratio,and a short-term prediction model based on *** data from a nationwide online car-hailing service in China ensures the method’s *** average RMSE(root mean square error)and MAE(mean absolute error)of the proposed method are 3.204 and 2.360,lower than the respective values of 4.056 and 3.101 obtained using theARIMA(autoregressive integratedmoving average)method,as well as the values of 4.278 and 2.994 obtained using k-means-SVR(support vector regression)*** other experiment is conducted on stock data froma public data *** proposed method achieved an average RMSE and MAE of 0.836 and 0.696,lower than the respective values of 1.019 and 0.844 obtained using the ARIMA method,as well as the values of 1.350 and 1.172 obtained usin

关键词： Time series short-term prediction multi-granularity event alignment event matching

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Modeling and analysis of the ocean dynamic with Gaussian complex network

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Chinese Physics B 2020年第10期29卷 588-597页

作者： Xin Sun yongbo yu yuting Yang Junyu Dong Christian Bohm Xueen Chen Department of Computer Science and Technology Ocean University of ChinaQingdao 266000China Frontiers Science Center for Deep Ocean Multispheres and Earth System Qingdao 266000China Institut für Informatik Ludwig Maximilian University of MunichMunich 80331-81929Germany College of Physical and Environmental Oceanography Ocean University of ChinaQingdao 266000China

The techniques for oceanographic observation have made great progress in both space-time coverage and quality, which make the observation data present some characteristics of big data. We explore the essence of global ocean dynamic via constructing a complex network with regard to sea surface temperature. The global ocean is divided into discrete regions to represent the nodes of the network. To understand the ocean dynamic behavior, we introduce the Gaussian mixture models to describe the nodes as limit-cycle oscillators. The interacting dynamical oscillators form the complex network that simulates the ocean as a stochastic system. Gaussian probability matching is suggested to measure the behavior similarity of regions. Complex network statistical characteristics of the network are analyzed in terms of degree distribution, clustering coefficient and betweenness. Experimental results show a pronounced sensitivity of network characteristics to the climatic anomaly in the oceanic circulation. Particularly, the betweenness reveals the main pathways to transfer thermal energy of El Niño–Southern oscillation. Our works provide new insights into the physical processes of ocean dynamic, as well as climate changes and ocean anomalies.

关键词： complex networks ocean dynamic Gaussian mixture model physical processes

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Correlation between TERT C228T and clinic-pathological features in pediatric papillary thyroid carcinoma

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Science China(Life Sciences) 2019年第12期62卷 1563-1571页

作者： Jiangqiao Geng yuanhu Liu Yongli Guo Huanmin Wang Jun Tai Yaqiong Jin Jie Zhang yongbo yu Shengcai Wang Yingluan Song Xin Ni Otolaryngology Children's Hospital of Hebei ProvinceShijiazhuang 050031China Otolaryngology Head and Neck SurgeryBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China Beijing Key Laboratory for Pediatric Diseases of Otolaryngology Head and Neck SurgeryBeijing Pediatric Research InstituteBeijing Children's HospitalCapital Medical UniversityNational Center for Childrens HealthBeijing 100045China Department of Surgical Oncology Beijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China

The aims of the present study were to reveal the prevalence of the TERT C228 T mutation in pediatric papillary thyroid carcinoma(PPTC) and to further investigate the role of the TERT C228 T mutation in PPTC. We also tested another TERT mutation, TERT C250 T, although this was not detected in PPTC patients. In this study, 48 patients with PPTC(41 with classic PPTC) were enrolled. DNA was extracted from PPTC tissues and TERT C228 T mutation analysis was performed. Chi-squared analysis,Fisher’s exact test, and a t-test were applied to test the significance of differences. The TERT C228 T mutation presented in 13(27.1%) of the 48 PPTC patients and 10(24.4%) of the 41 classical PPTC patients. There were significant differences between PPTC patients with the TERT C228 T mutation and those without in terms of modified radical neck dissection, multifocality,capsular invasion, extrathyroidal invasion, and American Joint Committee on Cancer(AJCC) tumor stage(P<0.05). In classical PPTC, there were additional significant differences in other clinic-pathological features, such as AJCC nodal stage(P=0.009)and American Thyroid Association(ATA) PPTC stage(P=0.021) between patients with and without the TERT C228 T *** findings indicate that the TERT C228 T mutation is significantly correlated with certain aggressive clinic-pathological features of PPTC.

关键词： pediatric papillary thyroid cancer TERT C228T mutation clinic-pathological characteristics

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MYC-associated protein X binding with the variant rs72780850 in RNA helicase DEAD box 1 for susceptibility to neuroblastoma

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Science China(Life Sciences) 2021年第6期64卷 991-999页

作者： Yaqiong Jin Jin Shi Huanmin Wang Jie Lu Chenghao Chen yongbo yu Yaru Wang Yeran Yang Dong Ren Qi Zeng Xin Ni Yongli Guo Beijing Key Laboratory for Pediatric Diseases of Otolaryngology Head and Neck SurgeryMOE Key Laboratory of MajorDiseases in ChildrenBeijing Pediatric Research InstituteBeijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China Department of Tuberculosis Beijing Tuberculosis and Thoracic Tumor Research InstituteBeijing Chest HospitalCapital Medical UniversityBeijing 101149China Department of Surgery Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China Department of Thoracic Surgery Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China Department of Allergy Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China Beijing Advanced Innovation Center for Big Data-Based Precision Medicine Beihang University&Capital Medical UniversityBeijing 100083China Department of Otolaryngology Head and Neck SurgeryBeijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China

Neuroblastoma(NB)is one of the most common malignant tumors in children,with variable clinical behaviors and a 15%death rate of all malignancies in ***,genetic susceptibility to sporadic NB in Han Chinese patients is largely *** identify genetic risk factors for NB,we performed an association study on 357 NB patients and 738 control subjects among Han Chinese *** focused on DEAD box 1(DDX1),a putative RNA helicase,which is involved in NB *** potential association of DDX1 polymorphisms with NB has not been *** results demonstrate that rs72780850(NM_004939.2:c.-1555 T>C)located in the DDX1 promoter region is significantly associated with higher expression of DDX1 transcript and increased NB risk(odds ratio=1.64,95%confidence interval=1.03%–2.60%,P=0.004),especially in aggressive NB compared with ganglioneuroma and ganglioneuroblastoma in a dominant model(TC+CC ***).Furthermore,the MYC-associated protein X(MAX)transcription factor showed stronger binding affinity to the DDX1 rs72780850 CC allele compared with the TT allele,explaining the molecular mechanism of the increased NB risk caused by the rs72780850 *** results highlight the involvement of regulatory genetic variants of DDX1 in NB.

关键词： neuroblastoma RNA helicase DEAD box 1 susceptibility

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从头算和ABEEMσπ/MM对(CH_3OH)_n(n=3～12)和[Na(CH_3OH)_n]^+(n=3～6)体系的研究

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高等学校化学学报 2016年第8期37卷 1468-1475页

作者：于泳博刘翠宫利东辽宁师范大学化学化工学院大连116029

采用从头算方法(ab initio)和原子-键电负性均衡浮动电荷分子力场方法(ABEEMσπ/MM),对甲醇团簇(CH_3OH)n(n=3~12)和[Na(CH_3OH)_n]^+(n=3~6)体系的结构、电荷分布和结合能进行研究.依据从头算结果构建上述体系的ABEEMσπ/MM浮动电荷... 详细信息

采用从头算方法(ab initio)和原子-键电负性均衡浮动电荷分子力场方法(ABEEMσπ/MM),对甲醇团簇(CH_3OH)n(n=3~12)和[Na(CH_3OH)_n]^+(n=3~6)体系的结构、电荷分布和结合能进行研究.依据从头算结果构建上述体系的ABEEMσπ/MM浮动电荷势能函数,并确定相关参数.结果表明,ABEEMσπ/MM所获得的结构和结合能等均优于OPLS/AA力场,并与从头算结果相符,其中键长的平均绝对偏差(AAD)小于0.004 nm,键长、键角和结合能的相对均方根偏差(RRMSD)分别小于3.8%,1.7%和6.8%;电荷分布与从头算结果的线性相关系数均大于0.99.

关键词：从头算原子-键电负性均衡浮动电荷分子力场方法甲醇钠离子分子间相互作用

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重复压裂前地应力场预测软件研究及现场应用

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石油学报 2007年第4期28卷 130-133页

作者：姚飞翁定为李阳于永波中国石油大学石油天然气工程学院北京102249 中国石油勘探开发研究院廊坊分院压裂酸化中心河北廊坊065007 大庆油田采油九厂黑龙江大庆163000

综合考虑初次裂缝的存在以及油气井的生产对原应力场的影响,研制了重复压裂前地应力场的预测软件。运用该软件考察了新站油田7口井重复压裂前的地应力场,对其中4口可能发生重复压裂裂缝转向的井实施了转向重复压裂。在现场施工中,用地... 详细信息

综合考虑初次裂缝的存在以及油气井的生产对原应力场的影响,研制了重复压裂前地应力场的预测软件。运用该软件考察了新站油田7口井重复压裂前的地应力场,对其中4口可能发生重复压裂裂缝转向的井实施了转向重复压裂。在现场施工中,用地面测斜仪监测了裂缝的形成和扩展过程,压裂后用数值模拟方法拟合的各井生产历史动态表明,试验井发生了重复压裂裂缝转向,证实了地应力场预测软件的有效性。

关键词：重复压裂井裂缝扩展地应力场历史拟合预测软件

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创意产业智力资本价值创造力与均衡投入

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科技进步与对策 2016年第3期33卷 78-82页

作者：于泳波彭华涛湖北工业大学经济与管理学院湖北循环经济发展研究中心湖北武汉430068 武汉理工大学管理学院湖北武汉430070

解释了创意产业与智力资本投入的内涵,探讨了基于智力资本的创意产业价值创造系统,揭示了智力资本与价值创造之间的因果联系,构建了创意产业智力资本的价值创造模型与智力资本均衡投入模型,并得出了相应的函数解,最后提出了提高创意产... 详细信息

解释了创意产业与智力资本投入的内涵,探讨了基于智力资本的创意产业价值创造系统,揭示了智力资本与价值创造之间的因果联系,构建了创意产业智力资本的价值创造模型与智力资本均衡投入模型,并得出了相应的函数解,最后提出了提高创意产业价值创造能力的若干建议。

关键词：创意产业智力资本价值创造

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自动铺带中红外加热技术研究

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航空学报 2011年第6期32卷 1124-1131页

作者：余永波文立伟肖军张建宝南京航空航天大学材料科学与技术学院江苏南京210016

为保证复合材料预浸带始终处于适宜铺放成型的工艺窗口内,自动铺带(ATL)成型过程中需要对预浸带的铺放温度进行精确控制。为适应高速率自动铺放,需要研究新的高效加热及精确控制方法。本文提出高加热效率、高响应速率的红外辐射加热方... 详细信息

为保证复合材料预浸带始终处于适宜铺放成型的工艺窗口内,自动铺带(ATL)成型过程中需要对预浸带的铺放温度进行精确控制。为适应高速率自动铺放,需要研究新的高效加热及精确控制方法。本文提出高加热效率、高响应速率的红外辐射加热方案。通过对红外热源与预浸带能量传输过程的分析,提出了红外加热过程中各传递系数的计算方法和公式。基于各传递系数的分析,建立了静止及运动状态下的红外加热控制方程,并通过两种状态下控制方程的对比,提出了红外辐射稳态因子概念。以静止状态下的实验数据为依据,利用红外辐射稳态因子,经理论推导,获得了预浸带匀速运行时的温度控制律,为红外加热技术在自动铺带成型中的应用奠定基础。

关键词：自动铺带红外加热角系数辐射稳态因子温度控制

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大气压低温等离子体射流器件层流特性的模拟研究

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真空科学与技术学报 2014年第7期34卷 724-730页

作者：占建英杨兰兰屠彦俞永波东南大学电子科学与工程学院南京210096

为分析大气压低温等离子体射流的特性,本文建立射流器件二维轴对称模型,利用Comsol软件对层流状态下等离子体射流的连续性方程、N-S方程和对流扩散方程进行耦合求解,分析了不同气体流速、喷口直径及工作气体条件下,喷射气流在空气中的轴... 详细信息

为分析大气压低温等离子体射流的特性,本文建立射流器件二维轴对称模型,利用Comsol软件对层流状态下等离子体射流的连续性方程、N-S方程和对流扩散方程进行耦合求解,分析了不同气体流速、喷口直径及工作气体条件下,喷射气流在空气中的轴向(z)和径向(r)摩尔分数分布,并研究了流速、喷口直径和工作气体对射流特性的影响。模拟结果表明,在层流状态下,可以用He与空气混合的摩尔分数为0.99时的轴向传播长度去估测射流传播的长度,该长度与入射气体流速、喷口直径的平方呈线性关系,即与气体体积流量呈正比,模拟结果与文献中实验结果一致;相同条件下,He、Ne、Ar三种工作气体在轴向上的摩尔分数分布依次增大,它们与空气混合的摩尔分数为0.99时的轴向传播长度依次增加,可推测同等条件下Ar气的射流长度最长。

关键词：低温等离子体射流层流模型轴向摩尔分数径向摩尔分数射流长度

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