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Heat Transfer and Flow Structure of a Turbine Blade's Air-cooled Leading Edge Considering Different Hole Shapes and Additional Flow Angles

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Journal of Thermal Science 2024年第4期33卷 1421-1442页

作者： qin Runxuan ZHOU Xun WANG Songtao CAI Le School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

A numerical study is conducted to elucidate the impact of hole shapes and additional flow angles on the flow structure of the coolant and temperature field in the leading edge area of the gas turbine *** typical hole shapes are considered for the GE-E3 *** impact of the additional flow angle(E)within each hole shape on the temperature field is *** results indicate that for the leading edge area and suction surface,the fan-shaped hole case performs best in decreasing temperatures,with a decrease of about 43 *** is mainly due to the fact that the fan-shaped hole has the maximum expansion in hole spanwise *** the pressure surface,the console hole case performs best in decreasing temperatures,with a maximum reduction of about 47.2 *** influence of E on the surface temperature at leading edge area varied between the different hole *** the cylinder hole and console hole,the E=-20°case has the lowest area-averaged *** both the fan-shaped hole and the 7-7-7 shaped hole are expansion holes,the pattern of variation of the leading edge area temperature with increasing E is similar for the fan-shaped hole case and 7-7-7 shaped hole *** E=20°case shows the lowest spanwise-averaged temperature near the hole outlet,and the E=-20°case shows the lowest spanwise-averaged temperature further downstream.

关键词： film cooling GE-E3 turbine rotor blade conjugate heat transfer leading edge

Capturability-based Fuzzy Footstep Planner for a Biped Robot with Centroidal Compliance

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Journal of Bionic Engineering 2024年第1期21卷 84-100页

作者： Zihan Xu qin Fang Yong Ren Chengju Liu Robot and Artificial Intelligence Lab(RAIL) College of Electronic and Information EngineeringTongji UniversityShanghai 201804China Applied Technology College Soochow UniversitySuzhou 215000China

Compliance motion and footstep adjustment are active balance control strategies from learning human subconscious *** force estimation without direct end-actuator force measurement and the optimal footsteps based on complex analytical calculation are still challenging tasks for elementary and kid-size position-controlled *** this paper,an online compliant controller with Gravity Projection Observer(GPO),which can express the external force condition of perturbations by the estimated Projection of Gravity(PoG)with estimation covariance,is proposed for the realization of disturbance absorption,with which the robustness of the humanoid contact with environments can be *** fuzzy footstep planner based on capturability analysis is proposed,and the Model Predictive Control(MPC)is applied to generate the desired *** fuzzification rules are well-designed and give the corresponding control output responding to complex and changeable external *** validate the presented methods,a series of experiments on a real humanoid robot are *** results verify the effectiveness of the proposed balance control framework.

关键词： Biped walking Centroidal compliance Gravity projection observer Fuzzy footstep planner

知识特性对高校体育教师知识转移绩效影响的实证研究

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山东体育学院学报 2015年第5期31卷 95-100页

作者：秦曼王兴司虎克上海金融学院体育教学部上海201209 上海体育学院体育教育训练学院上海200438

采用理论分析、问卷调查和数理统计方法,就知识特性对高校体育教师知识转移绩效所产生的影响进行分析。理论研究确立了知识特性是影响高校体育教师知识转移的关键因素之一,并从知识复杂性、知识默会性和知识嵌入性三个维度探索知识特性... 详细信息

采用理论分析、问卷调查和数理统计方法,就知识特性对高校体育教师知识转移绩效所产生的影响进行分析。理论研究确立了知识特性是影响高校体育教师知识转移的关键因素之一,并从知识复杂性、知识默会性和知识嵌入性三个维度探索知识特性对高校体育教师知识转移绩效的影响结果。

关键词：知识特性高校体育教师知识转移影响因素绩效

重度低龄儿童龋全身麻醉下治疗后再次患龋风险的前瞻性研究

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中华口腔医学杂志 2021年第9期56卷 857-865页

作者：田靖马文利夏斌秦满北京大学口腔医学院·口腔医院儿童口腔科国家口腔医学中心国家口腔疾病临床医学研究中心口腔数字化医疗技术和材料国家工程实验室口腔数字医学北京市重点实验室100081

目的对全身麻醉下接受龋齿治疗的重度低龄儿童龋(severe early childhood caries,S-ECC)患儿行前瞻性随访研究,分析其治疗前后患龋特点,并探究治疗后再次患龋的风险因素。方法纳入83例2~4岁、于2012年12月至2014年8月在北京大学口腔医... 详细信息

目的对全身麻醉下接受龋齿治疗的重度低龄儿童龋(severe early childhood caries,S-ECC)患儿行前瞻性随访研究,分析其治疗前后患龋特点,并探究治疗后再次患龋的风险因素。方法纳入83例2~4岁、于2012年12月至2014年8月在北京大学口腔医学院·口腔医院儿童口腔科接受全身麻醉下龋齿治疗的S-ECC患儿,在治疗前及治疗后1、7、13个月采集其口腔检查、临床诊疗内容和调查问卷信息。统计分析治疗前龋坏程度、临床诊疗内容、患儿及家长基本情况和口腔保健习惯等在治疗后无龋和再次患龋儿童之间是否存在差异,统计分析治疗后再次患龋特点及龋坏类型(分为再发龋和继发龋,前者指对原发龋病灶进行修复后在同一牙齿其他部位发生的龋,后者指在已有修复体边缘或底部发生的龋)。结果在完成7~13个月随访的70例患儿中,29例(41%)在13个月观察期内保持无龋,41例(59%)在13个月观察期内出现个别牙再次龋坏。全身麻醉下龋齿治疗后除下颌乳切牙外其他牙位均有不同程度的再次患龋,其中上颌乳切牙以继发龋为主(再发龋和继发龋牙数分别为1和12),上下颌乳尖牙及第一乳磨牙再发龋和继发龋牙数均较高(上下颌乳尖牙再发龋和继发龋牙数分别为12和6,上下颌第一乳磨牙再发龋和继发龋牙数分别为16和12),上下颌第二乳磨牙以再发龋为主(再发龋和继发龋牙数分别为19和5)。治疗后再次患龋牙面数从高到低依次为乳磨牙邻面(37)、乳磨牙面(28)、乳尖牙邻面(13)、乳磨牙颊舌面(12)、乳前牙唇舌面(10)、乳尖牙唇舌面(8)和乳前牙邻面(5)。治疗前龋坏程度、临床诊疗内容和患儿及家长基本情况在治疗后保持无龋和再次患龋的两组儿童间差异均无统计学意义(P>0.05)。饮食和口腔保健习惯方面,治疗后7和13个月随访时患龋组甜食摄入频率均显著高于无龋组(P<0.05)。结论2~4岁S-ECC患儿全身麻醉下治疗后有较高的再患龋风险,定期复查维护十分必要;复查中应着重预防和治疗乳磨牙新发和继发龋坏,以及乳前牙继发龋坏;较高的甜食摄入频率是治疗后再次患龋的重要风险因素。

关键词：龋齿重度低龄儿童龋麻醉,全身患龋风险前瞻性研究

Constitutive modelling of concrete material subjected to low-velocity projectile impact:insights into damage mechanism and target resistance

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 161-182页

作者： Shen LIU Xieping HUANG Xiangzhen KONG qin FANG Center for Hypergravity Experiment and Interdisciplinary Research Zhejiang UniversityHangzhou310058China Institute of Geotechnical Engineering Zhejiang UniversityHangzhou310058China State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing210007China

This paper presents a numerical study to improve the understanding of the complex subject of penetration and perforation of concrete targets impacted by low-velocity *** main focus is on the damage mechanisms and the major factors that account for the target resistance of the *** improved continuous surface cap model recently proposed was *** model was first equipped with element erosion criteria and was adequately validated by comparisons with ballistic *** numerical simulations were carried out where the individual influence of tensile,shear,and volumetric behaviors(pore collapse)of a concrete target on its ballistic performance was *** demonstrated that cratering on the front face and scabbing on the rear face of the concrete target were mainly dominated by its tensile *** major target resistance came from the second tunneling stage which was primarily governed by the shear and volumetric behaviors of the ***,this study captured the pore collapse-induced damage phenomenon during the high-pressure tunneling stage,which has been extensively reported in experiments but has usually been neglected in previous numerical investigations.

关键词： Penetration Perforation Damage mechanism Target resistance Projectile impact Pore collapse

Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： Zhan Zhao Yan Zhang Fang qin Mingzhi Jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening *** this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration *** material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen *** dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was *** screening parameters were randomly selected,and the corresponding relationships were established as a ***,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,*** training results indicated that ANFIS models had good stability and *** flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

Reynolds-number scaling analysis on lift generation of a flapping and passive rotating wing with an inhomogeneous mass distribution

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Chinese Journal of Aeronautics 2024年第2期37卷 259-269页

作者： Suyang qin Haotian HANG Yang XIANG Hong LIU J.C.Wu center for aerodynamics school of aeronautics and astronauticsshanghai jiao tong universityshanghai 200240china

Insects usually fly by passively rotating wings,which has been applied to the design of flapping-wing Micro-Air Vehicles(MAVs)to reduce mechanical *** this paper,a robotic passive rotating-wing model is designed to investigate wing kinematics and lift generation,which are measured by a high-speed camera and a force transducer,*** addition,flow fields are measured using the Particle Image Velocimetry(PIV).Experimental results demonstrate that passive rotating motion has a coordinative relationship with actively stroking *** the stroke amplitude or frequency increases,the rotating amplitude is *** characterize the active stroking motion,a driving Reynolds number Redrivingis defined,which varies from 68 to 366 in this *** the gravity center of the wing towards trailing ed ge induces the increase of additional torque M,which decreases the wing rotating amplitude and promotes the advance of wing *** find that the timing of wing rotation is gradually delayed and the mean lift coefficient C^(-)_(L)monotonously decreases as *** increasing the additional torque M,C^(-)_(L)is slightly improved and approaches to the lift coefficient of a real fruit fly at driving Re approximately equal to *** instantaneous lifts combined with the vortical structures further demonstrate that the lift generation associated with wing rotation is mainly attributed to the growth of the LeadingEdge Vortex(LEV)and the passive wake capture *** wake capture is influenced by LEV,reversal stroke motion and wing additional torque together,which can only maintain the lift at a high level for a considerable *** high-lift generation mechanisms of flapping and passive rotating flight could shed light on the simplified design of MAVs and the improvement of their aerodynamic performance.

关键词： Flapping flight Unsteady lift Passive rotation Vortex flow Leading-edge vortex

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北京市幼儿园3～4岁儿童龋齿活动性研究

现代口腔医学杂志 2006年第6期20卷 640-642页

作者：李静秦满谢盼北京大学口腔医学院儿童口腔科 100081 北京市西城区妇幼保健所

目的调查北京市幼儿园3～4岁幼儿龋的患病情况，了解该年龄组儿童患龋的特点；并通过龋齿活动性实验研究，揭示这部分儿童口腔中细菌的产酸能力与龋齿严重程度的关系。方法以北京市5所幼儿园3～4岁的207名儿童为研究对象，行龋齿检查并... 详细信息

目的调查北京市幼儿园3～4岁幼儿龋的患病情况，了解该年龄组儿童患龋的特点；并通过龋齿活动性实验研究，揭示这部分儿童口腔中细菌的产酸能力与龋齿严重程度的关系。方法以北京市5所幼儿园3～4岁的207名儿童为研究对象，行龋齿检查并采集菌斑和软垢混合样本进行龋活动性（Cariostat，Sankin Co，Tokyo）检查。结果该年龄组儿童患龋率为47．34％；龋均dmft（s）：1．96±2，92（2．96±5．10），dt（s）=1，84±2．77（2．82±4，92）；患龋儿童的龋均为dmft（s）：4．14±3．00（6．24±5．88），dt（s）=3，90±2．86（5，94±5．70）；其中重度低龄儿童龋（SECC）患儿53名，SECC发病率为25．60％；龋齿活动性比较，发现患龋组与无龋组在Cariostat值分布上有显著差异（P〈0．01）。结论本年龄组儿童一旦患龋累及牙齿和牙面多，但是治疗率很低；患龋组比无龋组龋齿活动性高。使用Cariostat龋齿活动检测有助于筛选龋齿易感者。

关键词：低龄儿童龋齿重度低龄儿童龋龋活动性试验

体育拓展训练对大学生人际交往和人际信任影响的研究

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沈阳体育学院学报 2017年第3期36卷 89-92页

作者：秦曼董海军上海立信会计金融学院体育与健康学院上海201209 上海理工大学体育教学部上海200093

为探索体育拓展训练对大学生人际交往和人际信任的干预效果,采用实验法,以POMS量表、信任量表、人际关系综合诊断量表对117名实验班学生和112名对照班学生进行测评。结果表明:实验前对照班和实验班学生心境状态没有显著性差异;实验班学... 详细信息

为探索体育拓展训练对大学生人际交往和人际信任的干预效果,采用实验法,以POMS量表、信任量表、人际关系综合诊断量表对117名实验班学生和112名对照班学生进行测评。结果表明:实验前对照班和实验班学生心境状态没有显著性差异;实验班学生实验前后人际交往(P=0.043)和人际信任(P=0.003)两个变量均产生显著性正向变化;对照班学生人际交往(P=0.881)和人际信任(P=0.825)未产生显著性变化。认为体育拓展训练对大学生人际交往和人际信任具有正向促进作用。

关键词：体育拓展训练人际交往人际信任评价