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Experimental investigation of the relation between the surface integrity and bending fatigue strength of carburized gears

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Science China(Technological Sciences) 2023年第1期66卷 33-46页

作者： CHEN DiFa ZHU JiaZan LIU HuaiJu WEI PeiTang mao tianyu State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China China Gas Turbine Establishment Chengdu 710025China

Bending fatigue is an essential parameter that needs to be considered in the improvement process of the power density and reliability of gear drives. Quantitative relations among the manufacturing parameters, surface integrities, and fatigue performance are not clear, which seriously limits the effectiveness of an anti-fatigue design. For this work, tooth-bending fatigue tests of carburized gears with different surface integrities were performed using a pulsator. The effects of the manufacturing parameters and surface integrities on the gear fatigue, such as surface hardness and residual stress, were investigated. The experimental results revealed that due to the improvement of surface integrities after shot peening, the nominal bending stress number(fatigue limit) increased by 6.3%–31.1%, with an amplitude range of 39–143 MPa. A supervised learning algorithm of a random forest was implemented to determine the contribution of the surface hardness and surface residual stress to the nominal stress number. An empirical formula was proposed to predict the nominal stress number considering the surface integrities. The prediction error was less than 7.53%, as verified by several gear-bending fatigue tests. This provided theoretical support for the modern, anti-fatigue design of the gears.

关键词： carburized gear surface integrity bending fatigue design formula

Design optimization of a wind turbine gear transmission based on fatigue reliability sensitivity

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Frontiers of Mechanical Engineering 2021年第1期16卷 61-79页

作者： Genshen LIU Huaiju LIU Caichao ZHU tianyu mao Gang HU State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China

Fatigue failure of gear transmission is one of the key factors that restrict the performance and service life of wind *** of the major concerns in gear transmission under random loading conditions is the disregard of dynamic fatigue reliability in conventional design *** issues,such as overweight structure or insufficient fatigue reliability,require continuous improvements in the reliability-based design optimization(RBDO)*** this work,a novel gear transmission optimization model based on dynamic fatigue reliability sensitivity is developed to predict the optimal structural parameters of a wind turbine gear *** the model,the dynamic fatigue reliability of the gear transmission is evaluated based on stress–strength interference *** variables are determined based on the reliability sensitivity and correlation coefficient of the initial design *** optimal structural parameters with the minimum volume are identified using the genetic algorithm in consideration of the dynamic fatigue reliability *** of the initial and optimized structures shows that the volume decreases by 3.58%while ensuring fatigue *** work provides new insights into the RBDO of transmission systems from the perspective of reliability sensitivity.

关键词： gear transmission fatigue reliability reliabi-lity sensitivity parameter optimization

家喻户晓能否门庭若市?“网红城市”旅游形象符号演变与圈层结构研究

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旅游科学 2024年第6期38卷 75-95页

作者：陆宇彤黄燕玲黄毅姚建盛冯义杰毛甜雨桂林理工大学旅游与风景园林学院广西桂林541004 澳门旅游大学中国澳门999078 桂林理工大学漓江保护与发展研究院广西桂林541004

社交媒体影响与日俱增,旅游城市形象传播路径与内容日益多元化。文章从符号学视角出发,基于“主-客”视角,运用LDA主题模型对“需求方”——典型“网红城市”(重庆)2012—2021年游客网络游记进行分析,结合“供给方”——旅游城市官方发... 详细信息

社交媒体影响与日俱增,旅游城市形象传播路径与内容日益多元化。文章从符号学视角出发,基于“主-客”视角,运用LDA主题模型对“需求方”——典型“网红城市”(重庆)2012—2021年游客网络游记进行分析,结合“供给方”——旅游城市官方发文与热点事件,探究旅游目的地形象传播与旅游者感知热度变化的关系,提出并解析“核心层-中间层-边缘层”旅游符号圈结构。研究发现:“网红城市”旅游符号可分为参与体验、观光游览、文化知识、情感4种类型,参与体验型与观光游览型旅游符号游客感知热度较高;“网红城市”形象传播主要通过影视、综艺等媒介与明星/网红同款打卡驱使旅游者产生网络亚文化行为(“网红打卡”)并吸引潜在消费群体;在“核心层-中间层-边缘层”旅游符号圈结构中,观光游览型与文化知识型旅游符号主要分布于核心层与中间层,参与体验型旅游符号处于中间层和边缘层,情感型旅游符号位于边缘层与核心层。其中,边缘层旅游符号更能有效激发旅游者关注与认同,是旅游城市形象优化的重点路径。

关键词：旅游符号关注热度符号圈 TF-IDF LDA 目的地形象

Genome-wide identification and characterization of the bHLH gene family in an ornamental woody plant Prunus mume

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Horticultural Plant Journal 2022年第4期8卷 531-544页

作者： Yanyan Wu Sihui Wu Xueqin Wang tianyu mao Manzhu Bao Junwei Zhang Jie Zhang Key Laboratory of Horticultural Plant Biology(Ministry of Education) College of Horticulture and Forestry SciencesHuazhong Agricultural UniversityWuhan 430070China

The basic helix-loop-helix(bHLH)transcription factor family is the second-largest family in plants,where it plays essential roles in development,and the responses to multiple abiotic and biotic ***,little information is available about this gene family in Prunus mume,which is widely cultivated in East Asia as an ornamental fruit ***,100 PmbHLH genes were identified,and their evolution and functions were explored in *** for the first *** PmbHLH genes were classified into 21 *** chromosomal distribution,physicochemical properties,bHLH domain,conserved motif,and intron/exon compositions were also ***,the evolutionary pattern,divergence time of the PmbHLH family,and genetic relationships among ***,Arabidopsis thaliana,and Prunus persica and Fragaria vesca of Rosaceae were *** functional prediction analysis of these PmbHLHs indicated that their functions varied,and included participating in the formation of organs and tissues,responding to stress,and the biosynthesis and metabolism of hormones and other secondary ***,expression analyses of PmbHLHs also revealed diverse expression *** of the PmbHLH genes were highly expressed in roots and stems,and a few were highly expressed in leaves,buds,and fruits,indicating tissue expression *** PmbHLH genes,which were upregulated during low-temperature stress,may have critical roles in the response to cold *** PmbHLHs were differentially expressed between weeping and upright branches in a *** F_(1) *** results shed light on the structure and evolution of the PmbHLH gene family,and lay a foundation for further functional studies of the bHLH genes.

关键词： Prunus mume bHLH gene family Evolutionary analyses Functional prediction Expression pattern analyses

Numerical Modeling of Floating Oil Boom Motions in Wave-Current Coupling Conditions

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Journal of Ocean University of China 2017年第4期16卷 602-608页

作者： SHI Yang LI Shaowu ZHANG Huaqin PENG Shitao CHEN Hanbao ZHOU Ran mao tianyu State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Tianjin Research Institute for Water Transport Engineering Ministry of Transport

Containment booms are commonly used in collecting and containing spilled oil on the sea surface and in protecting specific sea areas against oil slick *** the present study,a numerical model is proposed based on the N-S equations in a mesh *** proposed model tracks the outline of the floating boom in motion by using the fractional area/volume obstacle representation *** boom motion is then simulated by the technique of general moving *** simulated results of the rigid oil boom motions are validated against the experimental ***,the failure mechanism of the boom is investigated through numerical *** on the numerical results,the effects of boom parameters and dynamic factors on the oil containment performance are also assessed.

关键词： floating oil boom hydrodynamic performance CFD

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翘嘴鳜肝脏组织原代细胞培养技术的建立

水产科学 2024年第5期43卷 808-816页

作者：罗寒雨刘笑郑菲菲毛天宇冯柯尧孙艳红祝东梅华中农业大学水产学院水产养殖国家级实验教学示范中心湖北武汉430070 武汉市农业科学院湖北武汉430345

运用组织块贴壁法、酶消化法、组织块联合酶消化法探究体质量(33.2±0.2)g翘嘴鳜肝脏组织原代细胞最适培养方法,采用3种培养基(M199培养基、L15培养基、M199-L15)、3种培养容器(12孔板、6孔板、T25培养瓶)及有无CO_(2)探究翘嘴鳜肝脏组... 详细信息

运用组织块贴壁法、酶消化法、组织块联合酶消化法探究体质量(33.2±0.2)g翘嘴鳜肝脏组织原代细胞最适培养方法,采用3种培养基(M199培养基、L15培养基、M199-L15)、3种培养容器(12孔板、6孔板、T25培养瓶)及有无CO_(2)探究翘嘴鳜肝脏组织原代细胞最适培养条件,采用线粒体16S rRNA基因序列和染色体数目鉴定细胞,研究氯化铵(0、1、5、10mmol/L)对细胞形态和增殖的影响。试验结果显示:0.25%胰蛋白酶-EDTA消化翘嘴鳜肝脏组织获得细胞,接种到T25培养瓶,生长培养基为M199-L15(体积比1∶1)混合培养基并添加20%体积胎牛血清,在28℃含5%CO_(2)的培养箱中培养,第2~3天贴壁细胞占瓶底的25%~30%,第4~5天细胞长满瓶底的70%~80%,第6~7天得到可传代的原代细胞;传代后细胞饱满、增殖能力强,为上皮样和成纤维样的混合,以成纤维样细胞为主,已传到10代;细胞线粒体16SrRNA基因测序结果与GenBank中基因序列(HQ731435.1)的一致率达99.05%,染色体数目为48条,证明此细胞来自翘嘴鳜;5mmol/L和10mmol/L氯化铵暴露对细胞形态和活力有显著影响(P<0.05)。本试验建立了翘嘴鳜肝脏组织原代细胞培养技术,为开展翘嘴鳜生物学、疾病学、营养学及遗传学等提供重要基础,同时为鱼类肝脏组织细胞原代培养和建系提供重要参考。

关键词：翘嘴鳜肝脏原代细胞培养技术

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鲫腹膜分布、组织学及光照对其影响研究

淡水渔业 2024年第4期54卷 32-38页

作者：毛天宇李明轩冯柯尧郑菲菲张亚倩孙艳红陈见祝东梅华中农业大学水产学院水产养殖国家级实验教学示范中心武汉430070 武汉市农业科学院武汉430345

腹膜在脊椎动物中普遍存在,由间皮细胞构成,通过结缔组织的支持作用形成的一层膜状组织,具有润滑、支持和保护等功能。鱼类有腹膜且分布有色素细胞,本研究选取常见经济鱼类鲫(Carassius auratus)为实验对象,采用组织学方法研究其腹膜分... 详细信息

腹膜在脊椎动物中普遍存在,由间皮细胞构成,通过结缔组织的支持作用形成的一层膜状组织,具有润滑、支持和保护等功能。鱼类有腹膜且分布有色素细胞,本研究选取常见经济鱼类鲫(Carassius auratus)为实验对象,采用组织学方法研究其腹膜分布及色素细胞形态特征,并探究光照条件对鲫腹膜色素细胞的影响。结果显示:(1)鲫腹膜呈黑色,腹腔腹壁内侧、心腹隔膜靠近腹腔一侧有明显分布,腹腔腹壁内侧黑色腹膜在腹腔上方延伸包裹性腺后相连覆于鳔下侧。(2)鲫腹膜黑色素细胞为黑色的树突状细胞。(3)鲫腹腔腹壁内侧腹膜的石蜡组织切片显示黑色素细胞连续分布形成黑色色素带,细胞核椭圆形、呈蓝紫色;扫描电镜下腹膜组织凹凸不平,由嵴组成多角形的网状结构;透射电镜下黑色素细胞有细胞核和黑素小体,黑素小体分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四个时期。(4)不同光照影响鲫腹腔腹壁内侧腹膜黑色素细胞的形态,光照组黑色素细胞胞体变大、分支变粗,呈色变深;黑暗组黑色素细胞胞体变小、分支变细长。本研究为鱼类腹膜系统研究提供理论参考。

关键词：鲫(Carassius auratus) 腹膜黑色素细胞电镜光照

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理论与实践视角下我国科技档案分类研究综述

档案学研究 2016年第6期 18-22页

作者：毛天宇中国科学院文献情报中心北京100190 中国科学院大学北京100049

本研究从基础理论与具体操作两个层面对国内科技档案分类研究状况进行总结分析,发现目前国内科技档案分类研究中实践操作层面问题研究多,理论总结性研究少;基础理论认识性研究多,档案分类原理方面研究少;实体分类研究多,信息分类研究少... 详细信息

本研究从基础理论与具体操作两个层面对国内科技档案分类研究状况进行总结分析,发现目前国内科技档案分类研究中实践操作层面问题研究多,理论总结性研究少;基础理论认识性研究多,档案分类原理方面研究少;实体分类研究多,信息分类研究少;传统环境下分类问题研究多,新环境下分类问题研究少。加强科技档案分类研究需要各方面探索齐头并进,有效协调,共同发展。

关键词：科技档案分类内容分析

我国科技档案研究的发展现状与研究特征--基于国内档案学核心期刊的文献计量分析

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档案与建设 2015年第9期 8-12页

作者：毛天宇中国科学院文献情报中心北京100190

研究数据来源基于中国期刊全文数据库,选取档案学核心期刊中科技档案主题研究的1553篇论文作为研究对象,运用文献计量学方法与统计软件对科技档案研究文献的年度载文、期刊载文、著者及机构发文等内容进行统计分析,并运用词频分析法总... 详细信息

研究数据来源基于中国期刊全文数据库,选取档案学核心期刊中科技档案主题研究的1553篇论文作为研究对象,运用文献计量学方法与统计软件对科技档案研究文献的年度载文、期刊载文、著者及机构发文等内容进行统计分析,并运用词频分析法总结归纳出国内科技档案研究呈现持续性、业务性、时代性、实践性特征及数字化的研究趋势。

关键词：科技档案文献计量发展现状研究特征