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Releasing Hope Largest-ever number of Chinese sturgeons released into the Yangtze River amid ongoing e"orts to conserve the endangered species
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作者 LI YIN 《ChinAfrica》 2024年第5期32-33,共2页
Over 200,000 Chinese sturgeons in di"erent age groups ranging from infant to 15 years old were released into the Yangtze River on 28 March during the annual release event designed to bolster the population of thi... Over 200,000 Chinese sturgeons in di"erent age groups ranging from infant to 15 years old were released into the Yangtze River on 28 March during the annual release event designed to bolster the population of this endangered species and raise public awareness.The event,organised by the Ministry of Agriculture and Rural A"airs of China and China Three Gorges Group(CTG),took place in Yichang City,central China’s Hubei Province. 展开更多
关键词 Yangtze Rural easing
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Structural Design of Roadbed and Pavement in Transition Section of Roads and Bridges
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作者 Bai Fan 《Journal of World Architecture》 2024年第4期21-26,共6页
As the lifeline of social development,road and bridge projects are the main channel to realize resource transportation and economic circulation.Ensuring the quality of road and bridge project construction is crucial f... As the lifeline of social development,road and bridge projects are the main channel to realize resource transportation and economic circulation.Ensuring the quality of road and bridge project construction is crucial for the development of society,the economy,and people’s livelihoods.This paper studies the design of roadbed pavement structures in road and bridge transition sections.It aims to provide technical references and significance for China’s road and bridge engineering design and construction units,promoting scientific and standardized design in these actions.This will contribute to the safety and stable operation of road and bridge projects,offering effective technical support.Furthermore,it seeks to foster the sustainable and healthy development of China’s road and bridge engineering on a macro level. 展开更多
关键词 Road and bridge transition section Roadbed pavement structure design Lap plate Easing transition section Drainage system
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Breeding and Application of Japonica CMS Line Yangfujing 7A with Fine Grain Quality, Disease Resistance and High Combining Ability in Rice
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作者 周根友 夏华 《Agricultural Science & Technology》 CAS 2017年第2期377-379,共3页
Yangfujing 7A, derived from the cross between Xu 9201A and Yangfujing 7 and its successive backcrosses, is a BT-type japonica CMS line developed by the Agricultural Institute of Riparian Region of Jiangsu Province. It... Yangfujing 7A, derived from the cross between Xu 9201A and Yangfujing 7 and its successive backcrosses, is a BT-type japonica CMS line developed by the Agricultural Institute of Riparian Region of Jiangsu Province. It shows good integrat- ed characteristics, stable male sterility, good flowering habits, high out crossing rate, strong disease resistance, fine grain quality (reaching the 1st class of national standards for fine quality rice) and high combining ability. In 2012, it was technically identified in Jiangsu Province. Its F1 hybrid combination Tongyoujingl (Yangfujing 7 A/R98), showing high yield and good grain quality, was registered and released to commercial production by Jiangsu Crop Variety Appraisal Committee in 2013. 展开更多
关键词 Japonica hybrid rice CMS line Yangfujing 7A Fine grain quality Dis- ease resistance BREEDING
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Ease-off修形高减速比准双曲面齿轮接触仿真与动态性能试验
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作者 古德万 魏冰阳 +1 位作者 任明辉 何宏图 《机械传动》 北大核心 2023年第5期128-133,142,共7页
针对高减速比准双曲面(High Reduction Hypoid,HRH)齿轮大轮齿廓曲率不足、小轮大螺旋角齿面高度扭转的问题,提出了大轮采用刀具修形以实现齿面点接触的方法,小轮采用一般滚切法,简化机床加工参数;建立了大、小轮的三维模型,Ease-off拓... 针对高减速比准双曲面(High Reduction Hypoid,HRH)齿轮大轮齿廓曲率不足、小轮大螺旋角齿面高度扭转的问题,提出了大轮采用刀具修形以实现齿面点接触的方法,小轮采用一般滚切法,简化机床加工参数;建立了大、小轮的三维模型,Ease-off拓扑曲面;解析了接触路径、差曲率、传动误差等齿面接触性能参数;通过三维运动仿真对比修形前后齿面的接触区,修形后避免了边缘接触,接触区位于齿面中部靠近小端,与齿轮实际接触斑点一致。完成了HRH齿轮减速器动态性能试验,齿轮啮合传动性能优良,啮合质量稳定,验证说明所设计的HRH齿轮修形量控制合理、理论计算与运动仿真正确。 展开更多
关键词 准双曲面齿轮 刀具修形 差曲面 运动仿真 振动
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SARS-CoV-2 getting into the brain;neurological phenotype of COVID-19,and management by nano-biotechnology
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作者 Małgorzata Kujawska Ebrahim Mostafavi Ajeet Kaushik 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第3期519-520,共2页
Human coronavirus infection getting into the brain:By February 2022,the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection,causing the coronavirus disease 2019(COVID-19)outbreak,has infected around 4... Human coronavirus infection getting into the brain:By February 2022,the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection,causing the coronavirus disease 2019(COVID-19)outbreak,has infected around 415 million people,and caused~5.8 million deaths worldwide(WHO,https://covid19.who.int/).As SARS-CoV-2 replicates during the infection,it undergoes genetic mutation to generate variants with varying characteristics and mutation frequencies.The emerging,over time,new variants that differ with transmissibility,immunity,and infection severity pose continuous challenges to established COVID-19 management strategies and regulations.Several SARS-CoV-2 variants such as Omicron(B.1.1.529),Delta(B.1.617.2),UK(B.1.17),South Africa(B.1.351),Brazil(P.1),and New York B.1.525-B.1.526 were detected worldwide and accelerated severity of COVID-19 pandemic(Figure 1A;McQuaid et al.,2021). 展开更多
关键词 IMMUNITY FIGURE getting
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Quantitative Easing: Money Supply and Commodity Prices of Oil, Gold, and Cocoa in Ghana
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作者 Samuel Kwaku Obeng Samuel Bassah Kofi Quansah +3 位作者 Theresa Dowetin Ampem Darko Nsiah Ezekiel Nii Noye Nortey Ebenezer Okyere 《Open Journal of Statistics》 2023年第5期663-693,共31页
This study investigates the dynamic relationships between the money supply (M2) and key commodity prices (Cocoa, Gold, and Crude) in the context of Ghana. Utilizing Vector Error Correction Model (VECM) analysis, we an... This study investigates the dynamic relationships between the money supply (M2) and key commodity prices (Cocoa, Gold, and Crude) in the context of Ghana. Utilizing Vector Error Correction Model (VECM) analysis, we analyze the short-term and long-term Granger causality relationships among these variables, aiming to shed light on the potential linkages between monetary policy and commodity markets. The analysis covers the period from December 1999 to April 2023, using lag structures of 1 and 8 to capture both short-term and more enduring effects. Our findings reveal significant Granger causality relationships between the money supply and various commodities, with nuanced patterns emerging across different lags. In the short-run, our results suggest bidirectional causal relationships between COCOA and M2, CRUDE and M2, and GOLD and M2. Additionally, M2 Granger causes changes in COCOA, CRUDE, and GOLD. However, the causal relationship between COCOA and GOLD appears to be unidirectional, with COCOA not significantly Granger causing changes in GOLD. The short-term findings highlight the intricate interplay between monetary policy and commodity markets. In the long-run (lag 8), our analysis unveils robust Granger causality relationships between the variables. Past values of COCOA, CRUDE, and GOLD Granger cause changes in M2, indicating a notable influence of commodity markets on the money supply. Similarly, M2 Granger causes changes in CRUDE and GOLD. Notably, the findings underscore a more comprehensive and intertwined relationship between monetary policy and commodity prices in the long-run. Based on these results, we derive several policy implications. Policymakers should carefully consider the potential impact of monetary policy decisions, such as quantitative easing, on commodity markets and price dynamics. Measures to stabilize commodity prices, promote export diversification, manage inflation expectations, and enhance economic resilience are recommended. Additionally, effective data monitoring, international collaboration, and proactive risk management strategies are essential components for navigating the complex interactions between monetary policy and commodity markets. This study contributes to a deeper understanding of the intricate connections between monetary policy and commodity prices in Ghana, offering insights for policymakers, researchers, and stakeholders seeking to promote sustainable economic growth and stability. Further research can delve into the mechanisms underlying these relationships and explore their broader implications for trade balances, economic performance, and policy formulation. 展开更多
关键词 Quantitative Easing Money Supply Cocoa GOLD CRUDE VECM
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Getting the Gist of Chinese Modernization
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作者 AUGUSTO SOTO 《China Today》 2023年第4期48-50,共3页
The Chinese modernization, though sharing certain elements with other modernization processes in contemporary history, is characterized by features unique to the Chinese context.
关键词 MODERNIZATIon ConTEMPORARY getting
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Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases 被引量:5
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作者 Yanna Ko Rhys Butcher Rupert W Leong 《World Journal of Gastroenterology》 SCIE CAS 2014年第5期1238-1247,共10页
Inflammatory bowel diseases(IBD)are idiopathic chronic diseases of the gastrointestinal tract well known to be associated with both genetic and environmental risk factors.Permissive genotypes may manifest into clinica... Inflammatory bowel diseases(IBD)are idiopathic chronic diseases of the gastrointestinal tract well known to be associated with both genetic and environmental risk factors.Permissive genotypes may manifest into clinical phenotypes under certain environmental influences and these may be best studied from migratory studies.Exploring differences between first and second generation migrants may further highlight the contribution of environmental factors towards the development of IBD.There are few opportunities that have been offered so far.We aim to review the available migration studies on IBD,evaluate the known environmental factors associated with IBD,and explore modern migration patterns to identify new opportunities and candidate migrant groups in IBD migration research. 展开更多
关键词 Inflammatory bowel disease Crohn’ s disease Ulcerative colitis Epidemiology Risk factor Environment Hygiene hypothesis
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The Biomechanical Aetiology of the So-Called Idiopathic Scoliosis. The Role of Gait and Standing at “Ease” on the Right Leg in the Development of the Deformity
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作者 Tomasz Karski Jacek Karski 《Surgical Science》 2014年第2期33-38,共6页
The article presents the biomechanical etiology of the so-called idiopathic scoliosis. The research was conducted in the years 1985-2013, but the importance of the observations connected with the so-called idiopathic ... The article presents the biomechanical etiology of the so-called idiopathic scoliosis. The research was conducted in the years 1985-2013, but the importance of the observations connected with the so-called idiopathic scoliosis were completed in 2007 (4, 5, 6, 7, 8, 9). All types of spine deformity are proved to have a connection with gait and with standing “at ease” on the right leg. Every type of scoliosis begins to develop at the age of 2 - 3. The article provides short information about new screening tests and new exercises in the course of causal prophylaxis and treatment. 展开更多
关键词 BIOMECHANICAL AETIOLOGY of Idiopathic Scoliosis GAIT and STandING “At ease on the Right Leg in the Development of the DEFORMITY
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基于齿面Ease off拓扑的弧齿锥齿轮齿面偏差等效修正方法 被引量:8
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作者 聂少武 邓静 +2 位作者 邓效忠 杨建军 李聚波 《中国机械工程》 EI CAS CSCD 北大核心 2017年第20期2434-2440,共7页
为提高弧齿锥齿轮齿面修正的效率,提出了一种仅修正小轮齿面偏差的等效修正方法。通过比较实测齿面与设计齿面Ease off之间的失配值,计算出小轮齿面等效偏差。通过建立齿面等效偏差与加工参数之间的修正数学模型,反求出满足理论失配要... 为提高弧齿锥齿轮齿面修正的效率,提出了一种仅修正小轮齿面偏差的等效修正方法。通过比较实测齿面与设计齿面Ease off之间的失配值,计算出小轮齿面等效偏差。通过建立齿面等效偏差与加工参数之间的修正数学模型,反求出满足理论失配要求的小轮加工参数。实验结果表明:通过对小轮齿面偏差进行等效修正,小轮实际齿面与大轮实际齿面之间的失配值与设计值误差在5μm以内,传动误差幅值与理论值相差0.5″,实际齿面啮合结果满足理论设计要求。 展开更多
关键词 弧齿锥齿轮 齿面ease off拓扑 齿面偏差 等效修正
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Application of Chaihu plus Longgu Muli Decoction in Treatment of Physical and Mental Diseases
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作者 Bochao SU Yingfeng LIU 《Medicinal Plant》 CAS 2020年第2期79-81,共3页
Chaihu plus Longgu Muli Decoction is the representative treatment method of harmonizing and releasing combined with easing for lesser yang disease proposed by famous physician Zhang Zhongjing.Through clinical cases,th... Chaihu plus Longgu Muli Decoction is the representative treatment method of harmonizing and releasing combined with easing for lesser yang disease proposed by famous physician Zhang Zhongjing.Through clinical cases,this paper firstly introduced the main framework of Chaihu plus Longgu Muli Decoction,to make the treatment method of harmonizing and releasing become more flexible in clinical application.Besides,it introduced the common changes in the learning and application of the decoction,to respond to various changes in the clinical diseases. 展开更多
关键词 Chaihu PLUS Longgu Muli DECOCTIon Harmonizing and RELEASING combined with easing Physical and MENTAL diseases KNOWING the unchanging rule to MAKE changes
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Investigating the Impact of Familiarity and Product Conditions on The Ease of Use of a Product
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作者 Aththanayake Chandima Gayan PERERA 《Instrumentation》 2021年第2期40-48,共9页
Ease of use is one of the main criteria that customers consider when making a purchase decision.To provide a pleasant experience to the customers,offering products or services consisting of advanced features and funct... Ease of use is one of the main criteria that customers consider when making a purchase decision.To provide a pleasant experience to the customers,offering products or services consisting of advanced features and functions is no longer enough,due to the existing competition in the global market.In reality,the ease of use of any product is influenced by the conditions of the product and the familiarity of the user.This study examines the influence of the familiarity and the product conditions on the ease of use of a product.This only explains how the conditions of the product and the familiarity of the user,influence on the ease of use of a product when the usage hours of a product increases.A case study would be conducted to validate the results.The results of this study indicate that in the case where both the product conditions and the familiarity has been varied,the ease of use of the product has been increased from 0.229 to 0.380 gradually within the 10 weeks period.Through these results valuable guidance could be obtained by the manufacturers to identify how the ease of use level of a product deviates from the standard level when the usage hours of the product would increase. 展开更多
关键词 ease of Use Product Conditions FAMILIARITY
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基于Ease-off的螺旋锥齿轮齿面分区修形方法 被引量:7
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作者 严宏志 肖蒙 +2 位作者 胡志安 艾伍轶 明兴祖 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2018年第4期824-830,共7页
为预控双重螺旋法加工的螺旋锥齿轮的啮合性能,研究基于Ease-off的螺旋锥齿轮齿面修形方法。用大轮理论齿面展成得到小轮共轭齿面,基于预设的对称抛物线传动误差和接触迹,将齿面划分为小端、中间接触区、大端共3个区域,并基于局部共轭... 为预控双重螺旋法加工的螺旋锥齿轮的啮合性能,研究基于Ease-off的螺旋锥齿轮齿面修形方法。用大轮理论齿面展成得到小轮共轭齿面,基于预设的对称抛物线传动误差和接触迹,将齿面划分为小端、中间接触区、大端共3个区域,并基于局部共轭原理沿啮合线方向对3个区域进行3段抛物线修形,得到目标齿面;采用Ease-off齿面接触分析方法,对得到的目标齿面啮合性能进行分析。研究结果表明:传动误差的形状、幅值、接触迹线与接触印痕达到预置要求;分区修形方法为双重螺旋法加工的齿轮工作齿面、非工作齿面同步分区修形优化提供了新途径。 展开更多
关键词 螺旋锥齿轮 ease-off 分区修形 齿面接触
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Ease-off拓扑修正的准双曲面齿轮齿面修形方法 被引量:20
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作者 聂少武 蒋闯 +3 位作者 邓效忠 苏建新 杨建军 王建华 《中国机械工程》 EI CAS CSCD 北大核心 2019年第22期2709-2715,2740,共8页
为了提升驱动桥准双曲面齿轮传动的啮合性能,针对准双曲面齿轮刀倾半展成法(HFT)提出一种Ease-off拓扑修正方法。在建立齿面共轭啮合数学模型的基础上,推导出小轮基准齿面方程,通过计算小轮实际齿面与基准齿面之间的偏差,构建出Ease-of... 为了提升驱动桥准双曲面齿轮传动的啮合性能,针对准双曲面齿轮刀倾半展成法(HFT)提出一种Ease-off拓扑修正方法。在建立齿面共轭啮合数学模型的基础上,推导出小轮基准齿面方程,通过计算小轮实际齿面与基准齿面之间的偏差,构建出Ease-off拓扑。借助二阶多项表达式对Ease-off拓扑分解,计算出齿面失配系数,通过调整齿面失配系数构建出修正Ease-off拓扑。通过比较当前Ease-off拓扑与修正Ease-off拓扑,消除小轮当前齿面与修正齿面之间的偏差,反求出小轮加工参数。最后以一对准双曲面齿轮为例进行齿面拓扑修形与磨齿加工,实际齿面印痕与仿真结果一致,验证了齿面拓扑修形方法的有效性。齿面加载接触分析结果表明,修形后齿面接触应力分布得到了改善,实际载荷下齿面接触重合度增加,从而验证了修形方案的合理性。 展开更多
关键词 准双曲面齿轮 共轭齿面 ease-off修正 拓扑修形 加载接触分析
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Study on the Relation between Garment Style and Ease Distribution 被引量:12
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作者 王朝晖 张渭源 《Journal of Donghua University(English Edition)》 EI CAS 2004年第6期31-37,共7页
The shape of body and the ease of garment are the important elements in constructing garment style. However, the distribution of ease in garment is uneven and the curves showing different cross-sections of garment sty... The shape of body and the ease of garment are the important elements in constructing garment style. However, the distribution of ease in garment is uneven and the curves showing different cross-sections of garment style with ease are unavailable in the literature. This information is crucial when the three-dimensional garment style is transformed into two-dimensional garment patterns. Thus, several different X-line style garments are produced by 3D draping technology, and the cubic spline is used to fit the cross sectional curves of BL, WL of body and garment. By comparing cross sections of body and garment, the ease at different location can be derived. Besides, garments in 10 different dimensions and quantities of style ease are included in the current study. By numerical operation on discrete ease data at different location, the fitted functions of ease distribution are obtained. 展开更多
关键词 draping flat pattern design eases allowance ease distribution curve FITTING
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Ease-off拓扑修形准双曲面齿轮齿面数控修正 被引量:10
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作者 蒋进科 方宗德 刘红梅 《重庆大学学报》 EI CAS CSCD 北大核心 2021年第2期25-33,共9页
为了改善汽车驱动桥综合传动性能,提出基于ease-off拓扑修形准双曲面齿轮设计与加工方法。预置传动误差及抛物线修形参数设计小轮法向自由ease-off拓扑修形曲面,建立小轮拓扑修形齿面模型,可以准确获得任意自由ease-off修形齿面的解析... 为了改善汽车驱动桥综合传动性能,提出基于ease-off拓扑修形准双曲面齿轮设计与加工方法。预置传动误差及抛物线修形参数设计小轮法向自由ease-off拓扑修形曲面,建立小轮拓扑修形齿面模型,可以准确获得任意自由ease-off修形齿面的解析表达式。结合齿面承载接触分析(loaded tooth contact analysis,LTCA)方法,优化承载传动误差幅值(amplitude of loaded transmission error,ALTE)为最小,确定最优ease-off曲面参数,并推导其相对小轮理论齿面的目标修形量。基于刀具和计算机数控(CNC)机床各运动轴参数误差敏感性的齿面修正模型,分析各参数扰动对齿面误差的影响,进而确定合理的参数边界,以目标修形量误差平方和最小为目标函数,通过最小二乘法确定最优ease-off拓扑修形齿面的加工参数。结果表明:CNC机床各轴主要引起齿厚和对角修正,增加刀刃修正可以实现ease-off拓扑修形齿面的高精度修正,为高性能齿面自由ease-off修形设计与加工提供理论参考。 展开更多
关键词 准双曲面齿轮 ease-off拓扑修形 CNC面铣 齿面校正 承载传动误差
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齿面磨损最小直齿锥齿轮Ease-off修形设计与分析 被引量:6
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作者 蒋进科 刘钊 刘红梅 《西安交通大学学报》 EI CAS CSCD 北大核心 2020年第6期99-106,共8页
为了改善齿轮传动性能和可靠性,提出了直齿锥齿轮齿面抗磨设计与分析方法。该方法结合碟型刀具在摇台型机床切制直齿锥齿轮方法获得大轮齿面;通过预置传动误差及抛物线修形参数设计小轮法向Ease-off曲面,并叠加于大轮的共轭齿面表达修... 为了改善齿轮传动性能和可靠性,提出了直齿锥齿轮齿面抗磨设计与分析方法。该方法结合碟型刀具在摇台型机床切制直齿锥齿轮方法获得大轮齿面;通过预置传动误差及抛物线修形参数设计小轮法向Ease-off曲面,并叠加于大轮的共轭齿面表达修形齿面。结合齿面接触分析、承载接触分析、Archard磨损公式,提出考虑磨损深度影响的齿面承载接触分析数值方法,将齿面几何分析与力学分析融为一体,且充分考虑了安装误差、齿面修形和磨损的耦合性,可准确快速获得齿形重构后的齿面磨损量;以无磨损时承载传动误差幅值(ALTE)最小、齿面磨损次数最多进行修形优化设计,获得最优Ease-off曲面,并分析磨损对ALTE的影响。结果表明:相同磨损量下,随载荷的增加磨损次数逐渐减少且趋于相等;随齿形重构次数增加,主要是双齿啮合区的齿面初始间隙增加,导致承载变形增大;多载荷工况下,随磨损次数增加最小ALTE及其对应的载荷逐渐增大;共轭齿面轻度磨损后ALTE有所改善。 展开更多
关键词 直齿锥齿轮 ease-off修形 齿面磨损 承载接触分析
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Ease-Off修形准双曲面齿轮减振优化设计 被引量:7
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作者 蒋进科 刘钊 彭先龙 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2020年第5期134-141,148,共9页
为了改善汽车驱动桥动态性能,提出基于Ease-off修形准双曲面齿轮齿面减振优化设计方法。该方法通过预置传动误差参数及抛物线修形参数设计小轮法向Ease-off曲面,小轮修形齿面表示为与大轮共轭的小轮齿面叠加Ease-off曲面。结合齿面接触... 为了改善汽车驱动桥动态性能,提出基于Ease-off修形准双曲面齿轮齿面减振优化设计方法。该方法通过预置传动误差参数及抛物线修形参数设计小轮法向Ease-off曲面,小轮修形齿面表示为与大轮共轭的小轮齿面叠加Ease-off曲面。结合齿面接触分析(TCA)、齿面承载接触分析(LTCA)方法获得齿轮啮合刚度。以啮合位置受力分析为基础,应用集中质量法建立准双曲面齿轮弯-扭-轴耦合动力学模型,采用数值方法求解运动微分方程得到系统的振动响应。以法向振动加速度均方根最小为优化目标获得最佳修形齿面,并分析修形导致的刚度波形及幅值变化对系统动态性能的影响。算例表明:当修形量过大时导致刚度下降较多,引起法向振动增加;修形齿面的平均啮合刚度相差不大情况下,刚度曲线的形状较幅值对振动的影响更为敏感;最优Ease-off修形后系统振动明显降低,齿轮副的平均啮合刚度下降较少且刚度曲线中主要为啮合频率,基本无倍频成分;修形齿面承载传动误差幅值(ALTE)降低且曲线中的高频成分增加时,未必能减小振动;多载荷ALTE曲线基本可以反映振动随载荷的变化趋势。 展开更多
关键词 准双曲面齿轮 ease-off修形 振动 啮合刚度 承载传动误差 承载接触分析
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Ease-off拓扑修形准双曲面齿轮齿面多目标优化设计方法 被引量:17
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作者 蒋进科 方宗德 刘钊 《西安交通大学学报》 EI CAS CSCD 北大核心 2019年第6期44-53,共10页
为了提高汽车驱动桥综合传动性能,提出基于ease-off拓扑修形准双曲面齿轮齿面多目标优化设计方法。预置传动误差参数及抛物线修形参数设计小轮法向ease-off曲面,小轮修形齿面表示为大轮的共轭齿面叠加ease-off曲面。结合齿面接触分析(T... 为了提高汽车驱动桥综合传动性能,提出基于ease-off拓扑修形准双曲面齿轮齿面多目标优化设计方法。预置传动误差参数及抛物线修形参数设计小轮法向ease-off曲面,小轮修形齿面表示为大轮的共轭齿面叠加ease-off曲面。结合齿面接触分析(TCA)、齿面承载接触分析(LTCA)方法及齿轮摩擦理论最新进展,得到接触线离散点的滑动速度、啮合承载变形、载荷分布及局部摩擦系数,进而确定齿面瞬时啮合效率和Block闪温。以承载传动误差幅值(ALTE)最小、齿面闪温最小和平均啮合效率最大进行多目标优化,获得最佳修形齿面,并分析齿面滑动速度与综合曲率半径的变化及重合度对啮合性能的影响。算例表明:最优ease-off修形齿面在啮入、啮出端有足够的抛物线传动误差,可有效减小ALTE并降低安装误差的敏感性;在整个齿高方向有一定的齿廓修形且接触迹线角较小时,齿轮副则有较大重合度,且齿顶、齿根载荷向节线附近集中,而节线附近的滑动速度较小,导致接触线平均摩擦系数下降,因此,啮合效率增加,齿面闪温下降;齿面适配量过大时,接触线载荷增加,摩擦功耗增大,啮合效率减小。 展开更多
关键词 准双曲面齿轮 ease-off拓扑修形 齿面闪温 啮合效率 承载传动误差 承载接触分析
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Investigation of Jacket Silhouette Based on Ease Distribution 被引量:1
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作者 王朝晖 NG Roger NEWTON Edward 《Journal of Donghua University(English Edition)》 EI CAS 2014年第3期316-319,共4页
The silhouette of women's garment is diversified in its design. In this paper,a new model was developed to predict the silhouette of jacket for the given girth measurements. Sixty-three princess-seam women's j... The silhouette of women's garment is diversified in its design. In this paper,a new model was developed to predict the silhouette of jacket for the given girth measurements. Sixty-three princess-seam women's jackets with seven styles and nine girth dimensions of each style were produced. Their ease distribution was investigated at bustline,waistline,and hipline,respectively. The widths of the cross-sections for bustline,waistline,and hipline were formulated by multiple linear regressions. Then the silhouette was captured from the ratio of waist width to bust width of a designed jacket,together with that of waist width to hip width. 展开更多
关键词 GARMENT SILHOUETTE ease allowance ease distribution
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