Results 31 to 40 of about 8,397 (234)

Research on Force Transmission of the Artificial Hip Prosthesis and Osseointegration [PDF]

open access: yes, 2016
随着中国社会老龄化进程不断推进,由股骨头坏死、关节病变、骨折等原因产生的全髋关节置换手术量呈现逐年上升的趋势。 全髋关节置换手术利用人工髋关节假体置换病变的髋关节,假体一端与股骨髓腔装配,另一端与髋臼连接。人工髋关节假体置换失败的主要因素是影响假体近端骨整合的应力遮蔽,直柄假体与髓腔远端匹配度较低导致的假体无菌松动。 人工髋关节假体置换中的应力遮蔽、无菌松动等问题与假体的力传递特性密切相关。当假体上的力无法传导到股骨近端时,股骨近端将产生骨溶解,无法使假体与股骨形成良好的整合,假体在髓腔中的稳定性不足 ...
王爱民
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Research and Development of a New Type of Walking Aids for Lower Limbs [PDF]

open access: yes, 2017
目的设计一种新型助行器,要求能够分散受力点,减少上半身体部分局部受力以尽量避免腋部并发症与不适感,同时要求结构简单,制造方便。方法应用Solidwork软件进行结构设计:主体略呈长“T”形,主要包括腋托、手把、小腿支撑、拐杖脚等部分。主体及各主要部分受力情况采用ABAQUS软件进行有限元分析。结果采用普通304不锈钢管材制造的助行器符合强度要求。结论设计的新型助行器具有结构简单、使用方便、安全可靠、操作流程易懂的特点,可满足不同状态下的需求和不同高度人体的使用。研制出的新型下肢助行器 ...
侯亮   +4 more
core   +1 more source

A cross‐linguistic approach to investigating metacognitive regulation in writing among Chinese EFL learners: Insights for its trait/state distinction

open access: yesInternational Journal of Applied Linguistics, Volume 35, Issue 1, Page 274-290, February 2025.
Abstract Metacognitive regulation refers to learners’ ability to use a repertoire of metacognitive strategies to guide, observe, and manage thoughts, actions, and emotions in learning activities. It has been widely acknowledged as a significant predictor of language learning success, including writing.
Wandong Xu, Xinhua Zhu
wiley   +1 more source

Nonlinear finite element analysis for seismic performance of high-strength concrete beam-column joints with new reinforcement details [PDF]

open access: yes, 2006
Because the factors that affect the behavior of the beam-column joints are complicated, an experimental study alone is not sufficient. Therefore, a nonlinear finite element analysis was conducted to provide better understanding of the performance of the ...
Gan, L, Li, J, Pam, HJ
core  

钢管壁哑铃形屈服线模式及承载力计算方法

open access: yesJianzhu Gangjiegou Jinzhan, 2022
基于组件法将钢梁-钢管柱螺纹锚固单边螺栓平齐端板连接简化为T形件-钢管模型,并利用参数化的有限元模型分析了T形件-钢管节点在单向拉伸荷载作用下钢管壁平面外受拉性能,发现了钢管柱壁新型的哑铃形屈服线模式。通过虚功原理,建立了钢管壁发生该屈服线模式的塑性极限承载力的计算方法。对不同参数的T形件-钢管节点钢管壁平面外受拉承载力进行了有限元分析,钢管柱壁塑性极限承载力的计算结果与有限元分析结果基本吻合。
刘闵   +6 more
doaj  

Radiological findings in the proximal sesamoid bones of yearling and 2‐year‐old Thoroughbred sales horses: Prevalence, progression and associations with racing performance

open access: yesEquine Veterinary Journal, Volume 57, Issue 1, Page 87-100, January 2025.
Abstract Background Radiological findings in the proximal sesamoid bones (sesamoids) are a persistent source of controversy at Thoroughbred sales, due to inconsistent classification and conflicting assignment of potential clinical importance. Objectives To define the prevalence of sesamoid findings on sales repository radiographs in yearling and 2‐year‐
Frances J. Peat   +5 more
wiley   +1 more source

Behavior of a Flexspline in Harmonic Drive [PDF]

open access: yes, 1900
谐波齿轮传动是利用柔性工作构件的弹性变形波进行运动或者动力传递的一种新型传动方式,因其具有体积小、重量轻、精度高、单级传动比大、承载能力高等诸多优点,在航空航天、机器人、数控机床等领域得到了广泛的应用。柔轮作为谐波齿轮传动的关键构件很大程度上影响了谐波齿轮传动的承载能力、使用寿命等。柔轮为弹性薄壁件,在交变载荷作用下易导致齿面磨损和疲劳断裂。柔轮强度、变形与应力分析对谐波齿轮传动过程中的疲劳断裂评估及传动性能研究具有重要的意义。 本文首先根据已知参数、实际工况和谐波齿轮传动啮合参数选取原则 ...
刘淳剑
core  

新型无刷直流电机有限元分析及系统试验研究 The Finite Element Analysis and System Experimental Study of Novel BLDCM

open access: yes, 2016
无刷直流电机以其结构简单、效率高及易于控制等特点,已在汽车、航天、家用电器等领域得到了广泛的应用。新型无刷直流电机是在传统无刷直流电机的基础上提出的新结构电机,该电机采用双组凸极定转子结构,并利用中央线圈替代了转子永磁体励磁,具有高气隙磁通、启动转矩大的特点。该文对电机的结构及工作原理进行了介绍。根据电机结构的基本参数,构建电机的三维模型,运用三维有限元仿真对电机的电磁特性和机械运动特性进行研究,并通过空载实验验证了新型无刷直流电机不但具有传统无刷直流电机结构简单,可靠性高的特点,而且效率高、扩速能力强,
吴冠霖, 丁惜灜, 刘爱民
semanticscholar   +1 more source

Evaluating use of two‐step International Ovarian Tumor Analysis strategy to classify adnexal masses identified in pregnancy: pilot study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 64, Issue 6, Page 808-817, December 2024.
ABSTRACT Objectives The primary aim was to validate the International Ovarian Tumor Analysis (IOTA) benign simple descriptors (BDs) followed by the Assessment of Different NEoplasias in the adneXa (ADNEX) model, if BDs cannot be applied, in a two‐step strategy to classify adnexal masses identified during pregnancy. The secondary aim was to describe the
J. Barcroft   +8 more
wiley   +1 more source

Design and Simulation of Contact Fatigue Testing System of Flexspline and Circular Spline in Harmonic Drive [PDF]

open access: yes, 2016
谐波齿轮传动是随着空间技术的发展而诞生的一种新型传动方式,其工作原理是利用柔轮的弹性变形波来实现运动或者动力传递,因其具有结构简单、传动精度高、传动比大等诸多优点,在航空、航天、机器人等领域得到了广泛应用。在谐波齿轮传动过程中,柔轮的运动情况比较复杂,作为弹性薄壁构件需承载交变应力,容易造成齿面磨损和疲劳断裂。因此,建立合适的模型对谐波齿轮传动过程中柔轮的错齿运动进行模拟分析具有重要意义。 本文首先针对谐波齿轮传动过程中柔轮的错齿运动设计了一种新的接触疲劳试验装置 ...
吴泽林
core  

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