台州学院材料成型及控制工程专业毕业设计模式的创新实践     

程虎 《台州学院学报》2009,31(3):90-94

文章结合当前模具企业对模具设计人才需求的现状以及本校材料成型及控制工程专业的培养目标,介绍了2005级材料成型及控制工程专业毕业设计的创新实践过程,并建立了一套经实践证明可行的材料成型及控制工程专业毕业设计模式,即CAD/CAE/CAM技术与毕业设计内容紧密结合的毕业设计模式,同时指出了毕业设计内容同先进设计方法相结合的重要性。  相似文献   

Greater lower limb flexion in gymnastic landings is associated with reduced landing force: a repeated measures study     

Allana Slater  Anne Smith  Leon Straker 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):45-56

High impact forces during gymnastic landings are thought to contribute to the high rate of injuries. Lower limb joint flexion is currently limited within gymnastic rules, yet might be an avenue for reduced force absorption. This study investigated whether lower limb flexion during three gymnastic landings was related to force. Differences between landings were also explored. Twenty-one elite women's artistic gymnasts performed three common gymnastic techniques: drop landing (DL), front and back somersaults. Ankle, knee, and hip angles, and vertical ground reaction force [(vGRF) magnitude and time to peak], were measured using three-dimensional motion analysis and force platform. The DL had significantly smaller peak vGRF, greater time to peak vGRF and larger lower limb flexion ranges than landing from either somersault. Peak vGRF and time to peak vGRF were inversely related. Peak vGRF was significantly reduced in gymnasts who landed with greater hip flexion, and time to peak was significantly increased with increasing ankle, knee, and hip flexion. Increased range of lower limb flexion should be encouraged during gymnastic landings to increase time to peak vGRF and reduce high impact force. For this purpose, judging criteria limitations on lower limb flexion should be reconsidered.  相似文献   

Investigation of blood pulse PPG signal regulation on toe effect of body posture and lower limb height     

CRABTREE Vincent P.  AZORIN-PERIS Vincent  ECHIADIS Angelos  SMITH Peter R. 《浙江大学学报(A卷英文版)》2007,8(6):916-920

Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.  相似文献   

下(上)半连续的等价定义及其证明     

王见勇 《常熟理工学院学报》2003,17(2):15-17

综述定义在一般拓扑空间上的广义实值函数的下（上）半连续的几种定义，并证明了它们的等价性。  相似文献   

基于分簇波束成形算法的MIMO-OFDM系统信道容量的分析     

陈静锐  李忠武  李青 《保山师专学报》2012,31(5):26-30

提出了一种在有限反馈条件下多输入多输出-正交频分复用(MIMO-OFDM)系统中基于信道容量的分簇波束成形算法。该算法针对MIMO-OFDM系统在高信噪、低信噪比等不同情况时选择不同的波束成形向量来提升系统的容量。根据簇间、各子簇间均存在一定的相关性,设计出了次优波束成形算法。通过对所提出的算法仿真可知,在高信噪比、低信噪比情况下针对系统容量采用分簇的波束成形算法能够在一定程度上提升MIMO-OFDM系统在确定性信道与随机性信道的信道容量。  相似文献   

广安地区上三叠统须家河组六段储层特征研究     

罗艳杨  季春海  王利恩  吕源梅  樊莉 《兰州石化职业技术学院学报》2012,12(1):9-11

通过大量研究表明：广安地区须六段储层岩石学特征以中～粗粒岩屑砂岩及长石岩屑砂岩为主。须六段储层经历了强烈的压实——压溶作用、胶结作用和溶蚀作用。主要的储集类型以孔隙型为主,亦存在裂缝——孔隙型。储集空间主要为粒间溶孔和剩余原生粒间孔。储层主要是受沉积,成岩及构造作用的影响,其中沉积作用是根本,构造作用是条件,成岩作用是关键。  相似文献   

三对角M矩阵的Hadamard积的最小特征值下界估计式的研究     

李艳艳 《宁夏师范学院学报》2014,(6):44-48

研究了三对角M矩阵B和三对角M矩阵A的逆矩阵A-1的Hadamard积的最小特征值q(B°A-1)界的估计问题,利用A-1的元素新的上界估计式给出了q(B°A-1)新的估计式.若A=B,得到q(A°A-1)新的估计式.  相似文献   

Engagement as Co-Generative Theorizing     

Stanley Deetz 《Journal of Applied Communication Research》2013,41(3):289-297

To meet current and ever shifting problems people continually need new and better ways to attend to, talk about, and respond in the world. All communities can have an impoverished language for talking about human interaction and making decisions in times of fundamental and rapid change. Three current impoverishments are discussed. Engaged scholarship using co-generative theorizing can initiate productive conversations enriching the languages of both scholarly and everyday life communities.  相似文献   

Improving teaching and learning of basic maths and reading in Africa: Does teacher preparation count?     

Kwame Akyeampong  Kattie Lussier  John Pryor  Jo Westbrook 《International Journal of Educational Development》2013

Teacher education has an important role in ensuring quality of learning especially for the poorest children. The article draws on a study of teacher preparation for the early primary grades in six African countries – Ghana, Kenya, Mali, Senegal, Tanzania and Uganda – in reading and mathematics. Initial teacher education had the strongest impact on newly qualified teachers but also induced misplaced confidence leading to standardised teacher-led approaches that failed to engage learners. Learning to read was divorced from meaning while mathematical activities were not linked to learning concepts. We suggest that teacher education is reconstructed as a study of classroom practice that places children's learning at its centre.  相似文献   

完全图的循环图分解和4个Ramsey数的下界     

罗海鹏  苏文龙 《青海师专学报》2000,20(3):7-11

研究素数阶完全图分解为循环图的方法,给出了计算它的子图的团数的一种算法,得到２个三色,２个四色Ｒａｍｓｅｙ数的新的下界：Ｒ（３,４,１７）≥４４４,Ｒ（３,６,１７）≥８１２,Ｒ（３,３,４,１４）≥６９２,Ｒ（３,３,５,１５）≥１０２２。  相似文献