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1.
Braided composite materials for the production of lightweight, high rigidity golf shafts 总被引：1，自引：1，他引：0
Braiding is not currently used in the production of golf shafts. The objective of this work was to develop, through a modelling
process consisting of altering lamina sequence, a golf shaft, using braided laminas, which would have mass, stiffness and
torque comparable to commercially available composite and steel shafts. A 2D conical braided composite model was previously
developed and validated to predict elastic constants of braided closed meshed structures. Energy methods were used to calculate
the stiffness and torque of shafts using prescribed industry approaches. Shaft mass was calculated based on geometry and density
of constitutent materials. Modelled shafts had both braided and unidirectional layers and compared favourably with or were
better than commercially available composite and steel shafts in terms of deflection force and twist angle; they had the same
weight as composite shafts but were much lighter than steel shafts. If these findings are verified, braided composites would
be a viable and effective approach to the design of future golf shafts. 相似文献
2.
周树军 《商丘师范学院学报》2004,20(3):169-171
英语成对词是英语惯用语的一个重要组成部分，在结构上体现了英语合成短语的结构特征。虽然属于口语语体，但经常运用于其他语体，具有丰富的话语和文体功能。 相似文献
3.
Stephen A. Petrill Kirby Deater-Deckard Lee Anne Thompson Chris Schatschneider Laura S. DeThorne David J. Vandenbergh 《Reading and writing》2007,20(1-2):127-146
We examined the genetic and environmental contribution to the stability and instability of reading outcomes in early elementary
school using a sample of 283 twin pairs drawn from the Western Reserve Reading Project. Twins were assessed across two measurement
occasions. In Wave 1, children were either in kindergarten or first grade. Wave 2 assessments were conducted one year later.
Results suggested substantial genetic stability across measurement occasions. Additionally, shared environmental influences
also accounted for stability, particularly for variables more closely tied to direct instruction such as phonological awareness,
letter knowledge, and word knowledge. There was also evidence for independent genetic and shared environmental effects, suggesting
that new sources of variance may emerge as the demands of school change and children begin to acquire early reading skills. 相似文献
4.
针对单线双竖井机械通风的铁路隧道,以流体力学的恒定流理论为计算依据,推导出在隧道内列车活塞风计算方法. 相似文献
5.
钱秀银 《广播电视大学学报》2004,(2):11-13
在女性意识张扬得如此激越的当下文坛，年轻的女作家迟子建却始终以人的视角来观照文学人生。这种超性别意识的价值关怀使她的文本营构了一幅双性和谐的图景，而这种惯例化写作的超越也将是艰难的。 相似文献
6.
郭易欣 《中国科教创新导刊》2012,(19):52-52,54
本文证明了著名的黎曼猜想,连续统假设,第五公设,亲和数,Mersenne素数,偶完全数,孪生素数,以上均为不可证。 相似文献
7.
随着元宇宙时代的到来,5G、大数据、云计算、拓展现实(XR)和人工智能等技术得以广泛应用,人类已进入到场景(CT)时代。场景化正在不断影响并渗透教育领域,并促进教育领域进行快速地自我革新与升级。场景化特征包括智能动态性、联结共创性和情感连接性。研究从资源沉浸、人本服务、技术适宜三个维度,遵循多资源适配、多模态混合、多场景延续的原则,从场景洞察、场景制造、场景应用、场景优化四个步骤展开场景化设计;进而从数据内容、技术支持和过程体验三个方面,得出数据驱动、技术融合和多模态沉浸体验的全场景学习实施策略。由此,在元宇宙时代,教育场景化设计将从智慧学习场景流、泛在教育生态、虚实融合、全域交互、全纳教育五个方面,赋能全场景学习的实现和应用。 相似文献
8.
Linguistic awareness i.e. the ability to identify phonemes, to segment words into syllables and to rhyme is highly correlated with reading/spelling proficiency. Children with severe developmental language disorders DLD (syntagmatic type) have been shown to specifically lack linguistic awareness. Two non-identical twin boys with severe, specific DLD were studied longitudinally with respect to their linguistic, neurolinguistic and pragmatic development. In spite of poor linguistic awareness, the boys acquired normal reading/spelling skills. This might be due to the early and massive language training they were given. However, the boys differ considerably in some aspects of reading and spelling performance. These findings are discussed with reference to their different neurolinguistic and pragmatic profiles. 相似文献
9.
Torsional Oscillation Characteristics of Rotary Shafts Based on Torsion and Bending Coupled Vibration 总被引：1，自引：0，他引：1
THE TORSIONAL OSCILLATION CHARACTERISTICS ON THE BENDING AND TORSION COUPLED VIBRATION OF ROTARY SHAFT SYSTEM WERE INVESTIGATED USING THE ELASTO-DYNAMIC THEORY AND OTHER MATHEMATIC METHODS, SUCH AS DIFFERENCE APPROACH, FOURIER TRANSFORM, AND WAVELET TRANSFORM. IT IS CONCLUDED THAT MASS ECCENTRICITY AND OTHER EXCITING MODALITIES AFFECT THE BENDING AND TORSION COUPLED VIBRATION OF ROTARY SHAFTS. TORSIONAL VIBRATION CAUSED BY BENDING VIBRATION FEATURES LINEARITY ALONG WITH THE CHANGE OF AMPLITUDE OF BENDING VIBRATION. MEANWHILE, ENERGY SPECTRUM CONCENTRATES ON HIGH FREQUENCY ARE-A WITH THE WAVELET ANALYSIS. 相似文献
10.
李晓栋 《湖南广播电视大学学报》2006,(2):56-57
对线性双端口网络的表征加以说明,根据其参数中所选激励变量的不同,导致所描述的方程组和与其对应的参数组也不同的特点,整理出参数表征法归纳表,并对相关的物理意义给予了讨论。 相似文献