NISSIAN系列车用CDROM支架的优化设计及随机疲劳分析

根据NISSIAN系列车用CDROM支架的结构设计模型和设计要求,建立了支架的静力学模型和有限元模型,通过对模型在规定试验载荷下的静力学和随机疲劳分析,说明了减少CDROM支架设计时的材料厚度不仅不影响产品的设计要求,而且还大大降低了产品的成本和实现了轻量化设计的要求,也提高了企业的实际经济效益。     

The effects of a unilateral gluteal activation protocol on single leg drop jump performance

Warm-up protocols are commonly used to acutely enhance the performance of dynamic activities. This study examined the acute effect of low-load gluteal exercises on the biomechanics of single-leg drop jumps. Eight men and seven women (18–22 years old) performed 10 single-leg drop jumps on three separate days. The gluteal exercises were performed within the warm-up on day 2. Contact time, flight time, peak vertical ground reaction force (GRF), rate of force development, vertical leg-spring stiffness, and reactive strength index were determined. A repeated measures analysis of variance was used to examine differences on all variables across days. Significant differences were found for contact time, peak GRF, and flight time between days 1 and 2 and for flight time between days 1 and 3 (p ≤ 0.05) with no significant difference in any variables between days 2 and 3. This suggested that the improvements in day 2 were due to practice effects rather than the gluteal activation exercises. In addition, a typical error analysis was used to determine individual responses to the gluteal exercises. The results using this analysis showed no discernible response pattern of enhancement or fatigue for any participant.     

存现句语义对谓语动词的制约

存现句是现代汉语中一种很有特点的句式。从20世纪50年代开始,很多学者从结构形式、句法性质、动词特点、语法意义和变换关系的角度对存现句作了多方位的研究。本文试图以存现句的语义特征为研究的出发点,分析存现句语义对谓语动词在语义和句法上的各种制约关系,并重新划分存现句的类别。     

伸长法测量金属杨氏模量实验的改进

本文对传统的杨氏模量的测量方法作了改进:用电阻丝替代原来用的钢丝,用电桥替代光杠杆测量金属丝的微小伸长△l,结果使该实验操作简单,仪器调试容易,测量结果精度提高。     

浅谈三维动画中“Stretch IK”的实现方法

在三维动画角色绑定阶段涉及到"弹性"的话题非常多,这里仅对"stretch IK"实现的基本方法做一些讨论.在MAYA中实现"Stretch IK"的思路主要有两种,一种是依靠编写脚本来实现,即依靠MAYA的MEL语言,另一种是依靠MAYA的节点网络来实现.