基于HyperMesh与ANSYS联合仿真下万向联轴器的模态分析

针对万向联轴器在高速工作环境下出现振动问题,以SWC-225CH型万向联轴器为研究对象进行模态分析。首先利用HyperMesh优越的前处理功能,对该模型进行网格、非线性接触、耦合处理。前处理完成之后,导入ANSYS软件中进行模态设置,并求出六阶振型图。从振型图中可以发现SWC-225CH型万向联轴器最大振型位置随着阶数变化而变化。通过Hypermesh和ANSYS联合仿真不仅减少前处理的时间,又可以保证其计算精度的准确性,为万向联轴器设计、优化、谐响应分析提供了理论依据。     

Changes in joint range of motion and muscle–tendon unit stiffness after varying amounts of dynamic stretching

The purpose of this study was to examine the effects of varying amounts of dynamic stretching (DS) on joint range of motion (ROM) and stiffness of the muscle–tendon unit (MTU). Fifteen healthy participants participated in four randomly ordered experimental trials, which involved one (DS1), four (DS4) and seven (DS7) sets of DS, or control conditions/seated at rest (CON). Each DS set consisted of 15 repetitions of an ankle dorsiflexion–plantarflexion movement. The displacement of the muscle–tendon junction (MTJ) was measured using ultrasonography while the ankle was passively dorsiflexed at 0.0174 rad · s^?1 to its maximal dorsiflexion angle. Passive torque was also measured using an isokinetic dynamometer. Ankle ROM was significantly increased after DS4 and DS7 compared with the pre-intervention values (P < 0.05), but there were no significant differences in ankle ROM between DS4 and DS7. No differences were observed in ankle ROM after DS1 and CON. In addition, the stiffness of the MTU, passive torque and displacement of the MTJ at submaximal dorsiflexion angles did not change in any of the experimental conditions. These results indicate that DS4 increased ankle ROM without changing the mechanical properties of the MTU, and that this increase in ankle ROM plateaued after DS4.     

专项运动员半月板损伤的生理学及生物力学分析与预防对策

方法：采用问卷调查法、数理统计法和文献资料法,对陕西省优秀男子运动员膝关节半月板运动损伤情况进行研究。结果：在接触性运动项目中,关月板损伤率较大,且与训练年限有正相关。其损伤的原因主要是准备活动不充分、膝关节力量不足、训练方法不当、身体疲劳及长期局部劳损等。结论：根据半月板损伤的机制与病因,结合生物力和运动解剖学知识,提出科学的预防措施,为康复治疗和运动训练提供理论参考。     

Kinetic function of the lower limbs during baseball tee-batting motion at different hitting-point heights

ABSTRACT

The aim of this study was to investigate the kinetic functions of the lower limbs at different hitting-point heights to provide key information for improving batting technique in baseball players. Three-dimensional coordinate data were acquired using a motion capture system (250 Hz) and ground reaction forces were measured using three force platforms (1000 Hz) in 22 male collegiate baseball players during tee-batting set at three different hitting-point heights (high, middle, and low). Kinetic data were used to calculate joint torque and mechanical work in the lower limbs by the inverse dynamics approach. The peak angular velocity of the lower trunk about the vertical axis was smaller under the low condition. The joint torques and mechanical works done by both hip adduction/abduction axes were different among the three conditions. These results indicate that hip adduction/abduction torques mainly contribute to a change in the rotational movement of the lower body about the vertical axis when adjusting for different hitting-point heights. In order to adjust for the low hitting-point height which would be difficult compared with other hitting-point heights, batters should focus on rotating the lower trunk slowly by increasing both hip abduction torques.     

文献资源共建共享与知识产权保护冲突研究

论文提出既不能为了文献资源共建共享而无视知识产权保护,也不能过度扩张知识产权保护,阻碍文献资源共建共享。在文献资源共建共享建设中解决知识产权问题的主要对策,既要符合法律法规,维护知识产权,又要充分利用知识产权法的积极作用,保证文献资源共建共享实践的顺利开展。     

加强联合协作实现信息资源共享 --论高校图书馆在网络环境下信息资源管理的方法

本文通过对实现信息资源共享所面临的困难及实现信息资源共享的途径的论述,提出依靠现有的网络通讯系统,加强高校、公共和科研三大系统图书馆的联合协作,尤其高校图书馆之间的联合协作,实现局部范围的信息资源共享来提高信息资源的数量和质量,同时推动高校图书馆提高其在网络环境下信息资源的管理水平。参考文献6。     

建立大范围公私合作的机制:欧盟联合技术促进计划的启示

本文详细介绍了联合技术促进计划的选择机制、组织结构和权责制度,并提出对中国建立大范围公私合作机制的启示。为更好地发挥国家财政资金对产业发展的推动作用,促进官产学研合作,引导公私合作的科技计划要面向关系国家竞争力的重要技术,要扩大公私合作范围,并且要建立基于产业的项目选择机制和适合大范围公私合作的组织结构。     

NSFC－云南联合基金项目实施情况分析与对策研究

从NSFC-云南联合基金第一期(2008-2012年)、第二期(2013-2017年)和第三期(2018-2020年)的项目申请量、资助率等方面进行深入梳理分析,展示部分获资助的重点支持项目在提升云南省自主创新能力、促进解决云南省及周边地区的重要科学和关键技术问题等方面所取得的成效.同时为其加入区域创新发展联合基金服务,提出对策建议.     

武汉理工大学材料科学与工程学院国际合作办学的经验和探索

简要回顾武汉理工大学材料学院过去10年与澳大利亚蒙纳什大学（Monash University）、英国伦敦大学玛丽皇后学院（Queen Mary）,London University）、美国韦恩州主大学（Wayne State University）等国际知名高校联合办学的历程,并对其办学意义、教学管理的实施,存在的问题及解决的建议诸方面进行阶段性总结.     

Individual and joint toxic effects of cadmium sulfate and α-naphthoflavone on the development of zebrafish embryo

This paper aims to evaluate the individual and joint toxicities of cadmium sulfate (CdSO₄) and α-naphthoflavone (ANF) in zebrafish embryos. As a result, CdSO₄ caused both lethal and sub-lethal effects, such as 24 h post-fertilization (hpf) death and 72 hpf delayed hatching. However, ANF only caused sub-lethal effects, including 48 hpf cardiac edema and 72 hpf delayed hatching. Taking 24 hpf death and 48 hpf cardiac edema as endpoints, the toxicities of CdSO₄ and ANF were significantly enhanced by each other. Consistently, both CdSO₄ and ANF caused significant oxidative stress, including decreases in the reduced glutathione (GSH) level, inhibition of superoxide dismutase (SOD) activity, as well as increases in malondialdehyde (MDA) content in zebrafish embryos, but these mixtures produced much more significant alterations on the biomarkers. Co-treatment of CdSO₄ and ANF significantly down-regulated the mRNA level of multidrug resistance-associated protein (mrp) 1 and cytochrome P450 (cyp) 1a, which constituted the protective mechanisms for zebrafish embryos to chemical toxins. In conclusion, co-treatment of CdSO₄ and ANF exhibited a much more severe damage in zebrafish embryos than individual treatment. Meanwhile, production of oxidative stress and altered expression of mrp1 and cyp1a could be important components of such joint toxicity.