Study on the interactive deformation of bone needles and circum-pelvic soft tissue

During the robot-assisted pelvic fracture reduction,the needle-tissue interactive deformation characteristic is not clear,which affects the accuracy of robotic surgery.In this paper,a layered rig-id-flexible coupling model is proposed,and the needle-tissue interactive deformation under the load-ing is analyzed by the Rayleigh-Ritz method,in accordance with the principle of minimum potential energy.The pelvic musculoskeletal tissue is reversely reconstructed,and the structure of the bone is segmented into cancellous bone and cortical bone.The Mooney-Rivlin five-parameter hyperelastic model is used to simulate muscle,and the Ogden hyperelastic model is used to simulate adipose tis-sue.Finite element simulation is performed by loading different magnitudes of forces.The accuracy of the rigid-flexible coupling model is 0.432 mm,which indicates the correctness of the needle-tis-sue interactive deformation theory analysis.

小学数学竞赛活动与实施素质教育的几点思考

小学数学竞赛活动与素质教育本来不是一对矛盾,但随着素质教育的观念不断深入人心,素质教育的活动不断开展,就出现了把小数竞赛活动与素质教育对立起来的倾向,认为既然搞素质教育,就必须面向全体学生,竞赛活动是少数学生参与的活动,小学是打基础的阶段,要面向每一个学生,所以不能再搞面向少数学生的竞赛活动了。而小学数学竞赛活动能够极大的提高学生学习数学的兴趣,给学生提供活跃思维的机会。然而,有些人对实施素质教育下的小学数学竞赛活动有误解,由此本文主要阐明两者并不是相互对立的,并简要阐述其对素质教育的积极作用。