Electromagnetic armor is a new conceptual combat vehicle technology, which improves remarkably the defensive capability and maneuverability of vehicles. The authors present definitely to apply the electromagnetic theo...Electromagnetic armor is a new conceptual combat vehicle technology, which improves remarkably the defensive capability and maneuverability of vehicles. The authors present definitely to apply the electromagnetic theory to analyze the electromagnetic armor. Based on electromagnetics, the experienced expression of projectile and the physical model of PEMA (passive electromagnetic armor) are obtained when electric current flows through the system, and a computer simulation is given.展开更多
Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak posit...Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak positions, for the purpose of achieving the muscle strength development in an all-round way. In this paper, the anatomy, physiology, and biomechanics foundations for vibration training to increase muscle strength are mainly analyzed, and then the principle of vibration training to increase muscle strength is further expounded, and also the increase of muscle strength is discussed from the aspects such as vibration frequency, vibration amplitude, vibration posture, vibration intermittent time, and vibration mode, so as to clarify the domestic and foreign progress of the study on vibration training.展开更多
Immediate loading(IL)increases the risk of marginal bone loss.The present study investigated the biomechanical response of peri-implant bone in rabbits after IL,aiming at optimizing load management.Ninety-six implants...Immediate loading(IL)increases the risk of marginal bone loss.The present study investigated the biomechanical response of peri-implant bone in rabbits after IL,aiming at optimizing load management.Ninety-six implants were installed bilaterally into femurs of 48 rabbits.Test implants on the left side created the maximal initial stress of 6.9 and 13.4 MPa in peri-implant bone and unloaded implants on the contralateral side were controls.Bone morphology and bone-implant interface strength were measured with histological examination and push-out testing during a 12-week observation period.Additionally,the animal data were incorporated into finite element(FE)models to calculate the bone stress distribution at different levels of osseointegration.Results showed that the stress was concentrated in the bone margin and the bone stress gradually decreased as osseointegration proceeded.A stress of about 2.0 MPa in peri-implant bone had a positive effect on new bone formation,osseointegration and bone-implant interface strength.Bone loss was observed in some specimens with stress exceeding 4.0 MPa.Data indicate that IL significantly increases bone stress during the early postoperative period,but the load-bearing capacity of peri-implant bone increases rapidly with an increase of bone-implant contact.Favorable bone responses may be continually promoted when the stress in peri-implant bone is maintained at a definite level.Accordingly,the progressive loading mode is recommended for IL implants.展开更多
文摘Electromagnetic armor is a new conceptual combat vehicle technology, which improves remarkably the defensive capability and maneuverability of vehicles. The authors present definitely to apply the electromagnetic theory to analyze the electromagnetic armor. Based on electromagnetics, the experienced expression of projectile and the physical model of PEMA (passive electromagnetic armor) are obtained when electric current flows through the system, and a computer simulation is given.
文摘Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak positions, for the purpose of achieving the muscle strength development in an all-round way. In this paper, the anatomy, physiology, and biomechanics foundations for vibration training to increase muscle strength are mainly analyzed, and then the principle of vibration training to increase muscle strength is further expounded, and also the increase of muscle strength is discussed from the aspects such as vibration frequency, vibration amplitude, vibration posture, vibration intermittent time, and vibration mode, so as to clarify the domestic and foreign progress of the study on vibration training.
基金supported by the National Natural Science Foundation of China(10902010,11120101001)National Science&Technology Pillar Program of China(2012BAI22B02)Research Fund for the Doctoral Program of Higher Education of China(20131102130004)
文摘Immediate loading(IL)increases the risk of marginal bone loss.The present study investigated the biomechanical response of peri-implant bone in rabbits after IL,aiming at optimizing load management.Ninety-six implants were installed bilaterally into femurs of 48 rabbits.Test implants on the left side created the maximal initial stress of 6.9 and 13.4 MPa in peri-implant bone and unloaded implants on the contralateral side were controls.Bone morphology and bone-implant interface strength were measured with histological examination and push-out testing during a 12-week observation period.Additionally,the animal data were incorporated into finite element(FE)models to calculate the bone stress distribution at different levels of osseointegration.Results showed that the stress was concentrated in the bone margin and the bone stress gradually decreased as osseointegration proceeded.A stress of about 2.0 MPa in peri-implant bone had a positive effect on new bone formation,osseointegration and bone-implant interface strength.Bone loss was observed in some specimens with stress exceeding 4.0 MPa.Data indicate that IL significantly increases bone stress during the early postoperative period,but the load-bearing capacity of peri-implant bone increases rapidly with an increase of bone-implant contact.Favorable bone responses may be continually promoted when the stress in peri-implant bone is maintained at a definite level.Accordingly,the progressive loading mode is recommended for IL implants.
