Over the past two decades, femtosecond laser-induced periodic structures (femtosecond-LIPSs) have become ubiquitous in a variety of materials, including metals, semiconductors, dielectrics, and polymers. Femtosecond-LIPSs have become a useful laser processing method, with broad prospects in adjusting material properties such as structural color, data storage, light absorption, and luminescence. This review discusses the formation mechanism of LIPSs, specifically the LIPS formation processes based on the pump-probe imaging method. The pulse shaping of a femtosecond laser in terms of the time/frequency, polarization, and spatial distribution is an efficient method for fabricating high-quality LIPSs. Various LIPS applications are also briefly introduced. The last part of this paper discusses the LIPS formation mechanism, as well as the high-efficiency and high-quality processing of LIPSs using shaped ultrafast lasers and their applications.

In order to study the three jump training and competition on knee joint impact damage degree, left knee joint of one healthy male athletes is used as the research object, a complete knee three-dimensional model was established based on the jumper’s knee CT scan and magnetic resonance imaging (MRI), including the femur, tibia, fibula, patella and knee major cartilage, ligaments. The multi-body dynamics analysis (MDA) and finite element analysis (FEA) method are used to calculate the three jump, jump starting, landing process of athletes knee joint impact, the state should change the status of stress, strain and displacement. The results show that in the three jump process, the load on the lateral contact area of the knee joint is the largest, the displacement is the largest, and it increases with the impact of jump and landing. This exacerbated the degree of wear and tear of the tibia, it tends to induce knee injury in athletes. The results show that the combination of finite element and MDA can better study the knee joint’s shock and vibration during the three-level jump training and competition, and these open up a new research method for the knee joint injury. It also provides a certain reference for the prevention and treatment of knee joint injury.

The motion capture technology system definition is described in the paper, and its components are researched, the key parameters are obtained from motion technique, the quantitative analysis are made on technical movements, the method of motion capture technology is proposed in sport technical diagnosis. That motion capture step includes calibration system, to attache landmarks to the tester; to capture trajectory, and to analyze the collected data.

Abstract. According to the characteristics of the diving sports, a video analysis system is developed for diving sports in the paper. This system is mainly used in assisting coach to instruct athletes more effectively, and it can help the judgers give the correct judgments. Three components are composed in the research, the video analysis, 3D motion simulation and edit interface and the management of database. The background and meaning of developing this system is stated in the first section, and then the relation and the data flow are analyzed among the main modules. In the end, the key techniques and innovations are addressed in detail. In practice, this system can not only improve the efficiency of training, reduce the repeated training and the probability of false judgments, but also there is the high efficiency in the system and it is easy to be operated.