Search

The multimedia technology and computer technology supported by the development of modern science and technology provide an important platform for the development of college physical education teaching activities. To better play the role of network auxiliary teaching platform in college sports teaching and improve the effectiveness of college sports teaching, the construction method of multimedia auxiliary teaching effect evaluation model based on the random number forest algorithm is proposed. Through the specification of the random forest algorithm and the optimization of the teaching quality evaluation index, the auxiliary teaching level of the college physical education network is analyzed, and the evaluation of the multimedia auxiliary teaching effect of the physical education courses is completed. The experimental results verify the effectiveness of the evaluation model designed in this article, with a user satisfaction of 72%. Teachers and students can use the evaluation model to improve the teaching quality and teaching efficiency, improve the management work, and promote the scientific, standardization, and specialization of physical education teaching management in colleges and universities.

Measurement of lightning current plays a critical role in the field of atmospheric electricity. Traditionally, Rogowski coils or low-resistance shunts were employed for measuring lightning currents in the range from several amperes up to several hundreds of kilo-amperes, and high-value resistors were utilized for measuring corona discharge currents at sub-ampere levels. However, these approaches were not suitable for continuously recording the vast range of lightning currents. For this sake, we have developed a lightning current measurement system equipped with a shock-tolerant low-noise amplifier module. With the system installed on a tall tower, sub-ampere level currents just before the lightning initiation were observed for the first time. To confirm the authenticity of the recorded currents, the background noise of the measurement system and surrounding environment were identified, and a digital multi-frequency notch filter was proposed for de-noising. Results show that the system can achieve a current identification level of 50 mA even in complex electromagnetic environments, while having a measurement capability of 220 kA. [ABSTRACT FROM AUTHOR]

Objectives: To compare the core indexes of cardiopulmonary exercise test (CPET) in the patients with coronary artery disease and combining anxiety and/or depression, and to explore the effect of the emotional disorder with "anxiety and/or depression" on cardiopulmonary function and exercise tolerance in patients with coronary artery disease., Methods: A total of 255 patients with stable coronary artery disease and 302 patients without coronary artery disease were selected as subjects. According to the results of anxiety and depression scale, they were divided into a control group ( n =96), an anxiety group ( n =35), a depression group ( n =36), an anxiety and depression group ( n =135), a coronary artery disease group ( n =91), a coronary artery disease combined with anxiety group ( n =35), a coronary artery disease combined with depression group ( n =34) and a coronary artery disease combined with anxiety and depression group ( n =95). The differences in the core indexes of CPET among the different groups were compared., Results: Peak oxygen uptake, anaerobic domain, peak metabolic equivalent, and peak heart rate in all coronary artery disease groups were significantly lower than those in the control group, while peak systolic pressure and heart rate reserve were significantly increased (all P <0.05); among them, there were significantly difference in the above indexes between the coronary artery disease combined with anxiety and depression group and the coronary artery disease group (all P <0.05); there was no significant difference among the anxiety group, the depression group, and the anxiety and depression group and the control group (all P >0.05)., Conclusions: The cardiopulmonary function and exercise tolerance is significantly decreased in the coronary artery disease combined with anxiety and depression patients; there is a declining trend in the cardiopulmonary function and exercise tolerance in the simple anxiety or simple depression patients. Simple anxiety, simple depression and simple anxiety combined with depression don't cause a negative impact on cardiopulmonary function and exercise tolerance in non-coronary artery disease control population.