Physical Sciences and Engineering

There are many factors causing gear failure, which has an important impact on the working life of rotating machinery. The causes and characteristics of common faults of gears are analyzed, and different types of faults are detected by means of vibration waves. Aiming at the contact faults of gear pairs, the vibration testing equipment is used to diagnose the faults. The results show that there are significant differences among different types of fault waveforms. This method has high reliability and good economic and social benefits.

Teaching Friction coupler has an important application in the field of mechanical transmission. As typical wet friction transmission equipment, the strength characteristics of key components of the liquid-viscous friction coupler have a key impact on the reliability and service life of the whole friction coupler. Based on the finite element software ANSYS, the stress and deformation fields of the pump wheel and sector are calculated, and the response characteristics under different loads are obtained, which provides a basis for the optimal design of friction couplers.

Background: lymphocytes are a main component of the immune system, reaching an optimum level of lymphocytic count may improve immunity in healthy subjects or fasten recovery from diseases; therefore manual lymphatic draining effects were compared to mechanical lymphatic draining. Purpose: This study was conducted to investigate manual lymphatic drainage versus mechanical lymphatic drainage effects on total lymphocytic count in healthy subjects.

Based on the meridian expansion method, a mathematical model for the analysis of the unfolding motion of the bearing steel ball surface is established, and the trajectory equation of the unfolding motion of the ball surface is deduced, which provides a basis for the follow-up mechanical structure design. Through the mechanism simulation based on Pro/Mechanism, the scanning trajectory curve of the probe can be verified and the surface of the steel ball can be completely covered.

Charging and discharging of lithium batteries and their safety performance are one of the key indicators to determine their working ability. The state monitoring system of lithium battery pack designed in this paper not only fully meets the requirements of production, but also fully reflects the characteristics of reliability and cost-effective ratio. The system is based on single chip computer control, and fully considers charge and discharge signal monitoring, temperature signal monitoring, discharge maintenance and charge equalization in the design.

The response ability of ant colony algorithm and Ziegler Nichols method to unit step signal is compared and analyzed. Ant colony algorithm has excellent control ability, such as small overshoot and short steady-state response time. Therefore, ant colony algorithm can be effectively applied to the control of underground search and rescue robot. It is found that the introduction of ant colony algorithm with node activity can solve the problem of premature convergence before the improvement. The control scheme of hardware and software is designed and studied.

Objective: to determine the effect of Plyometric Training on Performance and Incidence of Injury in Volleyball Players. Material and Methods: Thirty male volleyball players participated in this study, their ages ranges from 15-30 years old.

Under the magnetic field, the shear stress and apparent viscosity of Magneto Rheological Fluid (MRF) increase significantly. The shear stress ranges from 1.08 kPa to 12 kPa, and the apparent viscosity ranges from 2.5 Pa•s to 28.7 kPa•s. When the magnetic field is constant, the shear stress increases and tends to stabilize with the increase of shear rate, and there exists shear thinning phenomenon. The shear yield stress calculated by Bingham and Casson models is 1043Pa ~ 8825Pa.

Antioxidants are compounds with large industrial applicationin the pharmaceutical, cosmetic, chemical and food sectors. Anthocyanins are thermosensitive natural pigments with important antioxidant and biofunctional action, and can be better preserved if kept encapsulated. This treatment can be performed by different techniques, among them spray-dying and lyophilization.

The creep phenomenon will inevitably occur in the course of railway vehicles traveling. By solving the creep mathematical model, the relationship among wheel-railway adhesion coefficient, vehicle speed and creep rate is obtained. On this basis, the mathematical model of ABS and AMESim simulation model are established, and the simulation and analysis are completed under the conditions of track drying and wetting. The temperature field of disc brake is analyzed based on ABAQUS.