This experiment demonstrated the resonance asymmetry phenomenon in the resonant fiber optic gyro. The asymmetry of resonant curve affects the system open-loop bias and its stability, which directly affects the accuracy of angular velocity measurement. In this paper, a new mathematic model is established. The influence of the coupler normal mode loss difference (the phase difference between the coupler cross port output optical field and direct port is less than the ideal π/2) on the symmetry of resonant curve, the resonant signal modulated by the triangular wave, and the demodulation curve are analyzed. Moreover, the asymmetry of the resonant curve leads to the asymmetry of the resonant signal, as modulated by the triangular wave and the demodulation curve from the theoretical simulation and the experiment.
The energy dissipation level of articulated mechanical arms directly affects the control stability of industrial robot systems. For a six-degree-of-freedom articulated robot driven by a DC servo motor and reduction gear, based on the Hamiltonian and Minimum theories, a model of the articulated manipulator drive system under load torque is established, and the expressions of optimal angular velocity and control current are obtained considering the viscous friction and coulomb factors. According to the analysis of actual parameter simulation experiments, it can be seen that the energy consumption of the joint manipulator drive system increases with the decrease of efficiency, the increase of the coulomb friction torque of the servo motor, and the increase of the load torque. Within the transit time, the total energy consumption of the drive system is smaller, so it is very important to obtain the transit time within the optimal area for the minimum energy consumption of the joint robotic arm drive system. At the same time, a soft neural network model based on the improved BP neural network built on the neural network toolbox for the energy consumption of the articulated mechanical arm is established. Finally, the experimental platform of servo motor drive system is built and used for the experiment of servo motor drive, and the purpose of closed-loop control is also achieved. Through experimental analysis, it can be seen that the proposed soft sensor model of joint minimum energy consumption based on improved BP neural network can more accurately realize the energy consumption prediction under unknown angular displacement and unknown load, and provide a theoretical basis for joint energy monitoring.
The polyphenolic extract of Ilex latifolia (PEIL) exhibits a variety of biological activities. An evaluation of the parameters influencing the ultrasonic extraction process and the assessment of PEIL antioxidant activity are presented herein. Response surface methodology (RSM) was used to optimize the experimental conditions for the polyphenols ultrasonic-assisted extraction (UAE) from the leaves of Ilex latifolia. We identified the following optimal conditions of PEIL: ethanol concentration of 53%, extraction temperature of 60 °C, extraction time of 26 min and liquid–solid ratio of 60 mL/g. Using these parameters, the UAE had a yield of 35.77 ± 0.26 mg GAE/g, similar to the value we predicted using RSM (35.864 mg GAE/g). The antioxidant activity of PEIL was assessed in vitro, using various assays, as well as in vivo. We tested the effects of various doses of PEIL on D-galactose induced aging. Vitamin C (Vc) was used as positive control. After 21 days of administration, we measured superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, malondialdehyde (MDA) levels in mouse serum and liver tissue. The results demonstrated that the PEIL exhibits potent radical scavenging activity against 1,1-diphenyl-2-picrythydrazyl (DPPH∙), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+), and hydroxyl (∙OH) radicals. The serum concentrations of SOD and GSH-Px were higher, and MDA levels were lower, in the medium- and high-dose PEIL-treated groups than those in the aging group (p < 0.01), and the activity of MDA was lower than those of the model group (p < 0.01). The liver concentrations of SOD and GSH-Px were higher (p < 0.05), and MDA levels were lower, in the medium- and high-dose PEIL-treated groups than those in the aging control group (p < 0.01). These results suggest that optimizing the conditions of UAE using RSM could significantly increase the yield of PEIL extraction. PEIL possesses strong antioxidant activity and use as a medicine or functional food could be further investigated.
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