Research on the suppression method of sensor impact vibration parasitic effects in surface reflection pressure measurement.

Ground reflection pressure plays a crucial role in evaluating the destructive power of ammunition explosions. Accurately measuring this pressure is essential for assessing ammunition's destructive capability and guiding ammunition design. In this study, a theoretical analysis of the parasitic effect of shock and vibration was conducted and COMSOL was employed for performing a multi-physics finite element numerical simulation analysis to elucidate the attenuation characteristics of stress waves in commonly used shock- and vibration-resistant materials.

Study on evaluation method for driving fragment ability of explosives.

The present study proposes an evaluation method for the driving fragment ability of explosives, which aims to provide theoretical and technical support for the selection of explosives used in warheads. The evaluation method is proposed in the light of the dimensional method and the similarity principle, and it uses TNT equivalent as the evaluation indicator. To acquire the evaluation indicator, a test system for driving fragment ability of explosives is constructed, which includes a dynamite gun type driven device, a spherical fragment, and a multi-zone fragment velocity measurement system.

The association between perfectionism and academic procrastination among undergraduate nursing students: The role of self-efficacy and resilience.

Aims: This study aimed to investigate the associations between perfectionism and undergraduate nursing students' academic procrastination, the mediating effects of self-efficacy and the moderating role of resilience.

Design: A cross-sectional survey.

Methods: The survey was conducted from March to May 2022 with a sample of 587 undergraduate nursing students in two undergraduate universities in China.

Measurement and Analysis of Shock Wave Pressure in Moving Charge and Stationary Charge Explosions.

Shock wave pressure is one of the most important parameters in an explosion. However, there have been few experimental and analytical investigations of moving charge explosions. In this article, we present an experimental method to measure the shock wave pressure from a moving charge explosion.

Development of a Fault Detection Instrument for Fiber Bragg Grating Sensing System on Airplane.

This study develops a fault detection device for the fiber Bragg grating (FBG) sensing system and a fault detection method to realize the rapid detection of the FBG sensing system on airplanes. According to the distribution of FBG sensors on airplanes, the FBG sensing system is built based on wavelength division multiplexing (WDM) and space division multiplexing (SDM) technologies. Furthermore, the hardware and software of the fault detection device and the relevant FBG demodulator are studied in detail.

Research on Electromagnetic Radiation Mechanism during Detonation of Energetic Material.

In the process of deflagration of energetic materials, strong electromagnetic radiation is generated, which causes the surrounding electronic equipment to fail to work normally. To solve this problem, it is necessary to clarify the mechanism of electromagnetic radiation generated by energetic materials. The mechanism of plasma changed by the deflagration of energetic materials is an important topic in the aerospace and geophysics fields.

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel.

During the launch and return of a spacecraft, the intense combustion of propellants generates strong electromagnetic radiation, which interferes with the operation of electronic equipment in the spacecraft. To improve the electromagnetic compatibility of electronic equipment in spacecraft, it is necessary to study the electromagnetic radiation characteristics of rocket fuel. An electromagnetic radiation measurement system based on antennas is designed to measure the electromagnetic radiation generated by rocket fuel, and the electromagnetic radiation characteristics are obtained through data analysis.

Crater detection from commercial satellite imagery to estimate unexploded ordnance in Cambodian agricultural land.

Unexploded ordnance (UXO) pose a significant threat to post-conflict communities, and current efforts to locate bombs rely on time-intensive and dangerous in-person enumeration. Very high resolution (VHR) sub-meter satellite images may offer a low-cost and high-efficiency approach to automatically detect craters and estimate UXO density. Machine-learning methods from the meteor crater literature are ill-suited to find bomb craters, which are smaller than meteor craters and have high appearance variation, particularly in spectral reflectance and shape, due to the complex terrain environment.

Absolute quasi-static calibration method of piezoelectric high-pressure sensor based on force sensor.

In this paper, a strain-gauge-type force sensor which can be directly mounted on the existing drop-weight device and used to calibrate the piezoelectric high-pressure sensor is designed. The absolute quasistatic pressure calibration principle and the measurement principle of the strain-gauge-type force sensor are described. Based on the mathematical relation model between force and pressure, the influence factors of pressure calibration accuracy are discussed, and the empirical formula for correcting the peak pressure is obtained.

Pressure prediction model based on artificial neural network optimized by genetic algorithm and its application in quasi-static calibration of piezoelectric high-pressure sensor.

This paper applies back propagation neural network (BPNN) optimized by genetic algorithm (GA) for the prediction of pressure generated by a drop-weight device and the quasi-static calibration of piezoelectric high-pressure sensors for the measurement of propellant powder gas pressure. The method can effectively overcome the slow convergence and local minimum problems of BPNN. Based on test data of quasi-static comparison calibration method, a mathematical model between each parameter of drop-weight device and peak pressure and pulse width was established, through which the practical quasi-static calibration without continuously using expensive reference sensors could be realized.