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The inhomogeneity in pressure inside the sample chamber of a diamond anvil cell (DAC) poses a major challenge to the accurate measurement of the properties of materials under high pressures, especially when the pressure medium solidifies under compression or is prohibited in the experiment. In this paper, the authors systematically investigate the pressure gradient in a DAC sample chamber and its evolution over time with changes in temperature. The results show that pressure gradients were formed along both the radial and the axial directions upon compression, and gradually decayed with time and increasing temperature. After a period of relaxation at room temperature, the pressure gradient along the axial direction gradually decayed and a new equilibrium was established. A similar process was observed along the radial direction but required a longer period before reaching equilibrium. Appropriate heating of the sample can cut the relaxation time to the order of tens of minutes and smoothen the pressure gradient in both directions. The electrical properties of olivine were significantly different when the measurements were conducted before and after relaxation was complete, indicating that the relaxation in pressure is essential for acquiring reliable data in a DAC under high pressures. [ABSTRACT FROM AUTHOR]

Flexible electronic devices have attracted significant attention due to their wide range of applications in evaluating the state of human wellness and intelligent robotics in the long term. Microstructure flexible pressure sensors are the optimal choice for the fabrication of flexible electronic devices due to their high sensitivity, wide strain range, affordability, low power consumption, and quick response time, which can accurately convert pressure stimuli into electrical signals. In this review, we summarize the latest progress in various strategies for combining microstructures in flexible pressure sensors to achieve both flexibility and stretchability, while ensuring excellent sensing performance for medical monitoring and intelligent robots. Specifically, we focus on the selection of materials, design mechanisms, and manufacturing strategies for micro pattern-, porous-, fiber network-, and multi microstructure-based pressure sensors. Furthermore, we also examine the applications of microstructure pressure sensors in the medical field for detecting human physiological signals and the development of human–machine interaction applications to establish a communication bridge between humans and machines, which effectively conveys human intentions to machines and collects machine response signals. Finally, we discuss the challenges and prospective views in the development of this exciting field, with the aim of guiding the design and implementation of advanced flexible pressure sensors through the construction of microstructures. [ABSTRACT FROM AUTHOR]

The effects of [gamma]-ray radiation on PBO fibers and its composite materials have been investigated, the results showed that the microstructure and the performance of radiated PBO fibers have been improved with 30-120 kGy radiation dose, crosslinking reactions came from PBO polymer molecule chains and micro-fibrils. As a result, the molecular weight the thermal stability were increased, the tendency of micro-fibrils to split-off also decreased, the hook force of radiated PBO fibers increased by 14.0% without tensile strength loss, and the nano-compression modulus and the flexure strength of radiated PBO fiber composites also increased by 21.0% and 22.7%, respectively. The work indicated that [gamma]-ray radiation could synchronously strengthen the microstructure and improve the properties of PBO fibers., INTRODUCTION Poly(p-phenylene benzoxazole) (PBO) fiber, a rigid-rod polymer material, showed superior tensile strength and excellent thermal stability, thereby being widely used in the fields of aerospace, military industry and automobile [...]

GaoFen-3 (GF-3) is the first commercial C-Band multi-polarimetric Synthetic Aperture Radar (SAR) satellite that was launched by China. The characteristics observed by both all-day and all-weather observation depict significant advantages of national sea area use dynamic monitoring. We have thoroughly discussed both the imaging mode and the standard preprocessing of GF-3 imagery by analyzing national sea area use dynamic monitoring. We have portrayed reclamation and aquaculture as significant examples of dynamic monitoring. We have presented both identification and classification results using various image modes of GF-3 satellite, compared with the existing approaches. Finally, we have elaborated on the scope for future research.