Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.
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http://dx.doi.org/10.1063/1.3491035 | DOI Listing |
Rev Sci Instrum
January 2025
School of Mechatronics Engineering, Anhui University of Science and Technology, Huainan 232001, China.
This paper presents a coaxial integrated macro-micro composite actuator. The macro-actuator of the macro-micro composite actuator is similar to a moving coil type voice coil motor, and a giant magnetostrictive actuator is installed coaxially inside it as a micro-actuator. In this work, kinetic models are established for both the macro-actuator and micro-actuator, and based on the models, an automatic disturbance rejection controller is adopted to control the macro-actuator, and a fuzzy sliding mode controller is adopted for the micro-actuator.
View Article and Find Full Text PDFLangmuir
January 2025
Center for Combustion Energy, Department of Energy and Power Engineering, and Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China.
The preference of water self-ions (hydronium and hydroxide) toward air/oil-water interfaces is one of the hottest topics in water research due to its importance for understanding properties, phenomena, and reactions of interfaces. In this work, we performed enhanced-sampling molecular dynamics simulations based on state-of-the-art neural network potentials with approximate M06-2X accuracy to investigate the propensity of hydronium and hydroxide ions at air/oil(decane)-water interfaces, which can simultaneously describe well the water autoionization process forming these ions, the recombination of ions, and the ionic distribution along the normal distance to the interface by employing a set of appropriate Voronoi collective variables. A stable ionic double-layer distribution is observed near the air-water interface, while the distribution is different at oil-water interfaces, where hydronium tends to be repelled from the interface into the bulk water, whereas hydroxide, with an interfacial stabilization free energy of -0.
View Article and Find Full Text PDFAnal Chem
January 2025
Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
Field analysis of heavy metals in biological samples is essential for assessing their potential threats to human health. The development of portable pretreatment and detection devices is crucial to address this challenge. Herein, a magnetic field-accelerated nonthermal plasma digestion device using dielectric barrier discharge (DBD) is designed for the rapid and environmentally friendly pretreatment of biological samples and subsequently combined with point discharge-optical emission spectrometry (PD-OES) for sensitive determination of heavy metals.
View Article and Find Full Text PDFFront Neurorobot
January 2025
School of Information and Communication Engineering, Hainan University, Haikou, China.
A reward shaping deep deterministic policy gradient (RS-DDPG) and simultaneous localization and mapping (SLAM) path tracking algorithm is proposed to address the issues of low accuracy and poor robustness of target path tracking for robotic control during maneuver. RS-DDPG algorithm is based on deep reinforcement learning (DRL) and designs a reward function to optimize the parameters of DDPG to achieve the required tracking accuracy and stability. A visual SLAM algorithm based on semantic segmentation and geometric information is proposed to address the issues of poor robustness and susceptibility to interference from dynamic objects in dynamic scenes for SLAM based on visual sensors.
View Article and Find Full Text PDFBrain Commun
January 2025
Department of Neurological Surgery, University of Louisville, Louisville, KY 40202, USA.
The subthalamic nucleus is thought to play a crucial role in controlling impulsive actions. Networked among the basal ganglia and receiving input from several cortical areas, the subthalamic nucleus is well positioned to influence action selection when faced with competing and conflicting action outcomes. The purpose of this study was to test the dissociable roles of the dorsal and ventral aspects of the subthalamic nucleus during action conflict in patients with Parkinson's disease undergoing intraoperative neurophysiological recording and to explore a potential mechanism for this inhibitory control.
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