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Abstract Magnetic reconnection in the relativistic regime has been proposed as an important process for the efficient production of nonthermal particles and high-energy emission. Using fully kinetic particle-in-cell simulations, we investigate how the guide-field strength and domain size affect the characteristic spectral features and acceleration processes. We study two stages of acceleration: energization up until the injection energyγinjand further acceleration that generates a power-law spectrum. Stronger guide fields increase the power-law index andγinj, which suppresses acceleration efficiency. These quantities seemingly converge with increasing domain size, suggesting that our findings can be extended to large-scale systems. We find that three distinct mechanisms contribute to acceleration during injection: particle streaming along the parallel electric field, Fermi reflection, and the pickup process. The Fermi and pickup processes, related to the electric field perpendicular to the magnetic field, govern the injection for weak guide fields and larger domains. Meanwhile, parallel electric fields are important for injection in the strong guide-field regime. In the post-injection stage, we find that perpendicular electric fields dominate particle acceleration in the weak guide-field regime, whereas parallel electric fields control acceleration for strong guide fields. These findings will help explain the nonthermal acceleration and emission in high-energy astrophysics, including black hole jets and pulsar wind nebulae.
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Electrically Controlled Biochemical Release from Micro/Nanostructures for in vitro and in vivo Applications: A Review
Abstract To release biosubstances, including drug molecules, DNAs, and proteins, at prescribed cellular and tissue locations with controllable rates is the Holy Grail of drug delivery that could enable an array of unprecedentedin vitroandin vivoapplications. Extensive research efforts have been focused on exploring innovative mechanisms and approaches for controlling biochemical release with prescribed dose, timing, and dynamics. Particularly, the utilization of electric fields to stimulate the release of biomolecules from synthesized micro/nanostructures has received considerable interest. In this review, we focus on the recent progresses in controlling the release of biomolecules with electric fields by a variety of mechanisms, including electrochemical desorption and actuation, electrically triggered erosion, and electrically driven nanopumps and mechanical motions. The research on external electric stimuli trigged biorelease has progressed rapidly and could make remarkable impact in single‐cell biology, cell‐cell communication, and drug discovery.
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- PAR ID:
- 10060253
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemNanoMat
- Volume:
- 4
- Issue:
- 10
- ISSN:
- 2199-692X
- Format(s):
- Medium: X Size: p. 1023-1038
- Size(s):
- p. 1023-1038
- Sponsoring Org:
- National Science Foundation
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