Impulsive Solar Energetic Particle Events: Extreme-Ultraviolet Waves and Jets

Impulsive solar energetic particle (ISEP) events show peculiar elemental composition, with enhanced 3He and heavy-ion abundances, markedly different from our Solar System composition. Furthermore, the events are characterized by a wide variety of energy spectral shapes from power laws to rounded spectra toward the low energies. Solar sources of the events have been firmly associated with coronal jets. Surprisingly, new observations have shown that events are often accompanied by so-called extreme-ultraviolet (EUV) coronal waves–a large-scale phenomenon compared to jets. This paper outlines the current understanding of the linkage of EUV waves with jets and energetic ions in ISEP events.

Design and Realization of Recovery System of Chang’e-5 Reentry Spacecraft

On December 17, 2020, the Chang’e-5 reentry spacecraft landed safely and brought back the lunar sample without damage. This paper describes the recovery system that has critically contributed to the scientific success of the Chang’e-5 missions and presents the technical requirements and constraints of the recovery system for the Chang’e-5 reentry spacecraft and discusses the design process of the recovery system, including the system composition, working procedure, and some other key aspects. Finally, the ground cover rejection tests and air drop and flight tests were carried out to confirm the design configuration. The results showed that the Chang’e-5 reentry spacecraft recovery system was designed correctly, and its functions and performances met the design requirements. A breakthrough in the recovery technology of the reentry spacecraft was achieved for Chinese first lunar sample-return mission.

Nano-Particles Carried by Multiple Dynein Motors Self-Regulate Their Number of Actively Participating Motors

Intra-cellular active transport by native cargos is ubiquitous. We investigate the motion of spherical nano-particles (NPs) grafted with flexible polymers that end with a nuclear localization signal peptide. This peptide allows the recruitment of several mammalian dynein motors from cytoplasmic extracts. To determine how motor–motor interactions influenced motility on the single microtubule level, we conducted bead-motility assays incorporating surface adsorbed microtubules and combined them with model simulations that were based on the properties of a single dynein. The experimental and simulation results revealed long time trajectories: when the number of NP-ligated motors Nm increased, run-times and run-lengths were enhanced and mean velocities were somewhat decreased. Moreover, the dependence of the velocity on run-time followed a universal curve, regardless of the system composition. Model simulations also demonstrated left- and right-handed helical motion and revealed self-regulation of the number of microtubule-bound, actively transporting dynein motors. This number was stochastic along trajectories and was distributed mainly between one, two, and three motors, regardless of Nm. We propose that this self-regulation allows our synthetic NPs to achieve persistent motion that is associated with major helicity. Such a helical motion might affect obstacle bypassing, which can influence active transport efficiency when facing the crowded environment of the cell.

Management ofCommunication System in Pipeline IndustryBased on OLP Technology

In order to effectively improve the fault self-healing ability of pipeline communication system and reduce the events of communication interruption caused by fiber break or performance degradation of optical line, this paper introduces the basic principle, system composition working mode and technical requirements of OLP technology. The OLP system is firstly introduced into the relay section of long-distance pipeline to build the standby route with the spare optical fiber as material. When the in-service route is broken or the performance of optical fiber is reduced, the OLP system can automatically switch to the standby route within 50 ms to ensure the communication transmission service be uninterrupted, and even no error code alarm. Through engineering test in pipeline industry, the operability of OLP technology applied to the pipeline communication system is verified. Using the real-time monitoring data of optical cable through OLP system, we can analyze the evolution trend of optical cable line quality, precontrol in advance, and improve the level of communication management.

Continuous Contract Based Verification of Updates in Maritime Shipboard Equipment

Modern control systems in the maritime domain are increasingly controlled by software systems and become subject to updates and configuration changes during operation. Moreover, with the shift to autonomous vessels and cars, these software-based systems are taking on more and more safety-critical tasks, so the risks associated with system failures are increasing. Unlike before, it becomes necessary to verify the continuously adapting modules of a vehicle not only before deployment, but to establish continuous verification capabilities during all phases of the product lifecycle, from the design to the system in operation. Hence, in case of an update, deviations from the expected behavior can be automatically detected and relevant measures can be initiated. In this work, a contract-based verification framework is presented that includes automatable and formally analyzable behavioral descriptors in form of assumption-guarantee contracts for all phases of the software lifecycle to provide static and dynamic verification capabilities alongside a dynamically changing system composition. By utilizing contractually defined behavior descriptions, classic test procedures, such as simulations, are supplemented by a formally testable level that is applied to all phases of the update process. A conceptual-deductive methodology was chosen, building on the identified requirements to develop an overarching update framework that adds contractual descriptions to the traditional development case. Based on the presented framework, the verifiable modification of a safety-critical software system is demonstrated. The approach is evaluated using a maritime collision-avoidance system and the verification steps are evaluated along the update process. The framework offers a novel approach to complement existing test procedures by enabling formal impact analysis and incremental verification of updates.