We describe the instrument concept of a high angular resolution telescope dedicated to the sub-GeV (from 10 MeV to 1 GeV) gamma-ray photon detection. This mission, named PANGU (PAir-productioN Gammaray Unit), has been suggested as a candidate for the joint small mission between the European Space Agency (ESA) and the Chinese Academy of Science (CAS). A wide range of topics of both astronomy and fundamental physics can be attacked with PANGU, covering Galactic and extragalactic cosmic-ray physics, extreme physics of a variety of extended (e.g. supernova remnants, galaxies, galaxy clusters) and compact (e.g. black holes, pulsars, gamma-ray bursts) objects, solar and terrestrial gamma-ray phenomena, and searching for dark matter decay and/or annihilation signature etc. The unprecedented point spread function can be achieved with a pairproduction telescope with a large number of thin active tracking layers to precisely reconstruct the pair-produced electron and positron tracks. Scintillating fibers or thin silicon micro-strip detectors are suitable technology for such a tracker. The energy measurement is achieved by measuring the momentum of the electrons and positrons through a magnetic field. The innovated spectrometer approach provides superior photon pointing resolution, and is particular suitable in the sub-GeV range. The level of tracking precision makes it possible to measure the polarization of gamma rays, which would open up a new frontier in gamma-ray astronomy. The frequent full-sky survey at sub-GeV with PANGU's large field of view and significantly improved point spread function would provide crucial information to GeV-TeV astrophysics for current/future missions including Fermi, DAMPE, HERD, and CTA, and other multi-wavelength telescopes.

Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100 kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches a maxima of approximately 200 km s−1 toward the central active galactic nucleus (AGN) and toward the AGN inflated northwestern “ghost” bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100 km s−1. We also detect a velocity gradient with a 100 km s−1 amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10% of the thermal pressure support in the cluster core. The well-resolved, optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100 kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift of the brightest cluster galaxy NGC 1275.

This article postulates that the successful development of the digital economy will be ensured by strengthening the position of corporations, increasing quality of corporate governance, and increasing the interaction and clarity of the structure of financial institutions in accordance with the latest technologies. A general definition of the term ‘digital economy’ is formulated to understand this transformation. The digital economy (as an environment) includes a combination of digital infrastructure, innodiversification information, and communication technologies for doing business. This article discusses issues related to the development of new methods of risk assessment and their impact on business processes in the formation and development of the digital economy.The article further emphasises that corporations must pay special attention to the risks inherent in the digital economy in the transformation process. The purpose of this study is to identify the most significant risks. The study was conducted through hierarchical methods for developing classifications, ranking, and a priori analysis. It has been established that the highest priority of research in the traditional economy is given to financial and commercial types of risk as a result of an a priori analysis. A classification of risks of the digital economy is herein proposed.The article further states that the most specific corporate risk for the digital economy is a specific risk, called technological risk. The concept of technological risk is suggested in order to understand the problems associated with large-scale acceleration of the digital economy, and the development and implementation of information and communication technologies. The development of these technologies appear almost impossible to halt due to their tending toward self-propagation and interactive innovation. The article highlights the positive trend of the emergence of an innovative financial system, which is based on digital platforms, technology and marketing. A well-thought and concerted strategy of digital transformation is important for corporations and successful businesses in modern conditions, instead of disparate use of separate tools.The article also notes that the contradictions in strategy and influence between the leading transnational corporations are becoming one of the main sources of risk in the new conditions of the digital economy from the point of view of ensuring national security issues.

The paper addresses up-to-date approaches to model design of manufacturing processes and production systems. In view of high complexity and labor intensity of designing manufacturing processes and production systems, it is quite expedient to use computer facilities. It is most appropriate to predict the results of designing manufacturing processes and production systems by means of simulation modeling. The stages of creating manufacturing process models, computer modeling and simulation modeling are described. The presentation of ongoing events with a full retention of their logical structures and time sequence takes place in simulation modeling of production systems or manufacturing processes. Simulation modeling makes it possible to determine the most accurate characteristics of manufacturing processes (technical performance, the time of processing and assembling, the use or load factors etc.). Some examples of practical application of models in design are given. It is revealed that model design is an optimal if not the only possible way for improving the structure of production systems and technological processes as well as for their control.

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