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IUCrJ ◽  
2022 ◽  
Vol 9 (2) ◽  
Author(s):  
Manfred Wildner ◽  
Boris A. Zakharov ◽  
Nikita E. Bogdanov ◽  
Dominik Talla ◽  
Elena V. Boldyreva ◽  
...  

Monohydrate sulfate kieserites (M 2+SO4·H2O) and their solid solutions are essential constituents on the surface of Mars and most likely also on Galilean icy moons in our solar system. Phase stabilities of end-member representatives (M 2+ = Mg, Fe, Co, Ni) have been examined crystallographically using single-crystal X-ray diffraction at 1 bar and temperatures down to 15 K, by means of applying open He cryojet techniques at in-house laboratory instrumentation. All four representative phases show a comparable, highly anisotropic thermal expansion behavior with a remarkable negative thermal expansion along the monoclinic b axis and a pronounced anisotropic expansion perpendicular to it. The lattice changes down to 15 K correspond to an `inverse thermal pressure' of approximately 0.7 GPa, which is far below the critical pressures of transition under hydrostatic compression (Pc ≥ 2.40 GPa). Consequently, no equivalent structural phase transition was observed for any compound, and neither dehydration nor rearrangements of the hydrogen bonding schemes have been observed. The M 2+SO4·H2O (M 2+ = Mg, Fe, Co, Ni) end-member phases preserve the kieserite-type C2/c symmetry; hydrogen bonds and other structural details were found to vary smoothly down to the lowest experimental temperature. These findings serve as an important basis for the assignment of sulfate-related signals in remote-sensing data obtained from orbiters at celestial bodies, as well as for thermodynamic considerations and modeling of properties of kieserite-type sulfate monohydrates relevant to extraterrestrial sulfate associations at very low temperatures.


Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 29
Author(s):  
Francesco De Paolis ◽  
Achille A. Nucita ◽  
Alexander F. Zakharov

Relativistic Astrophysics is the branch of astrophysics that studies astronomical phenomena and celestial bodies, for which classical mechanics and Newton’s law of gravitation are inapplicable to creation of suitable models and we have to generalize these approaches following general relativistic prescriptions [...]


2021 ◽  
Vol 3 (2) ◽  
pp. 272-300
Author(s):  
Alexander Vovin

Abstract The following lines are inspired by John Kupchik’s seminal article ‘Austronesian Lights the Way’ that appears in this volume of JEAL. It demonstrated beyond any reasonable doubt for the first time that there are reliable Austronesian loanwords in Japonic that reveal quite ancient and profound contacts, because without these profound contacts the borrowing of the names of the most basic celestial bodies, such as the sun and the moon, would not be possible. In my opinion, his article opened a new and an exciting direction in the Japonic historical linguistics. There are, however, two important differences between Kupchik’s article and the present one. First, while Kupchik mostly concentrated on the Amis language from Taiwan, and to a less extent on the languages of Philippines and other Western Malayo- Polynesian, my major focus is on the Philippines languages as potential donors, and much less on other Austronesian languages of the region. Second, while Kupchik looked mostly on mysterious words in the Omoro Sōshi, a collection of Old Okinawan and Amami sacred and folk poems (1531–1623 AD), this article focuses more on Old Japanese in particular and Japonic in general.


2021 ◽  
Author(s):  
Wenjing Qu

Most of metabolic processes are extremely complicated but occur spontaneously and steadily, the essential reason of which may be either a thermodynamic problem or related to some quantum properties. Here, collapse selection is interpreted with an analytical model of energy transfer, from which the concept of quantum cloud is defined as that during undetectable changes of a group of particles between its effective changes, particles are in the superposition of various energy states and the group is named as a cloud. It is deduced from a conservation notion of matter proportions that active cloud collapses have least-time expectation while passive collapses have matter-proportion expectation. As the results, quantum Zeno effect is a typical phenomenon of passive collapses while anti-Zeno effect is typical active collapses; moreover, the phenomenon of dark matter may be dark-cloud effect of normal matter while the phenomenon of accelerating universe may be induced by the luminescent asymmetries of bright celestial bodies.


2021 ◽  
Vol 5 (12) ◽  
pp. 82
Author(s):  
Maria Cristina Costa ◽  
Paulo Santos ◽  
João Manuel Patrício ◽  
António Manso

Mobile augmented reality applications are gaining prominence in education, but there is a need to design appropriate and enjoyable games to be used in educational contexts such as classrooms. This paper presents an interactive information system designed to support the implementation of an augmented reality application in the context of game-based learning. PlanetarySystemGO includes a location-based mobile augmented reality game designed to promote learning about the celestial bodies and planetary systems of the Universe, and a web application that interacts with the mobile device application. Besides face-to-face classes, this resource can also be used in online classes, which is very useful in social isolation situations as the ones caused by the COVID-19 pandemic. Furthermore, it is the inclusion of the web application, with a back-office, in the information system that makes it possible to include curricula contents according to the grade level of students. Moreover, it is intended that teachers use the information system to include the contents they find appropriate to the grade level they teach. Therefore, it is crucial to provide their professional development to be able to use this resource. In this regard, a pilot study was conducted with teachers who participated in a STEM professional development programme in order to assess if the system is appropriate to be used by them. It is concluded that teachers found this resource relevant to motivate students to learn, and also acknowledged that the web application facilitated the introduction of appropriate curricula contents and also was useful to assess student performance during the game. Teachers need support, however, to implement these types of technologies which are not familiar to them. The necessary support can be provided through collaboration among the researchers and teachers in their schools. Besides engaging students to learn about celestial bodies, it is concluded that the information system can be used by teachers to introduce appropriate curricula contents and to be implemented in class.


2021 ◽  
Author(s):  
Dong-il Song

Abstract In this research, we investigate the thermoelectric effects of general materials. The results of this showed that an electromotive force was generated under a temperature difference between two points in materials. As no material has infinite electric resistance, an electromotive force is expected to be generated under a temperature difference in all materials. In conclusion, the thermoelectric effect generates an electromotive force. This electromotive force causes an electric current to flow, thereby generating a magnetic field. This magnetic field generates the Earth's magnetic field, triboelectricity, sunspots, and kinetic energy of celestial bodies. This temperature differential electromotive force also generates lightning and creates an ionosphere that reflects radio waves.


Author(s):  
Zhenisgul Rakhmetullina ◽  
Indira Uvaliyeva ◽  
Farida Amenova

This paper presents an analytical solution of the differential equations of motion of a material point in the plane perpendicular to the plane of the gravitating disk. The differential equations of the problem under study and the applied Gilden's method are described in the works of A. Poincaré. Differential equations refer to nonlinear equations. The analysis of methods for solving nonlinear differential equations was carried out. The methodology of applying the Gilden method to the solution of the differential equations under consideration can be applied in studies of the problem of the motion of celestial bodies in the “disk-material point” system in perpendicular planes. To identify the various properties of the gravitating disk, an analytical review of the state of the problem of the motion of a material point in the field of a gravitating disk is carried out. Summing up the presented review on the problem under study, a conclusion is made. The substantive formulation of the problem is described, which is formulated as follows: the study of the influence of disk-shaped bodies on the motion of a material point and methods for their solution.


2021 ◽  
Vol 133 (1030) ◽  
pp. 124501
Author(s):  
Yujie Yang ◽  
Bin Jiang

Abstract In this paper, we pioneer a new machine-learning method to search for H ii regions in spectra from The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). H ii regions are emission nebulae created when young and massive stars ionize nearby gas clouds with high-energy ultraviolet radiation. Having more H ii region samples will help us understand the formation and evolution of stars. Machine-learning methods are often applied to search for special celestial bodies such as H ii regions. LAMOST has conducted spectral surveys and provided a wealth of valuable spectra for the research of special and rare celestial bodies. To overcome the problem of sparse positive samples and diversification of negative samples, a novel method called the self-calibrated convolution network is introduced and implemented for spectral processing. A deep network classifier with a structure called a self-calibrated block provides a high precision rate, and the recall rate is improved by adding the strategy of positive-unlabeled bagging. Experimental results show that this method can achieve better performance than other current methods. Eighty-nine spectra are identified as Galactic H ii regions after cross-matching with the WISE Catalog of Galactic H ii Regions, confirming the effectiveness of the method proposed in this paper.


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