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711.
M. I. Panasuyk V. V. Kalegaev I. N. Myagkova N. V. Kuznetsov M. V. Podzolko 《Cosmic Research》2017,55(6):464-468
Factors of radiation environment in near-Earth space in a period from December 1 to 10, 2014 have been analyzed, which could affect serviceability of the onboard systems of Vernov spacecraft. 相似文献
712.
Analysis of errors in atmospheric density measurements by lidar on board the ISS is performed. It is shown that using as the lidar transmitter a Nd:YAG laser with moderate parameters of emission at a wavelength of 353 nm and a receiving mirror diameter of 0.4 m, it is possible to cover with a 10% measurement error a height range, on average, from 40–60 km and 30–40 km in the nighttime and daytime, respectively, down to the troposphere. Working with emission at 266 nm with a 10% error, it is possible to move to the heights of the mesosphere (70 km) and penetrate the atmosphere down to a height of 40 km. Thus, the use of two harmonics makes it possible to assimilate the height range of atmospheric density measurements from on board the ISS beginning from 70 km and down to the troposphere. 相似文献
713.
V. M. Gureev A. Kh. Khairullin F. A. Varlamov I. F. Gumerov R. Kh. Khafizov 《Russian Aeronautics (Iz VUZ)》2016,59(4):554-558
This paper considers the problem of reducing the nitrogen oxide emissions in exhaust gases (EG) of the diesel aircraft engine by exhaust gas recirculation (EGR). The main directions in improving a working process of diesel engines with EGR system were formulated. 相似文献
714.
Elkin I.GUTIRREZ VELSQUEZ 《中国航空学报》2017,30(5)
Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion.In this paper,a review and analysis of the major loss mechanisms and loss models,used to determine the efficiency of a single stage centrifugal compressor,and a subsequent examination to determine an appropriate loss correlation set for estimating the isentropic efficiency in preliminary design stages of centrifugal compressors,were developed.Several semi-empirical correlations,commonly used to predict the efficiency of centrifugal compressors,were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correlation set to determine,with good approximation,the isentropic efficiency of single stage compressor.The aim of this study is to provide a suitable loss correlation set for determining the isentropic efficiency of a single stage centrifugal compressor,because,with a large amount of loss mechanisms and correlations available in the literature,it is difficult to ascertain how many and which correlations to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor.As a result of this study,a set of correlations composed by nine loss mechanisms for single stage centrifugal compressors,conformed by a rotor and a diffuser,are specified. 相似文献
715.
Sobolevsky N. M. Latysheva L. N. Kuznetsov H. V. Panasyuk M. I. Podzolko M. V. 《Cosmic Research》2021,59(4):259-267
Cosmic Research - A special version of the SHIELD transport code has been developed intended for radiation protection purposes in space. The calculation of the fluxes of primary and secondary... 相似文献
716.
Cosmic Research - We have analyzed the experimental data obtained in 2016–2019 from the measurements of plasma disturbances and electric currents induced at ionospheric altitudes upon the... 相似文献
717.
N. S. Dushin N. I. Mikheev I. M. Gazizov I. A. Davletshin 《Russian Aeronautics (Iz VUZ)》2017,60(4):583-590
A technique that allows simultaneous heating of the heat-exchange surface and estimation of its local temperature from the corresponding electrical resistance of the heating element is presented. The systematic error in measurements of the local heat transfer coefficient has been analyzed. A relation that takes possible heat loss into account and minimizes the measurement errors has been obtained. 相似文献
718.
Adrienn Luspay-Kuti Olivier Mousis Jonathan I. Lunine Yves Ellinger Françoise Pauzat Ujjwal Raut Alexis Bouquet Kathleen E. Mandt Romain Maggiolo Thomas Ronnet Bastien Brugger Ozge Ozgurel Stephen A. Fuselier 《Space Science Reviews》2018,214(8):115
The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument onboard the Rosetta spacecraft has measured molecular oxygen (O2) in the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) in surprisingly high abundances. These measurements mark the first unequivocal detection of O2 in a cometary environment. The large relative abundance of O2 in 67P/C-G despite its high reactivity and low interstellar abundance poses a puzzle for its origin in comet 67P/C-G, and potentially other comets. Since its detection, there have been a number of hypotheses put forward to explain the production and origin of O2 in the comet. These hypotheses cover a wide range of possibilities from various in situ production mechanisms to protosolar nebula and primordial origins. Here, we review the O2 formation mechanisms from the literature, and provide a comprehensive summary of the current state of knowledge of the sources and origin of cometary O2. 相似文献
719.
The algorithms for achieving a practical increase in the rate of data transmission on the space-craft–ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated. 相似文献
720.
Superluminous supernovae are a new class of supernovae that were recognized about a decade ago. Both observational and theoretical progress has been significant in the last decade. In this review, we first briefly summarize the observational properties of superluminous supernovae. We then introduce the three major suggested luminosity sources to explain the huge luminosities of superluminous supernovae, i.e., the nuclear decay of 56Ni, the interaction between supernova ejecta and dense circumstellar media, and the spin down of magnetars. We compare these models and discuss their strengths and weaknesses. 相似文献