Production of high titania slag by Electro-Slag Crucible Melting (ESCM) process

In this research, ilmenite concentrate of Iran region successfully was smelted by Electro-Slag Crucible Melting (ESCM) process to produce TiO₂-rich slag as primary product and pig iron as by-product. Moreover, effects of reductant (carbon) amount and smelting time on TiO₂ and FeO content of slag and iron recovery were studied. It is found that addition of carbon excess to stoichiometric amount decreases the iron recovery and TiO₂ content in slag. If the smelting time keeps between 0 to 17 min, the TiO₂ content and iron recovery will be increased, whereas smelting time in excess of 17 min will cause products decline significantly. At optimum conditions, TiO₂ content in slag and the iron recovery are 70 wt.% and 84%, respectively. Kinetic studies proved that the reduction of equivalent FeO was first-order reaction. The studies made by X-ray diffraction analysis showed that formation of the titanium sub-oxides (Ti₃O₅ and Ti₂O₃) causes the decrease in iron recovery and TiO₂ content.     

New alternative for general relativity theory

This paper presents a scalar-tensor theory of gravitation with a flat background metric and an arbitrary coupling function. In what concerns PPN approximation as well as the speed and polarization of the weak gravitational wave, the suggested theory coincides with GR, while in the case of the strong field of gravitation it may considerably differ from GR.     

Is there GR in the bimetric scalar-tensor theory of gravitation?

A theory of gravitation with a flat background metric and a dynamical variable (variable gravitational constant) is investigated. It is shown that such bimetric scalar-tensor theory (BSTT) generalized GR as all the solutions of GR equations and(x) = constant satisfy BSTT equations, firstly, and BSTT equations contain non-Einstein solutions with the variable, secondly. Due to this fact, the problem on the agreement of BSTT with the observational data is reduced to the problem on the agreement of GR with the observational data and to the interpretation of the solutions with the variable. The latter may prove useful for the prediction of new effects. Examples of such effects are discussed.     

uvbyβ Electrophotometry of the components of trapezium multiple star systems

The results of electrophotometric observations of the 19 components of six Trapezium multiple star systems with primary stars of class M are presented. The Strömgren spectral intervals are determined. Of the 19 components, 18 belong to interval 3 ("late group").Translated fromAstrofizika, Vol. 39, No. 3, pp. 407–410, July–September, 1996.     

On the internal structure of stars

A new model of the internal structure of certain types of celestial bodies is proposed. It is based on the concept that some neutron stars might have been formed earlier than all other type of stars, at an early stage of expansion of the universe, directly from continuous cosmic matter. Under such conditions, a neutron star after forming becomes an efficient center for the accretion of cosmic plasma. The plasma streams falling onto the neutron star carry magnetic fields with them that are created in the process (by thermoelectric currents and the dynamo process) and pack the fields tightly around the star. After a certain time, an extended and strongly magnetized plasma layer is formed around the neutron star. As a result, a stellar configuration is formed with an outer layer, mass, radius, and luminosity similar to those of an ordinary star. In the magnetized part of such a configuration, the gravitational attraction of the masses is compensated for by a magnetic pressure gradient, while the plasma is confifned by the magnetic field itself. Numerical estimates corroborate the possibility that magnetized stars exist. The radii and masses of the magnetized spheres of such stars are considerably less than the radii and masses of the corresponding configurations, so in observations they should not differ from ordinary stars: the outer layers (intermediate layer, photosphere, and chromosphere) of the magnetized configuration are the same as for an ordinary star. Structural differences may appear in the inner regions, however, involving magnetic activity and neutrino luminosity, for example.     

Spectrophotometry of carbon stars

The results of a spectrophotometric study of 13 carbon stars in the wavelength range from 4000 Å to 6800 Å with 2.75 Å resolution are given. The observed energy distributions for these stars relative to the flux at λ₀ = 5556 Å, represented in graphic form, were determined. Their color temperatures were determined from the [5710] ? [6680] color index. A dust shell is assumed to exist around U Cyg. The indices of the C_2’ MS, and CaCl molecular bands and the D_2,1 line were also determined.     

On the nature of compact galactic nuclei

Spherically symmetric stellar clusters (compact galactic nuclei and globular clusters), far advanced toward the state of complete statistical equilibrium in the course of evolution, are investigated. The equation of state of such systems (a polytrope with an index k = 0.5) is derived and their main characteristics are calculated. It is shown that compact galactic nuclei must consist mainly of rapidly rotating neutron stars and white dwarfs. It is demonstrated that pulsars may be created by the evaporation of neutron stars from the nucleus of our Galaxy. The number of such pulsars is ~3.10⁶. Translated from Astrofizika, Vol. 41, No. 1, pp. 41–50, January-March, 1998.     

基于FY-3号气象卫星的中国典型积雪覆盖区的时空动态研究

基于风云三号(FY-3)气象卫星的积雪产品数据(snow cover),提出了基于经验模态分解的趋势提取方法,探讨了2010—2019年中国积雪时空动态变化趋势。结果表明:1)中国积雪覆盖频率(Snow Cover Frequency,SCF)具有显著的季节性特征,呈现先增加后减少的特点,每年2月、3月SCF达到当年最大;东北的SCF呈显著下降的年际变化趋势,其他地区变化不大。2)中国整体的积雪覆盖率(Snow Cover Rate,SCR)下降了约1.2％,内蒙古和西藏的SCR下降了约1.5％,其他地区的SCR变化不显著;主要积雪覆盖区的SCR均在2016年发生由增加到减少的转变。