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Novel method for the preparation of Cs-containing FAU（Y） catalysts for aniline methylation

Frontiers of Chemical Science and Engineering 2018年第1期12卷 70-76页

作者： Olga A. Ponomareva Polina A. Shaposhnik marina vo belova Boris A. Kolozhvari Irina I. Ivanova Department of Chemistry Lomonosov Moscow State University Moscow 119991 Russia A.V. Topchiev Institute of Petrochemical Synthesis Moscow Russia

Cs-containing FAU（Y）-type zeolite catalysts were prepared by conventional and novel ion exchange procedures followed by incipient wetness impregnation with CsOH. The novel ion exchange procedure involved hydrothermal treatment of NaY zeolite in aqueous solution of CsCl at 140-200 ℃ for 6-24 h. The samples were characterized by low-temperature nitrogen adsorption, X-ray fluorescence analysis, X-ray powder diffraction, scanning electron microscopy, 23Na, 27Al and 133Cs magic angle spinning nuclear magnetic resonance, CO2 and NH3-Temperature programmed desorption. The results show that hydrothermal treatment at 200 ℃ allows to obtain higher degrees of ion-exchange （up to 83%） with respect to conventional method giving maximum 66%- 69%. Catalytic properties of Cs-containing FAU（Y） were studied in aniline methylation. The yield of Nomethylani- line is shown to correlate with catalyst＇s basicity. The best catalyst performance was achieved over the catalyst with the highest ion-exchange degree impregnated with CsOH. The selectivity to N-methylaniline over this catalyst reached 96.4%.

关键词： FAU(Y) zeolite ion exchange with cesium aniline alkylation N-methylaniline

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Spectroscopic and photometric observations of symbiotic nova PU Vul during 2009–2016

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Research in Astronomy and Astrophysics 2018年第8期18卷 83-88页

作者： Anna Tatarnikova marina Burlak Eugene Kolotilov Natalia Metlova Victor Shenavrin Sergei Shugarov Taisija Tarasova Andrey Tatarnikov Sternberg Astronomical Institute Moscow State UniversityMoscow 119234Russia Astronomical Institute of the Slovak Academy of Sciences 05960 Tatranska LomnicaSlovakia Federal State Budget Scientific Institution"Crimean Astrophysical Observatory of RAS" Nauchny298409Russia

A new set of low-resolution spectral and UBVJHKL-photometric observations of the symbi- otic nova PU Vul is presented. The binary has been evolving after its symbiotic nova outburst in 1977 and now it is in the nebular stage. It is found that the third orbital cycle （after 1977） was characterized by great changes in associated light curves. Now, PU Vul exhibits a sine-wave shape in all the light curves （with an amplitude in the U band of about 0.7 mag）, which is typical for symbiotic stars in the quiescent state. Brightness variability due to pulsations of the cool component is now clearly visible in the VRI light curves. The amplitude of the pulsations increases from 0.5 mag in the V band to 0.8 mag in the I band. These two types of variability, as well as a very slow change in the physical parameters of the hot component due to evolution after the outburst of 1977, influence the spectral energy distribution （SED） of the system. The variability of emission lines is highly complex. Only hydrogen line fluxes vary with orbital phase. An important feature of the third orbital cycle is the first emergence of the OVI, 6828A Raman scattering line. We determine the temperature of the hot component by means of the Zanstra method applied to the He II, 4686A line. Our estimate is about 150000 K for the spectrum obtained near orbital maximum in 2014. The vo spectral index derived near pulsation minimum corresponds to M6 spectral class for the cool component of PU Vul.

关键词： binaries symbiotic - novae - cataclysmic variables - stars individual (PU Vul)

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