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1. Positive solution to a singular (k, n − k) conjugate boundary value problem

Creator:
Yao, Qingliu
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
singular ordinary differential equation, higher order boundary value problem, positive solution, and existence theorem
Language:
English
Description:
The positive solution is studied for a (k, n - k) conjugate boundary value problem. The nonlinear term is allowed to be singular with respect to both the time and space variables. By applying the approximation theorem for completely continuous operators and the Guo-Krasnosel’skii fixed point theorem of cone expansion-compression type, an existence theorem for a positive solution is established.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. The present state of the international star cluster photometry programme

Creator:
Szécsényi-Nagy, G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
multilateral cooperation of astronomers, open star clusters, and astrometric, photometric and spectroscopic investigation
Language:
Czech
Description:
In the seventies, astronomers from some European socialist countries, participating in the multilateral cooperation of the academies of these states, decided to collaborate in the detailed astrometric, photometric and spectrometri investigation of open star clusters. Hungarian scientists were expected to carry out tthe multicolour photometry of cluster member stars (at least to a certain extent). Considering that the majority of the programme stars are far too dim to be measured by the moderate-sized photoelectric telescopes of the Hungarian Academy of Sciences and that incividual photoelectric photometry of cluster members would be extremely time-consuming, photographic UBV photometry was chosen as the most advantageous solution. The first steps in this task have been taken - more than 200 plates were collected in these spectral bands - and a short review is presented on the observations in order to inform out cooperating partners. At the same time, a proposal is made with a view to supplementing the list of jointly studied open clusters and information is requested from our collaborators on cluster membership probabilities and spectre of stars in order to take the preliminary steps in laboratory measurements.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public