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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">najo</journal-id><journal-title-group><journal-title xml:lang="en">Nanosystems: Physics, Chemistry, Mathematics</journal-title><trans-title-group xml:lang="ru"><trans-title>Наносистемы: физика, химия, математика</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2220-8054</issn><issn pub-type="epub">2305-7971</issn><publisher><publisher-name>Университет ИТМО</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.17586/2220-8054-2017-8-3-317-322</article-id><article-id custom-type="elpub" pub-id-type="custom">najo-603</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATHEMATICS</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИКА</subject></subj-group></article-categories><title-group><article-title>To the qualitative properties of solution of system equations not in divergence form of polytrophic filtration in variable density</article-title><trans-title-group xml:lang="ru"><trans-title></trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Aripov</surname><given-names>M.</given-names></name></name-alternatives><bio xml:lang="en"><p>Applied Mathematics and Computer Analysis</p><p>Universitet, 4, Tashkent, 100174</p></bio><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Matyakubov</surname><given-names>A. S.</given-names></name></name-alternatives><bio xml:lang="en"><p>Applied Mathematics and Computer Analysis</p><p>Universitet, 4, Tashkent, 100174</p></bio><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff xml:lang="en" id="aff-1"><institution>National University of Uzbekistan</institution><country>Uzbekistan</country></aff><pub-date pub-type="collection"><year>2017</year></pub-date><pub-date pub-type="epub"><day>11</day><month>08</month><year>2025</year></pub-date><volume>8</volume><issue>3</issue><fpage>317</fpage><lpage>322</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Aripov M., Matyakubov A.S., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Aripov M., Matyakubov A.S.</copyright-holder><copyright-holder xml:lang="en">Aripov M., Matyakubov A.S.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://nanojournal.ifmo.ru/jour/article/view/603">https://nanojournal.ifmo.ru/jour/article/view/603</self-uri><abstract><p>In this paper, the properties of solutions for the nonlinear system equations not in divergence form:</p><p>||x| n ∂u ∂t = u γ1∇  |∇u| p−2∇u + |x| nu q1 v q2 ,</p><p>|x| n ∂v ∂t = v γ2∇  |∇v| p−2∇v + |x| nv q4 u q3,</p><p>are studied. In this work, we used method of nonlinear splitting, known previously for nonlinear parabolic equations, and systems of equations in divergence form, asymptotic theory and asymptotic methods based on different transformations. Asymptotic representation of self-similar solutions for the nonlinear parabolic system of equations not in divergence form is constructed. The property of finite speed propagation of distributions (FSPD) and the asymptotic behavior of the weak solutions were studied for the slow diffusive case.</p></abstract><kwd-group xml:lang="en"><kwd>nonlinear system of equations</kwd><kwd>not in divergence form</kwd><kwd>global solutions</kwd><kwd>self-similar solutions</kwd><kwd>asymptotic representation of solution</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Shigesada N., Kawasaki K., Teramoto E. Spatial segregation of interacting species. J. Theor. 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