under no-flux boundary conditions in a smoothly bounded domain 916302385&_mathId=si2.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=6825181586dd13caeceed51341da455f">916302385-si2.gif">, 916302385&_mathId=si3.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=985e9b35aa8249ff094dedbb7789a518" title="Click to view the MathML source">N≥1, where 916302385&_mathId=si4.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=32ac875ec44b7cc72222094ce620ed19" title="Click to view the MathML source">χ,μ,m,α and 916302385&_mathId=si5.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=de2f026ace56c06a360e25c135adb9f4" title="Click to view the MathML source">γ are prescribed positive parameters fulfilling 916302385&_mathId=si6.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=74be938fea97002af04ae0ef3531f560" title="Click to view the MathML source">m≥1 and 916302385&_mathId=si7.gif&_user=111111111&_pii=S0893965916302385&_rdoc=1&_issn=08939659&md5=9c48b970c57462a0e93d8a58aeb596a6" title="Click to view the MathML source">γ≥1.