Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Local immobilization of particles in mass transfer described by the
  equation of the Jeffreys type   We consider the equation of the Jeffreys type as the basic one in three
different models of mass transfer, namely, the Jeffreys type and two-phase
models, and the $D_1$ approximation to the linear Boltzmann equation. We study
two classic 1 + 1D problems in the framework of each model. The first problem
is the transfer of a substance initially confined in a point. The second
problem is the transfer of a substance from a stationary point source. We
calculate the mean-square displacement (MSD) for the solutions of the first
problem. The temporal behaviour of the MSD in the framework of the first and
third models is found to be the same as that in the Brownian motion described
by the standard Langevin equation. Besides, we find a remarkable phenomenon
when a portion of the substance does not move.

21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph