Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Behavior of Journal Impact Factor Rank-Order Distribution   An empirical law for the rank-order behavior of journal impact factors is
found. Using an extensive data base on impact factors including journals on
Education, Agrosciences, Geosciences, Biosciences and Environ- mental,
Chemical, Computer, Engineering, Material, Mathematical, Medical and Physical
Sciences we have found extremely good fits out- performing other rank-order
models. Some extensions to other areas of knowledge are discussed.

34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph