Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Joule heating and high frequency nonlinear effects in the surface
  impedance of high Tc superconductors   Using the dielectric resonator method, we have investigated nonlinearities in
the surface impedance Zs = Rs + jXs of YBa2Cu3O7 thin films at 10 GHz as
function of the incident microwave power level and temperature. The use of a
rutile dielectric resonator allows us to measure the precise temperature of the
films. We conclusively show that the usually observed increase of the surface
resistance of YBa2Cu3O7 thin film as function of microwave power is due to
local heating.

29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci