Finally, obtain that increasing the absolute value of J increases the concurrence for a given T, but the concurrence decreases with the increase of temperature until it reaches the critical value of T, and becomes zero.

• 结果表明：对于一定的温度，耦合常数的增加能够增加纠缠度，但是纠缠度却随着温度的增加而减小，直到临界温度时纠缠度为零。