If the real numbers a and b satisfy |3a-1|+b**2=0, what is the value of ab?
若实数a、b满足|3a-1|+b**2=0，则ab的值为多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) ** 0</gadget>
<output>1</output>

<result>1</result>