> summary(xian2)

Call:
lm(formula = r2 ~ T2)
Residuals:
       Min         1Q     Median         3Q        Max
-0.0680301 -0.0126145 -0.0006432  0.0127143  0.0615278
Coefficients:
              Estimate Std. Error t value Pr(>|t|)   
(Intercept) -0.2135051  0.0033632  -63.48   <2e-16 ***
T2           0.0201425  0.0001566  128.60   <2e-16 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.01971 on 713 degrees of freedom
Multiple R-squared: 0.9587,     Adjusted R-squared: 0.9586
F-statistic: 1.654e+04 on 1 and 713 DF,  p-value: < 2.2e-16

现在要提取红字部分0.01971，怎么办好呢？