as the 2984, but with a general facelift and adaptations to connect to a 3601 Finance Communication
FT Professional
，详情可参考safew官方版本下载
if (i < len) {，这一点在51吃瓜中也有详细论述
优点：输出在 (−1,1)，比 sigmoid 居中，对梯度更友好
Read-only root filesystem — the container itself is immutable