It's hard to define what "kernel tech" is. But there are lots of know-hows that China doesn't possess for now. Some really appear simple. An example is the seal of a milk jug. It has to be tight enough to seal properly,
-sailor(Ocean & Mountain);
2020-7-29{90}(#13113329@0)+2
however should not require effort to pull off so that even weak seniors are able to do it.