在模式发生后拆分字符串

我有以下字符串向量.它包含两个元素.每个元素由两个折叠短语组成.

strings <- c("This is a phrase with a NameThis is another phrase",
         "This is a phrase with the number 2019This is another phrase")

我想将这些短语拆分为向量中的每个元素.我一直在尝试这样的事情:

library(stringr)

str_split(strings, "\\B(?=[a-z|0-9][A-Z])")

几乎给了我正在寻找的东西:

[[1]]
[1] "This is a phrase with a Nam" "eThis is another phrase"

[[2]]
[1] "This is a phrase with the number 201" "9This is another phrase"

我想在模式之后进行拆分,但无法弄清楚如何做到这一点.

我想我接近一个解决方案,并希望得到任何帮助.