R语言的一些错误

第一个问题：为何$后面中文列名要加引号才能运行，否则报错> myData[which(myData$员工姓名 == "庞卫东"),5]
错误：unexpected input in "myData[which(myData$\"
> myData[which(myData$"员工姓名" == "庞卫东"),5]
[1] "2009/7/1"




第二个问题：在rmd转pdf文件时只要有一个中文，就会产生如下错误，已按照提示网站尝试过无法解决，请大神提供下解决方案
! Package inputenc Error: Unicode character 绌?(U+7A7A)
(inputenc)                not set up for use with LaTeX.

Try other LaTeX engines instead (e.g., xelatex) if you are using pdflatex. See https://bookdown.org/yihui/rmarkdown-cookbook/latex-unicode.html
错误: LaTeX failed to compile 111.tex. See https://yihui.org/tinytex/r/#debugging for debugging tips. See 111.log for more info.
此外: Warning message:
In grepl("==> Fatal error occurred", x, fixed = TRUE) :
  输入的字符串1不适用于此语言环境
停止执行