The name is a filename convention used by the Founder Electronics library. Here is how to decode it:
In short: This is FangZheng HeiTi (Founder Black Sans-Serif). It is comparable in style to Arial or Helvetica in the Western world, but tailored for Chinese characters. Fzhtjw--gb1-0 Font
PDFs embed font names. If the PDF was created with a missing or corrupted font, some viewers show internal substrings. Use pdffonts (Linux/macOS) or Adobe Acrobat’s Properties → Fonts tab. The name is a filename convention used by
# On macOS/Linux
strings yourfontfile.ttf | grep -i "Fzhtjw"