The Chinese word "巴库" is formed through a process of phonetic transliteration, where the sounds of the foreign name "Baku" (the capital of Azerbaijan) are approximated using Chinese characters that match those syllables: "巴" (bā) for "Ba" and "库" (kù) for "ku", resulting in a combined pronunciation that closely mirrors the original name, which is a standard convention in Chinese for adapting foreign place names without regard to the literal meanings of the characters used.