并萘與精萘不是完全相同的物質，它們在結構上有一些差異。

Naphthalene and refined naphthalene are not exactly the same substance, they have some structural differences.

并萘（naphthalene）也被稱為萘，是一種具有分子式C10H8的芳香烴化合物。它由兩個苯環共享相鄰的碳原子而形成。并萘在室溫下為白色固體，具有特殊的香味，常用于制造香薰球、蟲膠、染料和防腐劑等。并萘也是煤焦油和石油中的常見組分之一。

Naphthene, also known as naphthalene, is an aromatic hydrocarbon compound with a molecular formula of C10H8. It is formed by two benzene rings sharing adjacent carbon atoms. Naphthalene is a white solid with a special aroma at room temperature, commonly used in the manufacture of aromatherapy balls, shellac, dyes, and preservatives. Naphthalene is also a common component in coal tar and petroleum.

精萘（tetralin）是一種萘的同分異構體，也是一種芳香烴化合物。它的分子式為C10H12，比并萘多了兩個氫原子。精萘在室溫下為無色液體，具有特殊的氣味，可溶于許多有機溶劑，常用作溶劑和反應試劑。

Tetralin is an isomer of naphthalene and an aromatic compound. Its molecular formula is C10H12, which has two more hydrogen atoms than naphthalene. Refined naphthalene is a colorless liquid at room temperature, with a special odor. It is soluble in many organic solvents and is commonly used as a solvent and reaction reagent.

總的來說，并萘和精萘在化學結構和性質上有所區別，但它們都屬于芳香烴類化合物。。

Overall, there are differences in chemical structure and properties between naphthalene and refined naphthalene, but they both belong to aromatic hydrocarbon compounds..