并萘与精萘不是完全相同的物质，它们在结构上有一些差异。

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

并萘（naphthalene）也被称为萘，是一种具有分子式C10H8的芳香烃化合物。它由两个苯环共享相邻的碳原子而形成。并萘在室温下为白色固体，具有特殊的香味，常用于制造香薰球、虫胶、染料和防腐剂等。并萘也是煤焦油和石油中的常见组分之一。

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）是一种萘的同分异构体，也是一种芳香烃化合物。它的分子式为C10H12，比并萘多了两个氢原子。精萘在室温下为无色液体，具有特殊的气味，可溶于许多有机溶剂，常用作溶剂和反应试剂。

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.

总的来说，并萘和精萘在化学结构和性质上有所区别，但它们都属于芳香烃类化合物。。

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