2 sentences

1. 重地，闲人免进。

   zhòng​dì, xián​rén miǎn jìn.

   Restricted area: no unauthorized personnel.

   Source: Dong Chinese Dictionary

2. 前方是实验重地，非工作人员请在此止步。

   qián​fāng shì shí​yàn zhòng​dì, fēi gōng​zuò rén​yuán qǐng zài cǐ zhǐ​bù.

   The area ahead is a restricted laboratory zone; unauthorized personnel please stop here.

   Source: Dong Chinese Dictionary