But his work was not dismissed within China though.

but 可以是并列连词，也可以是副词。即便是连词也可以跟副词 though 连用。副词与连词并用，语法没有错误，只是意思重复，属于强调用法。又如：

... but this gives us no stress, though.

但是这不会给我们带来压力。

This mapping is the common practice, but it is not necessary, though.

这种映射是常见的使用方式，但不是必要的。

though 单独使用、不跟 but 连用的例句：

Our team lost. It was a good game though.

我们队输了，可是这也不失为一场好球。

You said so though. 

不过你是这样说的。

I do have a problem though. 

不过，我的确有一个问题。

I dare not say anything, though. 

不过我什么都不敢说。He said he would come, he didn't, though.

他说他要来，可是并没有来。

Our team lost. It was a good game though.

我们队输了，可是这也不失为一场好球。

I've a bit of headache. It's nothing much, though.

我有一点头痛，不过并不厉害。

but 还可以跟 however 连用，跟副词 though 的用法，非常相似：

They can appear as a red tide in the daytime but when disturbed at night, however, they glow bright blue. 

它们在白天以赤潮的形式出现，但是，在晚上受到干扰时，它们会发出明亮的蓝光。

but 是并列连词，与前句转折。然后在 but 句中出现副词 however，完全可以。这属于强调“转折意义”。