The 400-word essay is an essay describing personal experiences. We can see that there are many essays about the heart beating, but the specific content is not provided. Therefore, based on the information provided, it was impossible to give the specific content of the 400-word essay about Xin 'er's thumping heart.
The standard of punishment for beating a turtledove was not explicitly mentioned. However, according to the relevant laws and regulations, illegal hunting and killing of precious and endangered wild animals under the state's key protection may constitute the crime of harming precious and endangered wild animals. According to article 341 of the Criminal Law of the People's Republic of China, anyone who illegally hunts or kills precious or endangered wild animals under special state protection shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention and shall also be fined; if the circumstances are serious, he shall be sentenced to fixed-term imprisonment of not less than five years but not more than ten years and shall also be fined; if the circumstances are especially serious, he shall be sentenced to fixed-term imprisonment of not less than ten years and shall also be fined or confiscated of property. However, whether hitting a turtledove constituted a crime and the corresponding punishment needed to be determined according to the specific circumstances of the case and the interpretation of the law.
The search results did not provide a clear answer to the question of Yan Bingyun being beaten up. Therefore, it was impossible to determine if Yan Bingyun had been beaten up.