Yes, it is. The Chinese language is capable of writing technical things. These technical terms, for instance, Physics, Chemistry, and Biology, could be translated into Chinese. When people learn about these subjects at middle school, they read textbooks written in Chinese. Here are few pictures of a textbook in Physics used in the nineth grade at middle schools.
This is a picture of the cover of this book. Physics is translated as 物理 in Chinese. These two characters are printed in a larger font.
Here are pictures of the Lesson 3 in the Chapter 13. This lesson centers on specific heat capacity, or 比热容 in Chinese. As you can see, this term was written in Chinese.
Of course, in the text of this lesson, the English counterpart of 比热容 also appeared. There were units and formulas in the text, too. They are often represented by alphabet letters.
As you see, majority of words were written in Chinese.
After learning about these subjects at middle schools, some students would choose to continue to learn these subjects at high schools, since Chinese students are required to decide whether they want to learn natural sciences or not, before they go to eleventh grade at high schools. If they choose to learn natural sciences, they could pursue further studies of natural sciences at colleges or universities.
Apart from international academic journals and books written in English, there are academic journals and books written in Chinese. For instance, there is an academic journal, Acta Physica Sinica, or 物理学报 in Chinese, which is under the aegis of Chinese Physical Society, or 中国物理学会 in Chinese, and Institute of Physics, Chinese Academy of Sciences, or 中国科学院物理研究所 in Chinese, a renowned institute focusing on the field of Physics in mainland China.
Here is a picture of a cover of one issue of this magazine.
Here are few pictures of an article from that issue, Transmission Characteristics of Optical Resonator, or 光学谐振腔的传输特性 in Chinese.
As you see, apart from formulas, functions and units, majority of the text were also written in Chinese.