What great Russian scientists expert mentioned in the text do you know?

As an AI, I don't have access to a specific text or context you are referring to. However, there have been many great Russian scientists throughout history. Some well-known Russian scientists include:

1. Ivan Pavlov: A physiologist known for his work on conditioned reflexes, which laid the foundation for behaviorism in psychology.

2. Dmitri Mendeleev: The creator of the periodic table of elements, which organizes chemical elements based on their atomic properties.

3. Nikolai Tesla: An inventor and electrical engineer known for his contributions to the development of alternating current (AC) electrical systems.

4. Lev Landau: A theoretical physicist who made significant contributions to condensed matter physics and quantum mechanics, including the theory of superfluidity.

5. Pavel Florensky: A polymath known for his work in mathematic analysis, electrical engineering, and philosophy, particularly his contributions to the philosophy of science.

These are just a few examples of the many great Russian scientists who have made significant contributions to various fields of study.