Cryogenic dewar flasks are typically constructed with a double-walled design, with a vacuum-sealedspace between the inner and outer walls. This vacuum acts as a thermal barrier, preventing heat fromentering the flask and maintaining the low temperature inside. The inner wall is usually made of stainlesssteel or other materials with high thermal conductivity, while the outer wall provides structural supportand additional insulation. The space between the fences is often evacuated to further reduce heattransfer through conduction and convection. Additionally, some dewar flasks incorporate reflectivecoatings on the inner surface to minimize radiant heat transfer. The YDS liquid nitrogen cylinder is used in various industries such as biotechnology, healthcare, and research. It contains liquid nitrogen, which is a commonly used cryogenic fluid. Its main purpose is to store and transport biological samples, cells, tissues, and other materials at ultra-low temperatures to ensure their long-term preservation and quality during storage and transportation.