English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Nitrogen is the main reaction and detonation product of energetic materials. Therefore, studying the equation of state and phase transition of nitrogen at high temperature and high pressure is very important for evaluating the energy characteristics of energetic materials, especially in the design of a new generation of nitrogen-rich energetic materials. Using density functional molecular dynamics simulation method, we calculated the pressure, internal energy and chemical components of fluid nitrogen in the range of 900-25000 K and 2-300 GPa. The negative change of pressure with temperature on isochores are observed under the temperature and pressure conditions of 3000-10000 K, 20-80 GPa. As the temperature increases, the pressure drop caused by the collapse of nitrogen molecules. This phenomenon is related to the phase transition from molecular fluid nitrogen to polymerized fluid nitrogen. The triple bond in the molecule breaks and a polymer forms which connected by single and double bonds with neighboring atom. We also studied the equation of state along Hugoniot under impact loading. The obtained Hugoniot curve is in good agreement with the experimental results. It is found that the softening of the experimental curve in the range of 30-60 GPa is related to the decomposition of nitrogen molecules of nitrogen molecules and the formation of polymeric nitrogen.

Phase transition and equation of state of dense liquid nitrogen at high temperature and high pressure