We measured the concentrations of molecular hydrogen in hydrogenated amorphous silicon $(a-\mathrm{S}\mathrm{i}:\mathrm{H})$ using a Jeener-Broekaert three-pulse sequence. For samples prepared by both plasma-enhanced chemical vapor deposition (PECVD) and hot wire chemical vapor deposition (HWCVD), the molecular hydrogen concentrations are about one order of magnitude larger than those inferred from spin-lattice-relaxation time ${(T}_1)$ measurements. There are two distinct environments for hydrogen molecules. In one the molecules are essentially isolated and act as relaxation centers for hydrogen bonded to silicon atoms. In the other, the hydrogen molecules are clustered and do not relax the bonded hydrogen. Samples prepared by HWCVD have a lower transition temperature for freezing of the molecular hydrogen motion than those prepared by PECVD. This behavior is attributed to a more ordered silicon structure in HWCVD samples. The nonexponential behavior of the dipolar relaxation and possible relation with the defects and doping is discussed.

This study develops a tripartite evolutionary game dynamic model with a time delay effect to analyze the interactions among food enterprise, government regulatory, and food inspection agencies in managing food safety risks. This model enables government regulatory agencies to more accurately assess and predict food safety risks, thereby implementing more effective preventative measures, ensuring the maximization of policy effectiveness and reducing food safety incidents. The results emphasize the significance of recent company performance by showing that regulatory and inspection entities’ strategic decisions are significantly impacted by delay effects from food companies. This study also shows that negative self-feedback intensity drives food enterprises to develop safer products and encourages tighter government oversight. Recommendations include improving consumer reporting channels, changing government incentives and penalties, allocating resources efficiently, and advancing information technology to decrease the effects of time delays and improve food safety management. Governments can improve food safety regulation by using strategic insights from numerical simulations.