No abstract

Canopy leaves are sinks of dry and wet nitrogen (N) deposition, most studies have not considered the response of canopy leaves to the alternating processes of dry and wet N deposition. We manipulated a close top chamber experiment to observe the effects of simulated N deposition with the same total deposition flux but different dry to wet ratios on leaf structure and physiology by spraying NH4Cl solution or supplying gaseous NH3 over the canopy of seedlings of three species (Betula platyphylla, Fraxinus mandshurica, Pinus koraiensis) placed in the chamber. After 32 days of N deposition and relative to the control, the leaf morphology and mesophyll tissue structure of the three species had no significant changes under all N deposition treatments. With the increase in the ratio of dry to wet N deposition, the N concentration, N metabolizing enzyme activity and soluble protein concentration in leaves of all three species increased continuously, but for the leaf light-saturated net photosynthesis rate, B. platyphylla showed a continuous increase, F. mandshurica showed a continuous decrease, and P. koraiensis showed no significant change. We found that F. mandshurica was the only species whose foliar chlorophyll and potassium concentration decreased with the increase in the ratio of dry to wet N deposition and its leaf light-saturated net photosynthesis rate was positively correlated with foliar chlorophyll and potassium concentration, respectively. Our results indicate that dry deposition is relatively more important on leaf physiological functions in alternating deposition. B. platyphylla and P. koraiensis may better acclimate to canopy NH3/NH4+ deposition than F. mandshurica. Most importantly, the results indicate that a single simulated dry and wet deposition would overestimate and underestimate the response of leaf function to atmospheric N deposition, respectively. Alternating processes of dry and wet deposition should be considered for more realistic assessments of the effects of atmospheric N deposition in forests.

Glare is a key factor that influencing the visual performance in light conditions of airplane cockpit, and intensity and layout of glare sources in cockpit are extraordinarily complex. This study investigates the relationship between complex glare sources and dis comfort glare evaluations of luminous environment in airplane cockpit. Different glare indices are proposed to predict the level of discomfort glare in the cockpit environment with non-uniform glare sources and irregular shape glare sources. The result shows the DGP can predict the visual comfort evaluation better than DGI and UGR in complex luminous environments.

A human-machine interaction (HMI) simulation design method for the aircraft flight deck has been introduced, including modular user interface design, logical dependency between display unit and control panel, and general aircraft model. Model-View-Controller (MVC) design pattern is a classic software architecture, which plays an important role in the interactive user interface design. This design pattern is to achieve the goal of decoupling the logic dependency and system model. The cockpit HMI design based on MVC design pattern has the features of convenient modification, modular design and strong portability. The design method has been applied in the prototype of autopilot system in the civil aircraft cockpit.

A project management method for the simulation work has been introduced, including agile methodology, scrum framework, and cockpit simulation projects. Agile development takes the evolution of user's needs as the core, and adopts step-by-step to develop software iteratively. In the agile development, the software project is cut into multiple sub items at the beginning of the construction, and the results of each subproject are tested, with the features of visual, integrated and operational use. This design methodology has been applied in the prototype of the civil aircraft cockpit simulation.