The emission of Greenhouse gases (GHG) during the life cycle of four hydropower stations with installed capacity from 95 MW to 500 MW are assessed by the integrated GHG reservoir tool developed by International Hydropower Association. Model inputs are extracted from multi-source geographic datasets and construction planning documents. Three main conclusions are summarized: (1) In pre-and post-impoundment stages, areal GHG emission balance in reservoir area depends on the climate background, humid subtropical regions are more active than arid temperate regions. In the construction stage, emissions from fill, concrete and equipment account for more than 70% of the total. (2) GHG intensity falls rapidly when lifetime increases from 10 to 40 years and then drops slightly when lifetime becomes longer, which is 13.60 tCO 2 e/GWh for 50 years and 8.13 tCO 2 e/GWh for 100 years on average. The emission rates of hydropower stations with lower installed capacity are obviously large if they work for less than 30 years and differ less with stations possessing a higher installed capacity when their lifetime approaches 100 years. (3) Comparing with electricity generated by coal in China whose GHG intensity is 822 tCO 2 e/GWh, hydroelectricity is almost 100 times more efficient and clean. Thus, hydropower station plays an important role in dealing with the global warming issue as a substitution for a fossil fuel power source.

Foreign countries have accumulated rich experience in the research of helicopter floating characteristics. From the model test in the 1950s to the current numerical simulation and extrapolation evaluation, its technical maturity is significantly higher than that in domestic related fields. In order to fully study the influence of wave parameters on helicopter floating characteristics, sort out and refine the model test methods suitable for the study of helicopter floating characteristics, this paper takes a helicopter model as the research object, and carries out the research on the helicopter model test technology with emergency buoys, focusing on the influence range of wave parameters and wave direction on helicopter test results. The results show that the motion response of the helicopter under regular wave conditions presents typical periodic changes. When the helicopter encounters the influence of transverse wave, the rolling amplitude decreases with the increase of wavelength, and the acceleration amplitude of the nose and in the aircraft first increases and then decreases with the increase of wavelength; Under other wave direction conditions, the rolling angle, the acceleration amplitude of the nose and in the machine first increase and then decrease with the increase of the wavelength.

The wave environment is the main service environment of surface aircraft in the process of surface duty. In order to comprehensively study the operating characteristics of aircraft under this condition, it is necessary to conduct research on wave parameter modeling methods and simulation technology based on different wave conditions. This paper adopts the three-dimensional potential theory and ball model to calculate the different wave cases. A high-precision numerical simulation method of complex sea conditions is formed by mastering the numerical wave-making technology of typical regular and irregular waves. The result shows that the regular simulation in this paper has a high precision that the wave height and period is in 1% error compared with theory. The calculation error of spectral peak and peak frequency of sea states at all levels are within ± 8%, and the simulation quality of irregular waves meets the calculation requirements.