<正>介绍了静液压储能传动车辆动力源的基本原理及特点，分析了动力源系统中主要元件液压泵和液压蓄能器的特性与选择，系统中的关键元件之一的储能元件一一气囊式蓄能器的各参数之间的关系，以及蓄能器的压力比、多变指数等参数的变化对能量密度的影响。结果表明，选用结构类型和容积合适的蓄能器及较低充气压力的蓄能器，可有效地增加回收能量并减轻车辆重量。

Adding the hydrogel into substrate is a cost effective method of drought resistant seedling cultures. The hydrogel STOCKOSORB was used as the additive to the substrates in the experiments. The effects of the seedling culture were evaluated by the indicators such as height,ground diameter, ratio of height/ground diameter, dry weigh of roots, stems and biomass, to provid a reference for the application of hydrogel in the seedling culture. The results showed that the addition of STOCKOSORB to seedling substrates improved height and diameter growth,increased biomass and dry material accumulation of seedlings, but did not influence the root/shoot ratio. The result showed that the seedlings height, diameter, underground dry weight, above-ground dry weight and the total dry weight under pearlite+3.0 g/bag STOCKOSORB increased respectively by 74.19%, 59.81%, 327.78%, 374.44%and 365.09o/oo compared with the controled without hydrogel. Furthermore, those seedlings under the hydrogel treatment had idea height/diameter ratio(89.39) and root/shoot ratio of (0. 209). However,considering both effects and costs,it is recommended that adding 1.8 g/bag is an ideal dosage in the container seedling culture.