Physiological response of corn seedlings to changes of wind-sand flow strength. Effects of wind and wind-sand flow on membrane permeability and membrane protection system of corn seedling leaf Response of the Growth and Photosynthetic Properties of Pinus sylvestris var.mongolica Saplings to Strong Wind-sand Flow Blowing Effects of sustained wind-sand flow on photosynthesis and transpiration rates of Pinus sylvestris var. mongolica saplings Effects of frequent uind-sand flow on photosynthesis and water metabolism of Pinus sylvestnis var. mongolica seedlings Characteristics of the Sand Flow Structure of Artificially governed Sand Dune on the East Shore of Qinghai