STUDY ON THE STOMATAL AND NONSTOMATAL LIMITATION DURING THE DIURNAL COURSE OF PHOTOSYNTHESIS IN SOYBEAN LEAVES Diurnal Course of Photosynthetic Characteristics of Pinus yunnanensisand Its Correlation with Leaf Surface Micro-meteorological Factors COMPARATIVE STUDIES ON THE INTENSITY OF PHOTOSYNTHESIS BETWEEN Bt TRANSGENIC HYBRID COTTON AND ITS PARENTS Characteristics of photosynthesis and photosynthetic carbon fixation capacity of five mangrovetree species in Zhanjiang City