An auxin increases the growth in length of a plant cell, thus causing the curving of a stem, or roof, in phototropism and geotropism . 植物生长素能加快植物细胞长势，因此使茎弯曲向着阳光，或使根深扎入土。
2.
Heliotropism a form of phototropism in which flowers move to point toward the sun , tracking it as it moves across the sky 向日性：趋光性的一种类型，植物的花在一天内朝向太阳，并随着日光照射的方向而转移方位。
3.
First , we studied the role of exogenous ca2 + ion in the hypocotyl phototropism . the curvature of hypocotyls was strongly depended on extracelluar ca2 + concentration . in the medium with low ca2 + ( < 200 nm ) , hypocotyl curvature was significantly inhibited 胞外钙离子对下胚轴向光弯曲影响的实验结果表明，不同的胞外钙离子浓度引起下胚轴向光弯曲角度发生变化。
4.
These include phototropism , light - driven chloroplast movements and stomatal movements . the phot i gene of arabidopsis encodes an autophosphosphorylating protein kinase that functions as a photoreceptor for phototropism in response to low - intensity bl . up to now 在高等植物中，蓝光调控多个重要生理反应过程，其中包括下胚轴的向光反应、叶绿体在光下的重新分布和气孔的开放等。
5.
On the other hand , the drawing part of the program applies the technology of illumination and texture mapping , taking into account some nature phenomena such as random natural factor and phototropism . the plant , generated by the program , thus is three - dimensional , vivid , and accord with natural law 另一方面，运用光照、纹理映射等技术，结合植物生长过程中的随机因素和趋光性等自然现象，实现了植物生长过程的计算机模拟，生成的植物具有三维立体效果，形态逼真，符合自然生长规律。
6.
The author mainly anticipates the task including the simulation of eye fundus imaging and image mosaic . on the base of the dr principle and ophthalmic phototropism study , the author analyze and contrast new fundus camera system with traditional fundus camera . the author will establish the eyeball model with 3ds max technology , imitate the simple eyeball dioptre system and simulate the narrow - angle imaging to ensure the rationality and authenticity of fundus image , which solves the object origin of later image process , then fast mosaics the nine piece of fundus images with the help of the image registration theory and acquire a piece of wide - view fundus image containing more information , thereby provides doctor with enough diagnostic detail , which solves the problem of narrow view 作者在熟悉糖尿病性视网膜病变原理和眼科屈光学的基础上,进一步研究分析了新型免散瞳眼底照相系统和传统眼底照相机原理和区别,拟采用3dsmax建立三维眼球模型,仿真眼球屈光系统,模拟眼底照相系统的小角度拍摄,使获取的眼底图像合理真实,解决后期系统图像分析处理的对象来源问题;然后运用医学图像配准理论对仿真获取到的九幅小角度眼底图像进行快速拼接,拼成一幅大角度的眼底图像,解决小瞳孔拍摄图像视角太小的问题;最后通过对眼底图像配准算法在相似性测度和搜索算法的比较,找到一种适合眼底照相系统的眼底图像拼接的快速算法。
