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461.
采用光学显微技术,对不同生长环境的梓树Catalpa ovata G.Don叶片进行了比较解剖研究.结果表明:梓树的阳生叶比阴生叶大得多,为1.94~2.64倍;阳生叶的栅栏组织厚度是阴生叶的1.96倍左右.阳生叶的气孔微下陷,有利于减少水分蒸腾;阴生叶的气孔大部分微上拱.阳生叶的上表皮比阴生叶厚,为1.91倍左右;阳... 相似文献
462.
Summary An unusual cell type consisting of free elements widely scattered over the marginal epithelium of the rat pituitary cleft is revealed by SEM. Most of these supramarginal cells characteristically have irregularly shaped cell bodies from which thin branched processes extend. Supramarginal cells bear resemblances to Kolmer (epiplexus) cells and to supraependymal cells of the brain ventricles. Their ultrastructural features make it probable that supramarginal cells are phagocytes, and can be regarded as scavengers of the cleft. Considering the close topographical association between the hypophysial cleft and the floor or the 3rd ventricle, supramarginal cells may be members of the motile macrophagic Kolmer cells populating the ventricular surfaces of the brain.Work supported by grants from MPI-60%-193/84 相似文献
463.
LIU Caichi HAO Qiuyan ZHANG Jianfeng TENG Xiaoyun Sun Shilong QigangZhou WANG Jing XIAO Qinghua 《北京科技大学学报》2006,28(8):793-793
The morphology and microstructure of flow pattern defects (FPDs) in lightly boron-doped Czochralski-grown silicon (Cz-Si) crystals were investigated using optical microscopy and atomic force microscopy. The experimental results showed that the morphology of FPDs was parabola-like with several steps. Single-type and dual-type voids were found on the tip of FPDs and two heaves exist on the left and right sides of the void. All the results have proved that FPDs were void-type defects. 相似文献
464.
M. Shirouzu T. Anraku Y. Iwashita M. Yoshida 《Cellular and molecular life sciences : CMLS》1990,46(2):201-204
Summary It has been thought that the ventral motor column in the rat spinal cord is virtually free of dopaminergic fibers. However, a new dopaminergic terminal plexus was visualized at all spinal levels in the ventral horn using electron as well as light microscopic immunohistochemistry. 相似文献
465.
利用原子力显微镜研究了不同淀积温度条件下低压化学气相淀积多晶硅薄膜的表面形貌。发现淀积时间一定时,随着淀积温度的升高,多晶硅薄膜的晶粒尺寸和表面粗糙度均非线性地增大。 相似文献
466.
467.
线虫角皮的特化构造在分类上具有十分重要的意义。用扫描电子显微镜对棘四棱线虫成虫的口、侧唇、头乳突、头感器、角质附属物、侧翼等部分及棘剌排列等进行观察,揭示其细微构造。 相似文献
468.
Electron microscopy, including bright field imaging, dark field imaging, high resolution imaging, (SAD) and (EDX), was employed to investigate the interfacial microstructure of silicon carbide fiber reinforced composites. It is found that SiC / SiC has well-defined interface layer between fibers and matrix, consisting primary of graphite crystallites. The interface of SiC / Pyrex displays a very poor bonding. For SiC / JG6 it is difficult to distinguish the interface region from fiber and matrix in TEM image. 相似文献
469.
Adsorption and self-organization of sodium alkyl sulfonates (STS and SHS) have been studied on HOPG by using the in situ scanning tunneling microscopy (STM). Both SHS and STS molecules adsorb on the HOPG surface and form long-range well-ordered monolayers. The neighboring molecules in different rows form a "head to head" configuration. In the high-resolution images of STS and SHS molecules, one end of the molecules shows bright spots which are attributed to the SO3- groups. 相似文献
470.
文章先列出量子围栏谱线中的现象,然后利用薛定谔方程解出电子在无限高圆环势阱中的波函数及其能量.利用波函数对谱中出现的现象加以解释及对量子图象简要的理论推导. 相似文献