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列宁指出:没有人的感情就从来没有也不可能有对真理的追求。可见珠算教学中教师要想方设法培养学生的珠算情感,使他们在整个珠算学习中情绪饱满、精神振奋、积极向上,那么如何培养学生积极的情感呢?下面就谈谈笔者的拙见。 一、简述情感 所谓情感是人对客观事物的态度和体验。它是一种比较复杂高级的心理活动现象;  相似文献   
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列宁指出:没有人的感情就从来没有也不可能有对真理的追求。可见珠算教学中教师要想方设法培养学生的珠算情感,使他们在整个珠算学习中情绪饱满、精神振奋、积极向上,那么如何培养学生积极的情感呢?下面就谈谈笔者的拙见。  相似文献   
3.
利用Pd催化合成单晶GaN纳米线的光学特性(英文)   总被引:1,自引:0,他引:1  
基于金属元素钯具有的催化特性,采用射频磁控溅射方法,在Si(111)衬底上沉积Pd:Ga2O3薄膜,然后在950℃下对薄膜进行氨化,制备出大量GaN纳米线.采用扫描电子显微镜(SEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和高分辨透射电子显微镜(HRTEM)等技术手段对样品的结构、形貌和成分进行分析.结果表明,制备的样品为具有六方纤锌矿结构的单晶GaN纳米线,直径在20-60nm范围内,长度为几十微米,表面光滑无杂质,结晶质量较高.用光致发光光谱对样品的发光特性进行测试,分别在361.1、388.6和426.3nm处出现三个发光峰,且与GaN体材料相比近带边紫外发光峰发生了较弱的蓝移.对GaN纳米线的生长机制也进行了简单的讨论.  相似文献   
4.
We report a new method for large-scale production of GaMnN nanobars, by ammoniating Ga2O3 films doped with Mn under flowing ammonia atmosphere at 1000oC. The Mn-doped GaN sword-like nanobars are a single-crystal hexagonal structure, containing Mn up to 5.43 atom%. Thickness is about 100 nm and with a width of 200-400 nm. The nanobars are characterized by x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and photoluminescence. The GaN nanobars show two emission bands with a well-defined PL peak at 388 nm and 409 nm respectively. The large distinct redshift (409 nm) are comparable to pure GaN(370 nm) at room temperature. The red-shift photoluminescence is due to Mn doping. The growth mechanism of crystalline GaN nanobars is discussed briefly.  相似文献   
5.
Fabrication of Syringe-Shaped GaN Nanorods   总被引:1,自引:0,他引:1       下载免费PDF全文
Syringe-shaped GaN nanorods are synthesized on Si(111) substrates by annealing sputtered Ga2O3/BN films under flowing ammonia at temperature of 950℃. Most of the nanorods consist of a main rod and a top needle, looking like a syringe. X-ray diffraction and selected-area electron diffraction confirm that the syringe-shaped nanorods are hexagonal wurtzite GaN. Scanning electron microscopy and high-resolution transmission electron microscopy reveal that these nanorods are as long as several micrometres, with diameters ranging from 100 to 300nm. In addition to the BN intermediate layer, the proper annealing temperature has been demonstrated to be a crucial factor for the growth of syringe-shaped nanorods by this method.  相似文献   
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