排序方式: 共有6条查询结果,搜索用时 0 毫秒
1
1.
Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition. The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-color emissions at the wavelength peak values of 437 nm and 620 nm at the excitation of 350 nm.
The two emission bands are coincident with the absorption spectrum for photosynthesis of plants. An obvious enhancement effect
has been observed upon addition of Dy3+ with amount of 0.03 mol%, in which the intensities of both blue and red bands reach a maximum. The origin of red and blue
emission bands is analysed. The photochromic parameters of the samples at the nearly UV excitation are tested. This fluoresence
enhancement is of great significance for special solid state lighting equipment used in plant cultivation.
This work has been supported by National Natural Science Foundation of China (Grant No 50872091) and the Natural Science Foundation
of Tianjin, China (06YFJMJC02300, 06TXTJJC14602). 相似文献
2.
3.
建筑工程施工安全关系涉及到整个工程项目以及施工人员的工程质量及生命财产安全,从而决定建筑工程施工安全在施工管理中的重要性相当关键,文章主要介绍了建筑工程的安全管理特点、现状及有效措施。 相似文献
4.
5.
建筑行业是一个高危险的施工行业,建筑工程问题是关系到国计民生、社会稳定的重大问题,所以各个建筑工程要把加强建筑施工的安全、质量作为头等大事抓紧抓好。文章将浅谈影响建筑施工安全因素以及加强建筑施工的措施。 相似文献
6.
图像分割是图像处理和分析的基础,本文通过分析遗传算法(Genetic Algorithm, GA)在图像分割中的应用优劣,提出利用模拟退火思想的改进遗传退火(Genetic Simulated Annealing Algorithm, GASA)的图像阈值分割算法,算法整个运行过程由冷却温度进度表控制,使用改进的最大类间方差公式作为遗传算法的适应度函数,从而求得灰度图像的一个最佳阈值用于图像分割。实验结果表明,基于改进遗传退火算法的最大类间方差图像分割方法能较好提高算法的全局搜索能力,避免遗传算法陷入局部最优,并且能更快速、更稳定收敛到最佳的分割阈值,得到更好的图像分割效果。 相似文献
1