排序方式: 共有57条查询结果,搜索用时 15 毫秒
1.
2.
Ta2O5/SiO2 dielectric mirrors deposited by ion beam sputtering (IBS) are studied. The multi-shot laserinduced damage threshold (LIDT) and its dependence on the number of shots are investigated, after which we find that the multi-shot LIDT is lower than that of single-shot. The accumulation effects of defects play an important role in the multi-shot laser damage. A simple model, which includes the conduction band electron production vsa multiphoton and impact ionizations, is presented to explain the experimental phenomena. 相似文献
3.
1-环丙基-6-氟-7-(4-酰基-1-哌嗪基)-1,4-二氢-4-氧代喹啉-3-羧酸的合成及其抗菌活性研究 总被引:2,自引:0,他引:2
以1-环丙基-6-氟-7-氯-1, 4-二氢-4-氧代喹啉-3-羧酸为原料经过两步反应合成出了16个新的1-环丙基-6-氟-7-(4-酰基-1-哌嗪基)-1, 4-二氢-4-氧代喹啉-3-羧酸, 并利用IR, 1H NMR, 13C NMR, MS谱及元素分析对其结构进行了表征. 初步体外抗菌活性研究表明, 大部分目标化合物对大肠杆菌有一定的抑菌活性, MIC值在0.312~20 g/mL之间, 但活性低于对照物环丙沙星和氧氟沙星; 目标化合物对绿脓杆菌无抑菌活性, 最低抑菌浓度(MIC)均大于20 g/mL. 相似文献
4.
The accumulation effects in high-reflectivity(HR) HfO2/SiO2 coatings under laser irradiation are investigated.The HR HfO2/SiO2 coatings are prepared by electron beam evaporation at 1 064 nm.The laser-induced damage threshold(LIDT) are measured at 1 064 nm and at a pulse duration of 12 ns,in 1-on-1 and S-on-1 modes.Multi-shot LIDT is lower than single-shot LIDT.The laser-induced and native defects play an important role in the multi-shot mode.A correlative theory model based on critical conduction band electron density is constructed to elucidate the experimental phenomena. 相似文献
5.
6.
在数字通信系统中,经常说到数字信号的传输速率.然而,信道是具有传输带宽的,那么,二者之间是什么关系呢?换句话说,对于一定的传输速率,合适的传输带宽应该是多少?让我们先从二进制的单元矩形脉冲的频谱特性开始讨论。单元矩形脉冲 相似文献
7.
本文对雷达A/R型显示器的显示原理进行分析,通过分析对其进一步改进提出了玫个方案,同时对改进的必要性加以间明,并从原理上对新方案的可行性进行初步探讨。 相似文献
8.
9.
10.
传统Mean Shift跟踪算法存在固定核窗宽导致目标尺度定位和空间定位不准确的问题。本文在背景加权的均值漂移算法(corrected background-weighted histogram ,CBWH Mean Shift)精确的目标定位基础之上,在RGB颜色空间下使用目标背景加权模型生成目标显著特征的颜色概率图,对其进行阈值分割和图像处理后获取二值图像,以此计算不变矩来调整下一帧的跟踪窗口,并在满足一定条件时及时更新背景加权模型以适应复杂背景下的跟踪任务。实验结果表明,上述方法能够自适应地更新核函数的带宽,提高了算法跟踪尺度变化目标的准确性和鲁棒性。 相似文献