【摘 要】
:
Cathode samples of nano-diamond by graphitization pretreatment with different temperatures were fabricated by electrophoresis, then the structures and morphologies of the cathode samples were characterized by scanning electron microscope (SEM) and X-ray d
【出 处】
:
OptoelectronicsLetters
论文部分内容阅读
Cathode samples of nano-diamond by graphitization pretreatment with different temperatures were fabricated by electrophoresis, then the structures and morphologies of the cathode samples were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD), and the field emission tests were conducted. The effects of graphitization pretreatment on the field emission characteristics of nano-diamond cathode surface on titanium substrate are studied. The results indicate that the surface morphologies of nano-diamond cathode samples after graphitization pretreatment change a lot, and the field emission characteristics in low-voltage area are improved obviously. However, in high-voltage area, the curve distortion happens, and it doesn’t conform the mechanism of field emission characteristics.
其他文献
Surface-plasmon (SP) enhancement of amorphous-silicon-nitride (a-SiNx) light emission with single-layer gold (Au) waveguides is experimentally demonstrated through time-resolved photoluminescence measurement. The a-SiNx active layer with strong steady-sta
A Mach-Zehnder interferometer (MZI) based on two spherical structures is proposed and temperature and humidity are measured simultaneously. The device is fabricated by inserting two spherical structures into a single mode optical fiber (SMF). The results
考虑在共振强驱动场作用下二能级原子所构成的Dressed原子和探测光的相互作用。把无限多个互相耦合的一阶微分方程(主方程)简化为四个独立的方程,从而得到Dressed原子与探测光相互作用的Bloch方程,可以把普通原子与光相干相互作用的全部过程推广到Dressed原子。求解了Dressed原子对两个频率探测光的极化率,研究了Dressed原子中的位相共扼波的产生和特性。
通过双离子束溅射方法在蓝宝石、硅衬底上制备了单层SiO2薄膜,分析了SiO2薄膜残余应力、表面形貌、微观结构以及光学性能(可见-近红外0.4~1.2 μm和中红外3~5 μm波段)在400 ℃~1 000 ℃温度范围内的演化规律.研究结果表明:在400 ℃附近,SiO2薄膜残余应力存在局部极小值;SiO2薄膜光学性能的演化与膜层表面质量、内部残余应力及微观结构变化密切相关;经1 000 ℃高温处理后,蓝宝石窗口表面SiO2薄膜红外透射性能仍能保持很好的稳定性,且膜层表面没有出现显著的气泡、开裂等损伤形貌.
用越来越短的时间分辨率来测量物理现象的变化情况是当代研究和发展的一个主要部分。实际上,在激光聚变、时间分辨光谱学和激光研究这样的领域,了解瞬态过程(所谓短脉冲)和稳态过程对于未来的发展是至关重要的。
针对电子侦察中PSK信号的载频估计问题,提出一种低信噪比下载频估计新方法。该方法将PSK信号划分为等长度的交叠区间,提取各个区间内信号频谱的聚集性测度作为特征参数,然后将此特征参数导入网格密度聚类算法,以聚类结果作为载频估计特征类,最后将特征类对应的频谱叠加后提取峰值得出信号载频估计值。该方法避免了传统PSK信号载频估计的非线性运算,显著降低了PSK信号载频估计的信噪比门限,且无需先验知识,适合于电子侦察场合。仿真实验结果证实了该方法在低信噪比下PSK信号载频估计的有效性。
针对所研制的光栅楔形平板干涉动态角度測量系统,提出了一种确定动态测量零点的新方法。利用干渉法找到360°自然角度基准中光程差达到最大和最小的特殊点,作为动态测量时的固定零点。采用这种标定方法不需要另外增加光路,结构简单,操作方便。实验表明,定位精度优于0.5"。
通过对薛定谔方程的数值解,给出了扫频脉冲光场对四能级原子系统作用的结果,说明了扫频脉冲光场应用于高斯分布的多普勒加宽原子统计系统,在适当的扫频条件和激光功率下能得到比单色或调幅脉冲光场更有效的三步光电离。
Patterning of self-assembled monolayer (SAM) was demonstrated by area-selective deposition of SAMs on a pattern made by synchrotron radiation (SR) stimulated etching SiO2 thin films. The etching was conducted by exposing the SiO2 films to SR through a Co