HCD中铀基态原子衰变时间常数和亚稳态原子寿命测量

利用窄脉冲和高重复率放电的铀空心阴极灯溅射的原子作为蒸气源,用CW染料激光激发并以荧光法探测,得到了铀基态原子的衰变时间常数和正稳态原子的寿命。     

钇原子亚稳态寿命的测量

原子的寿命是原子的重要参数之一。本文的寿命测量方法涉及原子束中原子的速度分布的测量。理论和实验已经证实,对于原子束中原子速度分布的测量,采用激光感应荧光的方法比传统的机械斩波法方法更为方便,且具有更高的分辨率,尤其是对超声速的束流。在此基础上,利用基态原子无穷长的寿命以及亚稳态原子在飞行过程中的衰减,比较测量到的原子基态和亚稳态的速度曲线,可以确定原子亚稳态的寿命。其原理与束箔法测量相似。 在本文实验中,用激光感应荧光法测量到的是原子数密度的速度分布,即信号是:     

利用HCD灯进行U激光敏化荧光光谱测量

利用直流稳定放电的Kr-U HCD灯作为放电等离子体源,在591.54nm波长对U原子进行共振激发,在400～800nm波长范围内观察到了几百条激光敏化荧光光谱线,并由此测定了UHCD灯中相应能级集居数增量的分布。     

利用IDDR简化亚稳态

如果在具有多个时钟的非同步系统中使用FPGA,或者系统中的时钟频率或相位与FPGA所使用时钟频率或相位不同,那么设计就会遇到亚稳态问题。不幸的是,如果设计遇到上述情况,是没有办法完全解决亚稳态问题的,不过还是有一些方法可降低系统出现亚稳态问题的几率。     

用HCD灯作金属原子蒸气源的激光光谱研究

利用Ne-Cu HCD灯研究了金属原子蒸气源的光电流光谱和激光荧光光谱,发现了Cu 4p~2P_(3/2)能级的表观寿命随灯电流增加而增大。认为这一现象起因于“共振俘获”效应。     

长寿命有机分散型灯

1.前言交流驱动有机分散型EL灯是不发热的固体发光器件,是即薄又均匀的光源,而其形状的自由度又很高。所以,以液晶显示背景光为主成为一种广泛使用的特殊光源。可是与其它光源相比,在亮度和寿命方面还有待改进。     

吸收光谱法对Kr亚稳态浓度测量

近年来光泵浦惰性气体亚稳态激光在高能激光领域逐渐得到人们的关注。搭建了一台高压纳秒脉冲放电产生惰性气体亚稳态粒子的装置,该装置增益尺寸较长,便于后续开展激光增益和放大实验。利用窄线宽可调谐连续光源探测了该装置放电生成的Kr亚稳态(5s[3/2]_2)粒子数浓度,达1.3×10~(12) cm~(-3),该状态持续时间约为3μs,满足后续激光体系运行条件。测量过程中出现了吸收饱和现象,给粒子数浓度拟合带来了不确定性,设计的复合拟合方法解决了这一问题。     

新型长寿命连续氪灯

本文对新型长寿命连续氪灯的特性及影响其寿命的因素进行了讨论。同时，也介绍了连续氪灯的正确使用方法。     

测量铜原子亚稳态密度的饱和吸收法

提出了测量连续脉冲放电余辉期激活粒子亚稳态密度的饱和吸收方法,在两台分别作为探测光源和吸收池的溴化亚铜激光器测量系统中得到证实。观察和讨论了D_(5/2)亚稳态能级布居在脉冲间隔的弛豫特性。     

辅助灯法测量LED灯光通量的研究

分析积分球测量LED灯光通量的原理,介绍两种测试方法(比较法和辅助灯法)的理论依据,然后通过实验进行验证,最后总结适用辅助灯法进行测试的情况。     

Metastable Phase Cu with Optimized Local Electronic State for Efficient Electrocatalytic Production of Ammonia from Nitrate

Electrocatalytic nitrate (NO₃⁻) reduction reaction (NITRR) is an inspiring route for ammonia (NH₃) synthesis at ambient condition. The metallic Cu-based material with low cost and high activity is one of the most promising electrocatalysts for NITRR. However, due to the weaker atomic H^*-providing capacity, the produced intermediate—nitrite tends to accumulate on its surface, leading to unsatisfactory NH₃ selectivity and Faradic efficiency (FE). Herein, a novel and facile O₂/Ar plasma oxidation and subsequent electro-reduction strategy is developed to synthesize a kind of metastable phase Cu. Excitingly, the metastable phase Cu demonstrates superior NITRR performance to conventional phase Cu with high NH₄⁺ selectivity (97.8%) and FE (99.8%). Density function theory (DFT) calculations reveal that the upshift of the d-band center to near the Fermi level in metastable phase Cu contributes to the enhanced activity, while the relatively strong adsorption of H^* facilitates the conversion from NO₂^*/NO^* to NOOH^*/NOH^* and thus ensures high selectivity and FE. Furthermore, when evaluated as cathode material in Zn-NO₃⁻ battery, high power density (7.56 mW cm⁻²) and NH₄⁺ yield (76 µmol h⁻¹ cm⁻²) are achieved by the metastable phase Cu-based battery.     

Gap states density measurement in copper oxide thin films

The density of gap states near the Fermi level have been measured in copper oxide (CuO) thin films deposited by spray pyrolysis technique. The measurement method is based on the exploitation of the current–voltage characteristics of the space charge limited current (SCLC) measured in a sandwich Au/CuO/Au structure. The measured gap states density is equal to 1.5×10¹⁴ cm⁻³ and 2.0×10¹⁴ eV⁻¹ respectively in films prepared at 300 and 400 °C substrate temperature, while the defect position are located at 16 and 20 meV above Fermi level. The carriers mobility and concentration are also determined from SCLC, the obtained results are in good agreement with Hall effect measurement ones.     

三核准分子辐射寿命估算的初步研究

本文简单介绍了一种新的估算三核准分子辐射寿命的公式。利用这公式计算了三原子准分子辐射寿命,计算结果与实验值非常吻合。     

V型三能级原子与双模奇偶纠缠相干光场相互作用的量子态保真度

研究了V型三能级原子与双模奇偶纠缠相干光场相互作用系统的量子态保真度,运用数值计算的方法讨论了失谐量、双模光场的强度和原子分布角对量子信息保真度的影响.结果表明:原子的量子态保真度优于系统的或光场的量子态保真度,原子初始处于基态时,原子的保真度好于激发态或叠加态的情况;原子的保真度随着失谐量或双模光场强度的增大而增大;系统的和光场的保真度时间演化特性是相似的.失谐量、双模光场的强度和原子的分布角都对量子态保真度的时间演化曲线的频率有影响.     

Influence of oxides on friction during Cu CMP

In this work, we investigated the frictional behavior of copper CMP. Using a laboratory polishing set up, we polished Cu with designed polishing media. After that the copper surface and the fumed silica particles Cu were analyzed. The surface analysis techniques used are the field emission SEM, the field-emission high-resolution analytical TEM, x-ray spectroscopy, and XPS. We found evident difference in friction value using different polishing media. Discussions lead to three mechanisms during copper CMP. The nature of copper oxides has a profound influence on friction and might be directly related to defects. Argonne National Laboratory     

延长分米波电视发射管使用寿命的探讨（上）

文章从原理上讨论了影响分米波电视发射管寿命的若干因素。并提出了若干延长寿命的建议：（１）正确的灯丝加热方法是行之有效的措施，经验证明：过分强调降低灯丝电压往往得到相反的效果。（２）必须有良好的冷却方式。（３）通过对帘栅电路的分析，说明对此电路必须作很好的处理以消除故障和防止寄生振荡。     

GHZ类态原子体系与Fock态光场相互作用的动力学

采用求解Schr(o)dinger方程和数值计算的方法,研究了处于GHZ类态的三个全同二能级纠缠原子与Fock态光场相互作用的动力学特性,讨论了原子布居算符和光场的二阶相干度与三原子体系初始态的纠缠度、Fock态光场的光场强度的依赖关系.结果表明:系统处在非纠缠态,原子布居呈现出周期性的崩塌和回复现象,当光场为真空场时,出现真空Rabi振荡现象;随着光场的增强,原子布居的Rabi振荡频率增大.当系统处在纠缠态,随着纠缠度的增加,光子开始出现聚束效应,在最大纠缠态,聚束效应和反聚束效应交替出现,二阶关联函数的振荡幅度随着纠缠度的增强而增强.