激光调Q CAI

从激光调Q速率方程出发,分析推导了激光调Q过程中,腔内光子数与工作物质内反转粒子数间的关系.再根据激光调Q的过程中,对腔Q值控制方式不同,将激光调Q技术分为:转镜调Q、声光调Q、电光调Q、饱和吸收调Q和脉冲透射式调Q.用C语言进行了激光调Q CAI软件的开发研制,获得了将文学、图形、动画和计算融为一体的,直观而生动地将调Q的理论和过程再现于屏幕的CAI课件.介绍了课件的内容、结构及其特点.     

二次谐波系统在浑沌态下的光子统计

数值分析了调制泵浦作用下的二次谐波产生系统的浑沌动力学行为.考虑到混沌运动的遍历性,提出一种研究浑沌态光场光子统计的数值方法,即通过数值积分求解系统动力学方程估计光子数的系统平均.运用这一方法于二次谐波系统,计算了其在浑沌态下的光子统计分布,结果表明是一种超Poisson分布.     

高能光源束流位置探测器支撑架结构优化设计

从热稳定性和振动稳定性两个角度出发,优化设计得到了超高稳定的刚性支撑架结构;通过ANSYS有限元模态分析,验证了结构的热膨胀变化量和特征频率;采用混凝土二次灌浆方法对支撑架进行地面固定和特征频率测试,结果表明,支撑架结构的特征频率达到61.9 Hz、振动幅值小于30 nm,均满足设计要求。最后采用动态刚度测试方法,得到混凝土二次灌浆层的主要刚度值,进一步验证支撑架结构优化结果的准确性。     

含铅聚合物微凝胶与硫化氢反应前后在良溶剂中的分子扩散行为

用溶液聚合法制备出轻度交联的含铅微凝胶,用光子相关光谱技术测定其在良溶剂中与H2S反应前、后的扩散行为,由外推法得到在浓度无限稀时的分子扩散系数,给出微凝胶的流体力学半径。结果表明:相同量的含铅微凝胶在不同的初始浓度下与H2S反应,生成含PbS纳米微粒的凝胶；但其体积增大不同,这说明H2S与含铅微凝胶的反应既可以在分子内也可以在分子间进行,分子间的反应使含硫化铅微凝胶扩散系数随浓度的变化曲线的线性范围变小。     

Platonic solids symmetry in particle physics

Non-linearity of the Yang-Mills fields caused by the commutator in the Lagrangian calls attention to symmetries helping to reveal important features of the system, while obviating the need of actual solutions. To this end, a charge fixing procedure is carried out by means of counting photon oscillations between test particles moving along trajectories that form Platonic solids shaped patterns. With the infinite-range electromagnetic interaction as its origin, the procedure defines a class of interactions allowed for particle physics. Besides the familiar electromagnetic, weak and strong interactions, the scheme suggests an unusual force that cannot be detected with conventional means though possibly contributes to gravitation.     

Implementation of a CNOT gate in two cold Rydberg atoms by the nonholonomic control technique

We present a demonstrative application of the nonholonomic control method to a real physical system composed of two cold Cesium atoms. In particular, we show how to implement a CNOT quantum gate in this system by means of a controlled Stark field.     

Helium atom in the monochromatic electromagnetic field

We apply a non-perturbative procedure for the calculation of the total photoionization cross-section of two-electron atomic systems. The procedure is based on the Floquet-Fourier representation of the time-dependent Schr?dinger equation. With the use of the Hylleraas-type basis functions, the total photoionization cross-sections obtained are within the accuracy of a fraction of a percent, which, we believe, is the most accurate estimate for the cross-sections available. The total photoionization cross-sections for neutral helium deviate notably from the benchmark experimental data [J.A.R. Samson et al., J. Phys. B 27, 887 (1994)].     

A qualitative estimation of the photon rest-mass and related topics

Photon rest-mass is estimated in a qualitative or semiquantitative way by considering photons moving in the quantum foam. In this context, photon energy as well as refractive index are discussed.     

Applications of a photoion-photoion-coincidence technique to the study of photon-stimulated ion-desorption process following K-shell excitation

We have investigated the photon-stimulated ion-desorption from deuterated formic acid (DCOOD) monolayer chemisorbed on Si(100) crystal by applying a photoion-photoion-coincidence technique. The true-coincidence yields of an ion pair C⁺---D⁺ are given in the photon energy range (275–400 eV) above the C 1s absorption edge. The partial ion yields and Auger electron yields re presented for comparison. It was found that the multielectron (shake-off) excitation promotes the multiple bond-breaking of the adsorbate and the ion pair C⁺–D⁺ desorption events.     

Photoinduced processes on alkali covered surfaces: NO desorption from K/Cr2O3(0001)

We have studied the ultraviolet laser induced desorption of NO/Cr₂O₃(0001), K/Cr₂O₃(0001) and the coadsorbate system NO/K/Cr₂O₃(0001) using resonance enhanced multiphoton ionization spectroscopy for state selective detection of the desorbing species after excitation with nanosecond laser pulses. The goal of our experiments was to study the influence of surface electronic modifications via alkali adsorption on the photodynamics of a simple molecule. The photochemistry of the isolated and the coadsorbate systems is strongly dependent on the coverage of the diverse components. In this paper we shall mainly focus on data for the low coverage regime of potassium. From the two adsorbate species of NO, a chemisorbed and a physisorbed species, we present data of the chemisorbed species. The velocity distributions show a strong dependence on the excitation energy which we interpret on the basis of electron energy loss spectra as being due to surface charge transfer states. This is corroborated with our coadsorption experiments with low coverages of potassium which alter the velocity distributions.