Introduction and Applications of a Generalized Intermediate Entangled State Representation

We introduce a generalized intermediate entangled state representation ｜β〉Λ to study the energy spectrum of an electron in a uniform magnetic field and a harmonic potential through algebraic calculatiOn. We find that the degeneracy of the energy levels is disappeared due to the existence of the additional potential. We make it clear that the eigenfunction is just the expression of eigenvector, defined in n Fock space, in ｜β〉Λ representation.     

小间隙高放大多丝室及其放电机制

对以强猝灭气体工作的小间隙多丝室及其放电机制进行了研究,实验表明,因为工作在饱和模式区,这种室同时具有很高的气体放大和相当快的时间特性.文中探讨了放电机制,雪崩中空间电荷效应以及电离光子的产生和作用是重要的因素,而其中后一因素又受到强猝灭气体的抑制.     

HL－1装置中LHCD和等离子体参数的关系

本文研究了在ＨＬ－１托卡马克的不同放电阶段的低混杂波驱动特性。给出了驱动电流及驱动效率和等离子体参数，如电子平均密度ｎｅ、等离子体电流Ｉｐ及纵向磁场的关系。也给出和分析了波驱动和入射波功率的关系。在放电平段，对正反向驱动效率进行了研究和比较。     

Yb原子高激发态的斯塔克光谱

采用ππ偏振激光，通过两步激发和光电离方法，在０－１５４Ｖ／ｃｍ电场范围内，测定了Ｙｂ原子ｎ－１８附近ｍ＝０的斯塔克光谱，首次把包含斯塔克效应的能量矩阵对角化方法推广到Ｙｂ原子，所获得的理论斯塔克图与实验结果基本符合，观察到低场中斯塔克簇随电场增加呈现线性结构以及＾１Ｐ１态与斯塔克簇在抗交叉过程中振子强度发生转移的现象，讨论了结构与量子亏损的关系。     

Matrix representation of three-dimensional astigmatic resonators

Three-dimensional astigmatic resonators, typical examples of which are the resonators bounded by cylindrical-spherical mirrors and cylindrical-cylindrical mirrors oriented at an arbitrary crossed angle, are investigated in detail by using a complex curvature tensor concept and generalized tensor ABCD law. Computerized numerical calculations illustrate some interesting characteristics of these astigmatic resonators.     

快度中心区强子物质输运系数和粘滞流体演化

用Chapman-Enskog方法计算了相对论性重离子碰撞快度中心区产生的π介子物质的输运系数,并建立了相应的粘滞流体力学方程,进而讨论了粘滞对π介子物质演化过程的影响.结果表明,粘滞将减缓快度中心区π介子物质的冷却速度.     

激光二极管侧面抽运Nd:YAG锁模激光器的研究

利用谐振腔的稳定条件对激光二极管侧面抽运的Nd：YAG锁模直腔的稳区特性和谐振腔内的光斑分布进行了分析。根据对腔参量的分析，选取合适的腔参量设计了一个简单的侧面抽运直腔，该谐振腔腔形简单，没有像散，振荡光模式好，有利于激光器的锁模运转。实验中采用国内自行研制的半导体可饱和吸收镜，实现了激光二极管侧面抽运半导体可饱和吸收镜锁模Nd：YAG激光器的连续锁模运转，平均输出功率为2W，锁模脉冲宽度为10ps，重复频率为100MHz。结合实验结果进一步讨论了半导体可饱和吸收镜的一些参量如饱和恢复时间、调制深度等对实现稳定连续锁模的影响。     

Effect of carbon content on the microstructure and the cracking susceptibility of Fe-based laser-clad layer

The laser cladding of Fe-based alloys on a medium carbon steel substrate was performed using a CO₂ laser and Ar shielding gas that was blown into a molten pool. The microstructure and cracking susceptibility of the laser-clad layers were studied in terms of carbon additions. Results show that the small change of the carbon content in the alloy powders can obviously change the microstructure and properties of the layers. When the carbon content is in the range of 0.3–0.4 wt.%, the decrease of the carbon content in alloy powders will increase the hardness and toughness of the layers simultaneously under the same process parameters. As a result, crack-free coatings with high hardness can be obtained. As the carbon content increases from 0.2 wt.% to 0.4 wt.%, the segregation ratio of chromium increases, while the segregation ratios of nickel, manganese, and silicon first decrease and then increase. At the same time, a new designing principle concerning the composition and microstructure has been put forward, and the principal mechanisms of strengthening and toughening of the layers are fine-grain strengthening and low carbon martensitic phase transformation strengthening.     

A note on an SOR-like method for augmented systems

Golub et al. (2001, BIT, 41, 71–85) gave a generalizedsuccessive over-relaxation method for the augmented systems.In this paper, the connection between the SOR-like method andthe preconditioned conjugate gradient (PCG) method for the augmentedsystems is investigated. It is shown that the PCG method isat least as accurate (fast) as the SOR-like method. Numericalexamples demonstrate that the PCG method is much faster thanthe SOR-like method.     

Rapid magnetization reversal in magnetic small particles induced by non-static bias field

Magnetization reversal processes by a switching field in single-domain nano-sized magnetic particles in the presence of a small transverse non-static bias field are studied. Applying an oscillating bias field instead of a static field, the reversal time becomes much shorter when the switching field is slightly stronger than the effective anisotropy field. A pulsed bias field of a suitably chosen duration in the nanosecond scale is found to induce a rapid switching, even when the switching field is smaller than the anisotropy field. The dependence of the reversal time on the frequency of an oscillating bias field and the duration of a pulsed bias field are studied. The present work thus complement the earlier studies on switching in the presence of a static bias field.