Study of thermal aging effect on space charge in poly(methyl methacrylate)

Charges evolution in poly(methyl methacrylate) (PMMA) samples under thermal aging effect has been studied by means of two complementary techniques, thermal step method (TSM) and thermally stimulated depolarization current (TSDC). For the first method, measurements reveal that injected charges, whose quantity is found depending on the number of applied temperature cycles, remain close to the surface sample. TSDC measurements have been carried out for different temperatures ranging from 25 °C to 140 °C. Three distinguishable dipolar relaxations (β₁, β₂ and α) have been highlighted. In the same way, the presence of polarization and injected charges has been confirmed. In support of electric characterization, X-ray reflectometry has been used. The obtained results equally emphasized the thermal aging effect on the material.     

利用KTP晶体实现1.08μmNd：YAP激光器锁模

本文描述了利用ＫＴＰ晶体和腔的基波输出镜构成非线性镜实现１．０８μｍＮｄ：ＹＡＰ激光器的被动锁模。实验表明，这种新的锁模技术比用染料作可饱和吸收体的被动锁模技术有很多突出的优点，具有很大的发展潜力。实验测得锁模时基波１．０８μｍ输出２．４ｍＪ，二次谐波０．５４μｍ输出０．５ｍＪ（同样条件下的静态输出为２．５ｍＪ），基波脉冲的平均脉宽为４０ｐｓ。     

Analysis of Threshold Current and Wall-Plug Efficiency of Diode Lasers with Asymmetric Facet Reflectivity

Threshold current and differential quantum efficiency of broad contact lasers with asymmetric facet reflectivity are discussed with the purpose to reveal factors essential for optimisation of the wall-plug efficiency of such lasers. Lasers with low front facet reflectivity and short cavity often exhibit behaviour difficult to explain with a classical theory. More rigorous calculation performed in this work show that differential quantum efficiency is indeed less affected by a change of the front facet reflectivity or cavity length than predicted by such theory. These findings greatly simplify criteria for optimisation of the wall-plug efficiency of broad contact lasers with coated facets.     

等效法在伏安法测量中的应用

本文提出了在伏安法测量中，消除电表内阻对实验结果影响的一种新方法     

复合结构丝中的电流密度分布和巨磁阻抗效应

提出了由中间为高电导率的非铁磁性金属丝外面包裹一层铁磁材料组成的复合结构丝的电流 密度分布和巨磁阻抗(GMI)效应模型，并对Cu/FeCoNi复合丝进行了数值模拟. 结果表明：在 相同的磁性材料几何尺寸和磁特性时，Cu/FeCoNi复合丝铁磁层内的电流随频率的升高比匀 质FeCoNi铁磁丝内的电流更趋于表面分布，而且开始出现趋肤效应时对应的频率明显降低. 当在比较低的频率下就可以观察到明显的MI变化时，复合结构丝中的电阻和电抗变化主要是 由趋肤效应引起，趋肤效应仍然是引起复合结构材料(包括多层薄膜结构) 关键词： 电流密度 巨磁阻抗效应 趋肤效应     

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用TSC程序模拟了EAST装置等离子体放电的全过程。模拟中考虑了自举电流，并加入了离子回旋共振加热ICRH和快波电流驱动FWCD，得到了中心电子温度4.5keV、中心离子温度3.8keV、中心电子密度1.2×1020m–3的D形截面的等离子体。根据模拟结果对EAST装置进行了伏秒数分析，并研究了不同等离子体电流上升时间、有效电荷数Zeff对放电的影响。     

Analytical Designing of Two-Aspherical-Mirror Anastigmats Permitting Practical Misalignments in a Soft-X-Ray Optics

A new analytical method of designing two-aspherical-mirror anastigmats was developed and applied to searching solution groups of soft X-ray microscopes of a large misalignment tolerance. The two-mirror anastigmat configurations were expressed by a practical variable related to pupil obstruction limiting the system throughput. Axial coma and other aberrations caused by a slight decenter of the system were then formulated to represent sensitivity to misalignment. These formulations enabled a global survey of solution groups as demonstrated by a designing example of soft X-ray microscopes with a magnification m = −1/50, which resulted in four solutions more insensitive to misalignment than a standard Schwarzschild optics in the soft X-ray region. Some solutions were also found to have much larger fields of view suitable for high resolution imaging as confirmed by computer ray tracing.     

双相位共轭镜的工作条件参数分析

本文讨论了纯扩散机制的光折变晶体用作单作用区的双相位共轭镜（ＤＰＣＭ）时的阈值耦合强度和允许的输入光强比范围，并与双作用区的情况进行比较后，给出了在输入光强比远离１的条件下，双相位共轭镜的正常工作的条件参数。     

热光双稳态的临界入射功率与临界温升

本文考虑到F—P腔夹层介质和后反射镜均具有一定的吸收时,推导出产生热致色散光学双稳态的临界入射光功率P_c和临界温升△T_c的数学解析表达式。理论计算的 △T_c值与实验值非常符合。为了得到最佳光学双稳态回线和避免腔内的纵向温度梯度,夹层介质和后反射镜应具有一定的匹配吸收。     

程控电流示波计时电位法

使用计算机产生极化电流具有纯度高，稳定性好和波形形状种类多等优点。研究了极化电流的频率，波形和相角对示波图的影响。对Ｃｄ＾２＋的测定的线性范围为２×１０＾－５～２×１０＾－４ｍｏｌ／Ｌ，相关系数为０．９９７，该方法可且希望用于分析测试和动力学方面的研究。