Relativistic Multichannel Treatment of Krypton Spectra across the First Ionization Threshold

The relativistic multichannel theory has been extended to calculate both the eigen quantum defects μα, transformation matrix Uiα, and the eigen dipole matrix elements Dα of krypton. The Rydberg and autoionization spectra of krypton across the first ionization threshold are calculated within the framework of multichannel quantum defect theory. Our calculated spectra are in agreement with the absolute measurement data.     

JGT-5型超声波钢轨探伤车

上海超声波仪器厂与郑州铁路局共同研制的JGT-5钢轨探伤车,是一种智能化,数字化并配有手推车的专用超声探伤设备。它有五个通道,能同时用超声脉冲反射法和穿透法进行探伤,各通道都配有定量衰减器,而且能用数字直接显示伤损位置,适用于全面探测各种钢轨的核伤、螺孔裂纹、轨腰的水平和纵向裂纹及焊缝裂纹等各种伤损。     

基于宽带毫米波工作体制的雷达目标识别方法探讨

对基于宽带毫米波工作体制的雷达目标特征获取和识别方法进行了综合分析和探讨.表明:在毫米波照射下,雷达目标可模型化为由多个散射中心组成的扩展目标;只要发射信号有足够的带宽,就可以从回波信号中获得各散射中心的空间分布、类型等特征;仿真结果说明,这种方法对高频区复杂目标的识别是有效的.     

我国IT产业创新面临的主要问题

最近，在中共中央关于制定国民经济和社会发展第十一个五年规划的建议中多处强调要增强自主创新能力，努力掌握核心技术和关键技术，提升产业整体技术水平，以此增强国际竞争力。在如何实现自主创新方面，韩国已经积累了丰富的经验，值得我们进行深入研究和学习。其中，在发展IT（电子信息产业）产业和产业创新方面，中国到底应该向韩国学习什么？政府需要做什么？企业又如何做？这些问题已经成为我国IT业界和众多学者关注的焦点问题。     

Fabrication and Characterization of Ni Thin Films Using Direct-Current Magnetron Sputtering

Ni films are deposited by using ultra high vacuum dc magnetron sputtering onto silicon substrates at room temperature, and the high-quality and high-density films are prepared. The parameters, such as thickness, density and surface roughness, are obtained by using small-angle x-ray diffraction (XRD) analyses with the Marquardt gradient-expansion algorithm. The deposition rate is calculated and the Ni single layer can be fabricated precisely. Based on the fitting results, we can find that the surface roughness of the Ni films is about 0.7nm, the densities of Ni films are around 97% and the deposition rate is 0.26nm/s. The roughness of the surface is also characterized by using an atomic force microscope (AFM). The changing trend of the surface roughness in the simulation of XRD is in good agreement with the AFM measurement.     

原子间偶极相互作用对辐射场非经典性的影响

研究了原子间的偶极－偶极相互作用力对相干态Ｔａｖｉｓ－Ｃｕｍｍｉｎｇｓ（Ｔ－Ｃ）模型中辐射场的压缩，振幅平方压缩和光子的反聚束效应的影响。     

可调谐激光二极管具有超窄线宽

窄线宽可调潴激光二极管可能广泛用于光谱学领域。对于具有一定谱宽的增益介质，我们希望可在整个增益区调谐。由于在光谱区边缘增益很弱，通常窄线宽操作会引起附加损失，并限制了调谐范围。最近德国Mainz大学研究人员为激光二极管开发一种透射光栅外腔装置，允许在全光谱增益区以超窄线宽运行。而且这种激光器已经作为稳定铯共振的波长计使用。