Gravitational perturbation of hydrogen spectrum in the space curved by intense laser pulses

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｇｅｎｅｒａｌｒｅｌａｔｉｖｉｔｙａｎｄｓｏｍｅｏｔｈｅｒｍｅｔｒｉｃｔｈｅｏｒｉｅｓｐｒｅｄｉｃｔｔｈａｔｇｒａｖｉｔａｔｉｏｎｗｉｌｃａｕｓｅｔｈｅｓｐａｃｅｔｉｍｅｃｕｒｖｅｄ．Ｄｅａｌｉｎｇｗｉｔｈｌａｒｇｅｓ...     

基于专利的技术发展趋势实证研究——以纤维混凝土为例

利用专利计量方法对1976年——2007年在美国专利商标局申请的515件纤维混凝土专利进行统计分析,并从技术生命周期、重点领域分布等两个方面深入研究纤维混凝土的技术发展趋势,为该领域内相关企业制定战略决策提供参考依据。     

碳纤维布在桁架桥加固设计中的应用

碳纤维是一种新型建材,因其质轻、耐腐蚀、片材薄、抗拉强度高而被广泛应用。本文对碳纤维布补强加固混凝土结构的受力特性和破坏机理进行了分析,并对碳纤维布加固设计计算原理、在提高桁架桥荷载等级加固设计中的具体应用进行了详细阐述。通过有限元程序计算对比在加固前后静载和动载数据,得出碳纤维布在桁架桥荷载等级加固设计中的优势。     

北京市碳纤维产业的全产业链发展模式构建

为促进北京市碳纤维产业快速发展,构建产业发展新模式,从专利视角,利用全球碳纤维产业数据,调研国内碳纤维产业链典型企业,分析碳纤维产业发展现状及我国存在的主要问题,研究北京市碳纤维产业转型升级的全产业链发展模式。研究结果表明,国际上碳纤维产业已长期被日本和欧美所垄断,我国的技术和产品与国外仍然存在代差,但在碳纤维领域我国已初步构建出产学研用合作发展模式。目前,北京市在碳纤维领域研发端的实力强劲,并涌现出一批在航空航天领域的碳纤维高端制造企业对北京市碳纤维产业发展起到牵引、推动作用,具备整合国内碳纤维领域优质资源的基础条件。根据研究结果,结合北京市的资源和技术优势,提出构建以高端需求为牵引的北京市碳纤维产业的全产业链发展模式对策建议。     

原子反弹激光中的光放大

本文引入了一种介于普通激光和自由电子激光之间的光放大机制,然后对其进行数值模拟,揭示了光放大的本质,并讨论原子密度、气体介质体积等工作参数对光放大的影响,对原子反弹激光有很好的指导意义。     

三维激光扫描系统的应用研究

本文就三维激光扫描成像系统的原理和发展趋势做了简要的叙述,以工程应用实例对三维激光扫描成像系统的工作流程和三维建模做了详细的说明,并对三维激光扫描系统采集的点云数据处理的方法和手段进行了研究。     

线性啁啾光纤Bragg光栅的分段切趾技术

基于耦合模理论和传输矩阵法,引入分段切趾变迹)技术,对线性啁啾光纤BRAGG光栅进行分析.以5段对称切趾为例,对切趾后光纤的反射谱、时延曲线等特性进行数值分析,对比传统的单一函数完全切趾和对称切趾技术,说明分段切趾对光纤光栅性能的优化作用.     

Effects of parameters in femtosecond laser micromachining on ablation of silicon

A series of ablation experiments on silicon surface by femtosecond laser system of 775 nm and 150 fs duration pulses were carried out.The morphological characteristics and the associated effect in the ablation were tested by atomic force microscope (AFM),scanning electron microscope (SEM),focused ion beam (FIB),and the optic microscope.The single pulse threshold can be obtained directly.For the multiple pulses,the ablation threshold varies with the number of pulses applied to the surface due to the incubation effect.By analyzing the experimental data,the thresholds of laser fluences under various laser pulse numbers were obtained,and the relationships between ablation area and laser energy and laser pulse number were concluded.Meanwhile,the periodic ripple structure on silicon surface was found.Under the condition of certain laser power,the number of laser pulse can influence the formation of ripples.     

Vibration shape testing of space sheet structure

The space sheet for a solar array structure is large in dimension, and flexible to induce complex distortion. It is difficult to measure the distortion. A large-scale flexible test prototype system is built for sheet structure vibration monitoring based on the vibration information of the solar array in space. The system provides an intelligent test method for flexible space structure with embedded sensors and non-visualization reinstruction. Multiple fiber Bragg grating （FBG） sensors are packaged and embedded into the structure with spatial division multiplexing （SDM） and wavelength division multiplexing （WDM）. The sensor interrogator distinguishes wavelength shifts that can be turned into curvature of the curve. The structure shape is reconstructed based on the curvature information and the arc-length, and then displayed. The experiment shows that the system has a high FBG sensitivity. The reconstruction algorithm is fast with high precision. The system has great potential for use in health monitoring of the space sheet structure.     

视神经神经纤维和胶质细胞研究进展

对视神经神经纤维和胶质细胞的研究进展作了综述。主要包括视神经纤维的结构、数量、直径及其对兴奋的传导速度和视神经胶质细胞结构。