共查询到20条相似文献,搜索用时 62 毫秒
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汽缸表面处理的新发展——激光珩磨 总被引:7,自引:1,他引:6
介绍了激光在发动机汽缸表面处理中的3个发展阶段:大斑点慢扫描螺旋式激光淬火、小斑点快扫描网纹式激光淬火和激光珩磨,在比较中揭示了激光珩磨的优点。并对激光珩磨的加工方法进行了探讨,从光束特性、加工原理、加工工艺等方面对YAG激光和准分子激光在激光珩磨中的使用作了对比和分析。 相似文献
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许晓军 《激光与光电子学进展》2024,(1):181-190
半导体泵浦碱金属激光器近年来发展迅速,其高能高效、轻量紧凑和单口径输出的优势日渐凸显。本文综述了碱金属激光器的技术特点,回顾其发展历程,重点对功率放大的关切因素进行了梳理和评估,同时对新兴的类碱金属激光器的发展进行了介绍。 相似文献
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激光深熔焊接技术的研究与动向 总被引:1,自引:0,他引:1
随着激光器光束质量的改善和输出功率的提高,激光深熔焊接技术在激光加工和焊接领域的份额逐渐增加。对近期国内外激光深熔焊接领域的主要成果进行了概括和总结,讨论了激光深熔焊接的特点和局限性,同时也对激光深熔焊接技术在大功率激光器的开发、激光深熔焊接过程的稳定性、等离子体控制、外加辅助电磁场、激光电弧复合焊接技术等方面的主要研究特点进行了分析和讨论。结合科技发展趋势和激光焊接技术的特点,对激光深熔焊接技术的研究重点进行了讨论和展望。 相似文献
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The article describes a model representation of radar probing data in form of a mixture of background and target samples, which is the sum of two random variables with very different parameters. For model development we research the behavior of the central moments of the distribution mix without assuming the distribution law form. An example it is described the detection of the signal at the output of compression system of chirp ionosonde. 相似文献
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解决IP网QoS问题是目前通信领域的研究热点之一.虽然研究已经取得了一定的进展,但人们对于IP 网QoS本身的含义及相关的问题还有着不同的理解.本文将从IP网QoS的定义入手讨论相关的一些问题以及解决IP网QoS问题所做的各种努力. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(6):1024-1032
Assuming that visual responses are due to the action of particles on the membrane of the visual cells, the stochastic variability of the response should be a function of the number of particles producing it. Quantitative predictions can be made with the aid of a model proposed in previous articles. It is found that responses produced in visual cells of Limulus by absorption of a single photon have the stochastic properties which would be expected if the response to one photon were brought about by 25 particles. It is concluded from this that the processes leading to visual responses produce multiplication of particles. The effects of temperature and of metabolic poisons suggest that these processes are of chemical nature. 相似文献
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By means of exact conformal mapping method we have defined character of dependence of squares amounts of angular part of film
element on angled part dimension. We propose relations, approximating obtained dependence. Calculation results and experimental
researches of large-scale models are represented. 相似文献
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Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献
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A. M. Emel’yanov 《Semiconductors》2010,44(9):1134-1139
A method for analyzing the luminescence spectra of semiconductors is suggested. The method is based on differentiation of
the spectra. The potentialities of the method are demonstrated for luminescence in the region of the fundamental absorption
edge of Si and SiGe alloy single crystals. The method is superior in accuracy to previously known luminescence methods of
determining the band gap of indirect-gap semiconductors and practically insensitive to different conditions of outputting
radiation from the sample. 相似文献
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“计算机组成原理”设计性实践教学模式研究 总被引:1,自引:0,他引:1
本文阐述了"计算机组成原理"设计性实验教学的重要性,对设计性实验教学的目的和基本特征进行了归纳,对"计算机组成原理"设计性实验教学的现状进行了调查,对存在的问题进行了较深入的分析;在此基础上.对组成原理设计性实验的教学模式进行了研究,对设计性实验的体系进行了初步设计,并对"计算机组成原理"设计性实验的实施方法进行了探讨. 相似文献