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用Nd:YAG激光加工玻璃内部结构 总被引:3,自引:0,他引:3
晓晨 《激光与光电子学进展》1996,33(1):27-29
用Nd:YAG激光加工玻璃内部结构1.引言用COz激光加工玻璃,如切割、打孔、标记在实践中已为众所周知’‘,””“。这是由于玻璃能吸收CO。激光器80~95%(视玻璃种类不同)的红外光。图1示出各种玻璃的透过率与波长的关系。由于波长入一1卜m时吸收可... 相似文献
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美国伊利诺斯州Erie工业产品公司自1946年以来一直是一家服务于公司的金属加工工场。1982年他们购买了一台CO2激光切割机,从而成为全美最先进的加工工场之一。“我们是芝加哥地区第一批购买激光器的公司之一。的确收到了效果。”公司总经理P.Selleck说。之后,公司又购买了三台激光器。作为加工零部件批量在1到1000之间的小工场,以前最昂贵的机械就是硬质工具。“现在,有了激光器,我们能够避开加工每种零件的工具成本问题。结果是,我们能够更快地转换工件。’剧总经理F.Baker说,“收外,我们还能加工这样的部件,其形状是用硬质冲… 相似文献
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高功率CO2激光加工设备的泵浦电源及研究状况 总被引:2,自引:0,他引:2
就高功率气体激光加工设备在广泛应用中,对泵浦电源性能和特点提出越来越高的要求,阐述了高功率激光电源的研究状况,论述了开关电源应用于激光设备的技术优势,提出了激光泵浦电源的发展方向。 相似文献
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激光加工技术发展现状及展望 总被引:1,自引:0,他引:1
本文论述了用于激光加工的各类激光器、光学系统、工件系统以及激光加工应用开发的发展现状与水平;并根据近期激光加工市场动态,预测了“八五”期间激光加工技术的发展趋势,提出了我国激光加工技术近期的研究方向。 相似文献
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中低功率双CO_2激光切割机的开发与应用 总被引:1,自引:0,他引:1
研究了大功率单CO2激光切割机和小功率双CO2激光切割机的切割原理,分析了在用这两种形式的激光切割机切割非金属材料木质模切板时,激光功率、切割速度与切割深度、切割的缝形缝宽之间的关系。试验结果表明,用中小功率双CO2激光切割机切割非金属木质板材,无论是设备的制造成本、运行成本,还是切割的精度和缝形缝宽,同用大功率单CO2激光头切割机相比有很多优势。 相似文献
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Zhang R. Lee F.C. Boroyevich D. Hengchun Mao 《Power Electronics, IEEE Transactions on》2000,15(3):456-463
A new, high performance, low cost power converter system architecture is proposed. The system consists of a main converter and a multifunctional load conditioner. The main converter deals with most of the power flow running at a low switching frequency. The load conditioner is designed at a much lower power level running at a high-switching frequency. The load conditioner can (1) act like a current source and inject harmonic currents required by the load; (2) act like an active resistor to provide damping to the main converter; and (3) for three-phase inverters, decouple the coupling sources in the main inverter model in the rotating coordinates to make the control loop design for the main inverter much easier. The concept has been proved by simulation and experimental results on a 150 kW high performance three-phase utility power supply prototype. The proposed system configuration can be used in high power DC-DC converters, inverters, PFC and UPS applications 相似文献
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Sławomir Stańczak Angela Feistel Marcin Wiczanowski Holger Boche 《Wireless Networks》2010,16(6):1691-1705
This paper addresses the issue of incorporating QoS requirements expressed in terms of some minimum SIR targets into the traditional
utility-based power control problem. As suitable projection methods seem to be not amenable to distributed implementation,
we first focus on a primal-dual algorithm to solve the utility-based power control problem subject to the SIR requirements.
We prove a global convergence of the algorithm for a large class of utility functions and show that it can be implemented
in a distributed wireless environment. However, the approach has an important drawback: An optimal solution may not exist
as the SIR targets may be infeasible due to, for instance, channel effects. This motivates a reformulation of the problem
so that an optimal solution always exists. We consider the possibility of using a barrier method to closely approach the desired
SIRs of the users and combine this approach with the conventional utility-based power control problem to incorporate best
effort users. We prove relevant properties of optimal solutions and propose a distributed recursive algorithm with global
convergence. Finally, the performance of the proposed approaches is verified by simulations. 相似文献
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《Circuits and Systems Magazine, IEEE》2004,4(3):16-23
In this work a framework for modeling power systems using hybrid input/output automata (HIOA) is proposed. The system is assumed to consist of several distinct components. Some of them drive the continuous dynamics while others exhibit event-driven discrete dynamics. Such behavior is characterized by interactions between continuous dynamics and discrete events. Therefore the power systems are an important example of hybrid systems. This hybrid modeling process is applied to a simple power system. 相似文献
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Sung-Min Yoon Nam-Yeal Lee Sang-Ouk Ryu Kyu-Jeong Choi Park Y.-S. Seung-Yun Lee Byoung-Gon Yu Myung-Jin Kang Se-Young Choi Wuttig M. 《Electron Device Letters, IEEE》2006,27(6):445-447
A phase-change material of Sb/sub 65/Se/sub 35/ was newly proposed for the nonvolatile memory applications. The fabricated phase-change memory device using Sb/sub 65/Se/sub 35/ showed a good electrical threshold switching characteristic in the dc current-voltage (I-V) measurement. The programming time for set operation of the memory device decreased from 1 /spl mu/s to 250 ns when Sb/sub 65/Se/sub 35/ was introduced in place of the conventionally employed Ge/sub 2/Sb/sub 2/Te/sub 5/ (GST). The reset current of Sb/sub 65/Se/sub 35/ device also dramatically reduced from 15 mA to 1.6 mA, compared with that of GST device. These results are attributed to the low melting temperature and high crystallization speed of Sb/sub 65/Se/sub 35/ and will contribute to lower power and higher speed operations of a phase-change nonvolatile memory. 相似文献
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Cianca E. De Fina S. De Luise A. Ruggieri M. Prasad R. 《Wireless Communications, IEEE Transactions on》2006,5(4):733-736
This paper aims at clarifying the role of the outer loop power control for CDMA satellite systems with on-board power constraints. If the inner loop of the power control is perfect, the channel turns into a AWGN channel and there is no need of the outer loop. In satellite CDMA systems, due to the longer propagation delay with respect to a terrestrial system, the inner loop of power control is only partly able to track power variations due to fast fading. Moreover, the Rice factor, which characterizes the channel statistics, can widely vary even if the user does not move but just because of the change of the elevation angle. Because of that, a wide range of target SNIR (and larger than in typical terrestrial systems) may be necessary to get the same BER performance. Therefore, the outer loop power control turns out to be essential to minimize the dynamic of the power link margins and avoid capacity degradations induced by the systematic use of static link margins. A semi-analytical model for the capacity evaluation has been developed, which is specifically intended for the power-limited satellite-to-mobile link with multi satellite reception. We found that the capacity gain with respect to a pure SNIR-based strategy (i.e., only inner loop) can reach the 40% of the total capacity in a single reception scheme. A smaller, but still noticeable capacity gain of the order of 20 - 30% is observed in presence of satellite diversity. Therefore, any dimensioning of CDMA satellite systems should not neglect this component of the power control. 相似文献
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在锶原子光晶格钟实验中,为了应对多变的实验环境和复杂的实验需求,使得某些光路中的激光不仅能够保证功率稳定,还可以进行时序性调控,采用了声光调制的方法,基于声光晶体的衍射效率随加载于其上的射频功率变化而变化这一原理,建立了一套反馈控制系统,实现了激光功率的主动稳定以及功率设定值的时序性可控。结果表明,在该系统中激光会根据时序控制信号稳定地工作在控制范围内的任意功率强度上,与无功率稳定的状态相比,激光功率的稳定度从10-2量级提高到了10-4量级。该系统的特点在于能够对功率进行稳定的时序控制。 相似文献
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for optimal BER and power distributions are derived in this article. Simulation results indicate the superiority of the proposed algorithm in terms of BER performance and algorithmic complexity. 相似文献
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A.M. Meystel 《IEEE transactions on systems, man and cybernetics. Part C, Applications and reviews》2003,33(1):86-101
Decision support systems gain better performance and higher accuracy by the virtue of building multiresolutional (multigranular, multiscale) representation, and employing multiscale behavior generation subsystem (planning and control). The latter are equipped by devices for unsupervised learning that adjust their functioning to the results of self-identification. We demonstrate that planning and learning are joint processes. The author's intention is to emphasize that the concepts of multiresolutional representation (MR) and multiresolutional decision support (MR-DSS) probably have in common a general significance that crosses the boundaries of particular domains of applications and disciplines. The paper explores this phenomenon. The ubiquity of a principle that somehow persistently delivers benefits to many areas of knowledge and technology seems to be more important than a habit to follow the pigeonhole principle of paper presentation. 相似文献
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