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通信光纤设备技术的发展推进了社会的发展,带来了极大的社会效应。本文对光纤通信设备的构成和现状进行了描述,对通信光纤设备的特点进行了深入分析,并阐述了光纤传输设备维护时需注意的问题,研究了光纤传输设备的维护措施,总结了光纤传输设备的维护方法。 相似文献
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通信光纤设备技术的发展推进了社会的发展,带来了极大的社会效应。本文对光纤通信设备的构成和现状进行了描述,对通信光纤设备的特点进行了深入分析,并阐述了光纤传输设备维护时需注意的问题,研究了光纤传输设备的维护措施,总结了光纤传输设备的维护方法。 相似文献
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陈中佛 《电子工业专用设备》1994,23(3):38-44
本文从半导体技术进步的角度阐述了半导体设备发展的几个主要方向。文章开头综述了半导体设备与器件发展的相互关系、半导体设备的学科综合性及设备市场简况,随后分述了半导体设备大直径化趋势,设备超净化发展,设备单片加工化及复合化,设备日益昴贵化及低成本努力,以及其他一些发展趋势,可供设备与器件两个专业的工作者参考。 相似文献
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本文阐述了选购录像设备和摄像设备的原则,并介绍了相应设备的性能、特点。对电视台及电视节目制作单位了解设备性能、选购设备有一定的参考价值。 相似文献
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本文指出了当前世界半导体设备的“十大”发展趋势,即设备与工艺互动化;设备加工晶圆大尺寸化;设备加工晶圆单片化;设备组合化;设备高精度化;设备全自动化;设备制造商垄断化;设备高价格化;设备研制联合化;设备用户化。 相似文献
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Beverley Christian Alexandre Romanov Irina Romanova Laura J. Turbini 《Journal of Electronic Materials》2014,43(11):4199-4213
Over the last few years, 85 cell phones have been disassembled, ground up, dissolved, and analyzed for elemental content, mainly for information about the metals present in the phones, but also for some metalloids and nonmetals. The following list of 38 elements were detected in some or all of the phones: Be, B, Mg, Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Y, Nb, Pd, Ag, In, Sn, Sb, Te, Ba, Ta, W, Pt, Au, Tl, Pb, Bi, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er. Cadmium was never detected. This paper discusses the methods used for carrying out the analysis, proposes possible sources in the telephones for the elements of interest, the reasons for the interest in most of the elements, and method repeatability. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》2005,51(9):3186-3199
A binary sequence satisfies a one-dimensional$(d_1, k_1, d_2, k_2)$ runlength constraint if every run of zeros has length at least$d_1$ and at most$k_1$ and every run of ones has length at least$d_2$ and at most$k_2$ . A two-dimensional binary array is$(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ -constrained if it satisfies the one-dimensional$(d_1, k_1, d_2, k_2)$ runlength constraint horizontally and the one-dimensional$(d_3, k_3, d_4, k_4)$ runlength constraint vertically. For given$d_1, k_1, d_2, k_2, d_3, k_3, d_4, k_4$ , the two-dimensional capacity is defined as $$displaylines C(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4) hfillcr hfill=, lim_m,n rightarrow infty log_2 N(m, n ,vert, d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)over mn $$ where $$N(m, n ,vert, d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$$ denotes the number of$m times n$ binary arrays that are$(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ -constrained. Such constrained systems may have applications in digital storage applications. We consider the question for which values of$d_i$ and$k_i$ is the capacity$C(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ positive and for which values is the capacity zero. The question is answered for many choices of the$d_i$ and the$k_i$ . 相似文献
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单片机体积小、重量轻、抗干扰能力强、环境要求不高、价格低廉、可靠性高、灵活性好、深受初学者喜欢。以STC90C58为核心控制芯片,DS1302为时钟芯片,DS18B20采集温度,完成多功能电子时钟的设计。该设计能够准确显示年、月、日、星期、时、分、秒及温度,通过按键可以调整年、月、日、星期、时、分、秒、12/24小时转换、整点提示以及闹钟,还可显示阴阳历。 相似文献
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Better breast cancer detection 总被引:2,自引:0,他引:2
《Spectrum, IEEE》2001,38(5):50-54
X-rays go digital, computers read film, and chemicals mark tumors, but will these new technologies make it in the clinic? The imaging technologies considered for breast cancer include film-screen mammography, full field digital mammography, ultrasound, magnetic resonance imaging, scintimammography, thermography, electrical impedance imaging, optical imaging, electric potential measurement, positron emission tomography, novel ultrasound techniques, elastography, magnetic resonance spectroscopy, thermoacoustic computed tomography, microwave imaging, Hall-effect imaging and magneto-mammography 相似文献
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Continuing efforts under the auspices of the National Earthquake Hazards Reduction Program are under way to improve earthquake risk assessment and risk management in earthquake-prone regions of Alaska, California, Nevada, Washington, Oregon, Arizona, Utah, Wyoming, and Idaho, the New Madrid and Wabash Valley seismic zones in the central United States, the southeastern and northeastern United States, Puerto Rico, Virgin Islands, Guam, and Hawaii. Geologists, geophysicists, seismologists, architects, engineers, urban planners, emergency managers, health care specialists, and policymakers are having to work at the margins of their disciplines to bridge the gap between research and practice and to provide a social, technical, administrative, political, legal, and economic basis for changing public policies and professional practices in communities where the earthquake risk is unacceptable 相似文献
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Daskalov R. Hristov P. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(11):3001-3005
Sixteen new binary quasi-cyclic linear codes improving the best known lower bounds on minimum distance in Brouwer's tables are constructed. The parameters of these codes are [102, 26, 32], [102, 27, 30], [142, 35, 40], [142, 36, 38] [146, 36, 40], [170, 16, 72], [170, 20, 66], [170, 33, 52] [170, 36, 50], [178, 33, 56], [178, 34, 54], [182, 27, 64] [182, 36, 56], [186, 17, 76], [210, 23, 80], [254, 22, 102] Sixty cyclic and thirty quasi-cyclic codes, which attain the respective bounds in Brouwer's table and are not included in Chen's table are presented as well. 相似文献
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Lei Zhang Tian Gong Zhiqiang Yu Huan Dai Zhenjingfeng Yang Ganlin Chen Jinhua Li Ruikun Pan Huide Wang Zhinan Guo Han Zhang Xiao Fu 《Advanced functional materials》2021,31(1):2005471
The emerging monoelemental 2D materials named as Xenes including borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene, bisthumene, selenene, and tellurene, have attracted rising attention experimentally and theoretically. Because of their excellent and versatile physical, chemical, electrical, and optical advantages, Xenes have been shown or have been predicted to have excellent performance in nanotechnology applications, addressing challenges and advances in electronics, energy, healthcare, and environment. In this review, the basic fundamentals in the classification of the periodic table group and the synthesis methods for the emerging materials are summarized. Then, the hybridization, doping and functionalization of 2D Xenes, and their corresponding applications are presented. Furthermore, a summary of research progress on 2D Xenes and the challenges and perspectives for their further development are discussed. 相似文献
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CompactPCI总线技术及系统设计 总被引:1,自引:1,他引:0
CompactPCI总线具有高总线带宽、高性能、支持热插拔,满足高速度、高性能尤其是复杂控制算法并要求可视化操作的应用场合的功能需求。首先,对CompactPCI总线技术在扩展性、封装和连接、被动式背板、热插拔和高性能等方面的技术特点。然后对其核心技术——热插拔技术做了简要的介绍,并在此基础上,对CompactPCI系统设计的相关问题进行了详细的论述。最后指出CompactPCI总线技术在工业、热力、石化、冶金、交通、现代通讯、核能、航空、航天、军事等领域具有广阔的应用前景。 相似文献