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51.
国内研制的20/30Ⅱ代倒象微光管经常出现微通道板真空体电阻偏高或偏低的问题,直接影响Ⅱ代倒象微光管荧光屏的亮度和目标分辨力,严重影响微光管的质量。经过对20/30Ⅱ代倒象微光管的研制和理论分析,证明英国马拉德公司对用于××1383Ⅱ代倒象微光管的H36微通道板技术条件中真空体电阻技术指标的规定也存在一定的问题。本文从目前国内外工艺水平和有关文献资料的分析出发,进行专题研究。本文中所推导的计算公式和对文献资料提供的技术数据的推导分析,同样适用于其他型号微通道板的真空体电阻与相应Ⅱ代、Ⅲ代微光管匹配关系的计算与研究。 相似文献
52.
从计划角度重点分析了钢铁生产中炼钢、连铸、热轧三者之间联接的较高模式-直接热装轧制计划系统的实现方式,并给出了较为具体的方案。 相似文献
53.
介绍钢管圆周剪切的另一种方法-单芯棒圆周剪切法。通过运动学分析阐述了剪切金属的变形原理;实验研究证明了该方法的可行性并对切口断面质量进行了分析。 相似文献
54.
陈新 《南京邮电大学学报(自然科学版)》1994,(3)
讨论了固定无线传输干线上中、大容量数字微波系统中的公务系统,并研制了一种性能优于现有单话路系统的3话路公务系统。采用集成度高的开关电容滤波器,构成高阶分路滤波器;还提出了数字公务系统的构成、704kb/s复接帧的帧结构及实现方案。 相似文献
55.
《厦门大学学报(自然科学版)》2002,(Z1)
Thanks to the fantastic development of power, transportation, chemical engineering, architecture and other fields, there has been an increasing demand for new type of section steel with large sections used for construction frame, such as type-H, type-T, and type-C section steel. New types of section steel usually are long and with large cross section. Therefore, for the sake of the cost, steel plate welding structure is used home and abroad. During the welding process, welding distortion seems unavoidable. ... 相似文献
56.
A. I. Vanin 《Journal of Applied Spectroscopy》1997,64(2):242-245
Light scattering by groups of spherical particles is considered. It is shown that the structure of the groups and their orientational
distribution can be judged from the spectrum and polarization of the scattered light.
Syktyvkar State University, 55, Oktyabr'skii Ave., Syktyvkar, 167001, Russia. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 2, pp. 228–231, March–April, 1997. 相似文献
57.
Calibration of the relationship between height and phase is of uttermost importance to perform accurate 3D measurements in phase measurement profilometry. This work reports a different approach to this problem by first looking at the analytical expression for this relationship and determining the regime spanned by the fringe analysis method. The conclusions thus ascertained, amply justify confronting the analytical expression with a simple normalization procedure of the experimental data, with a remarkable matching between both results. In light of this, a linear calibration procedure with just one plane is proposed and verified experimentally. 相似文献
58.
Zhitian Liu Lei Wang Junwu Chen Feng Wang Xiaoying Ouyang Yong Cao 《Journal of polymer science. Part A, Polymer chemistry》2007,45(5):756-767
2,5‐Bis(2‐bromofluorene‐7‐yl)silole was prepared by a modified one‐pot synthesis with a reverse addition procedure, from which novel silole‐containing polyfluorenes with binary random and alternating structures (silole contents between 4.5 and 25% and high Mw up to 509 kDa were successfully synthesized. The well‐defined repeating unit of the alternating copolymer comprises a terfluorene and a silole ring. Optoelectronic properties including UV absorption, electrochemistry, photoluminescence (PL), and electroluminescence (EL) of the copolymers were examined. The different excitation energy transfers from fluorene to silole of the copolymers in solution and in the solid state were compared. The films of the copolymers showed silole‐dominant green emissions with high absolute PL quantum yields up to 83%. EL devices of the copolymers with a configuration of ITO/PEDOT/copolymer/Ba/Al displayed exclusive silole emissions peaked at around 543 nm and the highest EL efficiency was achieved with the alternating copolymer. Using the alternating copolymer and poly(9,9‐dioctylfluorene) as the blend‐type emissive layer, a maximum external quantum efficiency of 1.99% (four times to that of the neat film) was realized, which was a high efficiency so far reported for silole‐containing polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 756–767, 2007 相似文献
59.
Zhang Tao 《中国科学G辑(英文版)》2007,50(5):591-600
The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium.
The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s
Law is applied to this conductor that is in the alternating magnetic field of the light. dB
M/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy,
i.e. the refractive energy, with the electron cloud conductor. Formulas of refractive index, which is the ratio of light speed
in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s
diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and
the nonlinearity of the refractive index are explained with the theory described in this work.
Supported by Beijing Science and Technology New Star Program (Grant No. 952870400), the Beijing Municipal Commission of Education
and the Excellent Young Teachers Program of Ministry of Education of China 相似文献
60.
Characterization of spherical particles using high-order neural networks and scanning flow cytometry
Vladimir V. Berdnik Alexander Shvalov Valeri Maltsev Valery A. Loiko 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,102(1):62-72
We retrieve the radius R, real n and imaginary k parts of the refractive index of homogeneous spherical particles using angular distribution of the light-scattering intensity. To solve the inverse light-scattering problem we use a high-order neural-network technique. The effect of network parameters on optimization is examined. The technique is evaluated for noise-corrupted input data at 0.6 μm<R<10.6 μm, 1.02<n<1.38, and 0<k<0.03. The errors of retrieval for nonabsorbing particles do not exceed 0.05 μm for radius and 0.015 for refractive index. The experimental verification is fulfilled by experimental data retrieved by means of a scanning flow cytometer. The light-scattering profiles of polystyrene beads and spherized red blood cells are processed with the high-order neural networks and a non-linear regression at Mie theory. The parameters retrieved by the high-order neural networks correlate well with the parameters retrieved by the least-square method. 相似文献