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61.
为了对G-16EP型电瓶进行维护和保养,根据电瓶厂家规定和适航规范,总结了该型电瓶的充电和容量测试(放电)方法,指出了影响电瓶寿命的主要因素,为该型号电瓶的维护提供了参考。 相似文献
62.
程宝蕖 《南京航空航天大学学报》1986,(3)
本文扼要介绍了有关文献中在温度变化影响协调误差方面的论点及其应用于分析和解决飞机大部件结合交点的协调问题尚存在的不足。分析了温滞和伪线膨胀系数之间的函数关系。针对典型协调路线及其伪线膨胀曲线导出综合考虑温差、温滞和温滞差的协调误差计算公式。给定一定条件,把温差、温滞和温滞差的影响区分开,从而揭示它们对协调误差分别的和综合的影响,以便采取针对性强而经济的控温方案和控温技术条件,提高飞机大部件结合交点的协调性。 相似文献
63.
L. Zampieri C. Germanà C. Barbieri G. Naletto A. Čadež I. Capraro A. Di Paola C. Facchinetti T. Occhipinti D. Ponikvar E. Verroi P. Zoccarato 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
We are developing fast photon-counter instruments to study the rapid variability of astrophysical sources by time tagging photon arrival times with unprecedented accuracy, making use of a Rubidium clock and GPS receiver. The first realization of such optical photon-counters, dubbed AquEYE (the Asiago Quantum Eye), was mounted in 2008 at the 182 cm Copernicus Observatory in Asiago. AquEYE observed the Crab pulsar several times and collected data of extraordinary quality that allowed us to perform accurate optical timing of the Crab pulsar and to study the pulse shape stability on a timescale from days to years with an excellent definition. Our results reinforce the evidence for decadal stability of the inclination angle between the spin and magnetic axis of the Crab pulsar. Future realizations of our instrument will make use of the Galileo Global Navigation Satellite System (GNSS) time signal. 相似文献
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66.
计算大型实对称特征问题的 Lanczos-QR 算法 总被引:1,自引:0,他引:1
为了计算大型实对称特征值问题Kx=λMx的少数低阶特征值对,本文给出Lanczos-QR迭代方法。首先,给定初始迭代向量v1,作m步Lanczos分解:KVm=MVmTm+hmemT。取Tm的d个最大特征值为移位量,对Tm进行d步带原点位移的QR分解。然后,修改初始迭代向量v1。迭代地重新开始这一过程,迫使初始迭代向量v1进入需求的特征子空间,从而使残量‖Kx-θMx‖→0。数值例子表明,该方法收敛性强,且稳定、有效。 相似文献
67.
K.J. Lee G.J. Qiao H.G. Wang R.X. Xu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(1):180-182
The electric properties of pulsar’s inner annular gap are explored in this paper. Under two main assumptions, (1) the pulsar is alive, (2) the total charge of pulsar should not vary with time, the condition for the acceleration of negative particle in the annular region is derived. The acceleration condition is j− ? 0.5j+, i.e., the current carried by negative particles is greater than or equal to 0.5 times of the current carried by positive particles. This condition holds even when the backward flow of positive particles exists in the annular region. It is noted that the outflow of negative particles offers good opportunities to understand the current closure problem of pulsar as well as wide radiation beam of pulsar observed at high energy band. 相似文献
68.
分析了国内外通用飞机机载数据记录仪的现状,指出我国现有通用飞机机载数据记录仪所存在的不足之处.同时,根据未来通用飞机的发展,深入研究了新型通用飞机机载数据记录仪的功能、特点需求,并且基于模块化思想,提出了新型通用飞机机载数据记录仪的设计思路,给出了新型通用飞机机载数据记录仪的软硬件体系结构,并对其核心模块的功能进行了详细的阐述.最后,简述了新型通用飞机机载数据记录仪的应用. 相似文献
69.
Probing the first stars and black holes in the early Universe with the Dark Ages Radio Explorer (DARE) 总被引:1,自引:0,他引:1
Jack O. Burns J. Lazio S. Bale J. Bowman R. Bradley C. Carilli S. Furlanetto G. Harker A. Loeb J. Pritchard 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
A concept for a new space-based cosmology mission called the Dark Ages Radio Explorer (DARE) is presented in this paper. DARE’s science objectives include: (1) When did the first stars form? (2) When did the first accreting black holes form? (3) When did Reionization begin? (4) What surprises does the end of the Dark Ages hold (e.g., Dark Matter decay)? DARE will use the highly-redshifted hyperfine 21-cm transition from neutral hydrogen to track the formation of the first luminous objects by their impact on the intergalactic medium during the end of the Dark Ages and during Cosmic Dawn (redshifts z = 11–35). It will measure the sky-averaged spin temperature of neutral hydrogen at the unexplored epoch 80–420 million years after the Big Bang, providing the first evidence of the earliest stars and galaxies to illuminate the cosmos and testing our models of galaxy formation. DARE’s approach is to measure the expected spectral features in the sky-averaged, redshifted 21-cm signal over a radio bandpass of 40–120 MHz. DARE orbits the Moon for a mission lifetime of 3 years and takes data above the lunar farside, the only location in the inner solar system proven to be free of human-generated radio frequency interference and any significant ionosphere. The science instrument is composed of a low frequency radiometer, including electrically-short, tapered, bi-conical dipole antennas, a receiver, and a digital spectrometer. The smooth frequency response of the antennas and the differential spectral calibration approach using a Markov Chain Monte Carlo technique will be applied to detect the weak cosmic 21-cm signal in the presence of the intense solar system and Galactic foreground emissions. 相似文献
70.
FBO经营发展具有多种商业形态,而当前国外通航发达国家FBO经营发展具有较为成熟的模式,国内FBO发展还处在起步阶段,必须学习借鉴国外的成熟模式,通过不同的方式尽快使经营走向成熟。同时,国内FBO又需要根据内外部发展环境,创新自身经营模式,更好地推进通用航空FBO的发展。 相似文献