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31.
ected g 《桂林航天工业高等专科学校学报》2006,(2)
with primary goat embryonic fibroblast showed no difference from traditional feederlayer-based culture method used in mouse and human. The putative primary EG colonies were multilayer clumps ofcompact cel 相似文献
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保证数控铣加工的尺寸精度 总被引:1,自引:0,他引:1
赵先仲 《北华航天工业学院学报》2008,18(2):5-6
本文介绍了数控编程和数控加工中保证零件的尺寸和公差要求的方法.一种方法是用公差的中间值作为终点坐标的尺寸编程;另一种方法是用公称尺寸编程,用公差的中间值作与公称尺寸的差值作为刀补值,通过刀具补偿保证尺寸要求. 相似文献
34.
半实物仿真试验中,要求计算机帧时间与计算积分步长相一致,但在实际试验中不容易精确地做到。本文分析了这种不一致给半实物仿真试验带来的影响,给出了解决的办法,文章中还给出了一实例来说明。 相似文献
35.
H. Thiemann R. W. Schunk 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(12):143-146
Heavy emission caused by impacting plasma ions results in a fast discharging effect of the initially large surface potentials on the dielectric solar cells. This eventually counteracts the energization process of the plasma ions to the cover glasses and leaves no significant electric fields. Thus, with an existing thermal plasma, electrons are again able to reach dielectric surfaces. Strong localized electric fields of the order of several 10 kV/cm form near the interconnector-cover glass interface. 相似文献
36.
T. J. Ponman A. M. Read 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1993,13(12):361-364
Using data from the Wide Field Camera EUV all-sky survey, we have established upper limits to the EUV flux from a sample of 30 bright, nearby, non-active spiral galaxies. These galaxies were chosen to be those most likely to be detected in the EUV on the basis of (i) low interstellar absorption within our own galaxy, (ii) brightness in other wavebands, (iii) high star formation activity, and (iv) proximity. The derived EUV upper limits are restrictive, and establish for the first time that the EUV flux escaping from galaxies does not constitute a major component of their bolometric luminosity, and in particular that it cannot be the sink for the energy injected into the interstellar medium by supernova explosions, as had been suggested following the failure to detect this power in the X-ray band. 相似文献
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The authors present a new scientific space mission consisting of a satellite carrying a receiving- only SAR which receives the signal transmitted by the ENVISAT-1 SAR. The integration of ENVISAT-1 SAR and bistatic radar data offers an improved potentiality of surface classification, three-dimensional observation, and the opportunity of advanced scientific experiments in the field of bistatic scattering. The small satellite nominal orbit and the attitude manoeuvres are designed in order to maintain an adequate overlap between the two radar swaths along the whole orbit, taking into account the ENVISAT-1 attitude and pointing. A preliminary satellite design (2-year lifetime) is then performed to evaluate the orbit decay and to determine the appropriate orbit manoeuvres (every 4 days) to control the satellites relative phase. The numerical simulation shows that a spacecraft of about 584kg is able to meet the mission requirements. 相似文献
40.
齐亚平 《西安航空技术高等专科学校学报》2004,22(2):36-38
高职高专学校规模一般都不是很大 ,在校园网建设中可供选择的方案很多 ,选择一个合适自身的方案是非常关键的。满足现在应用并着眼未来发展应该是高职高专校园网构建所应遵循的基本思路。 相似文献