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121.
提出以QDCORS作为青岛地铁卫星定位控制网的起算基准,介绍外业观测时的注意事项及数据解算时的流程,结合其在青岛地铁控制网中的应用和数据分析说明了用CORS作为城市地铁控制网的起算数据可以有效保证各条地铁线路空间基准的统一性。 相似文献
122.
Bosi Zhang Jiaqing Zhang Xiaomin Wang Shouxiang Lu Changhai Li Ruiyu Chen 《Fire Technology》2016,52(2):547-562
The effects of air inlet configuration on pool fire behavior in a mechanically ventilated cabin were investigated. The closed cabin used was a model of a certain machinery cabin on a naval ship. Two air inlet configurations of one vent and two vents were taken into account together with five different elevations of air inlet. In one-vent cases, mass loss rate and gas temperature were lower and oxygen concentrations were higher than those of two-vent cases. With the increase of air inlet elevation, a sudden drop in average mass loss rate and peak temperature were found in the two-vent cases at the air inlet elevation of 1.56 m. In one-vent cases, a similar drop in average mass loss rate was found at the air inlet elevation of 0.88 m, while the peak temperature was almost unaffected by inlet elevation. According to temperature profiles and the characteristic parameter of the smoke layer stability, the formation of the smoke layer was destroyed by increasing the air inlet elevation or reducing the air inlets, and furthermore a more uniform distribution could be found. For the current cabin, the one-vent case with a lower air inlet elevation was recommended for smoke control, and the inlet should be set away from the essential equipment and the entrances of the cabin. 相似文献
123.
20世纪80年代以来,灰色系统理论1)提出以后,便以一种有力的姿态立于科学之林,在学术界引起了较大的反响,并受到广泛关注。目前这一理论和方法已应用于不同学科及领域的研究之中,并获得相应的丰硕成果。文章以灰色系统理论为基础,以其模糊与不确定的特性切入建筑学学科领域的研究,通过灰色系统理论的植入及建筑“灰”的决定因素进而到建筑“灰”的形态,从空间的营造、形体的塑造、功能的使用、材料的应用等方面进行了较为深入系统的研究,探寻其蕴含的设计思想和营造理念,试图以灰色系统理论来探索建筑设计理论。 相似文献
124.
王卓伟 《导弹与航天运载技术》2010,(3)
介绍了新型集成化光学陀螺的概念和特点,总结了新型集成化光学陀螺的研究方案和研究进展,指出未来新型集成化光学陀螺可能的发展方向和发展前景. 相似文献
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127.
To further clarify the features of wedding dresses in new, style weddings in cities and towns of the Wu culture region, the author sorted out and made a statistical analysis of modern journals and periodicals as well as conducted a comparison in combination with diaries of celebrities and novels in modern times to collect 368 wedding photos in total in the Wu culture region. The analysis results indicate that wedding dresses in the Wu culture region were mainly of modified styles from 1859 to 1949, the development of wedding dresses went through the stages of unitary styles, mixed styles and diversified styles, in each of which there were also representative regular ways of matching. In general, wedding dresses were in simple, elegant and delicate styles, and the silhouettes kept up with popular western styles, showing a high level of acceptance of foreign cultures. The colors of wedding dresses tended to combinations of light colors, while traditional colors were gradually reduced. Besides, patterns of flowers and plants with thin stems and leaves were mainly used to decorate wedding dresses, showing the distribution features of scattering and covering. © 2018 China Silk Association. All rights reserved. 相似文献
128.
简述了影响振动沉管灌注桩施工过程中沉管的主要因素,根据振动沉管灌注桩的沉管贯入机理,提出了沉管过程中贯入阻力的估算公式,并通过具体实例进行了分析,以合理选择施工桩机与施工顺序,从而达到设计要求。 相似文献
129.
Seismic performance of a self-anchored suspension bridge with three-tower were investigated. A three-dimensional nonlinear finite element model of the bridge was developed using Sap2000. Nonlinear time history analysis was conducted using Fast Nonlinear Analysis Method (FNA), while beam-column effect and nonlinear behavior of bearing and damper were taken into consideration. The analyze results showed that the middle tower was more vulnerable compared with the two side towers; there existed risk of buckling of composite beam, and the most vulnerable part lied near steel-concrete composite segment. Viscous dampers were effective to reduce seismic response of towers as well as girders.
相似文献130.
Concrete structures may deteriorate over time due to aggressive service environments, leading to a reduction in their strengths, stiffnesses and reliabilities. In general, the assessment of time-dependent reliability of ageing structures must consider uncertainties in structural deterioration as well as non-stationarities in the structural load processes. This paper develops an approximate method for assessing the impact of structural deterioration and non-stationary live loads on structures, which requires only low-dimensional integration and reduces the cost of assessing time-dependent reliability over a service life extending to 50 years significantly. This approximate method is demonstrated through several examples. The importance of non-stationarities in the resistance and load processes on time-dependent reliability is illustrated and the accuracy of the method is confirmed in several cases utilising Monte Carlo simulation. 相似文献