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541.
济南市纬六路跨铁路斜拉桥南索塔施工技术 总被引:1,自引:1,他引:0
王成 《铁道标准设计通讯》2006,(8):37-39
介绍济南市纬六路跨铁路斜拉桥南索塔柱施工方法及爬架翻模施工技术。 相似文献
542.
The aim of this work was to develop a predictive model to forecast the mean zero-up-crossing wave periods (T
z
) for 3-hourly sea states at a location in the Pacific using artificial neural networks (ANNs). Seven multilayer ANNs were
trained with a simulated annealing algorithm. The output of each trained ANN was used to estimate each of the seven parameters
of a new distribution called the hepta-parameter spline proposed for the conditional distribution of T
z
, given some mean zero-up-crossing wave periods and significant wave heights. After estimating the parameters of the distribution,
the model was used to simulate and predict future values of T
z
. Forecasting a sea state and developing the joint distribution of sea state characteristics with the help of the simulated
characteristics are also discussed in this article. 相似文献
543.
结合分散自律调度集中系统具体结构,详细描述分散自律调度集中系统的综合防雷设计方案,提出实际可行的分散自律调度集中中心及车站系统防雷设计。 相似文献
544.
针对某型机械化桥桥跨结构,通过分析研究其实际的使用工况,建立了相应的结构分析有限元计算模型.数值分析结果与试验结果吻合较好,表明所建立的计算模型是合理的, 能够为同类机械化桥桥跨结构设计提供有益的参考. 相似文献
545.
546.
Hyung Seok Heo Suk Jung Bae Sung Mok Hong Seung Uk Park 《International Journal of Automotive Technology》2018,19(2):221-231
Although fuel cost has been the largest portion of annual operating costs of construction equipment, it is possible to save the energy and reduce cost using fuel economy enhancement technology. In this study, an organic Rankine cycle is applied to an excavator in order to recover waste heat, reproduce it into electrical energy, and consequently reduce the fuel consumption by 10 %. A design process was carried out to develop an exhaust gas superheater that recovers the waste heat from exhaust gas through a composite-dimensional thermal flow analysis. A one-dimensional code was developed to perform a size design for the exhaust gas superheater. The ranges for the major design parameters were determined to satisfy the target of the heat recovery, as well as the pressure drop at both fluid sides. Performance analysis was done through onedimensional design code results, which were compared with three-dimensional CFD analysis. By utilizing a 3D commercial code, the arrangement of the tubes was selected and the working fluid pressure drop was reduced through a detailed layout design. The design procedure was verified by a performance evaluation of the prototype, which yielded only a 7 % tolerance in heat recovery. 相似文献
547.
Research on the coefficient of sound absorption in turbid water 总被引:2,自引:0,他引:2
China’s coastal waters are turbid and the properties of the seabed are complex. This negatively impacts the performance of underwater detection equipment. The properties of sound absorption in turbid water are not well understood. In this paper, the coefficient of sound absorption in turbid water was measured by the reverberation technique. All work was done in a reverberation barrel made of seamless aluminum. First, pure water was poured into the reverberation barrel and its reverberation time measured. Next, various concentrations of turbid water were poured into the barrel and their reverberation time measured. After all data had been gathered, the coefficient of sound absorption in turbid water of different concentrations was calculated. From this we determined a law of sound absorption in turbid water as summarized in the paper. 相似文献
548.
549.
“Today, the idea of allowing aircraft pilots to operate as they see fit, without any control from the land, is unthinkable. Will the same things apply to ships in twenty to thirty years’ time?”Current maritime pilotage regimes are clearly seen in some quarters as too restrictive and old fashioned. Change is “in the air” and VTS, pilotage, and the relationship between them cannot be immune to it. Subject to the attainment of the appropriate standards by both ships and their crews there is no practical reason why more flexible Vessel Traffic Management cannot be introduced. The required technology is largely available and, with the introduction of AIS, the required dynamic data can be available. Technical problems foreseen are believed capable of solution. The more significant obstacles to implementation are, therefore, largely political, commercial, organisational, and cultural. These issues are discussed in this paper taking into account the viewpoints of major stakeholders. 相似文献
550.
Several algorithms were proposed relating to the development of a framework of the perturbation-based stochastic finite element
method (PSFEM) for large variation nonlinear dynamic problems. For this purpose, algorithms and a framework related to SFEM
based on the stochastic virtual work principle were studied. To prove the validity and practicality of the algorithms and
framework, numerical examples for nonlinear dynamic problems with large variations were calculated and compared with the Monte-Carlo
Simulation method. This comparison shows that the proposed approaches are accurate and effective for the nonlinear dynamic
analysis of structures with random parameters. 相似文献