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浅谈桥梁快速施工中的结构放置方法
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作者 樊步乔 刘伟 《江西建材》 2014年第6期133-133,共1页
桥梁快速施工(ABC)是一种新的桥梁施工模式。本文介绍了ABC的概念和优点,并分析了施工中常用且较成熟的技术形式:桥梁结构的放置方法。
关键词 桥梁快速施工 结构放置 ABC
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Damping of Oblique Ocean Waves by a Vertical Porous Structure Placed on a Multi-step Bottom 被引量:1
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作者 Santu Das Swaroop Nandan Bora 《Journal of Marine Science and Application》 2014年第4期362-376,共15页
Oblique ocean wave damping by a vertical porous structure placed on a multi-step bottom topography is studied with the help of linear water wave theory. Some portion of the oblique wave, incident on the porous structu... Oblique ocean wave damping by a vertical porous structure placed on a multi-step bottom topography is studied with the help of linear water wave theory. Some portion of the oblique wave, incident on the porous structure, gets reflected by the multi-step bottom and the porous structure, and the rest propagates into the water medium following the porous structure. Two cases are considered: first a solid vertical wall placed at a finite distance from the porous structure in the water medium following the porous structure and then a special case of an unbounded water medium following the porous structure. In both cases, boundary value problems are set up in three different media, the first medium being water, the second medium being the porous structure consisting ofp vertical regions-one above each step and the third medium being water again. By using the matching conditions along the virtualvertical boundaries, a system of linear equations is deduced. The behavior of the reflection coefficient and the dimensionless amplitude of the transmitted progressive wave due to different relevant parameters are studied. Energy loss due to the propagation of oblique water wave through the porous structure is also carried out. The effects of various parameters, such as number of evanescent modes, porosity, friction factor, structure width, number of steps and angle of incidence, on the reflection coefficient and the dimensionless amplitude of the transmitted wave are studied graphically for both cases. Number of evanescent modes merely affects the scattering phenomenon. But higher values of porosity show relatively lower reflection than that for lower porosity. Oscillation in the reflection coefficient is observed for lower values of friction factor but it disappears with an increase in the value of friction factor. Amplitude of the transmitted progressive wave is independent of the porosity of the structure. But lower value of friction factor causes higher transmission. The investigation is then carried out for the second case, i.e., when the wall is absent. The significant difference between the two cases considered here is that the reflection due to a thin porous structure is very high when the solid wall exists as compared to the case when no wall is present. Energy loss due to different porosity, friction factor, structure width and angle of incidence is also examined. Validity of our model is ascertained by matching it with an available one. 展开更多
关键词 porous structure oblique wave REFLECTION matching condition multi-step bottom friction factor energy loss
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竖炉导风墙托梁漏水的原因分析和改进建议
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作者 宋松 张桂花 《冶金设备管理与维修》 2008年第1期48-48,共1页
介绍了济钢2号竖炉水梁损坏情况,分析了托梁损坏原因,提出了改进建议。
关键词 鼓起变形 裂纹漏水 汽水分层 倾斜放置托梁结构
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Comparison of China's Carbon Emission Scenarios in 2050 被引量:2
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作者 Huimin Li Ye Qi 《Advances in Climate Change Research》 SCIE 2011年第4期193-202,共10页
Several representative studies on China's carbon emission scenarios in 2050 are compared in scenario settings, methodologies, macro parameters, energy consumption and structure, carbon emissions, and carbon emission ... Several representative studies on China's carbon emission scenarios in 2050 are compared in scenario settings, methodologies, macro parameters, energy consumption and structure, carbon emissions, and carbon emission intensity. Under the baseline scenario of the present policy framework, the future energy structure will be optimized and carbon emission intensity will decrease continually. China's carbon emissions up to 2050 show a significant increase reaching between 11.9 Gt and 16.2 Gt CO2 in 2050. By strengthening a low carbon policy, the optimization of energy structure and the decline in carbon emission intensity will become more obvious within the comparative scenarios, which show a significant decrease in carbon emission until 2050 reaching only between 4.3 Gt and 9.5 Gt CO2 bv then. 展开更多
关键词 carbon emission climate change emission scenario
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Aerothermal characteristics of bleed slot in hypersonic flows 被引量:2
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作者 YUE LianJie LU HongBo +1 位作者 XU Xiao CHANG XinYu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第10期46-59,共14页
Two types of flow configurations with bleed their aerodynamic thermal loads and related in two-dimensional hypersonic flows flow structures at choked conditions. are numerically examined to investigate One is a turbul... Two types of flow configurations with bleed their aerodynamic thermal loads and related in two-dimensional hypersonic flows flow structures at choked conditions. are numerically examined to investigate One is a turbulent boundary layer flow without shock impingement where the effects of the slot angle are discussed, and the other is shock wave boundary layer in- teractions where the effects of slot angle and slot location relative to shock impingement point are surveyed. A key separation is induced by bleed barrier shock on the upstream slot wall, resulting in a localized maximum heat flux at the reattachment point. For slanted slots, the dominating flow patterns are not much affected by the change in slot angle, but vary dramatically with slot location relative to the shock impingement point. Different flow structures are found in the case of normal slot, such as a flow pattern similar to typical Laval nozzle flow, the largest separation bubble which is almost independent of the shock position. Its larger detached distance results in 20% lower stagnation heat flux on the downstream slot corner, but with much wider area suffering from severe thermal loads. In spite of the complexity of the flow patterns, it is clearly revealed that the heat flux generally rises with the slot location moving downstream, and an increase in slot angle from 20° to 40° reduces 50% the heat flux peak at the reattachment point in the slot passage. The results further indicate that the bleed does not raise the heat flux around the slot for all cases except for the area around the downstream slot corner. Among all bleed configurations, the slot angle of 40° located slightly upstream of the incident shock is regarded as the best. 展开更多
关键词 boundary layer control boundary layer heat flow shock wave interactions separated flows
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