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排序方式: 共有498条查询结果,搜索用时 15 毫秒
1.
北京燕山石化两巨型塔器在国内首次使用整体液压连续平移技术安装成功。该项技术可缩短工期,降低费用,提高安装的平稳性。 相似文献
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The proposed mode of consideration of the steel-concrete interaction (Part I) is applied to real-life engineering structures. Two structures recently investigated numerically at Vienna University of Technology are considered: (1) the reinforced concrete (RC) cooling tower III Ptolema?s SES (Greece) and (2) a part of the shotcrete tunnel lining installed at the Lainzer tunnel (Austria). In both examples, the uniaxial fracture criterion used in Part I is replaced by the maximum stress (Rankine) criterion. Together with the Drucker-Prager criterion, which is used for the simulation of compressive failure of concrete/shotcrete, it defines the space of admissible stress states in the framework of multisurface plasticity. For the simulation of early-age fracture of shotcrete, consideration of the steel-concrete interaction presented in Part I of this paper is extended towards young shotcrete. Similar to the benchmark problem investigated in Part I of this paper, several analyses with different degrees of consideration of the steel-concrete interaction are performed. The obtained results give insight into the influence of the steel-concrete interaction on the load-carrying behavior of the investigated structures. 相似文献
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提出一种索塔式新型风力发电塔架,确定了纤绳锚固点高度、初张力及纤绳与地面夹角等参数;以实际工程为背景,根据ANSYS一阶优化方法,编制了索塔式风电塔架和单管塔的APDL优化程序,对两种塔架分别进行截面优化和结构优化.对比结果表明,索塔式塔架具有比单管塔基础工程量小﹑运输方便、施工难度小等优点.就索塔式塔架而言,增大纤绳初张力可有效减小塔底弯矩,在一定范围内增大纤绳初张力可有效提高塔架稳定性. 相似文献
5.
表面扩渗Al,Zn处理对ZM5镁合金性能的影响 总被引:8,自引:0,他引:8
通过铝锌(Al,Zn)混合粉对ZM5镁合金进行了表面固态扩渗铝锌(Al,Zn)处理,在衬底形成了Mg-Al-Zn合金层.研究结果表明:Mg-Al-Zn合金层主要由Mg-Al-Zn固溶体和Mg-Al-Zn金属间化合物(Al6Mg10Zn,Al5MgllZn4)组成,该合金层不仅使ZM5镁合金表面合金层显微硬度显著提高,而且在盐水浸泡腐蚀过程中,在衬底与腐蚀介质之间起到了良好的屏障作用,从而赋予试样良好的腐蚀性能. 相似文献
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CHEN Chang-jun WANG Mao-cai WANG Dong-sheng State Key Labatoryfor Corrosion Protection Institute of Metal Research Chinese Academy of Sciences Shenyang P.R.China 《材料热处理学报》2004,25(5)
MG and its alloys are widely used in aerospace andautomotive in industry.Its poor corrosion resistancerestricts application of Mg alloy.Laser cladding andlaser surface melting are advantageous processes forimprovement of the corrosion resistance of themagnesium alloy[1-2].In the present study,lasercladding of an Al-11.7Wt%Si alloy with two differentthickness on ZM5die cast alloy was performed withCC>2laser with different powder thickness.1.Experimental ProcedureDie cast plates of ZM5Mg a… 相似文献
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针对典型的酒精蒸馏五塔工艺流程及蒸馏过程各物流的组成、压力、温度等工艺条件,分析模拟计算的热力学方法和热力学数据,结果表明,本文所选用的热力学方法SRKM、IDEAL、NRTL及物流组分交互作用参数均适用于酒精蒸馏五塔工艺流程,各工艺物流的模拟数据与设计数据最大误差均小于4.5%,模拟值与设计值比较吻合,不超出设计误差(10%)的限度. 相似文献
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In Malenfant et al. [19], we have described a reflective model for a prototype-based language based on thelookup o apply reflective introspection protocol. In this paper, we augment our previous protocol by converting it to handle continuations reified as first-class objects. First-class continuations provide much more control over the current computation; during the introspection phase fired by message sending, they make it possible not only to change the behavior of the program for that message but also for the entire future computation. In this paper, we provide this introspection protocol with a formal semantics. This result is obtained by exhibiting a mapping from program configurations to priority rewrite systems (PRS) as well as a mapping from message expressions to ground first-order terms used to query the PRS. Other advantages of this approach are: to ensure the termination of the introspection using the smallest set of formally justified conditions and to provide a clear declarative account of this reflective protocol. The PRS also appears as a meta-level to the base language, independent of the implementation, but from which we derive fundamental clues to obtain an efficient language processor. By our new model, we finally highlight the link between reflection in object-oriented languages and the one originally proposed by 3-Lisp [24], although object-orientation provides reusability to reflection, making it easier to use. 相似文献