共搜索到19578条信息,每页显示10条信息,共1958页。用时:0小时0分0秒468毫秒
......
at 470 °C for 4 h. Due to the strengthening effect of GP zones, for alloys treated by under-aging process, the increase of aging time and aging temperature improved the ultimate tensile strength (UTS... the design requirements of automobile components. Key words: Al-Zn-Mg-Cu alloy; squeeze casting; under-aging treatment; GP zone; precipitation strengthening 1 Introduction In recent years......
钢坯加热过程数学模型的试验修正研究权芳民1,2,孙文强1,蔡九菊2,田永华3(1.辽宁省沈阳市东北大学国家环境保护生态工业重点实验室2.甘肃省嘉峪关市酒钢集团吉瑞再生资源开发有限责任公司3.东北大学 国家环境保护生态工业重点试验室,辽宁沈阳 110819)摘 要:复杂的炉内热交换过程容易导致根据总括热吸收率法建立的加热过程数学模型的计算精度降低.为解决该问题,在建立钢坯加热过程数学模型的基础上,提出了总括热吸收率的试验修正方法.采用拖偶试验测得了钢坯在炉内不同位置的温度,计算出不同位置处的总括热吸收率,并将其与......
......
Spatiotemporal model of open-pit based on 3-D deposit modelXIA Chun-lin1, ZHOU Hui1, LI Qing-yuan2, MA Zhen-li3(1. School of Geomatics, Liaoning Technical University, Fuxin 123000, China; 2. State... method was put forward to make up the three-dimensional deposit model, and the spatiotemporal models of open-pit with temporal dynamics were also studied combined with the corrected models......
(1) 图1 轨道空间振动分析模型 Fig.1 Spatial vibration analysis model of track 设t时刻,在计算长度为L的轨道上运行着m辆货车,按照弹性系统动力学总势能不变原理[13]及形成系统矩阵的"对号入座"法则[14],得出FTT系统在t时刻的矩阵方程为 (2) 式中:K,C,M和P分别为FTT系统空间振动的刚度矩阵,阻尼矩阵和质量矩阵及荷载列阵;,和...横向振动容许极限车速分别提高了18.7%,24.3%,26.6%和28.0%.当K2>120 MN/m时提升幅度较小. 表3 扣件强化条件下FTT系统横向振动稳定性计算结果 Table 3 Calculation results of lateral vibration stability of FTT system under fastener strengthening 为分析扣件强化对货物......
Influence of Sc on high temperature strengthening behavior of Ti-6Al-4V alloy LIU Hui-qun(刘会群)1, YI Dan-qing(易丹青)1, WANG Wei-qi(王韦琪)2, WANG Li-ping(王立平)2, LIAN Cai-hao(廉才浩)1 1. School... of alloys increases with increasing Sc content after deformation at 850 ℃, however, there is no obvious strengthening of Sc when the alloys are deformed at 1 000 ℃. Sc exists as Sc2O3 forms by internal......
A dynamic model for railway freight overbookingFENG Fen-ling(冯芬玲), ZHANG Jia-qi(张佳琪), GUO Xiao-feng(郭晓峰) (School of Traffic and Transportation Engineering, Central South University, Changsha 410075, China)Abstract:In order to apply overbooking idea in Chinese railway freight industry to improve revenue, a Markov decision process (dynamic programming) model for railway freight reservation......
discussed using the model mentioned above. 2 Determination of strength parameters Based on the localized progressive damage model[12], the process of cohesion weakening and friction strengthening can...-perfectly plastic model (a) and elasto-brittle-plastic model (b) Fig.5(a) shows the simulated failed zone by using the cohesion weakening and friction strengthening evolution law with the parameters......
Trans. Nonferrous Met. Soc. China 31(2021) 1587-1598 Refinement and strengthening mechanism of Mg-Zn-Cu-Zr-Ca alloy solidified under extremely high pressure Xiao-ping LIN1,2,3, Yang KUO1, Lin WANG1... of the intergranular second phase also increases to 22%. Owing to the combined strengthening of grain refinement, solid solution, and dispersion, the compression strength of the Mg–Zn–Cu–Zr–Ca alloy solidified under......