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61.
62.
AOD冶炼中,终点碳和终点温度的命中率是提高生产率和产品质量的关键。由初始温度,初始成分及补加合金量等原始数据,通过本模型可预报要达到目标终点碳所需要的脱碳时间以及相应的终点温度。本模型计算得到的终点碳与实际终点碳,在同等条件下,两者极为接近,可作为一般AOD冶炼中预报终点碳与脱碳时间关系之用。通过分级调整O2、Ar、N2气比例得到最佳脱碳效果,终点碳命中率可提高到98%以上,最高温度可以控制不超过1750℃,延长炉衬寿命。 相似文献
63.
Holahan Charles J.; Moos Rudolf H.; Holahan Carole K.; Brennan Penny L.; Schutte Kathleen K. 《Canadian Metallurgical Quarterly》2005,73(4):658
This study examined (a) the role of avoidance coping in prospectively generating both chronic and acute life stressors and (b) the stress-generating role of avoidance coping as a prospective link to future depressive symptoms. Participants were 1,211 late-middle-aged individuals (500 women and 711 men) assessed 3 times over a 10-year period. As predicted, baseline avoidance coping was prospectively associated with both more chronic and more acute life stressors 4 years later. Furthermore, as predicted, these intervening life stressors linked baseline avoidance coping and depressive symptoms 10 years later, controlling for the influence of initial depressive symptoms. These findings broaden knowledge about the stress-generation process and elucidate a key mechanism through which avoidance coping is linked to depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
T. AGODA E. MACHA A. NIESONY 《Fatigue & Fracture of Engineering Materials & Structures》2005,28(4):409-420
The paper contains a new algorithm for estimation of fatigue life in HCF regime under multiaxial random loading using spectral methods. Loading of Gaussian distribution and narrow‐ and broad‐band frequency spectra were assumed. Various characteristic states of multiaxial loading were considered. The equivalent stress history was determined with use of the failure criteria of multiaxial fatigue based on the critical plane. For determination of the critical plane position, the method of variance was applied. During simulation, the authors compared the results obtained by a spectral method in the frequency domain with those from the rain‐flow algorithm in the time domain. The paper also contains the results of fatigue tests for 18G2A structural steel subjected to bending and combined bending with torsion. The tests were performed in order to verify the proposed algorithms for determination of fatigue life. It has been shown that under multiaxial random loading results of fatigue life calculated according to the considered algorithms in frequency and time domains are well correlated with the results of experiments. 相似文献
65.
黄秀娟 《陕西科技大学学报》2003,21(4):134-136
通过对适时制(JIT)主要特点的论述,探讨了现代新的制造环境对传统成本管理会计所带来的冲击,提出了初步的应对措施。 相似文献
66.
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E. Georgiadou 《Cybernetics and Systems Analysis》2003,39(1):125-142
In this paper, a historical overview of significant attempts to get over the software crisis is presented. In particular, we trace the development of lifecycle models and information systems development methodologies during the last four decades. Finally, we explore the role of measurements and outline current and future works leading to process and product improvement. 相似文献
68.
This two-part paper presents modelling and scheduling approaches of flexible manufacturing systems using Petri nets (PNs) and artificial intelligence (AI)-based heuristic search methods. In Part I, PN-based modelling approaches and basic AI-based heuristic search algorithms were presented. In Part II, a new heuristic function that exploits PN information is proposed. Heuristic information obtained from the PN model is used to dramatically reduce the search space. This heuristic is derived from a new concept, the resource cost reachability matrix, which builds on the properties of B-nets proposed in Part I. Two hybrid search algorithms, (1) an approach to model dispatching rules using analysis information provided by the PN simulation and (2) an approach of the modified stage-search algorithm, are proposed to reduce the complexity of large systems. A random problem generator is developed to test the proposed methods. The experimental results show promising results. 相似文献
69.
70.
混凝土结构剩余使用寿命的评估 总被引:1,自引:0,他引:1
主要就混凝土结构剩余使用寿命的评估的最新发展情况及实用方法做详细论述,并提出了自己的见解. 相似文献