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合适的合作伙伴是保证企业动态联盟有效运行的必要条件,合理地选择合适的合作伙伴组成企业动态联盟,是实施网络化制造的关键技术之一。论文运用模糊数学中多级模糊综合评判的方法,建立合理的模糊综合评判模型,为企业动态联盟中合作伙伴的综合评价提供科学的方法,可以有效的提高企业动态联盟合作伙伴选择的水平。 相似文献
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基于ANSYS软件建立了X80管线钢(Nb-Mo系)三丝埋弧焊的三维热力耦合数值模型。研究三丝埋弧焊接头温度与焊后纵向残余应力的分布情况,以及焊接工艺参数(焊接速度、焊丝间距)对三丝埋弧焊接头应力场分布的影响。计算结果表明:焊接是一个温度急剧变化的过程,温度的分布不均匀是导致残余应力出现的主要原因。焊后最高纵向残余应力存在于焊缝区,在边界处纵向残余应力趋于0。增大焊接速度或焊丝间距均会引起焊后纵向残余应力的升高。使用盲孔法测量焊缝附近一些点的纵向残余应力,测量结果与模拟结果基本吻合。 相似文献
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爆炸焊接边界效应的产生,发展和消除 总被引:13,自引:2,他引:11
本文着重分析研究了在爆炸焊接过程中,三个不同边界区域边界效应的产生和发展,同时对如何消除边界效应的影响也进行了研究探讨。针对目前爆炸焊接普遍存在的这三类边界效应问题,通过优化爆炸焊工艺参数,采用爆炸切焊法,即融爆炸切割技术与焊接技术于一体,消除了边界效应的影响,使焊接复合率达到100%。 相似文献
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莫佳佳 《有色金属再生与利用》2005,(12):44-44
随着全球经济一体化的到来,扩大公司的横向或纵向边界,使规模经济和协同效应有效发挥作用。做大做强成为很多空业发展过程中的必经之路。兼并收购成为很多企业快速扩张的首选。这种情况下.总部委派一些职业经理人到被兼并收购企业主持工作的现象日益频繁。究竟该选派什么样的人做接管经理人.是一件颇费心思的事情。 相似文献
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虚拟共享--边界模糊化趋势下的企业创新模式 总被引:1,自引:0,他引:1
虚拟企业与共享服务是两种适应科技进步和经济发展的新型企业组织形式.从组织模式上看,虚拟企业和共享服务分别为企业外部市场半内部化和内部组织半市场化的两种形态.文章提出"虚拟共享"的思想,并指出随着企业边界的模糊化趋势的加强,虚拟企业和共享服务两种形态将走向这种全新的组织创新模式. 相似文献
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涂层合金对基体钢材浸润性的研究 总被引:1,自引:0,他引:1
本文用真空熔结方法,以及电镜、电子探针和X光衍射等测试手段,研究Ni-Cr-B-Si及Co-Cr-W涂层合金各种基体钢材的浸润性。通过测定熔融涂层合金对几种基体钢材的冷凝接触角,总结出冷凝接触角与Fe元素的界面浓度差之间存在有一定的五次方程关系;根据试验结果,讨论了浸润过程的机理,指出浸润性是界面互扩散性的宏观反映,是涂层与基体之间形成牢固冶金结合的前提;此外,还初步探讨了温度、介质及化学组成等因素对浸润质的影响。 相似文献
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For 7475 Al alloy,there were micrographs showing filaments or whiskers formation during the separation stage of superplastic elongation.This indicates the presence of liquid phase which accommodates grain boundary sliding to reach superplasticity.On the other hand,there is no such phenomenon reported regarding Mg alloy in literatures.Scanning electron microscopic(SEM)fractography exceptionally exhibits a mark of grain boundary sliding and its accommodating mechanism of inter-granular liquid phase.Under the testing conditions of 350℃ and 1×10- 4s -1,the initially fine-grained structure(3.7μm)yields 642%superplastic elongation and exhibits fluffy appearance on the fractured surface.For other specimens showing less superplasticity,their fractured surfaces exhibit partial fluffy appearance. 相似文献
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Two problems of rotation of a liquid in crossed electric and magnetic fields are formulated and solved as applied to the study
of the principles of the interaction between external electric and magnetic fields and weakly conducting water type liquids
(running water, sea water) and their solutions ((10-2-102) 1 m-1). In the first problem, the liquid is contained in the gap
of a vertical cylindrical capacitor, while the second problem deals with the liquid in a rectangular cuvette, two lateral
vertical walls of which are used as armatures of a plane-parallel capacitor. In either case, a constant vertical magnetic
field is applied to the liquid, while a constant voltage is maintained between the armatures of the capacitor. Three sets
of boundary conditions are considered in the first case: the capacitor is of infinite length (throughout the height); the
capacitor is confined by a solid bottom from below and has a free boundary with the atmosphere at the top; the capacitor has
closed ends and the liquid occupies the entire capacitor gap. The results can be used in various practical applications, for
example, for pumping of weakly conducting liquids. 相似文献
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运用有限差分法,对超轻Mg-Li合金(LA141)板坯直冷连铸过程温度场进行数值模拟,根据实际过程的物理现象以及文献资料确定包括一冷区、二冷区在内的边界条件,并且考虑底模与铸坯之间随着铸坯的变形而引起的换热系数的变化.通过计算铸坯内温度场的分布,固-液界面的形状和位置,分析各种铸造参数,包括浇注温度、冷却水量、铸造速度等对连铸过程的影响.另外也比较了在同等铸造条件下LA141铸坯和AZ31铸坯铸造过程中凝固前沿的形状. 相似文献
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Glass has useful optical properties but shows unfavorable mechanical performance such as poor impact resistance. As a way
to improve such inferior mechanical performance, glass undergoes tempering processes which introduce through-thickness residual
stress. Here, the residual stress is numerically analyzed for a soda-lime silicate glass plate under the one-dimensional through-thickness
symmetric boundary conditions. As for the constitutive law, the structural relaxation model was used to account for the non-equilibrium
thermodynamic state of micro-structures in calculating volume change during cooling and also the visco-elastic nature of mechanical
properties. Results obtained using improved numerical methods were compared with experiments as well as results available
in previous literatures. 相似文献
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以TA15钛合金粉末为原料,利用激光沉积制造方法制备TA15钛合金拉伸试样厚壁件。通过光学显微镜(OM)、扫描电子显微镜(SEM)和X射线衍射(XRD)等方法研究退火温度及沉积方向对TA15钛合金组织、拉伸性能的影响,以及α相变形机制。结果表明:随着退火温度升高,显微组织中α相长宽比呈上升趋势;激光沉积成形TA15钛合金厚壁件在沉积和垂直沉积方向上的力学性能存在差异,沉积方向上的抗拉强度明显均低于垂直沉积方向上的抗拉强度;柱状晶晶界对α片层的受力变形有一定的阻碍作用;α片层通过挤压变形和滑移变形两种机制发生变形或断裂;两种方向上拉伸断裂方式不同,沿沉积方向上断裂为韧性断裂,沿垂直沉积方向上断裂为半解理半韧性断裂。 相似文献
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Metal magnetic memory (MMM) technique can evaluate early damages of ferromagnets and search possible defect locations, while just classifies the defect types roughly. To promote study in this area, the magnetic gradient tensor (MGT) of the self-magnetic leakage field (SMLF) on the fracture zone of crack and stress concentration was measured using a tri-axis magnetometer. From measured results, both the plane and the vertical characteristics of SMLF distributions were discussed. To remove the influence of the measuring direction on experimental results, a new parameter of the analytical signal of magnetic gradient tensor (AMGT) was introduced to determine the location and boundary of the defect. Then, the vertical features were acquired by measuring the plane distributions of AMGT under different lift offs. Through analyzing the vertical features, it was concluded that change rule of the maximum AMGT can be used to predict the defect type. At last, the explanation of the relationship between the vertical feature and the defect type was discussed, which can give some useful inspirations to researchers on magnetic leakage field testing. 相似文献