FMA结构化分解下基于Bayes-GO的数控机床可靠性评估

为提高数控机床可靠性,提出一种FMA功能结构分解下基于Bayes-GO的可靠性评估模型。将产品按照功能－运动－动作进行功能结构化分解,得到实现产品功能的所有元动作单元;利用Bayes法综合元动作单元样本信息和验前信息,获取元动作单元可靠性模型;将FMA结构化分解树映射成GO图,并根据GO法操作符和信号流运算规则进行可靠性定量分析,为机床可靠性设计提供重要依据。以国产某磨齿机砂轮架为例进行可靠性评估,验证所提方法的合理性与可行性。     

基于改进BP神经网络的再制造工艺方案选择研究

针对实际生产过程中废旧零部件失效形式的多样性及再制造工艺路线的复杂性,为了能快速精确的确定再制造工艺方案,对废旧零部件再制造工艺特征属性进行提取,建立了再制造工艺方案决策的BP神经网络模型,提出一种将L-M算法引入到BP神经网络的训练过程中的方法,并对该模型进行求解。将改进后的BP神经网络模型应用于某废旧机床主轴再制造工艺决策中,借助Matlab软件实现了再制造工艺方案的智能决策,并且与未改进的BP神经网络方法进行对比,验证了所提出方法的优越性。     

废旧零部件可再制造质量评价与分类研究

围绕再制造机床质量不稳定的问题,建立了废旧机床再制造全过程的质量模型,反映了质量特性的传递与映射,并识别出导致质量不稳定的关键过程。并针对废旧零部件回收质量不确定的问题,提出了一种基于多指标区间数的可拓综合评价与分类方法:将回收质量分为三个等级,从经济可行性、质量可行性和绿色可行性三方面建立可再制造质量评价指标体系;采用区间数物元描述废旧零部件;改进序关系分析法,将区间数与群组判断结合,确定客观合理的指标权重;构建综合关联函数,确定废旧零部件的质量等级与可再制造度。最后,通过某废旧机床导轨的再制造实例,验证了该方法的可行性和有效性。该方法能够科学合理地对废旧零部件进行质量评价与分类,并为后续的再制造工艺决策提供理论依据。     

基于黑猩猩算法的组合机床零部件选配研究

针对组合机床零部件装配精度低，剩余零部件较多以及装配成本高等问题，提出一种以组合机床再制造装配为对象，基于改进黑猩猩算法的综合选配方法。构建了以封闭环偏差为约束条件，考虑质量、装配成本、再制造资源利用率的选配模型；根据所建选配模型特点，引入改进的黑猩猩优化算法进行最优选配方案的求解；最后，将该方法应用于某企业的CAK6150主轴箱的主轴装配过程。选配结果表明，该方法可以在满足装配精度要求的同时大幅度的降低了企业的加工成本并有效提高了再制造资源利用率。     

面向顾客满意度的废旧机床再制造设计参数规划方法

基于目前大多数再制造机床仅注重机床本身性能的恢复,从未无法达到预期市场竞争力的问题,结合顾客需求和废旧机床再制造设计,构建了再制造设计参数决策框架,并充分考虑顾客需求与再制造设计参数之间的不确定性,应用模糊非线性回归法分析顾客需求与再制造设计参数之间以及不同再制造设计参数之间的模糊相关关系。同时,针对基于传统模糊非线性回归法的规划方程不具备处理模糊关系的能力,导致规划结果与实际情况偏离的情况,将模糊度融入规划方程,构建基于改进模糊非线性回归法的废旧机床再制造设计参数规划方程。以某机床再制造企业的废旧CAK6163的再制造设计过程为例,应用改进的再制造设计规划方程对其再制造设计参数进行规划。结果表明,由改进的规划方程得到的再制造设计参数,相对于传统规划方程,能够获得更高的顾客满意度,进而有效提升了再制造机床的市场竞争力。     

机床再制造技术框架及产业化策略研究

机床再制造实际上是一种基于废旧机床资源循环利用的机床制造新模式，对于循环再利用我国量大面广的老、旧机床设备资源以及更新提升我国制造业机床整体质量和制造加工能力具有重要意义，并将导致若干新兴产业的形成。在分析国内外机床维改再利用现状及不足的基础上，总结提出机床综合再制造流程，并建立废旧机床再制造技术框架；结合机床再制造新兴产业的发展前景，分析并提出其产业需求、产业主体、产业模式等产业策略。     

基于状态的重载发动机再制造成本组合预测

针对企业重载发动机再制造决策中成本预测问题,基于重载发动机再制造过程,分析再制造成本的影响因素,采用灰色理论建立基于状态的再制造成本预测模型,在灰色系统预测模型基础上,运用统计粗糙理论建立再制造成本组合预测模型。实例分析证明,组合预测模型较灰色预测模型在精度上有明显的提高,为重载发动机再制造企业的再制造技术应用于成本控制提供理论基础。     

机床数字化再制造中滑动导轨耐磨性模糊可靠性分析

将模糊理论运用于再制造机床滑动导轨耐磨可靠性预测中,介绍了模糊可靠性分析过程,包括可靠度模型的建立、隶属函数的选择、磨损量分布参数的确定.通过实例阐述了可靠性预测过程和结果,以及与常规可靠性分析方法的不同.计算结果表明:在可靠性数据缺乏的情况下,运用此方法使计算结果更加符合实际,具有较好的工程应用价值.     

基于状态的重载发动机再制造成本组合预测

针对企业重载发动机再制造决策中成本预测问题,基于重载发动机再制造过程,分析再制造成本的影响因素,采用灰色理论建立基于状态的再制造成本预测模型,在灰色系统预测模型基础上,运用统计粗糙理论建立再制造成本组合预测模型.实例分析证明,组合预测模型较灰色预测模型在精度上有明显的提高,为重载发动机再制造企业的再制造技术应用于成本控制提供理论基础.     

基于可拓学理论的数控机床可靠性评价研究

为了全面评价数控机床的可靠性,建立了研究数控机床可靠性的评价指标体系,应用可拓学中的物元理论,建立机床可靠性评价物元模型。引入关联函数计算关联度,并结合可拓层次分析的方法确定影响数控机床可靠性各指标的权重,对数控机床可靠性进行综合评价。结合实例进行了数控机床可靠性评价,验证了该方法的可行性。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.