锰元素对Zr_(55)Cu_(30)Ni_5Al_(10)块体金属玻璃热稳定性和力学性能的影响

采用铜模吸铸法制备出直径3mm的块体(Zr0.55Al0.10Ni0.05Cu0.30)100-xMnx(x=0,2,4,6)金属玻璃试样,研究了锰的添加对Zr55Cu30Ni5Al10块体金属玻璃的非晶形成能力、热稳定性、力学性能和组织的影响。结果表明:添加适量的锰能降低Zr55Cu30Ni5Al10合金的热稳定性和非晶形成能力;当x=4时,合金过冷液相区ΔTx为61K,约化玻璃转变温度Trg为0.58,参数γ为0.40;锰的适量添加有利于提高锆基块体金属玻璃的抗压强度,当x=4时,合金的抗压强度提高到1 817MPa,而塑性无明显改善。     

铝基非晶合金非晶形成能力的评价方法

铝基非晶合金的非晶形成能力差,而评价非晶的形成能力对深入研究该合金具有重要意义。本文对采用热物性参数、热力学参数、热力学—动力学参数和临界冷却速率等评价铝基非晶合金非晶形成能力的4种方法进行了分析。     

大块非晶合金的形成准则及应用进展

综述了形成大块非晶合金的经验准则和评估非晶形成能力的经验判据，并简要评述了大块非晶合金的力学性能、电学性能、磁学性能及其应用。大块非晶合金的形成能力是目前和今后研究非晶合金的热点，通过研究非晶的形成，有望开发出更多的新型大块非晶合金体系。     

非晶合金变压器与硅钢片铁心变压器运行参数比较

分析比较了非晶合金变压器与硅钢片铁心变压器运行时的各种参数,包括对不同负载下变压器的空载损耗、负载损耗、温升、噪声、效率以及过载能力和过电压能力的比较,从而得出非晶合金变压器参数优于或不亚于硅钢片铁心变压器参数,为研究非晶合金变压器提供参考。     

锆基非晶合金冰冻切削加工特征及其无晶化加工工艺研究

锆基非晶合金切削过程中的高切削热会导致工件表面晶化,使非晶合金优异性能丧失.提出将冰冻盘夹具用于非晶合金铣削加工,提升切削散热能力,实现非晶合金冰冻切削加工.研究了非晶合金冰冻铣削过程中的燃烧发光特征及其影响因素;分析了冰冻切削工艺(切削速度、进给量和刀具涂层材料)对非晶切削力的影响规律;优化了适用于非晶合金无晶化加工的冰冻切削工艺参数,并揭示了涂层刀具的磨损失效形式.结果 表明,锆基非晶合金切屑燃烧发光是导致非晶冰冻切削加工表面晶化和表面粗糙度增大的根本原因;引起切屑燃烧发光的主要因素包括高切削速度、小进给量以及因切削长度增加导致的刀具磨损积累,改变刀具涂层不会导致切屑燃烧发光;切削力主要受切削速度影响,对进给量不敏感;TiSiN、TiAlN、CrSiN和AlCrN四种涂层刀具的失效形式均为后刀面黏结磨损、前刀面涂层剥落以及刀尖崩缺;CrSiN涂层具有最佳的抗黏结磨损能力,可获得最小切削力和最低表面粗糙度.通过优化冰冻切削工艺,可以实现锆基非晶合金的高速铣削加工,同时避免切屑燃烧发光,获得高质量的无晶化加工表面.     

元素添加对铜基块体金属玻璃形成能力的影响

利用铜模吸铸方法，在Cu—Zr合金中添加适当组元，研究组元添加对铜基块体金属玻璃形成能力的影响。样品的X射线衍射分析和差热扫描热分析仪测试结果表明，在铜基合金Cu-Zr中添加适量的Nb，Ti，Al元素，可以明显地提高其非晶形成能力。同样，在Cu—Zr-Ti三元合金中添加适量的Hf，其玻璃形成能力得以进一步提高。与常用的提高冷却速率方法相比，元素添加不需要特殊设备，制备成本明显降低。     

低频脉冲磁场致非晶合金Fe78Si9B13纳米晶化及机制

用TEM和穆斯堡尔技术研究了非晶Fe78Si9B13合金磁致晶化结构及晶化与脉冲磁场参数的关系，并粗略研究了非晶合金纳米晶化机制。结果表明：脉冲磁场作用产生的磁致伸缩能降低了非晶合金的形核势垒，使非晶合金得以纳米晶化。因为量子尺寸效应，试样电阻显现复杂性。     

陶瓷磨削表面变质层的产生机理

研究了陶瓷磨削表面变质层的产生机理。经扫描电镜观察发现了磨削表面非晶层的粘性行为和匀质化过程。采用物相分析和X射线衍射谱线分析证实了变质层中微晶的存在,通过能谱分析确定了非晶层的化学成分,在对玻璃相结构分析的基础上研究证实了Al 2O 3陶瓷表面变质层是由碎（微）晶和玻璃态化合物组成的塑性层,并解释了表面晶粒的碎化机理。     

机械合金化法制备Mg55Ni35Si10非晶合金粉体

采用机械合金化方法制备出了Mg55Ni35Si10非晶合金粉体，采用XRD、HRTEM、FESEM以及DSC试验，对所得粉末的微结构、相组成、颗粒形貌及热稳定性进行了表征。结果表明：对于配比为Mg55Ni35Si10的粉末，经约68h的球磨可以获得完全非晶态的合金粉末，其晶化温度约为420℃，证明该材料具有相对较高的热稳定性。     

基于微细电阻焊接的Fe_(78)Si_9B_(13)非晶薄带块体化成型研究

本文采用逆变直流电阻焊机实现了厚度为25μm的Fe_(78)Si_9B_(13)非晶薄带的快速电阻焊接。X射线衍射测试表明,焊接接头仍保持非晶结构。探讨了焊接工艺参数对非晶接头力学性能的影响;从理论上探讨了电阻焊成型非晶合金块体的可行性及缺陷造成的原因,指出了焊接参数的选择是成型的关键因素。本文的研究对于解决非晶合金的焊接及大块化难题有很好的实践意义。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...