Thermal Expansion Behavior of Amorphous Fe-Si-B Alloys

 To study the thermal expansion of amorphous Fe Si B alloys, the amorphous Fe78Si9B13 and Fe735Nb3 Cu1Si135B9 and their crystallized alloys were detected using thermal dilatometer. The results indicate that at the same temperature, the relative length change (ΔL/L0) values of the two Fe based amorphous alloys decrease with increasing heating rate, but those of their crystallized alloys show an opposite trend. It is concluded that the effect of heating rate on the ΔL/L0 of amorphous and crystallized alloys is related to free volume and defects, respectively.     

加利福尼亚州的商业景观与购物环境

自20世纪中期第个郊区购物中心兴起之后．北美的商业景观设计也开始逐渐走向成熟。当时的创新理念是打造一个可控制的、无机动车和犯罪行为、室外环境良好的安全购物形式。规模较小的零售点通常会设置在大型购物中心的两端，以吸引购物者。     

高分辨LEO 1530 VP扫描电镜在纳米技术研究中的应用

随着纳米技术和纳米产业化的进展、研究和制备纳米材料、纳米结构组装和纳米加工的尺寸越来越小，纳米级图像分析，尺寸测量和微区成分检测已成为纳米技术工作的主要内容之一。本文通过我们实际工作，概述了高分辨率LEO1530VP扫描电镜和EDAX能谱在纳米技术研制工作中的重要作用。实验表明LEO1530VP扫描电镜的超高分辨性能和可变压力模式下能直接观测绝缘样品的特点，在纳米技术各研究领域中，具有广泛的应用前景。     

Physical Simulation and Experimental Examination of εCu Particles Dissolution Evolution During Welding of Copper Precipitation Strengthening Steel

The kinetics of εCu particles dissolution in the matrix during welding of a copperprecipitation strengthening steel was determined by a combination of GleebleTM physical simulation, TEM examination and hardness measurement. The εCu particles underwent a coarsening and part dissolution and then complete dissolution reaction as the peak temperature increased from 750 to 1 000 ℃, which resulted in the decrease in the number density of εCu particles and hardness in the heataffected zone (HAZ). The results can be used to understand the evolution of this transformation and a softening behavior of the HAZ during welding of this type of steel.     

Influence of Billet Size on Flow, Solidification and Solute Transport in Continuous Casting

ListofSymbol　　B———Buoyancy ,m·s- 2 ;　　c———Concentrationofsoluteelement ;　　Cμ———Turbulentconstant;　　D———Diffusivityofsoluteelement ,m2 ·s- 1 ;　　fl,fs———Liquidandsolidfraction ;　　fμ———Turbulentcoefficient ;　　h———Enthalpy ,J·kg- 1 ;　　k———Turbulentkineticenergy ,m2 ·s- 2 ;　　kp———Equilibriumpartitioncoefficient;　　Kp———Permeabilityofmushyzone ,m2 ;　　K0 ———Permeabilitycoefficient;　　p———Pressure ,Pa ;　　Pr———Prandtlnumber ;…     

Investigation of the Hot Plasticity of Duplex Stainless Steel

Hot plasticity of a nitrogen alloyed 25Cr 7Ni-4Mo duplex stainless steel was investigated. The results indicate that the main factors affecting the hot plasticity of duplex stainless steel are listed as follows： coalescent force of phase interface, microstructure, and the phase ratio and difference between the mechanical properties of ferrite and austenite. The heat treatment and sulphur contents have a notable effect on the hot plasticity. The reasonable heat treatments and the increased interfacial coalescent force will effectively enhance the hot plasticity of duplex stainless steel.     

JEM-2010 FEF-TEM对纳米材料显微结构的研究

纳米材料的性质和纳米微颗粒的形状、大小和分布有密切的关系。因此深入研究纳米材料的显微结构,了解其结构特征,以便为制备纳米材料时有效地控制纳米颗粒的大小、形状和尺寸分布提供必要信息。我们用JEM-2010FEF场发射能量过滤透射电子显微镜对Pd-Al2O3催化剂和金纳米颗粒、单壁C纳米管及SiO2纳米颗粒标样进行了分析研究。在工作中,我们采用能量损失谱和能量过滤方法取得了高分辨的图像及元素面分布。图1为B、N、C能量损失谱曲线,根据这个谱线确定了B、N、C的元素面分布(图2)。图3是金纳米颗粒的高分辨像,大颗粒为五次孪晶结构,小…     

Traffic Measurement for Traffic Engineering in IP/MPLS Based Telecom Core Networks

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一种微机型的智能低周减载装置

根据统计表明，大约每10年就会有一次大系统的瓦解事故，在这些事故中，有一部分是因为减载装置的非正常运行所致。为了使系统更可靠的运行，应用工程师们将不断的调整减载继电器的定值以满足系统的需求。然而，他们既没有智能型继电器也没有方便的手段来改变继电器的定值。这就导致了使用多年使用者一个频率定值而不去更改它。本文介绍一种微机型的智能欠频/过频继电器的设计思想，它能在动态的情况下改变频率定值和时间延时。这将使系统在事故状态下，有更好的机会保持系统的稳定运行。