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23.
介绍与冲天炉熔炼有关的几个问题的处理方法,包括:(1)如何防止熔化带以上耐火砖容易掉落;(2)如何防止过桥、出铁口易被侵蚀;(3)固定式前炉容量大小的选择;(4)如何保持浇包尺寸;(5)加料口材料选择:(6)要否使用热风炉胆;(7)孕育处理方法与孕育量;(8)灰铸铁的含硫量;(9)风口比。 相似文献
24.
讨论了渐变刚度钢板弹簧的载荷、变形量、刚度和应力的计算,建立了少片渐变刚度钢板弹簧的优化数学模型,利用MATLAB优化工具箱进行优化,并给出了计算实例。 相似文献
25.
In this paper, the author dipped surface vapor oxidized H13 steel specimens into 700℃ molten aluminum liquid for a certain period of time. Analyze the intermetallic phases formed on the H13 samples surface with optical microscope and X-ray diffraction method. The observation of immersion test sample's cross-section shows that Fe3O4 film will protect die substrate from molten aluminum erosion. The identification of the intermetallic phases reveals that they consist of 2parts, which is named as the composite layer and the compact layer. Further investigations are made in order to know the phase constituents of the 2 layers, they are Al8Fe2Si (outer composite layer), (AlCuMg) and Al5Fe2 (compact layer),respectively. The experimental results show that on the same specimen, a convex surface with bigger radius of curvature is more likely to be molten and the melting loss speed is also faster than a flat and smooth surface. The thickness of compact layer on a smooth surface is much bigger than that of the convex surface. Therefore, the author supposes the compact layer is favorable in stabilizing the die surface material from further melting loss, as their formation on the die surface, the melting loss speed will decrease. 相似文献
26.
The constrained blister test is investigated through finite element analysis to determine the applicabilities and the limitations of the new technique. Numerical results confirm that the strain energy release rate asymptotically approaches a constant value. These results also show that the test technique and the approximate solution for strain energy release rate are applicable for some practical cases. 相似文献
27.
Effect of additives on formation of natural gas hydrate 总被引:1,自引:0,他引:1
The formation of natural gas hydrate (NGH) is studied in this work. Kinetics data of hydrate formation with no agitation were collected at various concentrations of the aqueous solutions with different additives such as alkylpolyglucside, sodium dodecyl benzene sulfonate and potassium oxalate monohydrate. Various kinds of additive increased the formation rates of NGH and its storage capacity and reduced the induction time of NGH formation. Moreover, the storage capacity, the induction time and the hydrate formation rate were influenced by the concentration of the aqueous solution. 相似文献
28.
L. Rodríguez-Liñares M.J. Lado X.A. Vila A.J. Méndez P. Cuesta 《Computer methods and programs in biomedicine》2014
In this paper, the gHRV software tool is presented. It is a simple, free and portable tool developed in python for analysing heart rate variability. It includes a graphical user interface and it can import files in multiple formats, analyse time intervals in the signal, test statistical significance and export the results. 相似文献
29.
The objective of this study was to determine how the fracture of adhesive joints depends on elastic beam parameters describing the adherends and the applied loads. The basic specimen geometry was the cracked lap shear joint constructed of aluminium alloy with various adherend and bondline thicknesses. Loads were applied in different combinations of bending, tension and shear to generate a failure envelope for each adhesive and specimen geometry. It was found that crack propagation for precracked specimens occured at a critical strain energy release rate but was also a function of the GI/GII ratio and the bondline thickness. The experiments also showed that the loads required to propagate a crack in a precracked specimen were always lower than the loads required to break the fillet. Hence, by treating uncracked joints as being cracked, where the fictitious crack tip is assumed to coincide with the location of the fillet, a conservative estimate of the failure load is obtained. 相似文献
30.
Phase transitions of canola oil sediment 总被引:3,自引:0,他引:3
H. Liu C. G. Biliaderis R. Przybylski N. A. M. Eskin 《Journal of the American Oil Chemists' Society》1993,70(5):441-448
Canola sediment was obtained from an industrial filter cake by solvent extraction. When heated in the differential scanning
calorimeter (DSC) (5–100°C), the sediment exhibited a single narrow melting peak at around 74.8°C. No solid-state polymorphic
transformation of the material could be detected over this temperature range. The X-ray powder diffraction pattern of canola
sediment resembled waxes from other sources with an orthorhombic unit cell. The phase transition behavior of canola sediment
in oil was studied by both DSC and polarizing microscopy. With increasing ratio of oil/sediment, a reduction in both melting
temperature and transition enthalpy was observed. The shape of the supercooling curve resembled that of the melting curve.
The induction time was determined by spectrophotometry and was used to calculate the interfacial free energyσ between sediment and oil; σ=4.71 erg/cm2. The effect of temperature and sediment concentration on the clouding time of canola oil was studied; the clouding time was
the shortest at 5°C. 相似文献