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71.
调质状态下40Cr钢的焊接 总被引:1,自引:0,他引:1
在合理制定焊接工艺的基础上,采用R307珠光体耐热钢焊条成功地进行40Cr钢在调质状态下的焊接,解决了通常采用25—13型奥氏体焊条焊接出现的焊缝强度低、焊接接头性能差的问题。 相似文献
72.
In this paper, the microstructure of a 1 wt.% Cu/γ-Al2O3 catalyst that was reduced in a 4% hydrogen/argon atmosphere at temperatures of 523, 773 and 1073 K, is studied by Z-contrast imaging and electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). Results show that the copper species are well dispersed when the catalyst is reduced below 523 K. At 773 K, separated Cu(I) and Cu(0) species are found existing as ring-like and bulk-like particles. This appears to indicate that the copper has not been reduced to its metallic form due to the interaction between the copper oxide and the support. Large spherical particles having core-shell structures with Cu(I) in the shells and Cu(0) in the cores are generated when the catalyst is reduced at 1073 K. The formation of partially oxidized copper species upon reduction at 1073 K is attributed to the metallic copper interaction with the alumina support. This study also demonstrates that high-spatial resolution Z-contrast imaging and EELS performed simultaneously can provide unique information on the morphology and chemistry of metal species in supported metal catalysts. 相似文献
73.
74.
通过改变高速车削淬火钢(Cr12)的切削用量,对切削力、切削温度、加工表面质量等进行了研究,结果表明合理选择切削用量,高速硬车削淬火钢可显著提高生产率及加工表面质量,并在一定程度上可取代磨削加工。 相似文献
75.
加强电炉钢短流程生产工艺研究与技术开发的建议 总被引:1,自引:0,他引:1
论述了加强电炉钢短流程生产工艺研究与技术开发的必要性和主要课题,并提出关于组织合金钢短流程生产工艺研究与技术开发“九五”国家科技攻关及提高高研究开发投资强度的建议。 相似文献
76.
T. D. Dzhafarov S. S. Yesilkaya N. Yilmaz Canli M. Caliskan 《Solar Energy Materials & Solar Cells》2005,85(3):371-383
The effective diffusion coefficients of Cu for thermal and photodiffusion in the CdTe films have been estimated from resistivity versus duration of thermal or photoannealing curves. In the temperature range 60–200°C the effective coefficient of thermal diffusion (Dt) and photodiffusion (Dph) are described as Dt=7.3×10−7exp(−0.33/kT) and Dph=4.7×10−8exp(−0.20/kT).It is found that the diffusion doping of CdTe thin films by Cu at 400°C results in a sharp decrease of resistivity up to 7 orders of magnitude of p-type material, depending on thickness of Cu film. The comparative study of performance of CdTe(Cu)/CdS and CdTe/CdS cells has been studied. It is shown that the diffusion doping of CdTe film by Cu increases efficiency of CdTe(Cu)/CdS cells from 0.9% to 6.8%. The degradation of photovoltaic parameters of CdTe(Cu)/CdS cell, during testing under forward and reverse bias at room temperature, proceeds at a larger rate than those of CdTe/CdS cell without Cu. The degradation of performance of CdTe(Cu)/CdS cells is tentatively assigned to electrodiffusion of Cu in CdTe, resulting in redistribution of concentration of Cu-related centers in CdTe film and heterojunction region. 相似文献
77.
Corrosion behaviour of decorative and wear resistant coatings on steel deposited by reactive magnetron sputtering - Tests and improvements 总被引:1,自引:0,他引:1
Depositions of decorative and wear resistant single layer coatings like TiN, Ti(B,N), CrN, NbN, NbON, (Ti,Mg)N and multilayer coatings like Cr/CrN, Nb/NbN, CrN/NbN and NbN/Nb-C:H were performed using reactive magnetron sputtering. The corrosion behaviour of the coated high speed steel substrates was studied in sodium chloride containing media by open-circuit-potential measurements, potentiodynamic corrosion tests and salt spray tests. Up to now, the best improvements with respect to the corrosion resistance in salt spray tests could be obtained for the system (Ti,Mg)N/high speed steel. 相似文献
78.
分析了钼精矿Cu、Pb含量高的主要原因 ,通过实施一系列措施 ,达到了降低钼精矿中Cu、Pb含量的目的 相似文献
79.
超低碳奥氏体不锈钢00Cr18Ni10还原脱磷研究 总被引:1,自引:0,他引:1
在 2 5kg真空感应炉上用镁钙合金对超低碳奥氏体不锈钢 0 0Cr18Ni10进行了还原脱磷试验。通过充入工业纯氩使炉内压力为 6 6 .6 6kPa和精炼时的反应温度 14 5 0~ 15 0 0℃ ,加入镁钙合金 5 0kg t和助熔剂CaF2 11kg t,可使精炼后 0 0Cr18Ni10的磷含量进一步降低到 (5 0~ 6 0 )× 10 - 6 ,钢中氧、硫含量分别稳定降到(4~ 6 )× 10 - 6 和 15× 10 - 6 。 相似文献
80.
Benedetto Bozzini Bertrand Busson Claudio Mele Abderrahmane Tadjeddine 《Journal of Applied Electrochemistry》2008,38(7):897-906
We report on potential-dependent in situ SFG and DFG spectroscopy carried out at Au(111), Au(210), polycrystalline Au, Au–Cu
and Au–Ag–Cu electrodes in contact with aqueous solutions containing CN− and 4-cyanopyridine (4CP). Spectroelectrochemical work was complemented by cyclic voltammetry. The chief stress has been
placed on systematising and quantifying the interaction between 4CP and CN− and the attending effects on the vibrational and electronic structures of the interface. The voltammetric behaviour of the
investigated electrodes, modified by the addition of 4CP to the CN− electrolyte, denote changes in the CN− adsorption characteristics and effects of the adsorbed CN− layer on the electrodic reactivity of 4CP. The differences among the investigated electrodes can be explained in terms of
their respective degrees of atomic packing or with alloying effects on the stability of adsorbed CN−. The potential-dependent spectra have been analysed quantitatively with a model for the second order non linear susceptibility
accounting for vibrational and electronic effects. The spectral changes induced by addition of 4CP denote interaction of the
aromatic with the electrode through the CN− monolayer. The non-resonant contribution yields information on the effects of 4CP on the fine structure of the bound electron
density of states. 相似文献