含钼废渣冶炼钼铁的优化试验

利用含钼废料钼酸钙为原料,采用碳还原法冶炼钼铁,通过单因素分析试验及正交试验优化得出最佳的试验条件,钼酸钙加入量应低于10%,熔炼温度为1 525 ℃,保温时间为25 min,碱度为1.3。通过XRD、SEM、EDS分析得出用此方法生产得到的钼铁合金中,钼以Mo₂C、Fe₃Mo以及Fe₃Mo₃C的形式存在,渣系为二元玻璃渣系,具有与普通玻璃相似的成分系统。经测定合金中钼的回收率大于99%,钼资源回收效益可观。     

确定电磁超声换能器钢管检测最佳磁化强度的试验研究

由于电磁超声换能器检测钢管缺陷时,其磁场强度影响超声波幅值,进而影响检测灵敏度。为此设计了确定最佳磁化强度的试验方案,通过试验得到超声波幅值随电磁场激励电流的变化曲线。确定了最佳磁化强度时的激励电流。     

谈谈民营涂料企业的管理误区

近些年来 ,不少民营企业的生产经营每况愈下 ,其原因是企业的经营者在思维上、管理上存在不少“误区”。例举了“误区”的几起典型事例     

Wear simulation of Si3N4 cutting tool material on a pin-on-disc tester

Si₃N₄-based ceramic cutting tools are used nowadays for machining cast iron, nickel-based alloys, etc. Austenitic stainless steel AISI 321 is one of the most difficult to cut materials. In order to investigate the wear behaviour of Si₃N₄ ceramic when cutting the stainless steel, wear tests are carried out on a pin-on-disc tribometer, which can simulate a realistic cutting process. The selected load range is from 58.8 N to 235.2 N, the speed range is from 0.8 m/s to 3.2 m/s. The test results show that the wear of Si₃N₄ ceramic increases with both load and speed and the wear of the ceramic is mainly caused by adhesion between the rubbing surfaces. Scanning electron microscope (SEM), electron probe microanalyser (EPMA) and energy dispersive X-ray analyser (EDXS) were used for examinations of the worn surfaces. The wear mechanisms of Si₃N₄ ceramic sliding against the stainless steel were discussed in detail.     

Electrodeposition of catalytically active nickel for the oxygen evolution reaction — effects of anionic composition

Nickel electrodes were prepared by electrodeposition in electrolytes of various anionic compositions. The deposition conditions and bath types were evaluated with special emphasis on the electrocatalytic properties for the oxygen evolution reaction (OER). Electrochemical characterizations in a 5 mol/L KOH solution at 25°C showed that the electrode deposited from the chloride bath, having a low Tafel slope of 50 mV/dec and an overpotential of 396 mV at 100 mA/cm², is the most catalytically active among electrodes prepared in electrolytes of various anionic compositions. The electrode activity for the OER is related to the real surface areas, which depend on the anion compositions in the deposition bath and the deposition conditions.     

油滴釉制作工艺的研究

在研制氧化气氛烧制油滴黑釉器的基础上 ,探讨了影响油滴釉形成的工艺因素。通过一系列试验 ,进一步验证了油滴釉在结晶过程中主要发生了液液分相 ;釉料的化学组成是油滴晶斑形成的先决条件 ;釉层厚度、烧成制度等是决定釉面效果的重要因素 ;油滴晶斑的呈色不仅与烧成气氛有关 ,还与着色氧化物的引入有关。     

Unipol气相法聚烯烃液体催化剂技术进展

介绍了Unipol气相法聚烯烃工艺液体催化剂的成分、加入反应器的方式和喷嘴结构及控制催化剂液滴尺寸方法等方面的最新进展情况。     

Electrodeposition of Ni-transition alloys for the oxygen evolution reaction

The oxygen evolution reaction (OER) is the anodic reaction in several industrial electrolytic processes. The objective of this work was to develop a new electrocatalytic material for long-lasting and economical high performance electrodes. New electrodes were prepared by electrodeposition of nickel, nickel-ruthenium and nickel-iridium alloys. They were then activated by anodic polarization at 100 mA cm^–2 to form an oxide layer. The electrocatalytic activity was characterized for the OER in 5M KOH solution. The results show that nickel-iridium alloys provide greater electrocatalytic activity for the OER and better corrosion resistance than nickel-ruthenium in alkaline solution. The effects of transition elements on improving the performance of the nickel electrode are then discussed.Notation b Tafel slope - i _ex exchange current density - i _dp electrodeposition current density - i _OER oxygen evolution reaction current density - C _dl double-layer capacity - o₂ oxygen overpotential     

工业废渣在复合无光乳浊釉中的应用

以废瓷粉、废玻璃粉、粉煤灰等工业废渣为主要原料．添加其它常用的陶瓷原料，成功研制出乳白色、彩色(添加色料)、费色(以粉煤灰着色)三个系列无光乳浊釉。这些釉的烧成温度为1180℃左右，烧成气氛为氧化气氛．它们具有废渣用量大(废渣总用量40-50％)、熔块用量低(0～12％)、成本低等特点。     

BaTiO3基PTC陶瓷的研究现状及展望

PTC陶瓷（正温度系数热敏陶瓷）具有电阻率随温度升高而增大的特点，是近年来发展迅速的新型电子材料之一，其在低压领域的使用更是一直为各国研究者所关注。阐述了PTCR的半导电性能，并着重介绍了BaTiO3基低阻PTC陶瓷的研究现状和展望。