稳恒场中场和势的研究

运用类比的方法得出稳恒电场和稳恒磁场的场和势在数学形式上的对应关系,并讨论静电场和稳恒电流场中几种典型的定解问题。     

无限长载流导体板磁场分布的计算

计算了在真空中无限长、有限宽、载稳恒电流导体板的磁场分布，得到了一个简单的解析表达式，应用叠加原理，可计算规则几何形状、载稳恒电流导体的磁场分布．     

电、磁场能量与机械功

通过两个理想的物理模形,分别讨论了电场E和磁通量Φ不变,及稳恒电流和稳恒电压的情况下,电场能量和磁场能量与机械功之间的相互转换,以及能量守恒关系。     

电磁媒质附加场的等效计算及其讨论

以稳恒场为例。研究了极化电介质附加场的等效计算,并借此进一步阐述了稳恒电场、磁场之间的对偶方法。     

无限长截流导体板磁场分布的计算

计算了在真空中无限长,有限宽,载稳恒电流导体板的磁场分布,得到了一个简单的解析表达式。应用叠加原理,可计算规则几保形状,载稳恒电流导体的磁场分布。     

关于位移电流激发磁场

本文证明了在似稳恒条件下，全空间的位移电流在任何一点激发的磁场恒为零。传导电流和位移电流的纵向分量对磁场无贡献。     

稳恒磁场对电镀铬的影响

利用直角阴极法、远近阴极法和恒电量称重法研究了稳恒磁场对电镀铬的镀液及镀层性能的影响，并对其原因进行了分析．实验结果表明，稳恒磁场的加入对提高镀铬液的覆盖能力、分散能力及电流效率都有明显的影响．     

从狭义相对论看电磁场的统一性

随着对电磁现象研究的逐步深入,人们早已认识到磁现象来源子电荷的运动,磁场和电场是相互联系的统一体,称之为电磁场。然而作为电磁场的两个特例静电场和稳恒磁场,它们具有完全不同的性质,这就给初学者认识电磁场的统一性带来很大的困难。为了找出稳恒磁场与电场的联系,本文根据狭义相对论洛仓兹变换,把电流的磁场对运动电荷的磁作用归结为电场的相对论效应。有力地说明了磁场的本质就是电场,无论在任何情况下磁场和电场都是相互联系的统一体。     

载流圆锥曲线空间磁场的分布

本文用毕奥——沙伐尔定律,导出曲线电流空间磁场积分式,讨论了稳恒电流圆锥曲线空间磁感应强度问题,通过计算机进行数值解并描出对应的空间磁感应强度分布曲线。     

铁锰氧化物对苯酚氧化降解的实验研究

为了考察铁锰氧化物对酚类污染物的氧化降解能力,采用天然以及合成的铁锰氧化物对苯酚的氧化降解进行对比实验研究。土壤中铁锰氧化物样品分别为天然针铁矿及氧化锰,合成铁锰氧化物样品分别为合成针铁矿及软锰矿。结果表明:苯酚与铁锰氧化物发生氧化还原作用时,还可能与土壤中杂质发生吸附等作用;铁锰氧化物还原反应强度随着反应介质pH值的升高而迅速下降;可用零级反应动力学方程拟合铁氧化物还原溶解反应,针铁矿溶解反应的强度与介质的pH值呈负相关关系;天然针铁矿对酚类污染物的氧化降解能力明显高于合成针铁矿,pH值对天然针铁矿溶解反应影响较大;可用一级指数衰减方程拟合锰氧化物还原溶解反应,锰氧化物溶解反应的强度与介质的pH值呈指数衰减关系;pH值对软锰矿还原溶解反应的影响大于对土壤中氧化锰的影响,pH值越小,影响越显著;对比pH值对铁和锰还原作用的影响发现,在pH=6.5时,锰氧化物仍有较强的氧化性能。     

Enrichment mechanisms of rare earth elements in marine hydrogenic ferromanganese crusts

A series of selective extraction experiments were conducted on marine hydrogenic ferromanganese crusts from the seamount near the Line Island to investigate the distribution of rare earth elements(REEs) and the mechanisms of combination between REEs and the hydrogenic ferromanganese crusts.The enrichment of REEs in hydrogenic ferromanganese crusts is attributed mainly to the mineral or oxide/hydroxide of the crust rather than the growth environment.The REEs are present mainly in amorphous ferric oxide/hydro...     

用锰铁渣和废碎玻璃制备泡沫玻璃的工艺研究

以锰铁渣和碎玻璃为主要原料,碳粉为发泡剂,硼砂为助熔剂,采用粉体烧结研制出了泡沫玻璃。对泡沫玻璃的表观密度和吸水率进行了测定。研究结果表明,当锰铁矿渣用量在12.5%~20%时,控制好工艺参数,可以制备出表观密度为407 kg/m3的泡沫玻璃。     

用锰铁渣和废碎玻璃制备泡沫玻璃的工艺研究

以锰铁渣和碎玻璃为主要原料,碳粉为发泡剂,硼砂为助熔剂,采用粉体烧结研制出了泡沫玻璃。对泡沫玻璃的表观密度和吸水率进行了测定。研究结果表明,当锰铁矿渣用量在12.5%~20%时,控制好工艺参数,可以制备出表观密度为407 kg/m3的泡沫玻璃。     

Evaluation of reduction roasting and magnetic separation for upgrading Mn/Fe ratio of fine ferromanganese

Low grade ferromanganese tailing was subjected to different mineralogical techniques, reduction roasting and magnetic separation to establish whether commercially acceptable manganese qualities and high Mn/Fe ratio could be obtained, and also to determine the best processing route for beneficiating this ore. The main manganese mineral within the feed sample is birnessite, with minor amounts of pyrolusite and todorokite. Size by assay analysis conducted presented a result with a yield of about 35.75% and Mn grade of 27.63% to coarse (?3.35 + 1 mm) and yield of 20.24% and Mn grade of 27.71% to (?1.18 + 0.50 mm) fraction. Two-stage high induced magnetic separations at 16,000 and 11,000 G produces Mn grades with similar grade to that obtained from the ferromanganese feed sample. Reduction roasting followed by magnetic separation on ?1.18 + 0.50 mm at 1000 G recovered 72.31% Mn with a grade of 58.44% Mn, 2.52% Fe and 3.29% Si at Mn/Fe ratio of 23.22. This study reveals the influence of roasting in converting the hematite and goethite to magnetite and the response of the roasted fraction to magnetic separation.     

Kinetics of Carbothermic Reduction of MnO2 and Catalytic Effect of La2O3

Kinetics of carbothermic reduction of manganese oxide and the catalyitic catalytic effect of La2O3 on the reduction have been studied by the measurement of mass loss in N2 atmosphere at differnet temperatures and followed by SEM analysis.It is concluded that the kineticxs of carbothermic reduction of manganese oxide is divided into three stages:gas diffusion controlling stage,carbon gasification controlling stage and solid state diffusion controlling stage .La2O3 has catalytic effect on the reduction.The catalytic effect of La2O3 increases with the added amount of La2O3.SEM analysis shows that the catalytic mechanism is that La2O3 promotes the transfer of oxygen ions so that cabon gasifying is catalyzed and thus carbotherimc reduction of MnO2 is Catalyzed.     

静电场和磁场对碳钢表面结垢和腐蚀的影响

在模拟循环冷却水系统中研究了高碱度、高含盐量、高硬度水质条件下 ,静电场和磁场对碳钢表面结垢和腐蚀的影响 .研究表明 ,静电场对结垢有明显的抑制作用 ,强磁场对结垢虽有一定的抑制作用 ,但是还存在不利的因素 .它们对碳钢腐蚀性能的影响主要与对沉积物的影响有关     

碳热还原法制取碳氮化钛的热力学原理分析

分析碳热还原法制取Ti(C,N)的热力学原理,结果表明,合成过程伴随着相变,当TiO2颗粒和C颗粒均匀混合时,还原反应主要依赖于CO/CO2传质的气固反应,当TiO2颗粒表面被C包膜时,主要是碳和钛氧化物之间的固固反应.升高温度有利于还原进行,钛氧化物的开始还原温度随气相中的CO分压降低而降低,但Ti(C,N)中的C,N含量则取决于温度和N2压力.     

Effects of Catalyst and Additive Containing Li, Na, or Ca on Reduction of Iron Oxide/Carbon Composite Pellets

The catalyst containing 0.69% (mass fraction) of Li, Na+, or Ca2+ were synthesized, and the catalytic effect on the reduction of iron oxide/carbon composite pellets were investigated by comparing with that of additive at 850 ℃. The effect of the catalyst was greater than that of the additive, it can be considered that catalyst promoted the formation of iron nucleus early on reduction processes of iron oxide/carbon composite pellets. In addition, both effects of catalyst and additive increased after added carbon powder into the pellets, but the extent of increase decreased when the carbon powder exceeded a suitable content (about 4%), this amount is less than that of car-bon needed theoretically on the reduction from hematite to iron.     

CaO对含锰贫铁矿含碳球团还原行为及对铁与锰磁选富集的影响

考察了ＣａＯ对含锰贫铁矿含碳球团的还原行为及磁选富集铁、锰效果的影响,通过热力学平衡的计算,还原动力学实验,岩相同结构的观察,认为在球团中添加质量分数为５％的ＣａＯ有助于球团中铁、锰的还原,并有助于铁的晶粒聚集长大,在此基础上,进行了磁选富集的研究,对提高铁的品位很有效果,但铁的回收率略有降低,对锰的富集效果不好。     

Extracting indium and preparing ferric oxide for soft magnetic ferrite materials from zinc calcine reduction lixivium

A hydrometallurgical process for indium extraction and ferric oxide powder preparation for soft magnetic ferrite material was developed.Using reduction lixivium from high-acid reductive leaching of zinc oxide calcine as raw solution,copper and indium were firstly recovered by iron powder cementation and neutralization.The recovery ratios of Cu and In are 99% and 95%,respectively.Some harmful impurities that have negative influences on magnetic properties of soft magnetic ferrite material are deeply removed ...