锂电化学嵌入尖晶石型二氧化锰研究

通过X—射线粉末衍射物相分析、微电极循环伏安法以及稳态极化曲线测量,研究了λ—MnO_2在非水锂电池体系中的充放电特性。发现在充放电过程中,涉及锂离子的嵌入、脱出过程,而λ—MnO_2的尖晶石骨架结构[Mn_2]O_4保持不变。讨论了锂离子嵌入过程的机理。     

锰硅合金生产中入炉锰矿的优化搭配

通过对以往配矿思路的缺陷分析,引入炉料含锰的概念和与配方思路,相应补充和推导部分配矿参数,浅谈了这些参数的应用方法及步骤,以达到合理与矿和优化配化的目的及效果。     

高炉锰铁液固态的锰磷成分差异

用数理统计方法对大量生产记录数据进行了分析核对,确认高炉锰铁在液、固两种状态时,锰、磷成分存在着差异这一事实。并确定了固态锰铁含锰量降低、含磷量增加的成分劣化区间为:锰的平均降低值在-0.275％和 0.022％之间,磷的平均升高值在-0.0015％和 0.0171％之间。按GB7730.1-7730.4-87规定与允许化验误差比较分析,也有一定超差比例存在。     

以富锰渣为原料在氯化锰体系中制备电解金属锰

氯化锰溶液电解金属锰具有电流密度大、槽电压低、电耗少等特点。本文叙述了以富锰渣为原料，用盐酸浸出，从氯化锰溶液中制备电解金属锰的试验结果。     

Lake sedimentary evidence of phosphorus,iron and manganese mobilisation from intensively fertilised soils

A study of historical P inputs to Friary Lough, Co. Tyrone, Northern Ireland used a multi-sediment core approach. One of the sediment cores taken from the littoral zone at 2.5m water depth showed exceptionally high P, Fe and Mn concentrations below 20 cm sediment depth. Concentrations increased to 14 mg Pg(-1), 238 mg Feg(-1) and 35 mg Mng(-1) in the sediment profile and compared with deep basin maxima of 7 mg Pg(-1), 70 mg Feg(-1) and 2 mg Mng(-1) in surface sediments at 8.5m water depth. It is proposed that the high concentrations in the littoral zone core are due to post-depositional intrusion of chemical-rich local groundwater from soils in adjacent fields that are excessively fertilised with organic slurry. Soil analyses showed Olsen-P concentrations in these fields up to 125 mgkg(-1) at the soil surface (0-7.5 cm) and 39 mgkg(-1) in the sub-soil at 20 cm depth. We suggest that the mobilisation of P, Fe and Mn is due to leaching following P saturation and/or the loss of P absorbing chemicals due to prolonged reduction and complexing in wet soils. Further work will explore this relationship and the nature of the hydrological pathways through soil.     

锰在永磁材料中的应用

概述了锰在永磁材料中的应用,其主要为Fe-Mn系永磁合金、Mn-Al系永磁合金、Mn-Bi系永磁合金、稀土锰基化合物、永磁薄膜以及Mn在永磁材料中的掺杂。     

化学沉积法制备氧化锰/多孔炭复合材料及其电化学性能

通过化学沉积法制备了氧化锰/多孔炭（Porous carbon,简称PC）复合材料,考察了氧化锰负载量及热处理温度对其理化性能的影响,探讨了氧化锰/多孔炭复合电极的充放电机理。SEM照片及孔结构测试结果表明,常温下化学沉积法负载氧化锰不但负载均匀,而且还对多孔炭的孔结构起到修饰作用;但经400℃以上高温处理后,其均匀性受到破坏。XRD测试结果表明,经110℃干燥处理及400℃高温处理的复合电极材料负载的氧化锰为无定型结构,800℃时则转变为γ-Mn2O3。经电化学测试表明化学沉积法负载氧化锰可以有效地提高多孔炭电极材料的电能存储容量,当多孔炭负载质量分数1.7%氧化锰,在空气中110℃干燥,制得复合材料的单电极比电容达到340F/g,比单纯的多孔炭电极提高34%。     

Characterization and photoluminescence studies on hydrothermally synthesized Mn-doped barium titanate nano powders

Manganese doped cubic barium titanate nanocrystals with [Mn/Ti] mole percent varying from 0.1 to 3 were prepared through hydrothermal route at 150 °C. The mean crystallite diameters obtained for different Mn concentrations varied within 26 to 30 nm. TEM of a typical sample showed most of the particles as single crystallites (particle size 15-40 nm) with some weakly agglomerated particles. The photo luminescent (PL) spectra of each sample showed a sharp peak in the blue band centered approximately at 464 nm and a weaker peak in the green band centered nearly at 494 nm. The luminescent efficiency passed through maxima for the sample with 2% [Mn/Ti] molar ratio. Effect of calcination temperature in the range of 200 to 600 °C on PL spectra showed that the intensity of peak corresponding to blue region decreased with the increase in calcination temperature from 200 to 600 °C and for the sample calcined at 600 °C, only a broad peak corresponding to green luminescence region was observed.     

The effect of manganese oxide on the sinterability of hydroxyapatite

The sinterability of manganese oxide (MnO₂) doped hydroxyapatite (HA) ranging from 0.05 to 1 wt% was investigated. Green samples were prepared and sintered in air at temperatures ranging from 1000 to 1400 °C. Sintered bodies were characterized to determine the phase stability, grain size, bulk density, hardness, fracture toughness and Young's modulus. XRD analysis revealed that the HA phase stability was not disrupted throughout the sintering regime employed. In general, samples containing less than 0.5 wt% MnO₂ and when sintered at lower temperatures exhibited higher mechanical properties than the undoped HA. The study revealed that all the MnO₂-doped HA achieved >99% relative density when sintered at 1100-1250 °C as compared to the undoped HA which could only attained highest value of 98.9% at 1150 °C. The addition of 0.05 wt% MnO₂ was found to be most beneficial as the samples exhibited the highest hardness of 7.58 GPa and fracture toughness of 1.65 MPam^1/2 as compared to 5.72 GPa and 1.22 MPam^1/2 for the undoped HA when sintered at 1000 °C. Additionally, it was found that the MnO₂-doped samples attained E values above 110 GPa when sintered at temperature as low as 1000 °C if compared to 1050 °C for the undoped HA.     

AES investigation of the stainless steel surface oxidized in plasma

Auger electron spectroscopy (AES) depth profiling was used to study the oxidation phenomena of AISI316L stainless steel during treatment with oxygen plasma. Samples were exposed to low-pressure RF plasma with a high dissociation degree, so that the flux of oxygen atoms onto the sample surface exceeded 10²⁴ m⁻² s⁻¹. A set of samples was oxidized 4 min at different temperatures up to 1300 K during plasma treatment. AES measurements showed that the oxide film thickness increased with the increasing temperature. The thickness of the oxide film on the samples oxidized in plasma at 300 K was nearly the same as for the untreated sample. The thickness of the oxide film of the samples which were oxidized at 1000 K was about 170 nm and it consisted of iron oxide. The thickest oxide film of about 350 nm was found on the samples heated in oxygen plasma to 1300 K. Depth profiling showed the uppermost layer of manganese oxide, followed by a mixture of chromium oxide and iron oxide. The scanning electron microscope analyses showed a dramatic increase of the surface roughness.