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91.
A new magnetic regime is presented in hematite hollow spheres. The numerous dangling bonds, formed in the H+ etching process during fabrication, endow the surfaces of the primary particles with paramagnetic and ferrimagnetic attributes. The freezing and coupling of these surface states have profound effect on the magnetic performance of the host hematite spheres – including enhanced ferromagnetism, a peculiar variation of thermal remanent magnetization, and an exchange bias training effect, which may find their potential applications in spintronic fields. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
92.
污泥化学链燃烧过程中氮迁移转化特性研究 总被引:1,自引:0,他引:1
污泥化学链燃烧过程中氮迁移转化特性研究 《燃料化学学报》2017,45(4):505-512
在单流化床反应器上探究了污泥化学链燃烧过程中氮迁移转化特性。由于赤铁矿载氧体反应活性低,采用30%水泥对其改性。结果表明,水泥改性可提高污泥热解气化反应速率以及赤铁矿还原反应速率,进而提高污泥碳转化率,但是NO生成率也增加。随着反应温度的升高,污泥的碳转化率和NO生成率均增加。另外,随着水蒸气浓度的增加,碳转化率增加,同时可降低NO生成。在污泥化学链燃烧过程中,NO生成率为0.286%-0.768%,低于污泥空气焚烧氮氧化物排放量。 相似文献
93.
94.
R. Ramesh K. Ashok G. M. Bhalero S. Ponnusamy C. Muthamizhchelvan 《Crystal Research and Technology》2010,45(9):965-968
We report synthesis of α‐Fe2O3 (hematite) nanorods by reverse micelles method using cetyltrimethyl ammonium bromide (CTAB) as surfactant and calcined at 300 °C. The calcined α‐Fe2O3 nanorods were characterized by X‐ray diffraction (XRD), high‐resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). The result showed that the α‐Fe2O3 nanorods were hexagonal structure. The nanorods have diameter of 30‐50 nm and length of 120‐150 nm. The weak ferromagnetic behavior was observed with saturation magnetization = 0.6 emu/g, coercive force = 25 Oe and remanant magnetization = 0.03 emu/g. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
95.
Protons in the region of 400 KeV have been used to study the channeling process in BaF2 and CaF2. The rate of loss of protons from the 111 linear channel, stopping power, and critical angle for the channel were found. Two techniques were employed, namely observationof elastic scattering by the lattice ions, and alpha particles produced by the reaction 19F(p,αy)16O, from the sharp resonance at 340 keV. Both techniques gave results in good agreement. The channel parameters were much closer together for the two crystals than had been anticipated on the basis of the large difference in charge between Ba and Ca. 相似文献
96.
V. V. Korolev I. M. Arefyev A. G. Ramazanova 《Journal of Thermal Analysis and Calorimetry》2008,92(3):691-695
The magnetocaloric effect (MCE) of aqua suspensions based on superfine magnetite (Fe3O4), hematite (α-Fe2O3), maghemite (γ-Fe2O3), samarium ferrite (SmFe2O4) and gadolinium ferrite (GdFe2O4) as well as of magnetite-based ferrofluids was calorimetrically determined in the range of the temperatures from 283 to 253
K. MCE has a positive magnitude for all investigated systems except a hematite-based system. For the suspensions on the basis
of MCE temperature dependence it was determined that superfine magnetite transformed into α-Fe2O3 at the temperature above 328 K in contrast to monocrystal magnetite. For aqua suspensions of samarium ferrite and gadolinium
ferrite and magnetite-based ferrofluids MCE temperature dependence has an extreme behavior which is connected with a second-order
phase transition. For the first time it is established that the magnetocaloric effect (MCE) is greatly increased when the
magnet is a nanosized material. 相似文献
97.
Liquid‐Crystal‐Mediated Self‐Assembly of Porous α‐Fe2O3 Nanorods on PEDOT:PSS‐Functionalized Graphene as a Flexible Ternary Architecture for Capacitive Energy Storage 下载免费PDF全文
Md. Monirul Islam Dean Cardillo Taslima Akhter Hua Kun Liu Konstantin Konstantinov Shi Xue Dou 《Particle & Particle Systems Characterization》2016,33(1):27-37
A novel aqueous‐based self‐assembly approach to a composite of iron oxide nanorods on conductive‐polymer (CP)‐functionalized, ultralarge graphene oxide (GO) liquid crystals (LCs) is demonstrated here for the fabrication of a flexible hybrid material for charge capacitive application. Uniform decoration of α‐Fe2O3 nanorods on a poly(3,4‐ethylene‐dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)‐functionalized, ultralarge GO scaffold results in a 3D interconnected layer‐by‐layer (LBL) architecture. This advanced interpenetrating network of ternary components is lightweight, foldable, and possesses highly conductive pathways for facile ion transportation and charge storage, making it promising for high‐performance energy‐storage applications. Having such structural merits and good synergistic effects, the flexible architecture exhibits a high specific discharge capacitance of 875 F g?1 and excellent volumetric specific capacitance of 868 F cm?3 at 5 mV s?1, as well as a promising energy density of 118 W h kg?1 (at 0.5 A g?1) and promising cyclability, with capacity retention of 100% after 5000 charge–discharge (CD) cycles. This synthesis method provides a simple, yet efficient approach for the solution‐processed LBL insertion of the hematite nanorods (HNR) into CP‐functionalized novel composite structure. It provides great promise for the fabrication of a variety of metal‐oxide (MO)‐nanomaterial‐based binder and current collector‐free flexible composite electrodes for high‐performance energy‐storage applications. 相似文献
98.
Alexilda Oliveira de Souza Maria do Carmo Rangel 《Reaction Kinetics and Catalysis Letters》2003,79(1):175-180
Aluminium and copper-doped magnetite was evaluated as high temperature shift catalyst and compared with a hematite-based sample.
The first one is less active but can save energy in industrial processes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
99.
100.
A. K. Helmy E. A. Ferreiro S. G. de Bussetti N. Peinemann 《Colloid and polymer science》1998,276(6):539-543
Adsorption of eight organic molecules on kaolin, α-Fe2O3 and hydroxy-Al montmorillonite was studied to examine the effect of sorbate area on the values of the surface area of these
materials. For each sorbent, the number of molecules at monolayer coverage per gram produced a single hyperbola when plotted
as a function of the area occupied by an adsorbate. The equations of the hyperbolas are: NA=22.23 A
0.098 for the kaolin, NA=53.70 A
-0.399 for α-Fe2O3 and NA=161.81 A
0.322 for the hydroxy-Al montmorillonite. These equations give accessible surface areas and not the true surface areas of the solids
studied, which remain elusive.
Received: 13 November 1997 Accepted: 24 January 1998 相似文献