浅谈磁化水对提高混凝土性能的影响

本文从磁化水提高水泥水化程度,提高混凝土和易性,增强混凝土密实度,对混凝土凝结时间及抗冻融循环能力和不同条件的磁化水对混凝土的影响等方面进行了论述。     

Structural and magnetic properties of phase controlled iron oxide rods

Iron oxide rods are synthesized by thermal decomposition of iron (II) acetate at 700 °C. The X-ray powder diffraction measurement confirms the hematite (α-Fe₂O₃) phase of iron oxide. We observed that the Morin transition depends on applied magnetic field and shift towards lower temperature with increase in applied magnetic field. The Morin temperature at applied field of 500 and 2000 Oe is observed to be 261.1 and 260.3 K respectively. Magnetization versus magnetic field measurements confirms the antiferromagnetic behavior below Morin transition and weak ferromagnetic behavior above Morin transition.     

Magnetic and magnetocaloric properties of FeMnO3

FeMnO₃, prepared by mechano-synthesis method using high energy planetary ball mill, crystallizes in bixbyite type cubic structure in space group Ia3. Magnetic measurements show that the compound is ferrimagnetic at room temperature and on cooling undergoes antiferromagnetic ordering around, T_o~ 36 K. Magnetization measurements exhibit strong magnetic anisotropy in this system. Change in the magnetic entropy, also known as the magnetocaloric effect, has been observed in FeMnO₃ on subjecting the sample to a changing magnetic field. We found maximum change of magnetic entropy ~1.5 J/kg K, for a field change of 90 kOe at T~2T_o with relative cooling power of 50 J/kg.     

铁谱磨粒磁化方向的自动识别方法

本文介绍了在磨粒图像中判断磨粒的磁化方向的算法，在普通的铁谱图像中，先分别计算出每一个磨粒的重心，再根据点到点的关系，求出每一个磨粒的方向，最后归纳出整个铁谱图像的磁化方向，它为判断机械部件的摩擦磨损情况提供了较好的依据。     

Correlating the microstructure with magnetic properties of Ti-doped high-frequency MnZn ferrite

In this study, high-frequency MnZn ferrites are prepared for power applications at 10 MHz using solid-state reaction method. The sample doped with 3000 ppm TiO₂ yields the optimal comprehensive magnetic properties, with an initial permeability of 792, power loss of 415 kW/m³ (10 MHz, 5 mT, 25 ℃), and saturation induction of 460 mT. This indicates significant progress compared to previously reported results. The mechanisms of property optimisation, microstructure and domain structure evolution also discussed with TiO₂ doping. The precipitation of Ti at the grain boundary can promote a high-density microstructure and favour the formation of magnetic monodomain in MnZn ferrites. Our results elucidate the correlations between microstructure, domain structure, and high-frequency performance, and present a potential roadmap for the development of high-frequency soft magnetic ferrites.     

Rapid green-assisted synthesis and functionalization of superparamagnetic magnetite nanoparticles using Sumac extract and assessment of their cellular toxicity,uptake, and anti-metastasis property

Modifying the surface properties of superparamagnetic magnetite nanoparticles (SPMNPs) is essential for their stabilization and functionalization in biomedical applications. This study explored the use of Sumac (Rhus coriaria) plant extract as a green stabilizer for SPMNPs. Herein, we fabricated the aqueous colloidal suspension of SPMNPs via a facile and rapid green-assisted co-precipitation method using the extract solution as a green stabilizer (S_S), the results were then compared to the uncoated SPMNPs (S_B). Physicochemical properties of the as-synthesized NPs were characterized. The XRD planes of both samples matched the typical Fe₃O₄ NPs with a high degree of crystallinity. FESEM and TEM revealed that S_S were spherical and mono-dispersed with an average particle size of 11 nm, while the average particle size of S_B was measured to be around 9.9 nm. The elemental compositions of the S_S were approved by the EDX technique. FTIR and TGA results confirmed the presence of functional groups in the extract components and their interactions with SPMNPs. Based on the DLS analysis, Sumac extracts significantly prolonged the stability and increased the zeta potential value of the SPMNPs nanofluid from ?28.2 to ?44.8 mV. The magnetization (Ms) values of S_B and S_S samples were found to be 62.95 emu/g and 139.56 emu/g, respectively. VSM results pointed out that Sumac extracts dramatically enhanced the saturation magnetization of the coated SPMNPs. In vitro cytotoxicity and scratch assays of the S_S against MCF-7 cells indicated the non-toxicity, proliferation modulation, and growth inhibition abilities (anti-metastatic properties) of the modified NPs. In addition, the cellular uptake assessment of S_S on the MCF-7 cancer cell line revealed a dose-dependent internalization. Our findings implied that this hydrophilic, highly magnetic, stable, and biocompatible S_S is probably capable of being used in a wide range of biomedical applications such as MRI, magnetic hyperthermia, and cancer treatment.