磁载纳米TiO2光催化剂的研究进展

磁载纳米TiO2光催化剂作为一种复合功能材料,不仅具有较高的催化活性,而且在外加磁场下容易回收分离,在污水处理方面有着诱人的应用前景.综述了磁载纳米TiO2光催化剂的磁粒子的制备和TiO2的负载方法,详细阐述了其磁性能和光催化性能,展望了磁载纳米TiO2光催化剂未来的发展和应用.     

磁载纳米二氧化钛的制备及在污水处理中的应用

将纳米二氧化钛粉末进行改性，并将之负载到磁基体上，从而使得这种污水处理光催化剂能够有效地降解污水中的有机物，同时，又可快速准确的分离，进行再利用。     

新方法可像钓鱼一样回收污水中的磷

正磷是水污染的原因之一,同时也是许多工业领域需要的原料。德国研究人员报告说发明了一种新方法,可像钓鱼一样将污水中的磷"钓"出来,回收后予以重新利用。德国弗劳恩霍夫应用研究促进协会19日说,从水中"钓"磷的关键是利用一类名为"超顺磁粒子"的特殊物质作"鱼饵"。超顺磁粒子在感受到磁场时,自己也会具有磁性;而当磁场撤去时,则会退去磁性。     

磁性催化剂研究进展

磁性催化剂是一类具有磁响应特性的催化剂,特别是纳米磁性催化剂不仅应具有磁分离特性,而且应具有纳米材料的优异特性以及不同于常规催化剂的优异催化活性.在化工生产过程中可以强化化学反应和分离过程,也可以简化整个工艺流程.介绍了磁性催化剂,特别是纳米磁性催化剂的特性,并综述了近年来磁性催化剂在固体酸催化、固体碱催化、相转移催化、光催化、生物催化等领域的应用研究进展.旨在探讨磁性催化剂制备方法和应用领域,同时提出了磁性催化剂应用过程中存在的问题和发展方向.     

磁性微粒的制备及其应用研究进展

磁性微粒作为一种新型高分子材料,因其兼具功能性微球的众多特性和磁响应性,已成为磁性材料研究领域的一个重点研究方向.文章阐述了磁性高分子微粒的结构类型及特点,对磁性微粒的几种制备方法的基本原理、工艺过程及特点进行了综述,评述了磁性微粒制备的研究工作,并分析了方法的优缺点.介绍了磁性微粒在免疫测定、细胞分离、蛋白质纯化、固...     

磁性纳米颗粒介导的电磁神经治疗的最新进展

目的 介绍磁性纳米颗粒的性质和生物医学应用,以及通过磁性纳米颗粒介导的电磁神经刺激治疗的最新进展.为今后优化刺激参数、提高磁神经刺激效率提供参考.方法 总结近年来国内外对磁性纳米颗粒的研究进展,并重点分析基于磁性纳米颗粒的神经磁刺激方法及效果.结果 磁性纳米颗粒具有成像、靶向给药、磁热疗等生物医学应用,以磁性纳米颗粒为基础进行神经磁刺激的类型可分为磁热刺激、磁电刺激及磁机械力刺激三种.这种刺激方式安全、高效且精准性高,能够改善传统磁刺激方式的缺陷.结论 磁性纳米颗粒性质独特,是近年来研究最多、发展速度最快的纳米材料之一.利用磁性纳米颗粒介导的神经磁刺激具有广阔的应用前景.     

磁场力对磁性杂质颗粒的作用的研究

磁场对处于其中的磁性颗粒有力的作用,通过对交流磁场和稳恒磁场的磁场力的比较分析,证明这2种磁场力可以统一,与磁性颗粒的作用规律相似.采用磁平衡法测量了MnFeAl36和MnFeSiAl42种金属间化合物的磁化率,证明它们是顺磁性的物质,利用磁场力可以将其分离.利用自制的交变磁场和稳恒磁场装置对铝熔体进行分离试验,结果表明磁场力可以将铝熔体中的磁性杂质颗粒分离出来.     

平面变压器及平面集成磁技术

采用平面变压器和平面集成磁技术可以显著降低磁性器件的高度,减小磁性器件的体积和重量,提高磁性器件的功率密度,可以实现开关电源"轻、小、薄"的要求.本文综述了平面变压器的现状和磁集成技术,介绍了最新的亚微米平面变压器的制备和特点,提出了研究平面集成磁件需要解决的关键技术问题.最后,对平面集成磁技术进行了展望.     

磁分离光触媒的制备及其在污水处理中的应用

纳米TiO2光催化剂是当前最有应用潜力的一种高级氧化水处理技术.然而,使用过程中纳米TiO2悬浮法污水处理过程中的回收再利用技术始终不令人满意.本文探讨了采用磁分离技术解决这一问题的可行性;采用溶胶-凝胶法,制备了磁载二氧化钛光催化剂;设计了一种新型污水处理设备,检验光催化剂回收率及二次使用时其催化活性的变化率;在改进的工艺基础上讨论了各种因素对制备纳米TiO2的影响.     

磁性高分子微球的制备方法与发展趋势

磁性高分子微球作为一种新型功能材料,兼具高分子微球的众多特性和磁响应性,在靶向药物、细胞分离、细胞标记、固定化酶和生物传感器等领域有着广阔的应用前景.综述了各类磁性高分子微球的制备方法及各自的优缺点,概述了磁性高分子微球的重要参数及表征方法,预测了高分子微球研究工作的趋势.     

Oil-field wastewater purification by magnetic separation technique using a novel magnetic nanoparticle

In the present work, oil-field wastewater purification through superconducting magnetic separation technique using a novel magnetic nanoparticle was investigated. The magnetic nanoparticle, which has a multi-shell structure with ferroferric oxide as core, dense nonporous silica as inter layer and mesoporous silica as outer layer, was synthesized by co-precipitation method. To functionalize the magnetic nanoparticle, plasma polymerization technique was adopted and poly methyl acrylate (PMA) was formed on the surface of the nanoparticle. The multi-shell structure of the nanoparticle was confirmed by transmission electron microscope (TEM) and the characteristic is measurable by FTIR. It is found that most of the pollutants (85% by turbidity or 84% by COD value) in the oil-field wastewater are removed through the superconducting magnetic separation technique using this novel magnetic nanoparticle.     

胶束强化超滤技术在重金属废水处理中的研究进展

胶束强化超滤技术(MEUF)作为一种新兴的水处理技术,在重金属废水净化方面有着较好的应用前景。本文通过总结前人的研究结果,综合讨论了影响金属离子截留效果的各个因素,为优化MEUF提出了一些建议。并就当前采用胶束强化超滤法处理金属离子技术的最新发展与表面活性剂的循环再利用作了简要的介绍。     

磁性MCM-41分离回收RT培司废水中四甲基氢氧化铵的研究

硝基苯法合成RT培司(4-氨基二苯胺)的废水色度高、组分复杂、催化剂四甲基氢氧化铵(TMAOH)难以分离回收。提出采用磁性MCM-41对RT培司废水中有机副产物进行选择性吸附分离。制备的磁性MCM-41样品采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、N₂吸附-脱附和振动样品磁场计(VSM) 等手段进行表征。结果表明, 磁性MCM-41颗粒的粒径范围为200~300 nm, BET比表面积约为655.2 m²/g, 孔径分布为0.5~4 nm, 内核铁酸镍的存在使磁性MCM-41具有超顺磁性。吸附研究表明磁性MCM-41对RT培司废水中吩嗪、偶氮苯和苯胺等有机物具有良好吸附作用, 经5次吸附磁分离后, RT培司废水中四甲基氢氧化铵能够达到回用要求, 吸附后的磁性MCM-41在外加磁场下极易分离。     

Superconducting Properties of Pb/Bi Films Quench-Condensed on a Porous Alumina Substrate Filled with Co Nanowires

Superconducting properties of a new ferro-magnet–superconductor hybrid structure have been investigated. Organized arrays of Co nanowires are first electroplated into the columnar pores of anodic aluminum oxide (AAO) membranes. Superconducting Pb/Bi (18 at.%) films are then quench-condensed onto the surface of the AAO membranes filled with Co nanowires. The Co nanowire array produces a magnetic field with a strong spatial variation in the superconducting film. Hysteretic superconducting properties and enhanced critical currents have been observed in applied external magnetic fields, which we explain based on the magnetic domain structure of the Co nanowire arrays.     

Study on industrial wastewater treatment using superconducting magnetic separation

The mechanism of industrial wastewater treatment using superconducting magnetic separation is investigated. Fe₃O₄ nanoparticles were prepared by liquid precipitation and characterized by X-ray diffraction (XRD). Polyacrylic acid (PAA) film was coated on the magnetic particles using plasma coating technique. Transmission electron microscope (TEM) observation and infrared spectrum measurement indicate that the particle surface is well coated with PAA, and the film thickness is around 1 nm. Practical paper factory wastewater treatment using the modified magnetic seeds in a superconducting magnet (SCM) was carried out. The results show that the maximum removal rate of chemical oxygen demand (COD) by SCM method can reach 76%.     

磁性累托石的制备及其对含有机染料废水的吸附性能

采用共沉淀法制备了纳米Fe3O4磁性微粒,将其与累托石复合制得一系列不同Fe3O4载量的磁性累托石,用XRD、SEM、TEM和VSM对样品的性质进行了表征,研究了样品对含有机染料废水的吸附性能与磁分离回收率。结果表明,Fe3O4粒度为10~25nm,结晶良好,具有尖晶石结构;制得的磁性累托石均具有良好的超顺磁性,当Fe3O4载量为25%时,Ms、Mr、Hci分别为12.867emu/g、0.355emu/g、15.524G;当吸附剂添加量为0.4%时,Fe3O4载量为16%的磁性累托石对含甲基橙及亚甲基蓝染料废水的脱色率分别达76.9%、99.4%;Fe3O4载量分别为10%~25%的磁性累托石,其磁分离回收率为95.6%~98.4%。     

Synthesis and Characterization of T1-1223 Substituted by Scandium

X-ray powder diffraction, scanning electron microscopy （SEM）, energy dispersive X-ray, electrical resistivity and AC-magnetic susceptibility measurements have been performed for polycrystalline superconducting samples of type TIBa2Ca2_xSCxCU309_δ （0.0 ≤ x 〈 0.6）. The powder X-ray diffractograms indicate that the tetragonal structure of T1-1223 is not affected by Sc-substitution whereas the lattice parameters are changed. The X-ray analysis indicates that the low-contents of scandium （x） enhance the formation of T1-1223 and reduce the secondary phases. The grain-size determined by SEM decreases as x increases. The electrical resistivity measurements show suppression in the superconducting transition temperature, Tc, and an increase in both the residual resistivity and the superconducting transition width as x increases. The suppression in Tc is attributed to the hole-filling mechanism.     

Deposition of superconducting niobium coatings on titanium from molten salts

Superconducting niobium coatings have been electrodeposited from molten salts onto titanium substrates with a copper, nickel, or molybdenum protective layer, and their structure and magnetic properties have been studied. The coatings are shown to be suitable as a starting material for the superconducting layer of the rotor of cryogenic gyroscopes.     

The development and investigation of superconducting magnetic systems for physical experiments

Superconducting solenoids designed for different physical experiments are described. The solenoids are made of multifilament niobium titanium wires and are connected in series. The magnetic induction achieved at 4.2 K is 9.5 T and with the use of an iron yoke with magnetic flux concentrators an additional 1.5–2 T could be added to the operating volume of about 50 cm³. Various modified cryostats which allow operation for several days without liquid helium refilling and which permit a wide range of physical experiments are described.     

Tiny Signals from the Human Brain: Acquisition and Processing of Biomagnetic Fields in Magnetoencephalography

Low-temperature superconductivity plays an important role in some specific biomedical applications, and, in particular, in non-invasive imaging methods of human brain activity. Superconducting magnets are indispensable for functional magnetic resonance imaging (fMRI) which allows functional imaging of the brain with high spatial but poor temporal resolution. Superconducting quantum interference devices (SQUIDs) are the most sensitive magnetic field detectors. Up to a few hundreds of SQUIDs are nowdays used in modern whole-head magnetoencephalography (MEG) systems. They allow tracking brain activation with a superior temporal resolution of milliseconds, which is a quintessential condition for the monitoring of brain dynamics and the understanding of information processing in the human brain. We introduce the prerequisites of MEG data acquisition and briefly review two established methods of biomagnetic signal processing: The concept of signal averaging, and the subsequent source identification as a solution of the biomagnetic inverse problem. Beside these standard techniques, we discuss advanced methods for signal processing in MEG, which take into account the frequency content of the recorded signal. We briefly refer to the prospects of Fourier analysis and wavelet transform in MEG data analysis, and suggest matching pursuit as a promising tool for signal decomposition and reconstruction with high resolution in time-frequency plane.