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羰基铁粉/锶铁氧体/MVQ吸波复合材料的制备与性能研究 总被引:1,自引:0,他引:1
以羰基铁粉与锶铁氧体为吸波填料制备羰基铁粉/锶铁氧体/甲基乙烯基硅橡胶(MVQ)吸波复合材料,研究羰基铁粉/锶铁氧体并用比对羰基铁粉/锶铁氧体/MVQ吸波复合材料性能的影响。结果表明,羰基铁粉/锶铁氧体/MVQ复合材料吸波峰处于羰基铁粉/MVQ和锶铁氧体/MVQ复合材料之间,在填料总体积分数不变的前提下,随着羰基铁粉用量的减小,复合材料吸波峰小于-10 dB的带宽先增大后减小、吸波峰向高频方向移动、拉伸强度和拉断伸长率变化不大、压缩永久变形减小、动态性能提高。 相似文献
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研究了羰基铁粉含量和硫化温度对天然橡胶基磁流变弹性体(MRE)结构和性能的影响。结果表明,随着羰基铁粉用量的增加,MRE的交联密度降低,硫化速率提高,硫化胶的拉伸强度和扯断伸长率明显下降,胶料的热稳定性提高;随着硫化温度的升高,MRE的焦烧时间缩短,硫化返原现象严重,128℃下制备的MRE中羰基铁粉的链状结构最为明显,143℃下则不呈链状结构;在硫化温度128℃、羰基铁粉用量为60份时,制得的MRE的磁流变效应最高,达到48.9%。 相似文献
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研究了羰基铁粉热处理前后的微观结构、磁性能以及二者在定向集热治疗肿瘤医用交变磁场下的发热性能,羰基铁粉经过热处理后在外部交变磁场作用下的发热性能明显提高.随着经过热处理的羰基铁粉用量的增大,能够达到的最高温度也随之增大,短时间内就能达到有效杀伤肿瘤细胞的温度,经过热处理后的羰基铁粉是定向集热治疗肿瘤的一种理想候选热籽材料,羰基铁粉在外部交变磁场作用下的发热主要来自磁滞损耗和奈尔松弛. 相似文献
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超细陶瓷粉及铁粉的表面化学包覆改性的研究 总被引:12,自引:0,他引:12
本语文根据化学电镀原理,采用的化学镀液,分别研究了超细铁氧体粉末和陶次 粉的表面化学镀层工艺。并采用电镀、能谱分析和俄歇能谱对粉体包覆层的结构均匀性、厚度及化学元素变化进行了详细的分析。通过表面处理,可降低粉体的红外发射率,所获得的粉体同时具有雷达吸波性和红外隐身性,可用于宽波段隐身材料。 相似文献
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以二水合乙酸锌为前驱体,氢氧化钠为矿化剂,并以柠檬酸为改性剂通过水热法制备了氧化锌球状粒子.采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)及粒度分析仪研究了水热处理前后所得粉体的物相组成、粒子形貌以及粒度分布.采用荧光光谱仪及红外辐射率测量仪测量表征了氧化锌粒子的光致发光(PL)性能及试样的远红外发射率.研究表明,水热前后所得粉体均为六方结构的氧化锌,而水热处理后所得粉体粒子形貌为球状粒子.水热处理前后粒子PL显示,水热处理有效改善了氧化锌晶体的完善性,使得粒子晶体缺陷得到改善.同时,红外发射率的结果表明,水热处理前后的粉体在8~14μm区域内的红外发射率区别不大,表明晶体缺陷对红外发射率的影响不大. 相似文献
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Dicarboxylic acid‐containing 1,3‐benzoxazine was synthesized and chemically bonded on iron carbonyl particles using a post‐coating method. Novel organic–inorganic hybrid magnetic composites were prepared via the interfacial reaction between magnetic phthalonitrile prepolymers and the benzoxazine functional coatings that chemically modified the iron carbonyl particles. The results showed that, compared with pure iron carbonyl particles, the modified particles could cure the phthalonitrile prepolymers efficiently and improve the interfacial compatibility of the functional composites. The magnetic composites with chemically modified particles exhibited stronger magnetism in comparison to composites containing bare particles: the saturation magnetization of the magnetic composites with equal concentration (5 wt%) of Fe(CO)5 increased from 41.12 to 48.82 emu g?1. Also, the magnetic composites obtained demonstrated excellent thermal stability up to 500 °C. Copyright © 2010 Society of Chemical Industry 相似文献
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Rong Du Mulin Hu Changsheng Xie Dawen Zeng 《Propellants, Explosives, Pyrotechnics》2012,37(5):597-604
Core‐shell Fe/Al composites were successfully prepared by chemical liquid deposition with iron carbonyl [Fe(CO)5] as precursor and kerosine as oil phase medium. Scanning electron microscopy (SEM), X‐ray diffractometer (XRD), and simultaneous thermogravimetry‐differential thermal analysis (TG‐DTA) were employed to characterize the samples and assess their thermal properties. The results indicated that the aluminum core was coated compactly by an iron layer and the the oxidation kinetics of the obtained composite powders showed a significant improvement compared to pure aluminum powders. The thermal reactivity of Fe/Al composites with oxygen is obviously higher than those of pure aluminum powders, which means that after coating much more heat can be released in the same temperature range and the heat release happens faster and more concentrated. On the basis of the results, a possible formation of the coating is proposed and a thermal reaction mechanism is also discussed. 相似文献
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《分离科学与技术》2012,47(11-12):1939-1945
Abstract Iron-dextran microspheres are easily and inexpensively made by coating uniformly sized carbonyl iron particles with dextran. The iron-dextran spheres can be conjugated with a variety of ligands (antibodies, lectins, avidin, etc.) and used with a permanent rare earth magnet to remove cells, organelles, or macromolecules from mixtures and suspensions. The spheres can be stored indefinitely for use when they are needed. Results obtained with iron-dextran particles in magnetic cell sorting are comparable to those with commercial products. They are particularly helpful when large numbers of cells are to be sorted or when a large panel of antibodies is needed. 相似文献
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煤制天然气过程中产生的羰基镍、羰基铁可对甲烷化催化剂造成不可逆的中毒反应。氯化碘甲醇溶液(碘、氢碘酸、盐酸和甲醇的混合溶液)可同时吸收合成气中的羰基镍和羰基铁,再利用石墨炉原子吸收光谱仪测定羰基镍和羰基铁含量。通过该方法测定出合成气中羰基镍的含量约为0.025 mg/L,羰基铁的含量小于0.001 mg/L。吸收液中碘浓度为6.0 g/L,氢碘酸浓度为100 mL/L最宜。羰基化合物总含量较低,不会使甲烷化催化剂中毒;在取样和测定过程中应注意个人防护,防止甲醇或CO中毒。 相似文献
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Direct coal liquefaction involves catalyzed interactions between molecular hydrogen and coal‐oil slurries at elevated pressure and temperature, typically in the presence of an iron‐based catalyst. Iron carbonyl powder as an alternative first‐stage catalyst was investigated. A series of experimental tests under mild liquefaction conditions were carried out with a high‐pressure batch reactor in order to compare the performance of the iron carbonyl precursor to the traditional superfine iron oxide catalyst. The carbonyl iron powder performed very well in terms of total conversion of coal as well as yield of coal oil product. The iron carbonyl powder acts as an effective precursor for the in situ generation of active iron sulfide. The simple kinetic models for coal liquefaction in the literature were found to be qualitatively consistent with the yields of preasphaltenes, asphaltenes, and oils obtained from the experiments. 相似文献
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An experimental technique was developed to perform in situ photo correlation spectroscopy measurements on length distribution of dynamic polydisperse iron oxide aerosols with diameters ranging from 0.01 to 0.05 μm. The cumulant analytical method is used to determine the average length of the chain aggregate. The experimental results show that the average length of the iron oxide aerosols obtained by the photo correlation spectroscopy technique is basically consistent with the results obtained by TEM. Results indicate that the length of the iron oxide samples increases as the liquid carbonyl temperature increases and the gas flow dilution ratio decrease. 相似文献
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Corrosion stability of polyester coatings on steel pretreated with different iron–phosphate coatings
B.V. Jegdić J.B. Bajat J.P. Popić V.B. Mišković-Stanković 《Progress in Organic Coatings》2011,70(2-3):127-133
The influence of steel surface pretreatment with different types of iron–phosphate coatings on the corrosion stability and adhesion characteristics of polyester coatings on steel was investigated. The phosphate coating was chemically deposited either from the simple novel plating bath, or with the addition of NaNO2, as an accelerator in the plating bath. The morphology of phosphate coatings was investigated using atomic force microscopy (AFM). The corrosion stability of polyester coatings on steel pretreated by iron–phosphate coatings was investigated by electrochemical impedance spectroscopy (EIS) in 3% NaCl solution, while “dry” and “wet” adhesion were measured by a direct pull-off standardized procedure. It was shown that greater values of pore resistance, Rp, and smaller values of coating capacitance of polyester coating, Cc, on steel pretreated with iron–phosphate coating were obtained, as compared to polyester coating on steel phosphated with accelerator, and on the bare steel. The surface roughness of phosphate coating deposited on steel from the bath without accelerator is favorable in forming stronger bonds with polyester coating. Namely, the dry and wet adhesion measurements are in accordance with EIS measurements in 3% NaCl solution, i.e. lower adhesion values were obtained for polyester coating on steel phosphated with accelerator and on the bare steel, while the iron–phosphate pretreatment from the novel bath enhanced the adhesion of polyester coating on steel. 相似文献