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991.
Rare earth oxides (REO = Gd2O3, Dy2O3, Tm2O3) and acrylic acid (AA) were in situ reacted in hydrogenated acrylonitrile–butadiene rubber (HNBR) to prepare HNBR/multi-walled carbon nanotube (MWCNT)/REO/AA composites. The HNBR/MWCNT/REO/AA composites have higher permittivity and dielectric loss than HNBR/MWCNT composite, leading to significantly enhanced microwave absorbing performance of the HNBR/MWCNT/REO/AA composites. Dielectric permittivity analysis reveals that the HNBR/MWCNT/REO/AA composites have longer dielectric relaxation time and higher conductivity than the HNBR/MWCNT composite. The HNBR/MWCNT composite has the minimum reflection loss of −15.1 dB, while the HNBR/MWCNT/REO/AA composites have the minimum reflection loss of −48.8 dB. The improvement of microwave absorbing performance is attributed to the stronger interfacial polarization and higher conductivity after formation of in situ prepared rare earth acrylates. 相似文献
992.
N Liu C Wang W Zhang Z Luo D Tian N Zhai H Zhang Z Li X Jiang G Tang Q Hu 《Nanotechnology》2012,23(33):335602
In this paper, tobacco mosaic virus (TMV) coated protein (CP) was genetically modified by introducing a hexahistidine tag into it for a well-defined one-dimensional template, on which Au nanocrystals (NCs) were grown. The results showed that genetic modification could not only ameliorate the one-dimensional structure of the template, but also improve the growth density of Au NCs on the template. This indicated that genetic modification could be an effective method to modulate the structure of the TMVCP template-based nanocomposites allowing for a broader application of them. 相似文献
993.
Sun L Sun GN Wang JS Wong PK Zhang Y Fu Y Zhai Y Bai XJ Du J Zhai HR 《Journal of nanoscience and nanotechnology》2012,12(8):6562-6566
(Fe50Co50)(1-x)-Gdx thin films (30 nm) with x<15% deposited on silicon substrates by magnetron sputtering were investigated by X-ray diffraction, vibrating sample magnetometer, and ferromagnetic resonance. Theoretical fittings of the angular dependent ferromagnetic resonance field of the FeCoGd films have been performed using the Landau-Lifshitz equation It is found that the ferromagnetic resonance experimental data is well fitted by the theory and various magnetic properties have been extracted in accordance. The saturation magnetization decreases from 22750 Oe at x = 0% to 14079 Oe at x = 14% in the FeCo-Gd film, and the perpendicular magnetic anisotropy has changed from an easy film plane to an easy film normal geometry. The gyromagnetic ratio, as well as the Landé g factor, are found increased also with increasing Gd content, i.e. from g = 2.08 at x = 0% to g = 2.29 at x = 14%. An enhancement of the L-S coupling in the presence of a low Gd content has been concluded based on an observable increase from 0.011 at x = 12% up to 0.015 at x = 14% in the Gilbert damping. 相似文献
994.
995.
以甲基丙烯酸羟乙酯(HEMA)和甲基丙烯酸(MAA)为聚合单体,异辛烷为分散介质,Span80和Tween80为复配乳化剂,采用反相微乳液聚合法制得不同单体配比的聚(甲基丙烯酸羟乙酯-co-甲基丙烯酸)(P(HEMA-co-MAA))纳米凝胶。确定了产物的pKa值及实际单体物质的量比,对产物的形貌进行了表征并研究了产物的pH响应性.结果显示,MAA物质的量分数为20%的纳米凝胶的pKa值为5.83,在pH=3和pH=7时其数均粒径分别为48 nm和90 nm;当环境pH接近pKa值时,纳米凝胶分散液的浊度明显降低,溶胀率明显上升,表观黏度急剧增加,说明纳米凝胶具有良好的pH响应性。 相似文献
996.
目的:评估彩色多普勒超声监测颈内静脉置管术的临床价值。方法:应用彩色多普勒超声实时监测120例患者的置管过程,对临床"盲穿"不成功的25例患者及"盲穿"后出现并发症的30例患者进行超声检查分析。结果:120例经实时超声监测的患者均取得成功,没有出现严重的并发症;临床盲穿不成功的原因有误穿颈总动脉、颈内静脉瓣膜过长、误穿颈外静脉、穿入颈内静脉或锁骨下静脉的对侧壁致使导丝不能下移;"盲穿"后出现的并发症主要为血肿、导管堵塞、胸锁乳突肌肿胀、静脉血栓形成、胸腔积血、误穿动脉、假性动脉瘤形成、导管周围纤维鞘膜形成等。结论:超声定位有助于顺利完成颈内静脉穿刺置管,并且对颈内静脉穿刺的各种并发症能够作出准确的诊断。 相似文献
997.
998.
针对即将实施的摩托车国Ⅲ燃油排放标准,介绍了我国摩托车燃油蒸发排放技术发展现状,对摩托车燃油蒸发排放控制系统进行合理的分析研究设计。试验证明,设计的燃油蒸发排放控制系统可以满足国Ⅲ燃油蒸发排放的限制要求,并且对原有发动机性能没有明显影响。 相似文献
999.
提出了一种高违约率下融资租赁信用风险的评价方法,基于专家群体对评价指标赋值类型的不同引入多属性决策的指标权重确定方法。以我国工程机械行业融资租赁信用风险评价为例,分析了我国工程机械行业融资租赁信用风险的特征,构建了以定量的财务指标与定性的非财务指标相结合的信用风险评价指标体系,进而运用上述方法确定了各级指标的权重,阐述了该评价方法的合理性。 相似文献
1000.
Qiang Li Jianhua LiuJianhua Zou Anindarupa ChunderYiqing Chen Lei Zhai 《Journal of power sources》2011,196(1):565-572
Multi-walled carbon nanotube (MWCNT)/polyaniline (PANI)/MnO2 (MPM) ternary coaxial structures are fabricated as supercapacitor electrodes via a simple wet chemical method. The electrostatic interaction between negative poly(4-styrenesulfonic acid) (PSS) molecules and positive Mn2+ ions causes the generation of MnO2 nanostructures on MWCNT surfaces while the introduction of PANI layers with appropriate thickness on MWCNT surfaces facilitates the formation of MWCNT/PANI/MnO2 ternary coaxial structures. The thickness of PANI coatings is controlled by tuning the aniline/MWCNT ratio. The effect of PANI thickness on the subsequent MnO2 nanoflakes attachment onto MWCNTs, and the MPM structures is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and field-emission scanning electron microscopy (FESEM). The results suggest that appropriate thickness of PANI layers is important for building MPM ternary coaxial structures without the agglomeration of MnO2 nanoflakes. The MPM ternary coaxial structures provide large interaction area between the MnO2 nanoflakes and electrolyte, and improve the electrochemical utilization of the hydrous MnO2, and decrease the contact resistance between MnO2 and PANI layer coated MWCNTs, leading to intriguing electrochemical properties for the applications in supercapacitors such as a specific capacitance of 330 Fg−1 and good cycle stability. 相似文献