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61.
MnxNi0:5-xZn0:5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2+, Ni2+, and Fe2+ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffrac-tion and transmission electron microscopy. The magnetic properties of the samples were stud-ied using a vibrating sample magnetometer. The results indicated that pure Ni0:5Zn0:5Fe2O4 nanorods with a diameter of 35 nm and an aspect ratio of 15 were prepared. It was found that the diameter of the MnxNi0:5-xZn0:5Fe2O4 (0≤x≤0.5) samples increased, the length and the aspect ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7~8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coer-civity of the samples again increased when the x value was higher than 0.4. When x=0.5,the coercivity of the MnxNi0:5-xZn0:5Fe2O4 sample reached the maximal value (134.3 Oe)at the calcination temperature of 600 oC. The saturation magnetization of the samples first increased and then decreased with the increase in the x value. When x=0.2, the satura-tion magnetization of the sample reached the maximal value (68.5 emu/g) at the calcination temperature of 800 oC. 相似文献
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熔盐处理MnO_2及其超级电容性能研究 总被引:1,自引:0,他引:1
以KCl-NaCl-LiCl熔盐体系处理由固相法制备的MnO2,经XRD、循环伏安、恒流充放电和交流阻抗测试表明,合成的MnO2样品含α-MnO2与γ-MnO2混合晶相,熔盐处理后其结晶程度增加,而且超级电容性能明显提高,放电比容量(129.07 F.g-1)比处理前的(100.94 F.g-1)提高了27.88%.熔盐处理后的样品循环性能良好,充放电效率接近100%,等效串联电阻(RESR)和电极电阻(RE)分别为0.28Ω和0.54Ω. 相似文献
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An Integrative Biosensor Based on Contra-Directional Coupling Two-dimensional Photonic Crystal Waveguides 下载免费PDF全文
We propose an integrative biochemical sensor utilizing the dip in the transmission spectrum of a normal singleline defect photonic crystal (PC) waveguide, which has a eontra-directional coupling with another PC waveguide. When the air holes in the PC slab are filled with a liquid analyte with different refractive indices, the dip has a wavelength shift. By detecting the output power variation at a certain fixed wavelength, a sensitivity of 1.2 × 10^-4 is feasible. This structure is easy for integration due to its plane waveguide structure and omissible pump source. In addition, high signal to noise ratio can be expected because signal transmits via a normal single-line defect PC waveguide instead of the PC hole area or analyte. 相似文献
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Two-dimensional photonic crystal slab waveguides on SOI wafer are designed and fabricated. Photonic band gap, band gap guided mode, and index guided mode are observed by measuring the transmission spectra. The experimental results are in good agreement with the theoretical ones. 相似文献
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葡萄糖生物传感器以其灵敏度高、选择性好、反应速度快以及稳定性好等优点吸引了许多研究者的关注。 本文将已发表的一些葡萄糖检测方法分为两类:葡萄糖酶生物传感器检测方法与无酶葡萄糖生物传感器检测方法,简要介绍了这2种检测方法的一些研究进展,并对葡萄糖检测方法的发展前景进行了展望。 相似文献
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人参皂苷Rg3的拉曼光谱研究 总被引:2,自引:0,他引:2
人参皂苷是人参的有效化学成分,其中人参皂苷Rg3因具有显著的生理活性而备受关注。运用拉曼光谱的方法,对人参皂苷Rg3的两种异构体20-(R)-Rg3和20-(S)-Rg3进行了测量和分析。因20位羟基空间位置不同,20-(R)- Rg3与20-(S)- Rg3相比,归属于亚甲基的振动峰发生了明显的变化,表明两种异构体的堆积方式不同。归属于CC振动的1 674 cm-1峰的强度明显降低,表明在20-(S)-Rg3中,C27和C28较20-(R)-Rg3处于分子内部。对比拉曼光谱还发现,这一对异构体中糖环的空间结构基本相同。两种异构体拉曼光谱的明显差异,使得拉曼光谱技术成为鉴别人参皂苷Rg3异构体的一种快速、简便的分析方法。 相似文献
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The deconvolution algorithm is adopted on the fiber Raman distributed temperature sensor (FRDTS) to improve the spatial resolution without reducing the pulse width of the light source. Numerical simulation shows that the spatial resolution is enhanced by four times using the frequency-domain deconvolution algorithm with high temperature accuracy. In experiment, a spatial resolution of 15 m is realized using a master oscillator power amplifier light source with 300-ns pulse width. In addition, the dispersion-induced limitation of the minimum spatial resolution achieved by deconvolution algorithm is analyzed. The results indicate that the deconvolution algorithm is a beneficial complement for the FRDTS to realize accurate locating and temperature monitoring for sharp temperature variations. 相似文献
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A dynamically tunable fiber filter realizing complex spectra of phase-shifted long period fiber gratings (LPFGs) is proposed and demonstrated experimentally. The principle of the filter is based on two acousto-optic coupling processes occurring simultaneously. The first coupling process acts as a normal LPFG, while the second makes the coupling direction of the first process change continuously, leading to a similar transmission spectrum with the phase-shifted LPFGs, in which the changing of coupling direction is realized by the discrete phase shifts of the index modulation. By adjusting the acoustic tuned to realize the phase-shifted LPFGs' spectra drive signals, its transmission spectrum can be dynamically under different phase shift numbers and locations. 相似文献