排序方式: 共有70条查询结果,搜索用时 343 毫秒
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Runru Liu Dapeng Xu Shuang Li Zhe Lü Yanfeng Xue Deyong Wang Wenhui Su 《Frontiers of Chemistry in China》2006,1(4):398-401
In this paper, perovskite oxide SmCoO3 was prepared by the solid-state reaction method using Co2O3 and Sm2O3 as raw materials. The structure and properties of the samples were investigated by XRD, Raman spectral techniques, and DC
measurements and so on. The results of XRD and Raman spectra showed that the mixtures of Co2O3 and Sm2O3 can react to produce a single phase perovskite oxide SmCoO3 around 1353 K. The single-phase SmCoO3 changes from an insulator to a semi-conductor and transition occurs around 470 K. The thermal expansion coefficient (2.17
× 10−5 K−1) of the single-phase SmCoO3 is approximately equal to that of doped LaGaO3, but much bigger than that of SDC(Ce0.85Sm0.15O2) above 873 K. 相似文献
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A simple, reliable, and reproducible method for in-vivo on-line separation and determination of levodopa has been based on microdialysis then high-performance liquid chromatography with chemiluminescence detection. The perfusate is perfused at a flow rate of 5 L min–1. The concentration of levodopa in the dialysate is determined on line with a chemiluminescence system. The dialysate sample volume is approximately 20 L. The response of the system is linearly related to the concentration of levodopa in the range 1×10–8 to 1×10–6 g mL–1 (r2=0.9995) with a detection limit (3) of 3×10–9 g mL–1 and sample throughput of 12 h–1; RSD is 2.8% (n=11). The method has been successfully used to study the pharmacokinetics of levodopa in vivo; the values of the pharmacokinetics parameters Cmax, AUC0–t and Tmax were 16.60, 20.92 ng mL–1, and 90 min, respectively. 相似文献
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基于luminolH2O2Co2+化学发光体系,设计了一种新的微流动注射芯片,准确测定了雨水中的H2O2含量。芯片由两块50mm×40mm×5mm的透明有机玻璃(PMMA)在实验室加工而成。由CO2激光雕刻机刻蚀出的微通道宽200μm,深150μm。方法的线性范围为0.05~2μmol/L;检出限为0.02μmol/L(S/N=3)。对0.6μmol/L的H2O2溶液平行测定9次,得方法的相对标准偏差(RSD)为4.6%。该方法已成功用于雨水中微量H2O2的测定。 相似文献
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氧化锌(ZnO)纳米线/棒阵列的质量决定了所构建光电器件的性能. 为了制备出比表面积更大、垂直性更好以及无根部融合的高质量ZnO纳米线/棒阵列, 本文概述了近几年两步水热法可控制备ZnO纳米线/棒阵列的研究进展, 分别探讨了种子层、生长液和生长方法对纳米线/棒阵列形貌的影响, 详细分析了氨水、六次甲基四胺和聚乙烯亚胺对于促进纳米线/棒阵列生长的作用机理, 提出了通过微流控技术可控制备ZnO纳米线阵列提高纳米线生长效率的方法. 最后介绍了ZnO纳米线/棒阵列的形貌对于提高染料敏化太阳能电池、纳米发电机、气体传感器和场发射器件性能的重要作用, 并对未来两步水热法制备ZnO纳米线/棒阵列的发展趋势进行了展望. 相似文献
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The reflected fields of a slightly divergent ultrasonic beam on a liquid-solid interface are recorded by a Schlieren system,
and the lateral beam displacements on the interface are measured. The range of the incident anglei is around the Rayleigh anglec. The displacements are found to decrease as the incident angle increases. Theoretical calculation reveals that the displacements
decrease with the increase in the incident angle for a divergent incident beam, but increase with that for a convergent one.
The calculated curve of-
i are in agreement with the experimental results. 相似文献
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Liang Lü 《中国光学快报(英文版)》2006,4(2)
An optimized design of laser range finding system using the self-mixing effect in a single-mode verticalcavity surface-emitting laser (VCSEL) is proposed. In order to improve the ranging accuracy and expand dynamic measurement range, we apply difference frequency analog phase-locked loop (PLL) instead of fast Fourier transform (FFT) to process signal, and choose the optimum triangular wave frequency fm= 500Hz and small modulation current △Ip-p = 0.28 mA to modulate single-mode VCSEL. The experiment results show that, without controlling the laser's temperature, the ranging accuracy is better than 2 mm and the measurement dynamic range is as large as 50-500 mm when the sampling time is 0.1 s and the room temperature is 0-55 ℃. 相似文献
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本文讨论了一类带小参数的二维反应扩散型方程组的数值方法,基于奇摄动理论,Green函数、分裂方法和半群理论,建立这种类型方程组的计算格式,在误差分析中,运用了不等距步长的可行等距度,并将Lorenz的技巧用于估计解的性状,最后,得到了不安l1「Ω」模意义下以O(h+l+△t)的速度一致收敛。 相似文献
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