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提出一种以乙酸镁和乙酸钠为原料合成四苯基卟啉镁(MgTPP)的新方法, 合成样品以柱层析法进行分离纯化. 分离产物经UV-Vis、1H-NMR、MALDI-TOF-MS(基质辅助激光解吸电离飞行时间质谱)等技术表征, 确定为MgTPP. UV-Vis光谱分析结果表明, 四苯基卟啉镁的Soret 吸收带为424 nm, Q 吸收带为563 nm 和602 nm. 此外, 光照对MgTPP的二氯甲烷溶液光谱性质的影响结果表明, 经光照射后MgTPP的UV-Vis光谱的Soret吸收带吸收强度明显降低, 同时, 经550 nm的光激发产生的荧光有明显的猝灭. 对光照后的MgTPP样品进行MALDI-TOF-MS分析, 发现有新的质核比(m/z)出现, 其为668, 这一结果表明, 在光照条件下, MgTPP分子可能与氧分子发生光化学作用, 形成MgTPP与氧的复合物MgTPP-O2. 相似文献
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A wide range fractional-N frequency synthesizer in 0.18μm RF CMOS technology is implemented. A switched-capacitors bank LC-tank VCO and an adaptive frequency calibration technique are used to expand the frequency range.A 16-bit third-order sigma-delta modulator with dither is used to randomize the fractional spur. The active area is 0.6 mm~2.The experimental results show the proposed frequency synthesizer consumes 4.3 raA from a single 1.8 V supply voltage except for buffers.The frequency range is 1.44-2.11 GHz and the frequency resolution is less than 0.4 kHz.The phase noise is -94 dBc/Hz @ 100 kHz and -121 dBc/Hz @ 1 MHz at the output of the prescaler with a loop bandwidth of approximately 120 kHz.The performance meets the requirements for the multi-band and multi-mode transceiver applications. 相似文献
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