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A new single-mode optoelectronic oscillator (OEO) with three coupled cavities is proposed and demonstrated. A Fabry-Perot (F-P) cavity fiber laser and an optical-electrical feedback branch are coupled together to construct an optoelectronic oscillator, where the F-P cavity fiber laser serves as a light source, and a modulator is placed in the laser cavity to implement reciprocating modulation, which simultaneously splits the laser cavity into two parts and forms a dual-loop configuration. To complete an optoelectronic oscillator, part of optical signal is output from the F-P cavity to implement the feedback modulation, which constructs the third cavity. Since only the oscillation signal satisfies the requirements of all the three cavities, a single-mode oscillation can be finally achieved. Three resonant cavities are successfully designed without adding more optoelectronic devices, and the side-modes can be well suppressed with low cost. The oscillation condition is theoretically analyzed. In the experimental demonstration, a 20 GHz single longitudinal mode microwave signal is successfully obtained. 相似文献
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采用扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)及BET方法对在硫酸中水热炭化前后的甘蔗渣进行了表征。结果显示,炭化后的甘蔗渣为骨状结构,表面有大量整齐排列的孔隙,比表面积大大增加,且化学结构与炭化前相比发生了改变。采用14 g/L甘蔗渣水热炭处理含50 mg/L Cr(Ⅵ)的模拟废水时,在温度35℃和pH=2的条件下反应90 min,Cr(Ⅵ)的去除率为99.8%,最大Cr(Ⅵ)吸附量为3.871 mg/g。Langmuir等温吸附模型和拟二级动力学方程能很好地反映吸附过程。采用该甘蔗渣水热炭,只要12 g/L就能令含总铬25.09 mg/L、Cr(Ⅵ)20.07 mg/L、Zn~(2+)1.88 mg/L、Ni~(2+)1.14 mg/L和Cu~(2+)1.68 mg/L的实际电镀废水达到GB 21900–2008《电镀污染物排放标准》的"表3"要求。 相似文献
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土壤中铜铅测定中的电热板消解方法研究 总被引:1,自引:0,他引:1
该实验采用3种不同的消解方法对土壤标准物质和实际样品进行前处理,用电感耦合等离子体质谱仪(ICP-MS)测定其中铜(Cu)和铅(Pb)的含量。结果表明:(1)四酸加热消解法对土壤中Cu和Pb这两种金属元素的提取更充分;(2)王水加热消解法和硝酸-硫酸加热消解法对土壤中铜和铅的检测结果偏低,但所用酸种类和用量更少;(3)王水加热消解法和硝酸-硫酸加热消解法的能耗相对四酸加热消解法较小,当土壤中铅和铜的含量较高,3种前处理方法检测结果差别较小。 相似文献
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