1000 resultados para 20-198A


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每种酸碱指示剂在其变色PH范围内都有一个明显的颜色变化,在其相应的PH-A曲线上总存在一段直线部分,通过选择一定PH变色范围和适当浓度的指示剂,就能使各指示剂PH-A曲线上的直线部分相互迭加成一条新的直线,从而加宽了混合指示剂的表现变色PH范围,依此原理,本论文以二种流动注射分析方法独立地完成了工艺流程中高浓定影液酸度的在线分析。并对这二种方法做了简单的对比。(一)工艺流程中高浓定影液酸度的在线分析方法研究(1)我们选择了内含0.08%溴甲酚紫,0.04%溴百里酚兰,0.02%甲酚红组成的混合指示剂的6%稀释液作为试剂,以C-41CX定影浓缩液作载流,用F2A-分光光度法完成了高浓度定影液酸度的在线测定,相对标准偏差在50.2%以内,采样频率为100次/h,分析周期很短(25秒),在5.5~8.0PH范围内,PH-A工作曲线具有很好的线性关系,相关系数0.9996,斜率即灵敏度达到:0.198A/PH。(二)工艺流程中高浓定影液酸遮掩在线分析方法研究(2)我们造反了0.005%的溴甲酚紫,0.009%的溴百里酚兰和0.025%的甲酚红作为混合酸碱指示剂,以蒸馏水作载流,通过选择最佳测定条件用流动注射-分光光度法(F2A-Spectrophotometry)在线测定了不宜用其它分析法测定的高浓溶液的酸度。该分析方法还可以推广到其它高浓溶液的酸度的在线测定。相对误差在±0.2%以内;分析周期为30秒;采样体积为60μL。在5.2~8.5PH范围内,混合指示剂的PH-A工作曲线具有良好的线性关系,相关系数达到0.9991,工作曲线斜率即是灵敏度达到0.376A/PH。

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本文通过分析A面(11-20)ZnO薄膜的低温PL(光致发光)光谱偏振特性来研究ZnO光致发光谱中杂质峰的来源.低温(4 K)下观察到476、479 nm两处新的杂质峰以及390 nm处激子峰,根据两个杂质峰的偏振特性,初步判定476nm峰来源于氧空位能级到价带轻空穴的跃迁,479 nm峰来源于氧空位价带重空穴的跃迁.

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We report all optical clock recovery based on a monolithic integrated four-section amplified feedback semiconductor laser (AFL), with the different sections integrated based on the quantum well intermixing (QWI) technique. The beat frequency of an AFL is continuously tunable in the range of 19.8-26.3 GHz with an extinction ratio above 8 dB, and the 3-dB linewidth is close to 3 MHz. All-optical clock recovery for 20 Gb/s was demonstrated experimentally using the AFL, with a time jitter of 123.9 fs. Degraded signal clock recovery was also successfully demonstrated using both the dispersion and polarization mode dispersion (PMD) degraded signals separately.