排序方式: 共有44条查询结果,搜索用时 15 毫秒
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紫外分光光度法间接测定果冻中甜蜜素 总被引:1,自引:0,他引:1
提出了紫外分光光度法间接测定食品中甜蜜素的方法。考察了酸性介质的种类,亚硝酸钠与碘化钾浓度、用量及反应时间对测定的影响。在优化的试验条件下,甜蜜素在1.0~14.0mg·mL-1范围内遵守比耳定律,检出限(3S/N)为0.3mg·mL-1。用此方法测定果冻中甜蜜素含量,加标回收率为102.6%~103.3%,相对标准偏差(n=5)为0.7%~1.3%。 相似文献
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固相萃取-气相色谱-质谱法测定土壤中阿特拉津 总被引:1,自引:0,他引:1
应用固相萃取-气相色谱-质谱法测定土壤中阿特拉津的含量。土壤样品采用索氏提取,硅胶固相萃取小柱净化。在气相色谱分离中用TR-5MS色谱柱为固定相,在质谱分析中采用选择离子检测模式。阿特拉津的质量浓度在5.00~200μg·L-1范围内与其峰面积呈线性关系,检出限为0.32ng·g-1。加标回收率在88.2%~90.7%之间,测定值的相对标准偏差(n=10)为4.8%。 相似文献
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High-Power Er^3+/Yb^3+ Codoped Double-Cladding Fibre Amplifier with More Than 2 W Output Power 下载免费PDF全文
A high-power Er^3 /Yb^3 -codoped double-cladding all-fibre amplifier was successfully demonstrated and exper-imentally investigated. The amplifier could be operated with a maximum output power of 2.18 W and 2.11 Wat 1541nm and 1550nm wavelengths, respectively, when the maximum pump power was 6.07W. The powerconversion effciency was up to 35.6% and 34.4% at the two wavelengths, respectively. The output power and the gain were greater than 2.00 W and 20.OdB, respectively, in the wavelength range from 1539nm to 1565nmfor 20.OmW input signal power. The gain fluctuation and the noise figure around 1550nm wavelength were less than 0.3 dB and 6.0 dB, respectively. 相似文献
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利用波动干涉理论推导了长周期光纤光栅的光栅方程. 利用色心模型和Kramers-Kronig原理,得到了长周期光纤光栅的中心谐振波长与曝光量的变化关系的理论公式,并进行了实验研 究. 理论和实验结果都表明,长周期光纤光栅的中心谐振波长与曝光量的关系按多项e负指 数之和规律变化,其变化率受到模板占空比的控制;另外,长周期光纤光栅的中心谐振波长 与模板占空比成反比关系.
关键词:
长周期光纤光栅
谐振波长
模板占空比 相似文献
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金属超微粒子-介质复合薄膜(Ag-BaO)的光吸收特性 总被引:6,自引:0,他引:6
测量了真空热蒸发沉积法制备的贵金属Ag超微粒子-介质(BaO)复合薄膜近紫外到可见的吸收光谱。这种薄膜的透射电镜显微像表明,Ag在介质中形成了较均匀的超微粒子,粒径为15nm。观察到吸收谱在410nm处有明显的等离子激元共振吸收峰,这是电偶极振荡的吸收。与以往文献的结果做了比较,讨论了吸收光谱对金属微粒尺寸的依赖关系。 相似文献
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A novel all fiber cavity Yb3+-doped double-clad fiber laser (DCFL) based on two double-clad fiber (DCF)Bragg grating is presented. The fiber Bragg gratings (FBGs) as the input and output mirrors have been formed in Yb3+-doped DCF with the phase-mask method, and their reflectivities are 99% and 22%,respectively. When the input pump power is 417 mW, the maximum output power is 144 mW with linewidth <0.1 nm at the wavelength of 1.057μm, over 40-dB signal-to-noise ratio (SNR), and 50.8% slope efficiency. 相似文献
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用多尺度快速配置法求解病态积分方程的隐式迭代方程.在积分算子是扇形紧算子时,该方法得到了离散隐式迭代方程的近似解.采用Morozov偏差原理作为停止准则,并证明了在该准则下隐式迭代正则化方法所得近似解的收敛率.最后,用数值实验证实理论结果和说明数值方法的有效性. 相似文献
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