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<正>Optically transparent Er~(3+)/Tm~(3+)/Yb~(3+) tri-doped oxyfluoride tellurite based nano-crystallized glass ceramics with the batching composition of 73TeO_2-15ZnO-7ZnF_2-3YF3-1.5YbF3-0.3ErF3-0.2TmF_3(mol%) is prepared by a conventional melting quenching and the subsequent heat treatment processes.The sizes of grown nano-crystals in glass matrix appear to be smaller than 100 nm from the scanning electron microscope measurement.Visible up-conversion luminescence of the as melted glass and glass ceramics is investigated.The three-color up-conversion luminescence intensities by 980-nm pumping are increased significantly due to the heat treatment,and the blue intensity increases with a higher magnitude than other wavelengths after heat treatment. 相似文献
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为了研究锗酸盐玻璃中采用Yb3+/Tm3+/Ho3+三掺杂方式实现2 μm激光的可行性,研究了3种稀土离子的掺杂浓度对近2 μm发光的影响,从而对稀土离子掺杂浓度进行优化选择以确定理想的掺杂浓度.实验结果表明,在TmF3掺杂摩尔分数为1%时,随着Yb3+浓度的提高Ho3+的2 μm荧光强度增强;当TmF3掺杂摩尔分数为3%时,随着Yb3+浓度的提高Ho3+的2 μm荧光强度降低;随着Yb3+浓度的提高,Tm3+的近2 μm荧光发射会得到增强,且当Tm3+浓度较高时其发光更为明显,这相对削弱了Ho3+的2 μm荧光.Ho3+2 μm发光受Tm3+/Ho3+的浓度比值影响很大,即用980 nm光抽运三掺杂样品,无论Tm3+浓度单一提高还是Ho3+浓度单一降低,对于Ho3+的2μm荧光都是不利的. 相似文献
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稀土材料红外多光子量子剪裁现象 总被引:1,自引:0,他引:1
稀土红外量子剪裁为目前国内外的研究热点,它对于提高太阳能电池的效率从而减低太阳能发电的造价很有意义。论文综述了稀土红外量子剪裁的研究意义,在总结了太阳能电池发电和损耗的原理的基础上,分析了稀土红外量子剪裁提高太阳能电池效率的具体途径。同时综述了单掺Er3+材料的稀土红外量子剪裁发光现象:光激发2H11/2能级有很强的4I13/2→4I15/2红外量子剪裁发光,速率很大的{2H11/2→4I9/2,4I15/2→4I13/2}交叉能量传递为导致光激发2H11/2能级有高量子剪裁效率的主要原因。 相似文献
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北五味子中一种新的莽草酸衍生物的分离纯化及其含量测定 总被引:1,自引:0,他引:1
从北五味子中提取分离得到一种新的莽草酸衍生物, 经一维、二维核磁共振波谱(1D NMR, HMQC, HMBC)等数据解析, 鉴定为莽草酸正丁酯. 并采用ZORBAX Extend C18柱, 以乙腈-0.05%磷酸为流动相进行梯度洗脱, 检测波长为215 nm, 流速1.0 mL/min, 建立了北五味子中莽草酸正丁酯含量的高效液相色谱分析方法. 结果表明, 莽草酸正丁酯在2~65 μg/mL浓度范围内线性关系良好, 相关系数r=0.9999, 平均回收率为98.25%, 相对标准偏差(RSD)为1.55%, 表明本法简单准确, 重复性好. 相似文献
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离子凝聚法制备负载流感疫苗的壳聚糖微球 总被引:2,自引:1,他引:1
采用三聚磷酸钠(TPP)作为离子交联剂, 应用离子凝聚法制备负载流感疫苗的壳聚糖微球. 筛选出壳聚糖起始质量分数为1%. TPP的浓度对壳聚糖微球的制备影响较大, 采用低浓度的TPP(200 μg/mL)制备的微球放置过夜均出现沉淀现象, 高浓度的TPP(800 μg/mL)在制备过程中出现絮状沉淀. 固化比影响微球的释放行为, 固化比为1∶1的微球爆炸式释放率达到90%, 固化比为1∶3的微球6 h后逐步释放, 12 h后释放率达到95%. 固化比为1∶5的微球6 h后没有明显的释放行为. 壳聚糖溶液的pH对微球的制备和释放没有显著的影响. 通过对负载流感疫苗的壳聚糖微球的制备条件和释放行为的研究结果表明, pH=5.6的壳聚糖溶液, 固化比为1∶3, TPP的质量浓度为400 μg/mL是较理想的流感疫苗壳聚糖微球的制备条件. 相似文献
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A new transparent Tm3+-doped ZrF4-based nanocrystallized glass with the composition of 55ZrF4-20BaF2-18.8YF3-5AlF5-1.2TmF3 (mol%) (ZBYA) has been prepared by a conventional melting quenching technique and the subsequent heat treatment processes. The glass characteristic temperatures, the apparent activation energy, and the Avrami parameter for crystallization are estimated on the basis of different scanning calorimetry (DSC). The sizes of grown nanocrystals in the glass matrix appear to be 30-36.5 nm and it is studied as a function of the nucleation temperature, also the peak intensity of the nanocrystalline is studied as a function of the nucleation temperature from the X-ray diffraction (XRD) measurement. The rnicrohardness measurement shows that the Vickers microhardness (Hv) values of the heat-treated glass samples are larger than that of the based glass about 17.26%-42.04%. 相似文献
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Optically transparent Er3 -doped tellurite-based nanocrystallized glasses with the composition of 70TeO2·15Li2O·15Nb2O5·0.5Er2O3 (mol) have been prepared by a conventional melting quenching and the subsequent heat treatment processes. The sizes of grown nanocrystals in glass matrix appear to be 35-50 nm from the X-ray diffraction (XRD) measurement. The microhardness measurement shows that the Vickers hardness values of the nanocrystallized tellurite glasses are larger (33%-62%) than those in the base glass. The Raman spectra imply that the maximum phonon energy of the based glass decreases and shifts from 668 to 638 cm-1 after heat-treatment. Visible upconversion luminescence and infrared luminescence of the base glass and heat-treated glasses under 980-nm laser diode (LD) excitation are investigated. The 524-, 546- and 656-nm upconversion intensities by 980-nm pumping increase significantly. 相似文献