排序方式: 共有18条查询结果,搜索用时 62 毫秒
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采用离子注入方法在氢化物气相外延法生长的AlN薄膜中注入了不同剂量的Dy~(3+)和Eu~(3+),制备了Dy~(3+)单掺、Dy~(3+)和Eu~(3+)共掺的AlN样品.对于Dy~(3+)单掺杂AlN样品,X射线衍射和拉曼散射实验结果表明随着Dy注入剂量的增加,样品的压应力也增加,形成了比较明显的损伤层;但当注入剂量由5×1014at/cm~2增加至1×1015at/cm~2时,压应力增加不明显,接近于饱和.对于Dy~(3+)和Eu~(3+)共掺的AlN样品,阴极荧光实验表明,AlN中Eu~(3+)和Dy~(3+)之间可能存在能量传递,能量传递途径为在声子辅助下从Dy~(3+)的4F9/2→6H15/2至Eu~(3+)的7F0→5D2的共振能量传递.此外,计算发现改变Dy~(3+)和Eu~(3+)离子的注入剂量比能实现发光色度坐标和色温的有效调控. 相似文献
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介绍了EAST偏滤器充气系统的改进措施,压电阀与冷屏一起安装在EAST颈管中,以缩短充气管道,将充气系统的延迟时间减少约200ms。冷屏起冷却阀门并屏蔽电磁场的作用。讨论了在准稳态条件下,延迟时间给偏滤器热流反馈控制带来的负面效应。在中性束加热条件下,通过在外靶板注入 Ar/D2(1:4)混合气体研究了靶板离子饱和流和热流分布的变化及充气对主等离子体的影响,得到了靶板离子饱和流显著降低、热流减少的结果。 相似文献
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采用提拉法生长yb3+掺杂浓度为0.5at;高质量的Yb∶Y3 Al5O12(Yb∶YAG)晶体.对晶体的结晶质量、分凝系数和光谱和激光性能进行了表征.结果表明:所生长的晶体结晶质量较好,在空气中退火后晶体吸收系数略有增加,晶体中自吸收效应的影响很小,具有宽的发射带.Yb∶YAG晶体和Yb∶YAG/YAG复合晶体分别在抽运功率为7.1W和6.15W的LD抽运下,获得2.19W和1.354 W的连续激光输出,斜率效率分别为34.58;和25.9;. 相似文献
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通过MOCVD方法在蓝宝石衬底上生长GaN薄膜,利用离子注入方法将Eu3+离子注入到GaN基质中。X射线衍射结果表明:经过退火处理后,修复了部分离子注入所导致的晶格损伤。利用阴极荧光光谱可得到GaN∶Eu3+材料在623 nm处有很强的红光发射,该发射峰来源于Eu3+离子的内部4f能级跃迁。另外,Eu3+离子注入会在样品中引入电荷转移态,产生408 nm附近的发光。退火处理有助于获得更强的电荷转移态发光和Eu离子特征发光。GaN基质的黄光峰与Eu离子之间存在能量交换,将能量传递给Eu离子,促进Eu离子发光。 相似文献
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To investigate the radiative divertor behavior and physics for the scenario of impurity seeded plasma in ITER, the radiative divertor experiments with argon(Ar) seeding under ITER-like tungsten divertor condition were carried out during recent EAST campaigns. The experimental results reveal the high efficiency of reducing heat load and particle flux onto the divertor targets owing to increased radiation by Ar seeding. We achieve detached plasmas in these experiments. The inner–outer divertor asymmetry reduces after Ar seeding. Impurities, such as Ar, C, Li, and W, exist in the entire space of the vacuum chamber during EAST operations, and play important roles in power exhausting and accelerating the plasma detachment process. It is remarkable that the contamination of the core plasma is observed using Ar seeding owing to the sputtering of plasma facing components(PFCs), particularly when Ar impurity is injected from the upper tungsten divertor. 相似文献
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采用离子注入的方法制备了Eu3+,Tm3+离子共掺杂GaN薄膜。通过温度依赖光致发光光谱研究了GaN:Eu3+薄膜中Eu3+的发光特性,发现了三类具有不同温度依赖特性的Eu3+发射峰。利用阴极荧光光谱探究了GaN:Eu3+,Tm3+薄膜的光谱性质,发现随着Tm3+剂量的增加,Eu3+发射强度以及Tm3+的I480/I806强度比值均发生降低,分析表明存在Eu3+→Tm3+离子的能量传递,并通过计算分析证明其能量传递机制主要为电偶极子-电偶极子相互作用。通过改变Eu3+、Tm3+离子在GaN薄膜中的剂量比例,实现了材料发光颜色的有效调控。 相似文献
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We investigate the spectra and scintillation properties of Ce:YA103,Ce:Y3Al5O12,and Ce:LaA103.For Ce:YAlO3,the excitation spectrum is very similar with the absorption spectrum;for Ce:Y3Al5O12 and Ce:LaAlO3,the excitation spectra are different from the absorption spectra.Further,Ce:YAlO3 has better scintillation performance than Ce:Y3Al5O12 whereas Ce:LaAlO3 has not demonstrated scintillation performance to date.We also provide reasonable explanations for these experimental phenomena from the viewpoint of energy level structure. 相似文献
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