排序方式: 共有81条查询结果,搜索用时 15 毫秒
41.
Xin-Yuan Sun Jun-Cheng ZhangXin-Gen Liu Liang-Wu Lin 《Physica B: Condensed Matter》2011,406(21):4089-4093
The Ca2.95−yDy0.05B2O6:yNa+ (0≤y≤0.20) phosphors were synthesized at 1100 °C in air by the solid-state reaction route. The as-synthesized phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE), photoluminescence (PL) spectra and thermoluminescence (TL) spectra. The PLE spectra show the excitation peaks from 300 to 400 nm due to the 4f-4f transitions of Dy3+. This mercury-free excitation is useful for solid-state lighting and light-emitting diodes (LEDs). The emission of Dy3+ ions on 350 nm excitation was observed at 480 nm (blue) due to the 4F9/2→6H15/2 transitions, 575 nm (yellow) due to 4F9/2→6H13/2 transitions and 660 nm (red) due to weak 4F9/2→6H11/2 emissions. The PL results from the investigated Ca2.95−yDy0.05B2O6:yNa+ phosphors show that Dy3+ emissions increase with the increase of the Na+ codoping ions. The integral intensity of yellow to blue (Y/B) can be tuned by controlling Na+ content. By the simulation of white light, the optimal CIE value (0.328, 0.334) can be achieved when the content of Na+-codoping ions is y=0.2. The results imply that the Ca2.95−yDy0.05B2O6:yNa+ phosphors could be potentially used as white LEDs. 相似文献
42.
Xin-Yuan Sun Liang-Wu Lin Wen-Feng Wang Jun-Cheng Zhang 《Applied Physics A: Materials Science & Processing》2011,104(1):83-88
Li2Sr1−3x/2Dy
x
SiO4 phosphors were synthesized at 900°C in the normal atmosphere by a solid-state method. The synthesized phosphors were characterized
by X-ray powder diffraction (XRD) and photoluminescence (PL) spectra. The photoluminescence excitation (PLE) spectra show
excitation peaks ranging from 300 to 400 nm due to the 4f-4f transitions of Dy3+. This mercury-free excitation is useful for solid-state lighting and light-emitting diodes (LEDs). The predominant emission
of Dy3+ ions under 349 nm excitation is observed at 479 nm (blue) due to the 4F9/2→6H15/2 transitions and 572 nm (yellow) due to 4F9/2→6H13/2 transitions, respectively. The PL results reveal that the optimal concentration of the Dy3+ ions in Li2Sr1−3x/2Dy
x
SiO4 phosphors is x=0.03 mol. The nature of the resonance energy transfer for the Dy3+ ions is confirmed by Huang’s rule. Simulation of the white light excited by 349 nm near-ultraviolet (n-UV) light is also
performed for its potential for white LEDs. 相似文献
43.
采用共混-旋涂技术在ITO导电玻璃上制备出经山梨醇掺杂的PEDOT:PSS导电膜,将所制得的薄膜作为空穴传输层用于有机太阳能电池研究.通过对比分析掺杂前后光电池暗电流曲线与光电流曲线的变化,考察了山梨醇掺杂对器件光伏性能的影响,并就其中的影响机理进行了讨论分析.结果表明,山梨醇的加入,可以明显提高光电池的短路电流,填充因子以及能量转换效率.较未掺杂器件,8wt %山梨醇掺杂条件下,器件短路电流由8.82 mA/cm2增加至11.27 mA/cm2,FF由0.43
关键词:
PEDOT:PSS薄膜
山梨醇
有机太阳能电池
性能 相似文献
44.
随着高性能第三代同步辐射光源的建成开放,基于X射线相干特性的实验方法得到了快速发展和广泛应用.作为一个典型的例子,X射线相位衬度成像已经成为常规的X射线实验方法并向用户开放.相干散射、相干衍射成像、光子关联谱等X射线实验方法正日益受到重视,在高空间分辨、时间分辨等研究领域已显示出其独特的优越性.因此,研究和测量第三代同步辐射的空间相干特性对进一步发展这些新的实验方法具有重要意义.基于Talbot自成像原理成功测量了上海光源X射线成像线站发射的X射线的空间相干长度,并进而测得了相应光源的空间尺度.光子能量为33.2 keV时,测得的X射线光束垂直方向空间相干长度为8.84μm,对应的光源尺寸为23μm,测量结果与理论分析相符. 相似文献
45.
提出了一种基于NI PXIe-7966R(National Instruments Corporation,美国)的磁共振成像(MRI)接收机设计方案,进行磁共振信号直接采样、数字下变频(DDC)和数据上传,以及磁共振图像恢复.使用NI LabVIEW FPGA(National Instruments Corporation,美国)开发平台,对NI PXIe-7966R板载现场可编程门阵列(FPGA)内构建的所有功能模块进行了设计仿真和硬件描述语言生成,使其能灵活实现DDC功能.设计的接收机的采样速度为50 Mbps、模数转换位数为16位、带宽设置范围为100 Hz~1 MHz,并具有较好的滤波效果.实验结果表明,该设计方案是一种高性能的磁共振接收机方案. 相似文献
46.
Xiang-Feng Wu Hui Li Jun-Zhang Su Jia-Rui Zhang Yan-Mei Feng Jun-Cheng Pan Ying Zhang Li-Song Sun Wei-Guang Zhang Guo-Wen Sun 《Journal of nanoparticle research》2018,20(6):155
The In2.77S4 microspheres had been firstly fabricated by using polyethylene glycol (PEG) as the morphological modifier and then used to hybridize with In(OH)3 nanocubes by a simply depositional method. The structure, optical properties, morphology, chemical compositions, and charge carrier behaviors of the as-prepared In2.77S4/In(OH)3 composites were characterized, respectively. The methyl orange, tetracycline, rhodamine B, and Cr(VI) dilute solution were selected to evaluate their photocatalytic activities. Experimental results showed that In(OH)3 nanocubes could improve the photocatalytic activity and recyclability of the In2.77S4 microspheres under the visible light irradiation. With the usage of In(OH)3 increased, the photocatalytic efficiency of the hybrids was firstly increased and then decreased. When the mass ratios of In2.77S4 to In(OH)3 were 6:2, it reached the maximum of 100% in 15 min for methyl orange, obviously higher than 67.4% of In2.77S4 and 1.1% of In(OH)3. Meanwhile, it could also oxidize 85.6% of tetracycline in 20 min, 97.8% of rhodamine B in 7.5 min, and reduce 92.9% of Cr(VI) in 30 min under the visible light irradiation. Moreover, it could still degrade 91.7% of methyl orange solution after 3 cycles, which was much higher than 40.7% of In2.77S4 microspheres. In addition, the possible mechanism of enhancing photocatalytic properties was proposed. 相似文献
47.
采用气态源分子束外延方法生长了束缚态到连续态跃迁太赫兹量子级联激光器(terahertz quantum-cascade laser,简称THz QCL)有源区结构,并且采用电化学CV仪、霍尔测试仪以及高分辨X射线衍射对材料的质量进行表征,得出THz QCL有源区具有很高的晶体质量.另外,采用蒙特卡罗方法模拟了共振声子THz QCL器件的I-V曲线,分析了在不同偏压下子能级的对齐状况和电子的输运特征.
关键词:
太赫兹
量子级联激光器
分子束外延
X射线衍射 相似文献
48.
We demonstrate the growth of terahertz quantum cascade laser (THz QCL) by gas source molecular beam epitaxy. X-ray diffraction and cross-sectional transmission electron microscopic measurements show the high crystalline quality of the THz QCL active region, From the cross-sectional transmission electron microscopy image, sharp interfaces are observed and the deduced cascade period thickness is consistent with the result of x-ray diffraction. The test device is lasing at 3.39THz and operating up to lOOK in pulsed mode. At IOK, the maximum output power is greater than 1 mW with a threshold current density of 738 A/cm^2. 相似文献
49.
Li Zhi-Ping Huang An-Chi Tang Yan Zhou Hai-Lin Liu Ye-Cheng Huang Chung-Fu Shu Chi-Min Xing Zhi-Xiang Jiang Jun-Cheng 《Journal of Thermal Analysis and Calorimetry》2022,147(21):12177-12186
Journal of Thermal Analysis and Calorimetry - Toluene sulfonation is a typical synthetic process in the modern chemical industry. However, there are unexpected thermal hazards in this process,... 相似文献
50.
Su CH Sheu HS Lin CY Huang CC Lo YW Pu YC Weng JC Shieh DB Chen JH Yeh CS 《Journal of the American Chemical Society》2007,129(7):2139-2146
Nanocontrast agents have great potential in magnetic resonance (MR) molecular imaging applications for clinical diagnosis. We synthesized Au(3)Cu(1) (gold and copper) nanoshells that showed a promising MR contrast effect. For in vitro MR images, the large proton r1 relaxivities brightened T(1)-weighted images. As for the proton-dephasing effect in T(2), Au(3)Cu(1) lightened MR images at the low concentration of 0.125 mg mL(-1) (3.84 x 10(-7) mM), and then the signal continuously decreased as the concentration increased. For in vivo MR imaging, Au(3)Cu(1) nanocontrast agents enhanced the contrast of blood vessels and suggested their potential use in MR angiography as blood-pool agents. We propose that (1) the cooperativity originating from the form of the nanoparticles and (2) the large surface area coordinated to water from their porous hollow morphology are important for efficient relaxivity. In a cytotoxicity and animal survival assay, Au(3)Cu(1) nanocontrast agents showed a dose-dependent toxic effect: the viability rate of experimental mice reached 83% at a dose of 20 mg kg(-1) and as much as 100% at 2 mg kg(-1). 相似文献