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排序方式: 共有61条查询结果,搜索用时 31 毫秒
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用场方法研究了相对论速调管放大器辐射频率的可调性。发现调制电流频率的可调性与一阶Bessel函数的周期相关,对应相同的一阶Bessel函数值,可以有多个不同数值的宗量,调制电流的频率与Bessel函数宗量数值包括中间腔与提取腔之间的距离和电子束的传输速度等因素相联系。理论估计的调制电流频率可调范围与实验测得的结果符合得很好。相对论速调管放大器辐射频率的可调性还取决于提取腔的设计。 相似文献
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Bulk assemblies of zero-dimensional (0D) metal halides with ‘host-guest’ system provide a promising platform for rationally structural tunability and photoluminescence modulation. In this work, we first report a series of ternary 0D metal halides, (bmpy)9[Pb3Cl11](MnCl4)2-2x(SbCl5)2x (bmpy+ = 1-buty-1-methylpyrrolidinium+, C9NH20+), where the organic cation bmpy+ cocrystallizes with [Pb3Cl11]5- trimer clusters, [MnCl4]2? tetrahedra, and [SbCl5]2? pyramids. The emission color of (bmpy)9[Pb3Cl11](MnCl4)2-2x(SbCl5)2x can be easily tuned from green to warm white and finally to orange-red by controlling the excitation wavelength or the [SbCl5]2?/[MnCl4]2? molar ratio, promising its potential for application in multicolor light-emitting devices or even in encrypting multilevel optical codes. This work presents a novel structural modulation strategy to fabricate superior ordered single-crystalline multicomponent materials with multifunctionalities of 0D luminescent metal halides. 相似文献
4.
In this paper, we demonstrate a kind of broadband metamaterial perfect absorber using both graphene and metal resonator elements. Through step by step design and simulation, wider absorption band from about 4.22 THz to 7.48 THz with average absorption rate up to 98.21% is achieved in the absorption spectrum. In addition, the absorber has characteristics of polarization insensitivity and wide incident angle due to its inherent rotational symmetry. Moreover, the absorption band can be adjusted by changing the chemical potential of the graphene. The superiorities of broadband, high absorption rate, polarization independent and wide-angle characteristics make it have potential application prospects in electromagnetic wave absorbing, signal sensing and detection, and other optoelectronic devices. 相似文献
5.
采用分子束外延技术生长了两个叠层结构的双色量子阱红外探测器结构,并经过光刻和湿法刻蚀制作成两端结构的量子阱红外探测器单元器件. 通过改变量子阱势垒高度,势阱宽度,掺杂浓度,重复周期数等器件参数,可以使总电压在两个叠层之间产生适当的分布,从而使器件表现出不同的电压响应特点. 光电流谱测量显示,器件1随着外加偏置电压可实现对于中波大气红外窗口(3—5 μm)和长波大气红外窗口(8—12 μm)红外响应的切换,器件2在不同的偏置电压下可以对这两个波段同时做出响应. 本文探讨了两端叠层结构量子阱红外探测器的工作原
关键词:
电压调制
同时响应
量子阱红外探测器
双波段 相似文献
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Low phonon energy Tm3+/Ho3+/Yb3+ triply doped bismuth tellurite glasses exhibiting multicolor upconversion fluorescences have been fabricated and characterized. The multicolor fluorescence composed of three primary colors green, red and blue upconversion emissions from Ho3+ and Tm3+ has been investigated. By adjusting the excitation power, the fluorescence colors can be tuned from multicolor to white color, and the dependence of color tunability on pump power has been presented in the CIE 1931 chromaticity diagram. With the increase in pumping power, the color coordinates move along the down-left direction and hit the equal energy point. The upconversion and color tunability via changing the pump power of infrared excitation in Tm3+/Ho3+/Yb3+ triply doped bismuth tellurite glasses will lead to new breakthrough in the field of three-dimensional solid-state displays and white-light emitting devices. 相似文献
8.
Changji Liu Yuanyuan Huang Fangrong Hu Yiwen E Xiaoxiang Dong Yong Yang Yanping Jin Xinlong Xu 《Annalen der Physik》2020,532(3):1900398
Inspired by the chiral structure from mode interaction, a chiral terahertz metamaterial and its complementary structure with the coexistence of asymmetric transmission and circular dichroism response are designed. The asymmetric transmission happens in the presence of electric and magnetic modes perpendicular to each other, resulting from intrinsic chirality under normal incidence. Circular dichroism exists in the presence of electric and magnetic modes parallel to each other under oblique incidence because of extrinsic chirality. Both asymmetric transmission and circular dichroism are enhanced by complementary structures, benefitting from the coupling between adjacent units. The maximum of chiral parameter κ can achieve 450, which is one hundred times higher than previously reported. The chiral response can be tuned by the incident angle and is sensitive to the environmental refractive index. The results highlight the potential applications of these metamaterials in chiral sensing and polarization transformation devices. 相似文献
9.
Yiping Guo Daisuke Akai Kazuaki Sawada Makoto Ishida Mingyuan Gu 《Journal of Sol-Gel Science and Technology》2009,49(1):66-70
Highly (110)-oriented Ba0.65Sr0.35TiO3 films were deposited on Pt/LaNiO3/SiO2/Si substrates by a sol–gel method. It was found that the (110)-preferred Pt film was very effective for growing (110)-oriented
ferroelectric films with perovskite structure. The as-grown Ba0.65Sr0.35TiO3 films showed good dielectric properties with dielectric constant and loss tangent tan δ = 0.026. Excellent dielectric tunability was also achieved in the (110)-oriented films. With applying
an electric field of 230 kV/cm at 100 kHz, the dielectric tunability and the figure of merit can reach up to 63.4% and 16,
respectively. These results indicate that the highly (110)-oriented Ba0.65Sr0.35TiO3 film is a promising candidate for the applications in microwave tunable devices. 相似文献
10.