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51.
Plasmonic Dual‐Enhancement and Precise Color Tuning of Gold Nanorod@SiO2 Coupled Core–Shell–Shell Upconversion Nanocrystals 下载免费PDF全文
Fengwen Kang Jijun He Tianying Sun Zhi Yong Bao Feng Wang Dang Yuan Lei 《Advanced functional materials》2017,27(36)
The last decade has witnessed the remarkable research progress of lanthanide‐doped upconversion nanocrystals (UCNCs) at the forefront of promising applications. However, the future development and application of UCNCs are constrained greatly by their underlying shortcomings such as significant nonradiative processes, low quantum efficiency, and single emission colors. Here a hybrid plasmonic upconversion nanostructure consisting of a GNR@SiO2 coupled with NaGdF4:Yb3+,Nd3+@NaGdF4:Yb3+,Er3+@NaGdF4 core–shell–shell UCNCs is rationally designed and fabricated, which exhibits strongly enhanced UC fluorescence (up to 20 folds) and flexibly tunable UC colors. The experimental findings show that controlling the SiO2 spacer thickness enables readily manipulating the intensity ratio of the Er3+ red, green, and blue emissions, thereby allowing us to achieve the emission color tuning from pale yellow to green upon excitation at 808 nm. Electrodynamic simulations reveal that the tunable UC colors are due to the interplay of plasmon‐mediated simultaneous excitation and emission enhancements in the Er3+ green emission yet only excitation enhancement in the blue and red emissions. The results not only provide an upfront experimental design for constructing hybrid plasmonic UC nanostructures with high efficiency and color tunability, but also deepen the understanding of the interaction mechanism between the Er3+ emissions and plasmon resonances in such complex hybrid nanostructure. 相似文献
52.
莲花面板堆石坝填筑施工中,注意对筑坝料源做出符合工程实际情况的规划:利用其他建筑物的开挖料降低造价;采用分区填筑的措施,加快施工进度和解决寒冷季节施工问题;方便的上坝交通道路网和良好的路面,为高强度填筑提供有力保证;选择合理配套的施工设备使设备得到优化利用。 相似文献
53.
A photoelectric autocollimator with high accuracy and extended measurement range based on the quadrangular pyramid is proposed, and the corresponding algorithms are also deduced. A new image processing algorithm has been proposed to improve the accuracy, and the corresponding errors are also estimated, the error does not exceed half a pixel when the distance between the marks more than two radii. The experimental results have verified that the measurement range of the proposed two-dimensional (2D) quadrangular pyramid photoelectric autocollimator can be increased times than that of the flat mirror photoelectric autocollimator from 10′ to 15′. The accuracy is better than 1″ when the deflection is less than 15′. 相似文献
54.
Ultra-Stable and Sensitive Ultraviolet Photodetectors Based on Monocrystalline Perovskite Thin Films
Xu Li Chang Liu Feng Ding Zheyi Lu Peng Gao Ziwei Huang Weiqi Dang Liqiang Zhang Xiaohui Lin Shuimei Ding Bailing Li Ying Huangfu Xiaohua Shen Bo Li Xuming Zou Yuan Liu Lei Liao Yiliu Wang Xidong Duan 《Advanced functional materials》2023,33(15):2213360
The detection of ultraviolet (UV) radiation with effective performance and robust stability is essential to practical applications. Metal halide single-crystal perovskites (ABX3) are promising next-generation materials for UV detection. The device performance of all-inorganic CsPbCl3 photodetectors (PDs) is still limited by inner imperfection of crystals grown in solution. Here wafer-scale single-crystal CsPbCl3 thin films are successfully grown by vapor-phase epitaxy method, and the as-constructed PDs under UV light illumination exhibit an ultralow dark current of 7.18 pA, ultrahigh ON/OFF ratio of ≈5.22 × 105, competitive responsivity of 32.8 A W−1, external quantum efficiency of 10867% and specific detectivity of 4.22 × 1012 Jones. More importantly, they feature superb long-term stability toward moisture and oxygen within twenty-one months, good temperature tolerances at low and high temperatures. The ability of the photodetector arrays for excellent UV light imaging is further demonstrated. 相似文献
55.
宽波段DMD动态红外景象仿真器投影光学系统设计 总被引:2,自引:3,他引:2
宽波段红外景象仿真器可用于内场评价和验证中波/长波红外双波段成像仪。详细介绍了基于数字微镜器件(DMD)的动态红外景象仿真器的组成和工作原理。重点介绍了覆盖中波和长波红外的宽波段红外投影光学系统的指标要求、设计思想和设计结果。基于离轴三反射镜系统设计的系统,具有无色差、适用波段宽、相对孔径大、结构较紧凑、成像质量好等优点。根据待测设备要求,设计了一款口径100、相对孔径F/2.84、全面视场角4.4°、成像质量接近于衍射极限的宽波段投影光学系统。 相似文献
56.
Hongbin Zhang Chuangyin Dang Jian Zhang 《Circuits, Systems, and Signal Processing》2012,31(4):1297-1318
This paper considers the problem of H ∞ control of piecewise-linear control systems under unreliable communication links. Due to the limited bandwidth of the channels, signal transmission delays and data packet losses can occur between the plant and the controller. In the presence of random signal transmission delays and data packet losses, a piecewise controller is designed to stabilize the piecewise-linear system in the sense of mean square and also achieve a prescribed H ∞ disturbance attenuation performance based on piecewise-quadratic Lyapunov–Krasovskii functionals. It is shown that the H ∞ controllers can be designed by solving a set of linear matrix inequalities (LMIs) that are numerically feasible. Moreover, the controller design method is further extended to uncertain case where the system matrices’ uncertainties are represented in polytopic frameworks. Finally, an example is provided to illustrate the effectiveness of the developed theoretical results. 相似文献
57.
本文提出了一种利用车辆行驶时产生的声音信号进行汽车噪声源识别的新方法。对所采集的车辆行驶时的声音信号,运用小波变换对信号进行处理,找出汽车噪声主要集中的频段,通过与汽车各噪声源位于的频段进行比较就可以较为准确地找出汽车的主要噪声源,并通过实验论证了上述方法的可行性。 相似文献
58.
通过调查分析晋西王家沟流域水源现状及人畜用水情况,提出了该区旱地果园的用水模式,即旱井集流节水栽培技术模式,这一模式首先利用现代材料和传统技术相结合的旱井修筑马天然降水贮存于旱井之中,然后采用节水保墒技术,充分把有限集流用于果园生产,提高了水的利用率和果园效益。 相似文献
59.
Chunliu Xu Weibo Hua Qinghua Zhang Yuan Liu Rongbin Dang Ruijuan Xiao Jin Wang Zhao Chen Feixiang Ding Xiaodong Guo Chao Yang Liangrong Yang Junmei Zhao Yong-Sheng Hu 《Advanced functional materials》2023,33(33):2302810
Na superionic conductor of Na3MnTi(PO4)3 only containing high earth-abundance elements is regarded as one of the most promising cathodes for the applicable Na-ion batteries due to its desirable cycling stability and high safety. However, the voltage hysteresis caused by Mn2+ ions resided in Na+ vacancies has led to significant capacity loss associated with Mn reaction centers between 2.5–4.2 V. Herein, the sodium excess strategy based on charge compensation is applied to suppress the undesirable voltage hysteresis, thereby achieving sufficient utilization of the Mn2+/Mn3+ and Mn3+/Mn4+ redox couples. These findings indicate that the sodium excess Na3.5MnTi0.5Ti0.5(PO4)3 cathode with Ti4+ reduction has a lowest Mn2+ occupation on the Na+ vacancies in its initial composition, which can improve the kinetics properties, finally contributing to a suppressed voltage hysteresis. Based on these findings, it is further applied the sodium excess route on a Mn-richer phosphate cathode, which enables the suppressed voltage hysteresis and more reversible capacity. Consequently, this developed Na3.6Mn1.15Ti0.85(PO4)3 cathode achieved a high energy density over 380 Wh kg−1 (based on active substance mass of cathode) in full-cell configurations, which is not only superior to most of the phosphate cathodes, but also delivers more application potential than the typical oxides cathodes for Na-ion batteries. 相似文献
60.