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1.
针对激光聚变冲击波速度测量的需求,设计了一种集被动式扫描高温计和主动式冲击波速度测量于一体的复合冲击波速度测量系统。通过采用多种耐辐射光学玻璃材料,实现了共用光路的400~700 nm耐辐射消色差设计;通过采用自动控制干涉仪简化了系统操作;主动测速系统通过切换不同焦距的中继成像镜头,实现了不同放大倍率的切换。系统的物方视场为φ2.0 mm,主动式测速系统的放大倍率为10×,20×,30×,静态实验干涉条纹平直,调制度达到0.69以上,物方分辨率达到4.72μm。该系统在激光聚变装置上能够实现冲击波速度的动态测量。  相似文献   
2.
In this paper, we report the controlled fabrication of layer-by-layer (LbL) films deposited on gold substrates with three different supramolecular architectures using polypyrrole (Ppy) and magnetite nanoparticles (Fe3O4-np), besides conventional poly(allylamine hydrochloride) (PAH) e poly(vinyl sulfonic acid) (PVS) polyelectrolytes, demonstrating the synergistic effect between Ppy and Fe3O4-np such as a result of their interaction. Modified gold electrodes were analyzed by contact angle (wettability), surface plasmon resonance (SPR), raman spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The (Fe3O4-np/Ppy)3 architecture was also evaluated by scanning electron microscopy. The modified gold electrodes present more homogeneous covering, higher electron transfer and a decrease of resistance with the incorporation of the nanostructured materials such as Ppy and Fe3O4-np forming (Fe3O4-np/Ppy)3 LbL film. The results carried out in this study suggest that the (Fe3O4-np/Ppy)3 LbL film can be applied as a possible electrochemical or optical non-enzymatic sensor for analytical detection.  相似文献   
3.
Design and fabrication of contactless optical thermometer with rapid and accurate performance has become a research hotspot in recent years. Herein, CaSc2O4: Yb3+/Er3+ is employed as the intermediary for temperature sensing under the excitation of 980 nm, which is proven to afford an ultra-sensitive and high-resolution optical thermometry in multiple ways based on the fluorescence intensity ratio (FIR) technology. The optimal thermal sensing behaviors are realized by the FIR of Er3+:2H11/2 → 4I15/2 to 4S3/2 → 4I15/2 transition, which has a relative sensitivity of 1184/T2 and a minimal resolution of 0.03 K along with a maximal absolute error of 0.96 K. Besides that, the FIR between the thermally coupled Stark sublevels of Er3+:4F9/2 manifold (FIRR) as well as that of Er3+4I13/2 manifold (FIRN) can also provide excellent optical thermometry. The relative sensitivity of FIRR-based and FIRN-based optical thermometers are calculated to be 402/T2 and 366/T2, respectively, with a same minimal resolution of 0.09 K, which possess the potential to be used for biomedicine due to the inherent advantage of their operating wavelengths located in the biological window. The results demonstrate that CaSc2O4: Yb3+/Er3+ is a promising candidate for temperature sensing with multipath, high sensitivity, and superior resolution.  相似文献   
4.
The rising demand for faster and more efficient electronic devices forces electronics industry to shift toward terahertz frequencies. Therefore there is a growing need for efficient, lightweight, and easy to produce absorbing materials in the terahertz range for electromagnetic interference (EMI) shielding and related applications. This study presents a study on basic optical properties of two types polymer-based composites loaded with two-dimensional structures—graphene and MXene phases (Ti2C). In said range, total EMI shielding efficiency (SE) and its components, the absorption coefficient (α ), refractive index, and complex dielectric function are investigated. The ratio of SE absorption component to reflection component (SEABS :SER ) of fabricated composites is equal or higher than 30:1 in over 80% of studied range. The fabricated composites exhibit low (<0.1) loss tangent in studied range. The addition of 1 wt% of graphene increases the composite α over 10-fold in respect to pure polymer–up to 60 cm−1 for frequency higher than 2 THz.  相似文献   
5.
The compounds based on calcium molybdate (CaMoO4) are the subject of extensive research due to their excellent optical properties and a broad range of potential technological applications. In this work, we report a systematic study of CaMoO4:Tm3+ phosphors synthesized by coprecipitation and processed in a microwave-hydrothermal system at low temperature (100°C) and stirring. The effect of the Tm3+ doping content (0%–12%) is studied in full detail to understand their role in the CaMoO4:Tm3+ morphological, structural, and luminescent properties. The X-ray diffraction, Raman, and Fourier Transform Infrared spectroscopic techniques revealed that all the prepared powders have a tetragonal crystal structure with a distinct density of cation vacancies and structural disorders. The band gap remains almost constant for doping levels lower than 8%, but it narrows strongly for powders doped with 12% Tm3+ ions. The designed phosphors have shown two emission bands in which intensity depends on the Tm3+ ions doping level. For doping levels lower than 2%, the photoluminescence profile displays a broad emission band peaking at 543 nm (green). For concentrations higher than 4%, the band centered at 543 nm decreases in intensity and the near-infrared emission band at around 800 nm, assigned to 3F3, 3H4 → 3H6 transitions from Tm3+ ion, become more intense. The outcomes of this work reveal that appropriated Tm3+ ions doping levels can be applied to suppress the PL emission in the visible range and improve that in the near-infrared region in CaMoO4-based materials.  相似文献   
6.
Optical imaging has played a pivotal role in deciphering in vivo bioinformatics but is limited by shallow penetration depth and poor imaging performance owing to interfering tissue autofluorescence induced by concurrent photoexcitation. The emergence of near-infrared (NIR) self-luminescence imaging independent of real-time irradiation has timely addressed these problems. There are two main kinds of self-luminescent agents, namely inorganic and organic luminophores. Inorganic luminophores usually suffer from long-term biotoxicity concerns resulting from potential heavy-metal ions leakage and nonbiodegradability, which hinders their further translational application. In contrast, organic luminophores, especially organic semiconducting luminophores (OSLs) with good biodegradable potential, tunable design, and outstanding optical properties, are preferred in biological applications. This review summarizes the recent progress of OSLs used in NIR afterglow, chemiluminescence, and bioluminescence imaging. Molecular manipulation and nanoengineering approaches of OSLs are discussed, with emphasis on strategies that can extend the emission wavelength from visible to NIR range and amplify luminescence signals. This review concludes with a discussion of current challenges and possible solutions of OSLs in the self-luminescence field.  相似文献   
7.
为了解决光学频率梳长时锁定困难的问题,对光学频率梳重复频率(fr)与载波相位偏移频率(f0)的控制方法进行了改进。采用上、下两块半导体制冷片(TEC)对振荡器局部环境进行温度控制,并微调TEC温度将fr与f0漂移量分别稳定在10 Hz和600 Hz以内。利用锁相电路反馈控制有效腔长和泵浦光功率对fr与f0进行了精密锁定。光学频率梳在170 h时间内连续锁定,fr与f0抖动标准偏差分别为0.83 MHz和280 MHz。结果表明,该方法可以实现光学频率梳的长时锁定,增强其环境适应能力。  相似文献   
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刘欢欢 《中州煤炭》2021,(5):218-221
针对光纤绕制过程中可能出现的爬线、断线、绕丝不均匀等问题,基于视频图像分割识别技术,设计了基于视频的图像光纤绕制检测系统。比较分析了背景图像差分法、帧间差分法和光流法,给出了它们各自的优缺点,并认为综合背景图像差分法、帧间差分法可以得到较好的效果。基于上述结论,提出了改进的光线缠绕检测识别方法,并进行了相应方法的MATLAB仿真。结果表明,运用改进算法可取得较好的检测效果,并且能够满足检测系统实时性的要求。  相似文献   
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