- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Y2(CO3)3?H2O and (NH4)2Ca2Y4(CO3)9?H2O: Partial Aliovalent Cation Substitution Enabling Evolution from Centrosymmetry to Noncentrosymmetry for Nonlinear Optical Response
摘要： An effective approach, the partial aliovalent cation substitution (PACS), was successfully employed to develop nonlinear optical (NLO) material. Two novel rare earth carbonates, Y2(CO3)3·H2O (YC) and (NH4)2Ca2Y4(CO3)9·H2O (CYC), were synthesized, which feature the same honeycomb-like framework structure. From YC to CYC, the partial substitution of Y3+ with Ca2+ led to the evolution of space group from centrosymmetric P63/mcm to noncentrosymmetric P63mc. The CYC exhibited a second harmonic generation (SHG) effect of 2.1 × KH2PO4 (KDP) and a deep-UV cut-off edge (<200 nm). It was concluded that the SHG effect originates from the ordered arrangement of (CO3)2- groups and the dipole polarization enhancement of [Ca0.33Y0.67O9] polyhedra. Specifically, the long-range ordered electric field of channels induced the ordered arrangement of (CO3)2- groups. This synthetic approach and SHG-activated induction mechanism may afford new strategies for the design and synthesis of NLO materials.
关键词： nonlinear optical materials,partial aliovalent cation substitution,rare earth carbonates,deep-UV cut-off edge,second harmonic generation
更新于2025-09-04 15:30:14
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Label-free detection of brain invasion in meningiomas by multiphoton microscopy
摘要： Brain invasion in meningiomas relates to the poor prognosis. Therefore, accurate detection and treatment of brain invasion are of particular importance. In this study, multiphoton microscopy (MPM) was introduced for label-free detection of brain invasion in meningiomas by the combination of the two-photon excited fluorescence imaging, second-harmonic generation imaging and spectral imaging. Results show that MPM has the ability to morphologically and spectrally identify brain invasion in meningiomas. What is more, the intensity ratios of the cerebral cortex over meningiomas at 475 nm, 511 nm and 540 nm were extracted as quantitative indicators for differentiating meningioma from surrounding normal cerebral cortex tissue. Together with custom-developed image processing algorithms, MPM could further identify the tumor boundary. With miniaturization and optimization of probes and optical fiber for in vivo imaging, combined with a laser ablation system, MPM would be used in an operating room for both the diagnosis and treatment of brain invasion in meningiomas.
关键词： brain invasion,two-photon excited fluorescence,multiphoton microscopy,second harmonic generation
更新于2025-09-04 15:30:14
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Second Harmonic Light Manipulation with Vertical Split Ring Resonators
摘要： The second harmonic generation (SHG) of vertical and planar split-ring resonators (SRRs) that are broken centro-symmetry configurations at the interface of metal surface and air is investigated. Strong interactions, better electromagnetic field confinements, and less leakage into the substrate for vertical SRRs are found. Experimental results show a 2.6-fold enhancement of SHG nonlinearity, which is in good agreement with simulations and calculations. Demonstrations of 3D metastructures and vertical SRRs with strong SHG nonlinearity majorly result from magnetic dipole and electric quadrupole clearly provides potential applications for photonics and sensing.
关键词： nonlinear plasmonics,vertical split ring resonators (VSRR),second harmonic generation
更新于2025-09-04 15:30:14