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关键词： 偏振消光比   线偏振   超连续谱   保偏光纤   光纤激光器  

摘要： 线偏振超连续谱光源是具有线偏振特性的宽光谱激光光源,是连接偏振光学与非线性光学的一个很好的纽带,在高光谱成像照明、光学相干层析等领域有重要应用。近几年关于线偏振超连续谱的研究报道逐渐增多,研究人员已经针对线偏振超连续谱的偏振度提高、相干性增强、光谱平坦度提高、功率提升以及光谱拓展等重点问题开展研究工作,并取得重要进展。本文介绍线偏振超连续谱的研究进展,总结分析线偏振超连续谱产生中的关键技术,并介绍与分析两种针对线偏振超连续谱的偏振消光比测量方法。

ISBN: (纸本)9787118129335

摘要： 本书分析了凝视阵列系统的技术, 内容包括基础知识, 成像系统链分析, 信噪比, 目标和背景, 图像质量量度, 捕获距离六大部分内容, 阐述了光电成像系统涉及的各方面技术及其相互关系。

摘要： Long-lived particles are a class of particles that are predicted by many different theo- ries of physics beyond the Standard Model. They are a promising avenue for discovering new physics because their signatures can be quite different from most Standard Model backgrounds. This dissertation presents a search for long-lived particles. The search utilizes the full Run 2 dataset totaling 138 fb −1 of proton-proton collisions recorded by the CMS experiment at √ s = 13 TeV. Hits in the barrel muon system drift tubes are clustered together and properties of the cluster are used to reject backgrounds. The results of the search are interpreted using a Twin Higgs model, showing sensitivity to Higgs-mediated long-lived particle production with proper lifetimes up to 100m and long-lived particles masses as low as 0.4 GeV. Limits are also set on a previously untested model where a dark quantum chromodynamic sector couples to the Higgs boson through various possible portals. Limits as low as 10 −3 are set on the Higgs branching fraction to long-lived particles for both interpretations.

关键词： 晶体  

ISBN: (纸本)9787030759306

摘要： 本书介绍晶体学基础与X射线在材料结构、形貌和成分方面的分析技术。其中，结构分析技术包括X射线的物理基础、衍射原理、物相分析、织构分析、小角散射与掠入射衍射分析、位错分析、层错分析、非晶分析、单晶体衍射与取向分析、内应力分析、点阵常数的测量与热处理分析等；形貌分析技术即三维X射线显微成像分析；成分分析技术包括特征X射线能谱、X射线光电子能谱及X射线荧光光谱等。书中研究和测试的材料包括金属材料、无机非金属材料、高分子材料、非晶态材料、金属间化合物、复合材料等。

摘要： A framework has been constructed for predictive modelling of the stimulated Raman scattering (SRS) instability at ignition scale in laser direct-drive inertial confinement fusion (ICF). An extended ray-tracing methodology from literature was found to underpredict SRS, and to be computationally inefficient. This was corrected by modification of the energy-exchange process between laser and Raman light, and introduction of thresholds and bounds physically informed by collisional absorption and Rosenbluth gain. Predictions were further improved by Gaussian process (GP) regression surrogates, which at the first instance fully resolved the SRS solution in the steady-state strong damping limit. Subsequently, additional physics were captured using the plasma wave solver LPSE, with scope for future capture of more complex solvers within the hierarchical machine learning framework. An additional GP surrogate was used to replace the costly resonant frequency search part of the algorithm. The framework was implemented in the 1D ICF code Freyja, allowing for investigation of the effects of SRS on fusion performance for a shock ignition case. It also allowed for efficient training of the GP surrogates by keeping the predicted error below thresholds across a full simulation. SRS was found to have a detrimental effect on fusion performance, but this was mitigated to some extent when modelling the secondary effects of the hot electron populations which are created. These hot electrons were found to strengthen the ignition shock, but an uncertainty quantification study still showed a much reduced probability of ignition compared to the case without SRS. As well as predictive modelling, a separate probabilistic study was carried out to show the approach of calibrating modelling coefficients for laserplasma interactions and energy transport against experimental data. The results of this study were used to both set certain modelling parameters for later simulations, and to highlight th

摘要： The discovery of the Higgs boson has opened up new possibilities for investi- gating physics beyond the Standard Model (SM). New particles may interact with the SM through the Higgs boson, and deviations from SM predictions can indicate the presence of new physics. This dissertation focuses on the search for exotic Higgs decay, H → aa → (b ¯ b)(b ¯ b) where a is a new scalar boson and focuses on the case where the Higgs boson is produced in association with a Z boson. The data were col- lected by the ATLAS detector at the Large Hadron Collider at center-of-mass energy √ s = 13 TeV from 2015 to 2018 with a total integrated luminosity of 140 fb −1. A new general-purpose low-mass double-b tagging algorithm was developed and applied in the search. With new machine-learning reconstruction techniques, the search is able to set a strong limit on the branching ratio of Br(H → aa → (b ¯ b)(b ¯ b)). Furthermore, the search also considers models with two new scalars of different masses, a 1 and a 2, and sets the limits on the branching ratio of Br(H → a 1 a 2 → (b ¯ b)(b ¯ b))

标准号: T/CPSS 1004-2023

关键词： Bismuth  

摘要： The X-ray Φ scanning method was used to characterize the spatial orientation of Bi2201 film, especially the in-plane orientation, by taking bismuth-based superconducting thin films growing on a single-crystal MgO substrate as an example, combined with the crystal structure characteristics of the studied materials. The single-crystal film Bi2201 did not exhibit simple ‘cube-on-cube’-style growth on the single-crystal MgO substrate. Based on c-axis epitaxial growth, Bi2201 film was epitaxially grown by rotating 45° around the MgO (001)crystal direction in the a-b plane;that is, the film was selectively (001)[100]Bi2201(001)[110]MgO in in-plane-oriented epitaxial growth. The work describes the principles and specific experimental steps of the measurement method in detail. The results indicate that the method provides a new way to measure and analyze the in-plane preferred orientation of single-crystal or strongly preferred orientation film materials and the mismatch relationship between single-crystal or strongly preferred orientation film materials and a single-crystal substrate. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.