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51.
The thermalization process of the holographic entanglement entropy(HEE)of an annular domain is investigated in the Vaidya-AdS geometry.We determine numerically the Hubeny-Rangamani-Takayanagi(HRT)surface,which may be a hemi-torus or two disks,depending on the ratio of the inner radius to the outer radius of the annulus.More importantly,for some fixed ratio of the two radii,the annulus undergoes a phase transition,or a double phase transition,during thermalization from a hemi-torus to a two-disk configuration,or vice versa.The occurrence of various phase transitions is determined by the ratio of the two radii of the annulus.The rate of entanglement growth is also investigated during the thermal quench.The local maximal rate of entanglement growth occurs in the region with a double phase transition.Finally,if the quench process is sufficiently slow,which may be controlled by the thickness of the null shell,the region with a double phase transition vanishes. 相似文献
52.
对脉冲工况下超导磁体失超保护系统的晶闸管阀组缓冲回路参数进行设计和优化。基于晶闸管反向恢复电流的指数衰减模型建立了晶闸管关断时刻的电流数学模型。通过测试实验获得关键参数之间的关系并结合晶闸管性能及系统要求在Matlab中建立晶闸管电流反向恢复模型。考虑关断时刻电流下降率、反向恢复电压峰值等性能指标要求及回路研制费用,提出了一种脉冲工况下晶闸管缓冲回路的参数设计及优化方法。在Matlab中搭建失超保护系统模型,对比优化前后缓冲回路对系统在晶闸管关断时刻电气性能的影响,仿真结果显示,相比于原参数,最优参数下,反向恢复电压峰值降低了11%,反向恢复电压变化率峰值降低了43%。同时,回路制造成本降低为原先的1/7。 相似文献
53.
Lorenzo Rossi Fabrizio Dolcini Fabio Cavaliere Niccol Traverso Ziani Maura Sassetti Fausto Rossi 《Entropy (Basel, Switzerland)》2021,23(2)
When a parameter quench is performed in an isolated quantum system with a complete set of constants of motion, its out of equilibrium dynamics is considered to be well captured by the Generalized Gibbs Ensemble (GGE), characterized by a set of coefficients related to the constants of motion. We determine the most elementary GGE deviation from the equilibrium distribution that leads to detectable effects. By quenching a suitable local attractive potential in a one-dimensional electron system, the resulting GGE differs from equilibrium by only one single , corresponding to the emergence of an only partially occupied bound state lying below a fully occupied continuum of states. The effect is shown to induce optical gain, i.e., a negative peak in the absorption spectrum, indicating the stimulated emission of radiation, enabling one to identify GGE signatures in fermionic systems through optical measurements. We discuss the implementation in realistic setups. 相似文献
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55.
本文对近两年来有关淬火动力学过程中拓扑现象的研究做简要综述.这些动力学拓扑现象被动力学过程中的衍生拓扑不变量保护,与淬火前后体系的拓扑性质有密切关系.基于人工量子模拟平台的高度可控性,已在诸如超冷原子、超导量子比特、核磁共振、线性光学等众多物理体系中,通过对人工拓扑体系动力学过程的调控,观测到如动力学涡旋、动量-时间域的Hopf映射及环绕数、拓扑保护的自旋环结构、动力学量子相变、动量-时间斯格明子等诸多动力学拓扑现象.其中某些拓扑结构还可以在非幺正动力学淬火过程中稳定存在.这些研究将人们对拓扑物相的认识和研究从平衡态推广到非平衡动力学领域,具有重要的科学价值. 相似文献
56.
57.
对托卡马克装置内壁产生巨大电磁力是等离子体破裂重要和直接的影响, 这会对装置的安全运行造成巨大威胁. 等离子体破裂期间电流猝灭率不仅与真空室内第一壁的负载设计有关, 并且与装置重大部件的设计也相关. 本文选用100%-40%区间统计研究等离子体破裂现象. 分析结果表明: 100%-40%区间统计下HL-2A上最小电流猝灭时间为0.7 ms, 对应的最小面积归一化电流淬灭时间为1.4 ms m-2. 瞬时最大电流猝灭率与平均电流猝灭率的比值大部分都大于1. 相似文献
58.
Adrian Boborodea Sophie Hermans 《International Journal of Polymer Analysis and Characterization》2018,23(5):435-441
A high temperature gel permeation chromatograph (GPC) was coupled with a gas chromatograph (GC) oven to obtain an analytical temperature rising elution fractionation (TREF) system with evaporative light scattering detection. On this instrument, a new column partially filled with pristine carbon nanotubes (CNT) was tested by evaluating the elution profiles in function of temperature (thermograms) of different polyethylene (PE) types. By comparing these thermograms with those obtained with a traditional TREF column filled with metallic wires, the adsorption of polymer chains on the pristine CNT was clearly evidenced. The thermograms given by the column filled with CNT are similar with those provided by literature when chromatographic columns filled with porous graphitic carbon are used for this application, usually described as high temperature thermal gradient interaction chromatography (HT-TGIC). 相似文献
59.
选用(口恶)花菁染料为光敏剂,将其镶嵌到双炔酸LB膜中,利用Ar~+离子激光514.5 nm照射LB膜,观察到双炔酸LB膜的光敏聚合及(口恶)花菁染料荧光的猝灭,对其光敏聚合机理进行了讨论。 相似文献
60.
Injection of high-Z impurities into plasma has been proved
to be able to reduce the localized thermal load and mechanical forces on
the in-vessel components and the vacuum vessel, caused by
disruptions in Tokamaks. An advanced prediction and mitigation
system of disruption is implemented in HL-2A to safely shut down
plasmas by using the laser ablation of high-Z impurities with a
perturbation real-time measuring and processing system. The
injection is usually triggered by the amplitude and frequency of
the MHD perturbation field which is detected with a Mirnov coil and leads
to the onset of a mitigated disruption within a few milliseconds. It
could be a simple and potential approach to significantly reducing the
plasma thermal energy and magnetic energy before a disruption,
thereby achieving safe plasma termination. The plasma
response to impurity injection, a mechanism for improving plasma
thermal and current quench in major disruptions, the design of
the disruption prediction warner, and an evaluation of the mitigation success rate
are discussed in the present paper. 相似文献