Entanglement Dynamics of a Generic-Spin Model

We investigate the entanglement dynamics of a generic-spin model with weak external field. We first derive the time-dependent solutions of angular momentum operators with short-time approximation and then numerically calculate the entangled witness. It’s shown that one can dynamically generate quantum entanglement by adjusting coupling strength.     

同轴强流双环形阴极的发射特性分析

提出了一种同轴双环形阴极结构二极管,并进行理论求解和仿真研究,得到了双环形阴极二极管中,内外环上场强一致时二极管内尺寸分布关系。并采用粒子仿真软件进行了双环形阴极爆炸发射模拟研究,研究结果表明,双环形阴极发射束流由高压加载后初始时刻二极管内电场分布和内外环形阴极相互之间屏蔽作用的竞争结果决定。提出了两阴极相互之间屏蔽作用的经验公式,指出该相互屏蔽作用程度随发射总束流呈线性关系,随两阴极距离呈指数关系,最终采用粒子仿真软件进行了验证。     

辐射成像系统模拟软件NUCRPD的研发与应用

在辐射成像系统的设计研发中,经常需要计算系统的各项物理性能指标。为了提升产品研发的效率,同方威视联合清华大学,基于蒙特卡罗程序包Geant4,研发了国内首套具有自主知识产权的辐射成像系统模拟软件NucRPD(NUCTECH Radiography Performance Design Tools),其能够快速、精确地模拟系统的各项性能指标。该软件对常用的一些辐射成像系统进行了参数化建模,用户通过修改软件界面上的少量参数,就可以快速建立各类辐射成像系统的几何体、源项、物理模型和统计量,然后在服务器上以并行计算方式完成模拟计算,能在较短的时间内模拟出系统的性能指标,并给出直观的图形帮助用户深入理解模拟结果。NucRPD的模拟结果经过了大量的实验验证,其剂量场分布和物理指标等模拟结果和实验结果符合得很好。NucRPD已经应用于同方威视辐射成像系统产品的设计研发,在产品的物理指标优化和辐射防护优化中发挥了重要作用。     

Estimating the thickness of diffusive solid electrolyte interface

The solid electrolyte interface (SEI) is a hierarchical structure formed in the transition zone between the electrode and the electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which are highly dependent on the thickness. Thus, understanding the formation mechanism and the SEI thickness is of prime interest. First, we apply dimensional analysis to obtain an explicit relation between the thickness and the number density in this study. Then the SEI thickness in the initial charge-discharge cycle is analyzed and estimated for the first time using the Cahn-Hilliard phase-field model. In addition, the SEI thickness by molecular dynamics simulation validates the theoretical results. It has been shown that the established model and the simulation in this paper estimate the SEI thickness concisely within order-of-magnitude of nanometers. Our results may help in evaluating the performance of SEI and assist the future design of Li-ion battery.     

Recent progress in econophysics: Chaos,leverage, and business cycles as revealed by agent-based modeling and human experiments

Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like “intelligence” remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents’ intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.     

掺钕微球的受激辐射激光和自受激拉曼散射

采用溶胶-凝胶法在SiO_2微球表面覆盖上一薄层Nd~(3+)掺杂SiO_2,并经电极放电熔融后形成表面光滑的高Q值微球.采用锥光纤将808 nm的抽运激光耦合入钕离子掺杂的高Q值微球形成回廊模,激发产生了1080—1097 nm波段受激辐射激光.由于所产生的激光有足够高的功率密度,在高Q SiO_2微球中激发产生了波长为1120—1143 nm一级自受激拉曼散射激光.推导了锥光纤掺钕微球组合的自受激拉曼散射的输出功率和阈值公式.描述了输出激光的特性:阈值、输出功率、线宽、边模抑制比.     

CosmologicalΦ 4,Φ 6, and Sine-Gordon theories with broken symmetry

Particular solutions to the Einstein equations with cosmological constant are presented and discussed for an isotropic, spatially homogeneous, and spatially flat space-time in the case that the matter fields are ⁴, ⁶, and sine-Gordon fields.     

N2（A）及N（2D）对IF（X）的传能研究

在微波放电系统中,对NH_3-F-F_2-CF_3I体系进行研究,结果表明,向IF(X)传能的诸多媒介中,N_2(A)及N(~2D)起着主要作用,并且这一结论在经微波激发后的N_2与CF_3I的直接反应中得到了进一步证实。     

茶刺蛾颗粒体病毒色涵体的拉曼光谱研究

得到了茶刺蛾颗粒体病毒(Darna trima Granulosis Virus 缩写为 DtGV)包涵体的拉曼光谱。分析表明,DtGV 包涵体蛋白的二级结构主要为β折叠和无规卷曲,后者含有大量β回折结构;蛋白的所有酪氨酸残基均“暴露”于溶剂中;其 C—C—S—S—C—C 构型属于扭曲—扭曲—扭曲式。     

一种多通道纳秒分幅相机

相机采用棱镜分光,薄片管增强象,电选通分幅。由四个薄片管组成四个通道,每一个通道代表一个单幅相机,分幅时序由专门电控电路进行控制,接触相机记录图象,最短曝光时间3ns,动态空间分辩率5～81lp/mm,最高分幅速率2×10⁸幅/秒,动态范围50°,在爆炸、激光、放电,光谱学等方面有广泛的应用。