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131.
Improved nonlinear optimization in the storage ring of the modern synchrotron radiation light source 总被引:1,自引:0,他引:1
In the storage ring of the third generation light sources, nonlinear optimization is an indispensable course in order to obtain ample dynamic acceptances and to reach high injection efficiency and long beam lifetime, especially in a low emittance lattice. An improved optimization algorithm based on the single resonance approach, which takes relative weight and initial Harmonic Sextupole Integral Strength (HSIS) as search variables, is discussed in this paper. Applications of the improved method in several test lattices are presented. Detailed analysis of the storage ring of the Shanghai Synchrotron Radiation Facility (SSRF) is particularly emphasized. Furthermore, cancellation of the driving terms is investigated to reveal the physical mechanism of the harmonic sextupole compensation. Sensitivity to the weight and the initial HSIS as well as dependence of the optimum solution on the convergent factor is analyzed. 相似文献
132.
LED照明与可见光通信技术相结合,构建出基于LED可见光无线通信系统。对室内VLC(Visible Light Communication)系统的白光LED光源特性和系统信道模型分析,提出照明光源布局设计与接收光功率分布的关系;对强度调制直接检测方式的室内VLC系统中信噪比和多径效应引起的码间串扰分析,提出采用光分集接收技术克服码间串扰和提高信噪比,并给出光检测器阵列布局的模型。建立VLC系统仿真模型,给出OOK-NRZ (On-Off Keying & Non-Return Zero)和OOK-RZ(On-Off Keying & Return Zero)调制方式的误码率和均方根时延扩展之间的关系曲线。仿真结果表明,接收光功率相同时,均方根时延扩展时间大于1.0 ns时,OOK-RZ特性优于OOK-NRZ。 相似文献
133.
依据相空间邻近轨道演化相似性特点建立训练模式,提出了基于自适应高阶非线性Volterra滤波器(HONFIR)的混沌时间序列多步预测模型(MSP-HONFIR);通过定义距离相似度、趋势相似度来衡量轨道演化相似度,提出了混沌吸引子邻近轨道判别的新方法;从模型训练充分性角度出发探讨了MSP-HONFIR滤波器模型训练集规模控制的依据.数值研究表明MSP-HONFIR滤波器模型的多步预测性能优于原有HONFIR滤波器模型.
关键词:
混沌
非线性自适应预测
Volterra滤波器模型
训练模式 相似文献
134.
Jiangjiang Feng Xiaohui Li Abdual Qyyum Ying Zhang Chuang Zheng Yamin Wang Jie Liu Jiangbo Lu Gangqiang Zhu 《Annalen der Physik》2019,531(10)
As a member of the 2D group IV monochalcogenides (MX; M = Sn, Ge; X = S, Se), SnS has attracted great interest due to its outstanding optical, electrical, and optoelectronic properties. Especially, SnS nanosheets material have a large absorption coefficient and high photoelectric conversion efficiency, it can be potentially used in optical modulators, saturable absorbers, solar cells, supercapacitors, and other optical devices. However, the nonlinear optical properties of SnS nanosheets and their applications in ultrafast photonics are seldom studied. In this paper, the nonlinear optical properties of SnS nanosheets have been characterized through a dual‐balance detection system, whose modulation depth is 5.8%. More importantly, 105th harmonic soliton molecule based on SnS saturable absorbers has been realized for the first time to the authors’ knowledge. A compact mode‐locked fiber laser with a pulse duration of 1.02 ps and a repetition rate of 459 MHz is realized near 1.5 µm. It is demonstrated that SnS nanosheets have outstanding nonlinear properties and play an extremely important role in the field of ultrafast photonics. 相似文献
135.
提出了光谱数据解析中的信息冗余系数的问题,从光谱数据处理过程中波段优化选择的方法入手,考察了多环芳烃(polycyclic aromatic hydrocarbons,PAHs)中的蒽、芘和菲三组分混合体系的荧光光谱数据,采用化学计量学中的主成分回归分析和波段变量选择的窗口移动法,通过理论分析和实验论证得到结论:(1)荧光光谱信号中存在信息冗余;(2)经冗余优化后的荧光光谱数据可以反演出更真实的样本的定量信息,对光谱重叠严重的多组分混合体系,采用冗余优化分析过的数据可以增加预测模型的灵敏度和稳定性。 相似文献
136.
137.
Wei Jiang YanLin Ye ZhiHuan Li ChengJian Lin QiTe Li YuCheng Ge JianLing Lou DongXing Jiang Jing Li ZhengYang Tian Jun Feng Biao Yang ZaiHong Yang Jie Chen HongLiang Zang Qiang Liu PengJie Li ZhiQiang Chen Yun Zhang Yang Liu XiaoHui Sun Jing Ma HuiMing Jia XinXing Xu Lei Yang NanRu Ma LiJie Sun 《中国科学:物理学 力学 天文学(英文版)》2017,60(6):062011
A transfer-reaction experiment of 9Be(9Be, 10Be)8Be was performed at a beam energy of 45 MeV. Excited states in 10Be up to 18.80 MeV are produced using missing mass and invariant mass methods. Most of the observed high-lying resonant states, reconstructed from the α + 6He and t + 7Li decay channels, agree with the previously reported results. In addition, two new resonances at 15.6 and 18.8 MeV are identified from the present measurement. The 18.55 MeV state is found to decay into both the t + 7Lig.s. and t + 7Li* (0.478 MeV) channels, with a relative branching ratio of 0.93 ± 0.33. Further theoretical investigations are encouraged to interpret this new information on cluster structure in neutron-rich light nuclei. 相似文献
138.
139.
Cun Zhu Rui Deng Jie Zeng Gamal E. Khalil Dana Dabiri Zhongze Gu Younan Xia 《Particle & Particle Systems Characterization》2013,30(6):542-548
A facile approach to the synthesis of pressure and temperature dual‐responsive polystyrene (PS) microbeads with controlled sizes via dispersion polymerization is described. Three different luminophors are selected and directly introduced into the reaction system and thus incorporated into the resultant PS microbeads during polymerization. By manipulating the reaction conditions, including concentrations of the initiator and monomer, polarity of the reaction medium, and injection rate for the monomer, uniform PS microbeads with sizes ranging from 1 to 5 μm are obtained. When a light source centered at 365 nm is used to excite all the luminophors in the PS beads, three distinct and resolvable emission peaks corresponding well with the luminophors are observed. By taking advantage of their sensitive responses to both pressure and temperature, the PS beads can be utilized for quantitative measurements of these two stimulations simultaneously. The PS beads loaded with multiple luminophors have the ability to serve as building blocks for the fabrication of novel sensing and imaging devices and therefore provide a promising strategy for the study of aerodynamics. 相似文献
140.