检索结果-南通市图书馆

Recurrence spectra of He atoms in strong external fields

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2004年第4期47卷 477-484页

作者： LIN Shenglu1, LI Hongyun1, WANG Dehua2. ZHAO Wenli1 & GAO Feng1 1. department of physics,{2., jinan 2.0014, China 2. department of Mathematics and physics, shandong Institute of Architecture and Engineering, jinan 2.0014, China 1. department of physics Shandong Normal University 250014 Jinan China 2. department of Mathematics and physics Shandong Institute of Architecture and Engineering 250014 Jinan China

By employing a model potential including the electron exchange energy, we extend the semiclassical closed orbit theory to study the multielectron atoms. Using special region-splitting consistent and iterative method, we figure out the closed orbits in the corresponding classical system and calculate the recurrence spectra of triplet helium atoms in parallel electric and magnetic fields at scaled energy ε=?0.03,n≈40,n=0. The core-scattering effects have been taken into account, which lead to more peaks in the spectra. It has also been confirmed by means of the direct comparison between the spectral portrait in such a plot and those of hydrogen case. In order to compare the theoretic results with experiment, we investigate the closed orbits and recurrence spectra of helium atoms for the similar exchange potential but applied only by single electric field at scaled energy ε=?2.7 case. The spectra are in good agreement with the experimental observation. We conclude that our model is correct and it is necessary to consider the exchange effect for determining the photoabsorption spectra of multielectron atoms in strong external fields.

关键词： exchange potential, recurrence spectra, semiclassical closed orbit theory, core-scattering.

An investigation of hadronization mechanism at a Z^0 factory

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第11期53卷 1998-2004页

作者： JIN Yi 1,SI ZongGuo 2.XIE QuBing 2.& YAO Tao 2.1 department of physics,{2. of jinan,jinan 2.002.,China 2.School of physics,shandong {2.,jinan 2.0100,China 1. department of physics University of Jinan Jinan 250022 China2. School of Physics Shandong University Jinan 250100 China

We briefly review the hadronization pictures adopted in the LUND String Fragmentation Model (LSFM),Webber Cluster Fragmentation Model (WCFM) and Quark Combination Model (QCM),*** of hadron multiplicity,baryon to meson ratios and baryon-antibaryon flavor correlations,especially those related to heavy hadrons at a Z 0 factory obtained by LSFM and QCM,are reported.

关键词： Z0 factory hadronization model baryon to meson ratio B correlation

The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2. SONG Hongsheng2. LIU Chunxiang2. REN Xiaorong2. ZHANG Ningyu3, TENG Shuyun1 & XU Zhizhan1 1. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-2.1, Shanghai 2.1800, China 2. department of physics, shandong normal university,{2., China 3. shandong Institute of Architecture and Engineering,{2., China 1. Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences P. O. Box 800-211 201800 Shanghai China 2. department of physics Shandong Normal University 250014 Jinan China 3. shandong Institute of Architecture and Engineering 250014 Jinan China

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.

The Ambient Gas Effects on Pulsed Laser Ablation of Target

在线全文

学校读者我要写书评

暂无评论

光电子·激光 1996年第1期7卷 12-15页

作者： Gongtang Wang Xiangtai Wang Baoyuan Mian(department of physics,{2. normal university,jinan 2.0014)Bingzhang Xu Liangmo Mei(department of physics.{2. university,jinan 2.0100) 山东师范大学物理系山东济南山东大学物理系山东济南

ＴｈｅＡｍｂｉｅｎｔＧａｓＥｆｆｅｃｔｓｏｎＰｕｌｓｅｄＬａｓｅｒＡｂｌａｔｉｏｎｏｆＴａｒｇｅｔ￥ＧｏｎｇｔａｎｇＷａｎｇ；ＸｉａｎｇｔａｉＷａｎｇ；ＢａｏｙｕａｎＭｉａｎ（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，... 详细信息

ＴｈｅＡｍｂｉｅｎｔＧａｓＥｆｆｅｃｔｓｏｎＰｕｌｓｅｄＬａｓｅｒＡｂｌａｔｉｏｎｏｆＴａｒｇｅｔ￥ＧｏｎｇｔａｎｇＷａｎｇ；ＸｉａｎｇｔａｉＷａｎｇ；ＢａｏｙｕａｎＭｉａｎ（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，ＳｈａｎｄｏｎｇＮｏｒｍａｌＵｎｉ...

关键词： Al￣+ ion mean projected range laser ablation ambient gas effect.

Formation and Evolution of Ancient Lakes on South Coast Plain of Laizhou Bay

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2005年第4期3卷 26-32页

作者： Han Mei 1, Zhou Baohua 2. Yang Peilin 1,Gao Guiqin 1 & Zhang Weiying 1 1. department of Geography, shandong normal university,{2., China 2. department of Geography, jinan university, jinan 2.0001, China department of Geography Shandong Normal University Jinan 250014 China department of Geography Jlnan University Jinan 250001 China

Based on the data of historical geography, the analysis of the stratigraphic section, and the textual research of place names and satellite photographic interpretations, the authors study the formation and evolution of ancient lakes on the south coast plain of Laizhou Bay where there were once three lakes: Judian Lake, Qingshuibo Lake and Biehua Lake. All the lakes formed 6000 years ago evolved from the lagoons near the estuary and went through two periods, the golden age in the Middle Holocene and the shrinking age in the Late Holocene. The disappearance of the lakes resulted from the drying climate, the migration of the river courses and the activities of human beings. Among the three reasons, the migration of the river courses is the main one.

关键词： ancient lake cause historical evolution south coast plain of Laizhou Bay

The dynamical properties of Rydberg hydrogen atom near a metal surface

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2. DU Mengli3 & LIN Shenglu1 1. College of physics and Electronics, shandong normal university,{2., China 2. department of Mathematics and physics, shandong Institute of Architecture and Engineering,{2., China 3. Institute of Theoretical physics, Chinese Academy of Sciences, Beijing 100080, China 1. College of physics and Electronics Shandong Normal University 250014 Jinan China 2. department of Mathematics and physics Shandong Institute of Architecture and Engineering 250014 Jinan China 3. Institute of Theoretical physics Chinese Academy of Sciences 100080 Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 2.. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d < dc, and the system tends to be non-integrable. The trajectories become unstable and the electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.

The kink-soliton and antikink-soliton in quasi-one-dimensional nonlinear monoatomic lattice

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2005年第2期48卷 150-157页

作者： XU Quan1 & TIAN Qiang2.1. Scientific and Technological Office, Daqing Teacher College, Daqing 163712. China 2. department of physics , Beijing normal {2., Beijing 100875, China Scientific and Technological Office Daqing Teacher College Daqing 163712 China department of physics Beijing Normal University Beijing 100875 China

The quasi-one-dimensional nonlinear monoatomic lattice is analyzed. The kink-soliton and antikink-soliton are presented. When the interaction of the lattice is strong in the x-direction and weak in the y-direction, the two-dimensional (2.) lattice changes to a quasi-one-dimensional lattice. Taking nearest-neighbor interaction into account, the vibration equation can be transformed into the KPI, KPII and MKP equation. Considering the cubic nonlinear potential of the vibration in the lattice, the kink-soliton solution is presented. Considering the quartic nonlinear potential and the cubic interaction potential, the kink-soliton and antikink-soliton solutions are presented.

关键词： two-dimensional nonlinear lattice, quasi-one-dimensional nonlinear lattice, kink-soliton, antikink-soliton.

Extraction of Surface Roughness from the Central δ-peak of Light Scattering Using a Multi-wavelength Ar~+ Laser

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 2000年第3期9卷 22-27页

作者： LIU Deli QI Dongping CHENG Chuanfu (department of physics,{2., jinan 2.0014, China) 山东师范大学山东济南

In this paper, a new light scattering method for measuring t he roughness of random surfaces is proposed. The method is based on the relation between the specularly reflected intensity I s, i.e., the central δ-peak intensity and wave vector component k z. The linear fit of the logarithm graph of the normalized central δ-peak intensity I sr versus k-2.z, whose variation is induced by changing illuminating wavelength, gives the square of the surface roughness w. The roughnesses of 6 silicon backside samples were measured.

关键词： random surface roughness light scattering multi-wavelength

Existence of the solutions and the attractors for the large-scale atmospheric equations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2006年第6期49卷 650-660页

作者： HUANG Haiyang1 & GUO Boling2.1. department of Mathematics, Beijing normal {2., Beijing 100875, China 2. Institute of Applied physics and Computational Mathematics, Beijing 100080, China 1. department of Mathematics Beijing Normal University Beijing 100875 China 2. Institute of Applied physics and Computational Mathematics Beijing 100080 China

In this paper, firstly, the proper function space is chosen, and the proper expression of the operators is introduced such that the complex large-scale atmospheric motion equations can be described by a simple and abstract equation, by which the definition of the weak solution of the atmospheric equations is made. Secondly, the existence of the weak solution for the atmospheric equations and the steady state equations is proved by using the Galerkin method. The existence of the non-empty global attractors for the atmospheric equations in the sense of the Chepyzhov-Vishik’s definition is obtained by constructing a trajectory attractor set of the atmospheric motion equations. The result obtained here is the foundation for studying the topological structure and the dynamical behavior of the atmosphere attractors. Moreover, the methods used here are also valid for studying the other atmospheric motion models.

关键词： atmosphere equations, weak solution, trajectory attractor, global attractor, equilibrium.