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Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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Science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3.& PAN Liuzhan1, 2 1. Institute of Laser Physics and Chemistry, Sichuan university, Chengdu 610064, china 2. Department of Physics, Luoyang normal College, Luoyang 471022, china 3. State Key Laboratory of Laser Technology, Huazhong university of Science and Technology, Wuhan 43.074, china Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2003 1. Institute of Laser Physics and Chemistry Sichuan University 610064 Chengdu China 2. State Key Laboratory of Laser Technology Huazhong University of Science and Technology 430074 Wuhan China 3. Department of Physics Luoyang Normal College 471022 Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction

Run off-on-out method and models for soil infiltrability on hill-slope under rainfall conditions

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Science china Earth Sciences 2006年第2期49卷 193-201页

作者： LEI Tingwu1,2, LIU Han1, PAN Yinghua3. ZHAO Jun2, ZHAO Shiwei2 & YANG Yonghui2 1. The Key Laboratory of Modern Precision Agriculture System Integration Research, College of Hydraulic and Civil Engineer-ing, china Agricultural university, Beijing 100083. china 2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Yangling 712100, china 3. Geographic and Resources Management College, Yantai normal university, Yantai 264025, china 1. The Key Laboratory of Modern Precision Agriculture System Integration Research College of Hydraulic and Civil Engineering China Agricultural University Beijing 100083 China 2. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Yangling 712100 China 3. Geographic and Resources Management College Yantai Normal University Yantai 264025 China

The soil infiltrability of hill-slope is important to such studies andpractices as hydrological process, crop water supply, irrigation practices, and soil erosion. A newmethod for measuring soil infiltrability on hill-slope under rainfall condition with run off-on-outwas advanced. Based on water (mass) balance, the mathematic models for soil infiltrability estimatedfrom the advances of runoff on soil surface and the water running out of the slope were *** of 2 cases were conducted. Case Ⅰ was done under a rainfall intensity of 20 mm/h, at aslope gradient of about 0° with a runoff/on length (area) ratio of 1 : 1. Case Ⅱ was under arainfall intensity of 60 mm/h and a slope of 20° with a runoff/on length (area) ratio of 1 : *** ring method was also used to measure the infiltrability for comparison purposes. Theexperiments were done with soil moisture of 10%. Required data were collected from laboratoryexperiments. The infiltrability curves were computed from the experimental data. The resultsindicate that the method can well conceptually represent the transient infiltrability process, withcapability to simulate the very high initial soil infiltrability. The rationalities of the methodand the models were validated. The errors of the method for the two cases were 1.82%/1.3.% and4.49%/3.529% (Experimental/Model) respectively, as estimated by comparing the rainfall amount withthe infiltrated volume, to demonstrate the accuracy of the method. The transient and steadyinfiltrability measured with double ring was much lower than those with this new method, due towater supply limit and soil aggregates breaking down at initial infiltration stage. The method canovercome the short backs of the traditional sprinkler method and double ring method for soilinfil-traility. It can be used to measure the infiltrability of sloped surface underrainfall-runoff-erosion conditions, in the related studies.

关键词： Infiltrability, runoff-on-out, rainfall, sloped surface, model.

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan university Journal of Natural Sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2, 3.,HUANG Zhiqin 2, 3. 4 1. The Faculty of Geography and Resources Science, Sichuan normal university, Chengdu 610066, Sichuan, china 2. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, china 3. Graduate university of the Chinese Academy of Sciences, Beijing 100049, china 4. Information Center of Land and Resources Department of Sichuan Province, Chengdu 610041, Sichuan, china The Faculty of Geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate university of the Chinese Academy of Sciences 100049 Beijing China Information Center of Land Resources Department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992 is extracted from the dynamic polygons of 2002. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 3.°. The areas of steep land cultivated had been slowly reduced from 1992 to 2002. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

STUDY OF Ag DIFFUSION INTO Cu SINGLE CRYSTALS BY RUTHERFORD BACKSCATTERING SPECTROMETRY

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 332-334页

作者： R.Wang 1) Key Laboratory of Beam Technology and Materials Modification, Ministry of Education, Beijing 100875, china2) Institute of Low Energy Nuclear Physics, Beijing normal {3., Beijing 100875, china3. Beijing Radiation Center, Beijing 100875, china Key Laboratory of Beam Technology and Materials Modification Ministry of Education Beijing 100875China Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China Beijing Radiation Center Beijing 100875 China

4.0Me V 7Li++ RBS was used for investigations of thermal diffusion of Ag in Cu single crystals. The annealing of samples was carried out in vacuum in the temperature range from 498K to 613.. The element depth concentration profiles transformed from RBS spectra indicate that the diffusion of Ag into Cu is a typical volume diffusion. The Arrhenius parameters corresponding to the diffusion were obtained.

关键词： Ag diffusion single crystal

The feature study on the π and proton rapidity distributions at AGS, SPS and RHIC

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 198-206页

作者： FENG ShengQin1,2 & YUAN XianBao1,3.1 College of Science, china Three Gorges university, Yichang 443.02, china 2 School of Physics and Technology, Wuhan university, Wuhan 43.072, china 3.Institute of Particle Physics, Central china normal university, Wuhan 43.070, china 1. College of Science China Three Gorges University Yichang 443002 China 2. School of Physics and Technology Wuhan University Wuhan 430072 China 3. Institute of Particle Physics Central China Normal University Wuhan 430070 China

The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.

关键词： non-uniform flow model average rapidity loss baryon number density nuclear stopping power

Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS

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Chinese Journal of Population,Resources and Environment 2005年第4期3卷 20-25页

作者： Wang Geng 1,2 , Nie Baochi 3. Wang Lin 1 & Wu Wei 1 1. School of Environmental and Biological Science and Technology, Dalian university of Technology, Dalian 116024, china 2. Urban and Environmental School, Liaoning normal university, Dalian 116029, china 3. Shenyang Buraue of Water Resources, Shenyang 110013. china. School of Environmental and Biological Science and Technology Oalian University of Technology Oalian 116024 China Urban and Environmental School Uaoning Nonnal University Oalian 116029 China Shenyang Buraue of Water Resources Shenyang 110013 China

Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis.

关键词： the middle and lower reaches of the Liaohe River ecological security assessment indicators system GIS spatial differences

On asymptotics of t-type regression estimation in multiple linear model

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Science china Mathematics 2004年第4期47卷 628-639页

作者： GUI HengjianDepartment of Mathematics, Beijing normal university, Beijing 100875, {3. 1. Department of Mathematics Beijing Normal University 100875 Beijing China

We consider a robust estimator (t-type regression estimator) of multiple linear regression model by maximizing marginal likelihood of a scaled t-type error *** marginal likelihood can also be applied to the de-correlated response when the withinsubject correlation can be consistently estimated from an initial estimate of the model based on the independent working assumption. This paper shows that such a t-type estimator is consistent.

关键词： t-type regression estimator, M-estimator, one-step estimate, consistency, asymptotic normality.

The dynamical properties of Rydberg hydrogen atom near a metal surface

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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, Jinan 250014, china 2. Department of Mathematics and Physics, Shandong Institute of Architecture and Engineering, Jinan 250014, 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 = 20. 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.

Observations favor the crossing of phantom divide lines

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 562-566页

作者： HUANG TieTie1,2,3. WU PuXun2,3.& YU HongWei2,3.1Department of Physics, Xiangnan College, Chenzhou 423.00, china 2Department of Physics and Institute of Physics, Hunan normal university, Changsha 410081, china 3.ey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan normal university, Changsha 410081, china 1. Department of Physics Xiangnan College Chenzhou 423000 China2. Department of Physics and Institute of Physics Hunan Normal University Changsha 410081 China3. Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education Hunan Normal University Changsha 410081 China

Using three different parameterized dark energy models, we reconstruct the properties of dark energy from the latest 3.7 Sne Ia, CMB and BAO with the present matter density, Ωm0, given prior. We find that, when Ωm0 is not small, for example, Ωm0 = 0.28 or 0.3., an evolving dark energy with a crossing of phantom divide line is favored and this conclusion seems to be model independent. We also find that the evolving properties of dark energy become more and more evident with the increase of Ωm0 given prior.

关键词： cosmology auelerating expansion dark energy