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Plus cupping degrees do not form an ideal

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Science in China(Series F) 2004年第5期47卷 635-654页

作者： LI Angsheng1,2.& ZHAO Yicheng1 1. Institute of Software,Chinese Academy of sciences,beijing 100080,China {2.,beijing normal university,beijing 100871,China 1. Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. school of information sciences Beijing Normal University 100871 Beijing China

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0 详细信息

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0

关键词： computably enumerable set Turing degree definability.

The study of two-color excitation upconversion of Pr(0.5)Yb(3):ZBLAN

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Science China(Physics,Mechanics & Astronomy) 2006年第2期49卷 169-177页

作者： CHEN Xiaobo1 & SONG Zengfu2.1. Applied Optics beijing Area Major Laboratory, Analysis and testing center, beijing normal university, beijing 100875, China 2. Peking university, Physics school, beijing 100871, China Applied Optics beijing Area Major Laboratory Analysis testing center Beijing Normal University Beijing 100875 China Physics school Peking University Beijing 100871 China

The excited state absorption upconversion of Pr(0.5)Yb(3):ZBLAN glass material, under two-color excitation of the 960 nm semiconductor laser and the Xe lamp light simultaneously, is reported in this article. It was found that the upconversion emission spectra of 480.1, 519.0, 601.9 and 631.8 nm coincide with the common emission spectra. Meanwhile, the upconversion-excitation spectrum has three obvious peaks under two-color excitation, and they respectively correspond to the 856.0 nm upconversion ex-citation transition [1G4(Pr3+)→1I6(Pr3+) and 1G4(Pr3+)→3P1(Pr3+)], the 789.0 nm upconver-sion excitation transition 1G4(Pr3+)→3P2.Pr3+), and the 803.7 nm upconversion excitation transition 3H6(Pr3+)→1D2.Pr3+). The upconversion excitation transition 1G4(Pr3+)→1I6(Pr3+) is strong because its oscillator strength f = 2..040×10?6 is large, which results in a large peak appearing in the upconversion excitation spectrum. That is just the new interesting two-color excitation upconversion luminescence phenomenon of Pr(0.5)Yb(3):ZBLAN induced by one laser and one continuous normal light simultaneously.

关键词： upconversion volumetric three-dimensional display two-color excitation.

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

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Science China(Technological sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2.1. school of Environmental sciences, {2., beijing 100875, China 2. Institute of Geographic Science and Natural Resources Research, beijing 100101, China beijing normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982.1998, soil moisture of all layers of soil-profile (0—1 m) in the Yellow River basin over the 17 years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1982.to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

Integrative inversion of land surface component temperature

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Science China Earth sciences 2005年第11期48卷 2011-2019页

作者： FAN Wenjie1 & XU Xiru1,2.1. Institute of Remote Sensing and Geographical information System, Peking university, {2., China 2. Center of Remote Sensing and GIS of beijing normal university, beijing 100875, China 1. Institute of Remote Sensing and Geographical information System Peking University 100871 Beijing China 2. Center of Remote Sensing and GIS of beijing normal university 100875 Beijing China

In this paper, the row winter wheat was selected as the example to study the com-ponent temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evi-dently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field ex-periment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inver-sion stability of components temperature. Just two parameters were sufficient for accurate at-mospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric trans-mittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

关键词： components temperature, inverse pattern, atmospheric correction

Weight hierarchies of linear codes satisfying the Near-Chain condition

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Progress in Natural Science:Materials International 2005年第9期15卷 784-792页

作者： LIU Zihui1** and CHEN Wende2.1. school of Mathematical sciences, Peking {2., beijing 100871, China 2. Laboratory of Systems and Control and Key State Laboratory of information Security, Institute of Systems Science, Academy of Mathematics and Systems Science, Chinese Academy of sciences, beijing 100080, China) school of Mathematical sciences Peking University Beijing 100871 China. Laboratory of Systems and Control and Key State Laboratory of information Security Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The weight hierarchies of a linear [n,k;q] code C satisfying the Near-Chain condition are studied, almost all the weight hierarchies of such code are determined.

关键词： weight hierarchy Near-Chain condition difference sequence linear code.

Suitability evaluation for land reclamation in mining area:A case study of Gaoqiao bauxite mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 506-515页

作者： WANG Shi-dong1, 2. LIU Chang-hua2. ZHANG He-bing2.1. College of Resources Science and Technology, beijing normal university, beijing 100875, China 2. {2. of Surveying and Land information Engineering, Henan Polytechnic university, Jiaozuo 454000, China [a] College of Resources Science and Technology Beijing Normal University Beijing 100875 China [b] school of Surveying and Land information Engineering Henan Polytechnic University Jiaozuo 454000 China

Suitability evaluation plays an important role in land reclamation because the choice of evaluation methods affects the accuracy and objectivity of the suitability evaluation results. Furthermore, it influences the decision-making related to land reclamation. An improved method, which is called limit comprehensive conditions method, was developed after different suitability evaluation methods were studied. Based on this method, the reclaimed land of the Gaoqiao bauxite mining area was evaluated. The Gaoqiao mining area was divided into seven evaluation units that were evaluated respectively by selecting evaluation factors and establishing grade standards. The results show that the proposed method is more applicable and easier to handle. Moreover, its evaluation results are more scientific compared with the traditional evaluation methods. The improved method can be beneficial to the rapid monitoring and the effective management of reclaimed land in the opencast mine area.

关键词： mining area land reclamation suitability evaluation Gaoqiao bauxite mine

Automatic generalization of metro maps based on dynamic segmentation

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Science China(Technological sciences) 2010年第S1期53卷 158-165页

作者： DONG WeiHua 1,TIAN Yuan 2.& ZHANG Yi 2.1 Institute of Geography and Remote Sensing,beijing normal university,beijing 100875,China 2.Institute of Remote Sensing and Geographic {2. System,Peking university,beijing 100871,China 1. Institute of Geography and Remote Sensing Beijing Normal University Beijing 100875 China 2. Institute of Remote Sensing and Geographic information System Peking University Beijing 100871 China

A metro map is usually optimized for the readability of connections and transportation networks *** order to assure good readability and meet aesthetic considerations,a set of principles for good metro map layout are *** to these principles,a new methodology based on dynamic segmentation is presented to produce the metro maps ***,routes are constructed according to the line attribute similarity and geometry *** a set of cartographic generalization methods about the shape,angle,length,and topology are presented for these *** method is validated by beijing metro plan *** the experiment results,it can be concluded that this new method is more effective than the static segmentation method to produce metro maps with better readability for route plans.

关键词： metro maps generalization dynamic segmentation visualization

Sieve M-estimation for semiparametric varying-coefficient partially linear regression model

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Science China Mathematics 2010年第8期53卷 1995-2010页

作者： HU Tao 1,2.& CUI HengJian 1,2.1 school of Mathematical sciences,{2.,Laboratory of Mathematics and Complex Systems,Ministry of Education,beijing 100875,China 2.school of Mathematical sciences,Capital normal university,beijing 100048,China 1. school of Mathematical sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing 100875 China2. School of Mathematical Sciences Capital Normal University Beijing 100048 China

This article considers a semiparametric varying-coefficient partially linear regression *** semiparametric varying-coefficient partially linear regression model which is a generalization of the partially linear regression model and varying-coefficient regression model that allows one to explore the possibly nonlinear effect of a certain covariate on the response variable.A sieve M-estimation method is proposed and the asymptotic properties of the proposed estimators are *** main object is to estimate the nonparametric component and the unknown parameters *** is easier to compute and the required computation burden is much less than the existing two-stage estimation ***,the sieve M-estimation is robust in the presence of outliers if we choose appropriate ρ(·).Under some mild conditions,the estimators are shown to be strongly consistent;the convergence rate of the estimator for the unknown nonparametric component is obtained and the estimator for the unknown parameter is shown to be asymptotically normally *** experiments are carried out to investigate the performance of the proposed method.

关键词： partly linear model varying-coefficient robustness optimal convergence rate asymptotic normality

The relative generalized Hamming weight and the semilinear equivalence of codes

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Science China(information sciences) 2011年第4期54卷 787-794页

作者： LIU ZiHui 1 & WANG Jie 2.1 Department of Mathematics,beijing Institute of Technology,beijing 100081,China 2.{2. of Mathematical sciences,beijing university,beijing 100871,China 1. Department of Mathematics Beijing Institute of Technology Beijing 100081 China2. School of Mathematical Sciences Beijing University Beijing 100871 China

Certain equivalent conditions are given for the semilinear equivalence of linear codes by using the relative generalized Hamming weight and the value function.

关键词： value function semilinear equivalence support weight relative generalized Hamming weight