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Empirical likelihood-based inference in a partially linear model for longitudinal data

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Science china Mathematics 2008年第1期51卷 115-130页

作者： xue liugen~(1+) & zhu lixing~2 1 college of applied sciences, beijing university of technology, beijing 100022, china 2 Department of Mathematics, Hong Kong Baptist university, Hong Kong, china college of {1. sciences Beijing University of Technology Beijing China Department of Mathematics Hong Kong Baptist University Hong Kong China

A partially linear model with longitudinal data is considered, empirical likelihood to infer- ence for the regression coefficients and the baseline function is investigated, the empirical log-likelihood ratios is proven to be asymptotically chi-squared, and the corresponding confidence regions for the pa- rameters of interest are then constructed. Also by the empirical likelihood ratio functions, we can obtain the maximum empirical likelihood estimates of the regression coefficients and the baseline function, and prove the asymptotic normality. The numerical results are conducted to compare the performance of the empirical likelihood and the normal approximation-based method, and a real example is analysed.

关键词： partially linear model empirical likelihood confidence region longitudinal data 62G05 62G1. 62G20

Cu(Ⅱ) Potentiation of Alzheimer Aβ1.40 Cytotoxicity and Transition on its Secondary Structure

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 765-772页

作者： xue-Ling DAI~1.Ya-Xuan SUN~2 Zhao-Feng JIANG~2* 1.{1. of Life Science,Capital Normal university,beijing 1.0037,china 2 {1. of applied sciences and Humanities,beijing Union university,beijing 1.0083,china college of Life Science Capital Normal UniversityBeijing 100037 China college of {1. sciences and Humanities Beijing Union UniversityBeijing 100083 China

Mounting evidence has shown that dyshomeostasis of the redox-active biometals such as Cuand Fe can lead to oxidative stress,which plays a key role in the neuropathology of Alzheimer's disease（AD）.Here we demonstrate that with the formation of Cu（Ⅱ）·Aβ1.40 complexes,copper markedly potentiatesthe neurotoxicity exhibited by β-amyloid peptide （Aβ）.A greater amount of hydrogen peroxide was releasedwhen Cu（Ⅱ）·Aβ1.40 complexes was added to the xanthine oxidase/xanthine system detected by potassiumiodide *** bound to Aβ1.40 was observed by electron paramagnetic resonance（EPR） *** dichroism （CD） studies indicated that copper chelation could cause a structuraltransition of Aβ.The addition of copper to Aβ introduced an increase on β-sheet as well as α-helix,whichmay be responsible for the aggregation of Aβ.We hypothesized that Aβ aggregation induced by copper maybe responsible for local injury in *** interaction between Cu2+and Aβ also provides a possible mechanismfor the enrichment of metal ions in amyloid plaques in the AD brain.

关键词： Alzheimer’s disease Cu(Ⅱ)·Aβ1.40 complex neuron injury Aβ secondary structure

Palynological characters of Glycyrrhiza,Glycyrrhizopsis,and Meristotropis(Leguminosae),with special reference to their taxonomic significance

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Journal of Systematics and Evolution 2010年第6期48卷 455-463页

作者： 1.2Lei MENG 2Xiang-Yun zhu 1.{1. of Biological sciences,china Agricultural university,beijing 1.0094,china) 2(Institute of Botany,Chinese Academy of sciences,beijing 1.0093,china) (college of Biological {1. China Agricultural University Beijing 100094 China) (Institute of Botany Chinese Academy of Sciences Beijing 100093 China)

The pollen morphology of 1. species of the genus Glycyrrhiza *** one from each of the genera Glycyrrhizopsis Boiss.& *** Meristotropis Fisch.& *** investigated by scanning electron *** pollen morphology,the main differences between Glycyrrhizopsis and Glycyrrhiza are:Glycyrrhizopsis-pollen grains 36.63 × 40.42 μm in size,oblate spheroidal in shape;and Glycyrrhiza-pollen grains 24.47-33.1. × 23.82-31.83 μm in size,prolate spheroidal in *** and Glycyrrhiza should be recognized as two distinct genera based on palynological and morphological *** and Glycyrrhiza are similar in many important palynological and morphological characters,suggesting that the two should be *** Glycyrrhiza,two types of pollen grains,3-lobed-circular or subtriangular in polar view,are found in different species,in accordance with morphological differences in the two groups,shedding light on the classification and evolution of the genus.

关键词： exine sculpture morphological character pollen morphology taxonomic revision.

Adjoint method for the optimum planning of industrial pollutant sources

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Science china Earth {1. 2005年第8期48卷 1270-1279页

作者： LIU Feng1.2, HU Fei2 & zhu Jiang2 1. {1. of Environmental sciences, Peking university, beijing 1.0871. china 2. LAPC, Institute of Atmospheric Physics, Chinese Academy of sciences, beijing 1.0029, china college of Environmental {1. Peking University Beijing China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001. substrates

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Science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3, WANG Yong2, DU Xiaolong1, MEI Zengxia1, KONG Xianghe3, JIA Jinfeng1, xue Qikun1 & ZHANG Ze2, 4 1. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of sciences, beijing 100080, china 2. Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of sciences, beijing 100080, china 3. college of Physics and Engineering, Qufu Normal university, Qufu 273165, china 4. beijing university of technology, beijing 100022, china State Key Laboratory for Surface Physics Institute of Physics Chinese Academy of Sciences Beijing China college of Physics and Engineering Qufu Normal University Qufu China Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing China beijing university of technology Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001. substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30 rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.

Size-dependent hydroxyl radicals generation induced by SiO_2 ultra-fine particles: The role of surface iron

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Science china Chemistry 2009年第7期52卷 1033-1041页

作者： SHANG Yu1. zhu Tong1. LI Yi1.2 & ZHAO JinCai3 1.{1. of Environmental sciences and Engineering, Peking university, beijing 1.0871. china 2 Chinese Academy of Meteorological sciences, beijing 1.0871. china 3 Institute of Chemistry, Chinese Academy of sciences, beijing 1.0871. china college of Environmental {1. and Engineering Peking University Beijing China Chinese Academy of Meteorological sciences Beijing China Institute of Chemistry Chinese Academy of Sciences Beijing China

Oxidative stress and hydroxyl radicals (·OH) play important roles in adverse health effects caused by inhalable ambient air particles (PM1.). The ultra-fine fraction of PM1. has been hypothesized as one of the critical contributors to ·OH generation. Both in vivo and in vitro studies have shown that ultra-fine particles (UFPs) or nano-particles generate more ·OH than larger particles with identical mass and composition. Both the surface area and surface-adsorbed redox-active metals have been suggested as factors to determine the oxidative capacity of UFPs. In this study, the ·OH-generating capability of dif-ferent sizes of SiO2 particles was investigated in order to determine which factor influences particle-induced ·OH generation. The amount of ·OH generated in both acellular and cellular systems was quantified using a capillary electrophoresis method following exposure to SiO2 particles with diameters of 1., 1.0, and 500 nm. The amount of ·OH was strongly dependent on particle size, and a significant enhancement was observed only with 1. nm particles. Further studies indicated a close association between ·OH and iron ion concentration (R2 = 0.81., p1.. Washed particles, with their surface iron being removed, did not generate ·OH. The iron-containing leachate from these washings was able to enhance ·OH production as untreated particles did. Therefore, the presence of adsorbed iron on the surface of the SiO2 particles is presented as a possible mechanism of UPFs-induced ·OH generation. The SiO2 acted as an inert substrate, and the surface of ultra-fine SiO2 particles acted as a carrier for iron.

关键词： ultra-fine particles nano-particles ·OH oxidative stress size-effect

3D building modeling,organization and application in digital city system

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中国科学：技术科学英文版 2010年第S1期53卷 134-142页

作者： YANG xue 1.WENG JingNong 1.2,XIA YuBin 2,WU Lun 3 & SUI ZhengWei 3 1.{1. of Software,Beihang university,beijing 1.01.1.china 2 {1. of Computer,Beihang university,beijing 1.01.1.china 3 Institute of Remote Sensing and GIS,Peking university,beijing 1.0871.china college of Software Beihang University Beijing China college of Computer Beihang University Beijing China Institute of Remote Sensing and GIS Peking University Beijing China

The real world is a three-dimensional(3D)space requiring that 3D geospatial information applications be developed in alignment with the observer’s visual and perceptive ***,3D building model data are required in a wide range of areas such as urban planning,environmental protection,real estate management and emergency *** the same time,the development of Web service[LU1.technologies allows the possibility of the widely distributed 3D geospatial data on the web.3D city building model with its related information is an important part in the construction of a digital city system,and has become a staple resource on the web *** view of the hierarchical representation of a 3D building model,an abstract of a 3D building model based on structure details is studied,and a novel representation approach named 3D transparent building hierarchical model is presented in this *** approach fully uses both the existing 3D modeling technologies and CAD constructing mapping *** the spatial relationship description,structural components inside a building can be represented and integrated as hierarchical models in a unified 3D *** addition,based on the characteristics of the 3D building model data,a service-oriented architecture and Web service technologies for 3D city building models are *** aim of the approach is that 3D city building models can be used as a kind of data resource service on the web,and can also exist independently in various different web applications.

关键词： 3D modeling 3D transparent building hierarchical models china Star web services

A heuristic path-estimating algorithm for large-scale real-time traffic information calculating

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Science china(Technological {1.) 2008年第S1期51卷 165-174页

作者： L WeiFeng1.zhu TongYu1.WU DongDong2,DAI Hong3 & HUANG Jian1.1.State Key Laboratory for Software Development Environment,Beihang {1.,beijing 1.0083,china 2 beijing Transportation Information Center,beijing 1.0055,china 3 college of Arts & Science,beijing Union {1.,beijing 1.0083,china State Key Laboratory for Software Development Environment Beihang University Beijing China beijing Transportation Information Center Beijing China college of Arts & Science Beijing Union University Beijing China

As the original Global Position System (GPS) data in Floating Car Data have the accuracy problem,this paper proposes a heuristic path-estimating algorithm for large-scale real-time traffic information calculating. It uses the heuristic search method,imports the restriction with geometric operation,and makes comparison between the vectors composed of the vehicular GPS points and the special road network model to search the set of vehicular traveling route candidates. Finally,it chooses the most optimal one according to weight. Experimental results indicate that the algorithm has considerable efficiency in accuracy (over 92.7%) and com-putational speed (max 8000 GPS records per second) when handling the GPS tracking data whose sampling rate is larger than 1.min even under complex road network conditions.

关键词： path-estimating floating car data (FCD) road network vector GPS

Synergistic governance:china's roadmap to improved health through climate and clean air actions

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Environmental Science and Ecotechnology 2024年第4期20卷 14-15页

作者： Tao xue Tong {1. Institute of Reproductive and Child Health National Health Commission Key Laboratory of Reproductive Health and Department of Epidemiology and BiostatisticsMinistry of Education Key Laboratory of Epidemiology of Major Diseases(PKU)School of Public HealthPeking University Health Science CentreBeijingChina SKL-ESPC and SEPKL-AERM College of Environmental Sciences and EngineeringCenter for Environment and HealthPeking UniversityBeijing100871China

The COP28's inaugural Health Day highlighted the growing recognition of the connection between climate and health,while china's State Council released its third air quality action plan aiming at ongoing health *** Synergetic Roadmap project[1.,which aims to track china's progress towards carbon neutrality and clean air,provides valuable insights to answer a set of intriguing questions concerning environmental health determinants,their source sectors,and the methods for harmonizing disparate actions to maximize health gain.

关键词： concerning neutral clean