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Reducing component estimation for varying coefficient models with longitudinal data

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Science china Mathematics 2008年第2期51卷 250-272页

作者： TANG QingGuo~(1,2+) WANG JinDe~2 1 Institute of Sciences,People’s Liberation Army university of Science and Technology,nanjing 210007,china 2 {3. of Mathematics,nanjing university,nanjing 210093.china Institute of Sciences People’s Liberation Army University of Science and Technology Nanjing China department of Mathematics Nanjing University Nanjing China

Varying-coefficient models with longitudinal observations are very useful in epidemiology and some other practical *** this paper,a reducing component procedure is proposed for es- timating the unknown functions and their derivatives in very general models,in which the unknown coefficient functions admit different or the same degrees of smoothness and the covariates can be time- *** asymptotic properties of the estimators,such as consistency,rate of convergence and asymptotic distribution,are *** asymptotic results show that the asymptotic variance of the reducing component estimators is smaller than that of the existing estimators when the coefficient functions admit different degrees of *** sample properties of our procedures are studied through Monte Carlo simulations.

关键词： varying coefficient model longitudinal data nonparametric estimation reducing component estimators asymptotic normality 62G07

A STUDY ON THE RELATION BETWEEN THE VARIATION OF THE PRECIPITATION IN EASTERN JIANGHUAI WATERSHED AND SEDIMENT TRANSPORT IN CHIHE RIVER VALLEY

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Chinese Geographical Science 2002年第1期12卷 44-49页

作者： ZHANG Jian chun, PENG Pu zhuo(department of Urban and Resources Sciences,nanjing university,nanjing 210093.P.R.china ) department of Urban and Resources Sciences Nanjing University Nanjing P. R. China

Rainfall resource is very important to the development of society and economy,especially to eastern Jianghuai watershed which is now facing serious challenge of water shortage. Based on the observational records covering the period from 1957 to 1999,the characteristics of precipitation changing over eastern JiangHuai watershed and its connection to sediment discharge in Chihe River valley were studied using tendency analysis and correlation analysis .Results show that the rainfall in this area had a declining tendency in Spring at a rate of -21.2mm/10a, annual and Summer precipitation was increasing at the rate of 10.6mm/10a and 14.8mm/10a. The gray correlation analysis shows that sediment discharge correlates most closely with runoffs and the frequency of the rainstorm with a daily precipitation of 50-100mm, on the second place,with the rainfall and the frequency of the rainstorm of a daily precipitation no less than 100mm;and thirdly with the number of rainy days. In addition, the paper suggests the major countermeasures and methods for controlling of soil and water losses in this area.

关键词： eastern Jianghuai watershed Chihe River rainfall sediment discharge correlation grade

Karst conduit flow and its hydrodynamic characteristics——Houzhai River drainage basin in Fueling,Guizhou,china as an example

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Chinese Science Bulletin 2001年第S1期46卷 45-51页

作者： WANG Lachun & ZHANG Yongzhandepartment, of Urban & Resource Sciences, nanjing university, nanjing 210093. china Key Laboratory of Coast & Island Development of Ministry of Education of {3., nanjing university, nanjing 210093. china department of Urban & Resource Sciences Nanjing University Nanjing China Key Laboratory of Coast & Island Development of Ministry of Education of china Nanjing University Nanjing China

Conduit flow is a special geomorphologic and hydrological phenomenon in karst area. Houzhai River drainage basin in Puding, Guizhou Province is a large-scale test field in the main and broad karst area in the southern part of china, where conduit flow is a general reserve and drainage system for groundwater. Based on the great deal of field investigation and indoor research work during the 1970s-1980s, pulse tests were done four times there during 1988-1991 in wet and dry seasons. It shows that water level at each observation site changes from 10 to 1800 mm, with the larger variation in upper stream and at karst windows than in lower reaches and at each exit along subterraneous rivers. The average flow velocity in conduit system is determined within 200-800 m/h, with the less change from flood to dry seasons, and it is higher in principal conduits and in upper stream area. Also, the reliable divided discharge ratio among each hydrological conduit of sunken system has been got. Thus, combined with

关键词： conduit flow karst pulse test Houzhai River.

Extraction of the spectral information of terahertz signals using superconducting Josephson junction

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Science china(Technological Sciences) 2010年第5期53卷 1247-1251页

作者： XU WeiWei,CHEN Jian,KANG Lin & WU PeiHeng department of Electronic Science & Engineering,nanjing university,nanjing 210093.china department of Electronic Science & Engineering Nanjing University Nanjing China

Using YBa2Cu3.7-δ/MgO bicrystal Josephson junction,we have developed a setup for spectrum analyses of terahertz signals,up to 2.5 THz,with a frequency resolution of 3.*** junction works at liquid nitrogen temperature when the signal frequencies are low while for signals at 1.6 THz and 2.5 THz the junction is cooled to 6 *** signal processing(DSP) chips are made use of to build a data acquisition and processing system so that it can be compact,fast,and *** the completion of the relevant hardwares and softwares,the measurements are now automated.

关键词： Josephson junction THz wave spectrum detection DSP technology

The Figure and Dynamical Parameters of Io Inferred from Internal Structure Models

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Chinese Journal of astronomy and Astrophysics 2001年第3期1卷 275-280页

作者： HongZhang Cheng－ZhiZhang departmentofastronomy NanjingUniversityNanjing210093 departmentofastronomy NanjingUniversityNanjing

The recent Galileo spacecraft explored Jupiter and its satellite system and provided us with new geodetic data. In order to discuss the dynamical parameters and secular tidal effect of Io, the theory of synchronous satellite is described in detail. Using the new geodetic data of Io, two sets of Io's internal structure models are constructed based on the asthenosphere assumption. The liberation parameters α,β,γ and dynamical flattening H are calculated for the models of Io. A comparison of Io with the Moon indicates that they are quite different in many characteristics in spite of the fact that they are approximately equal in mass and size and that they both orbit synchronously.

关键词： Io-synchronous orbit-dynamical parameters

Effects　of　copper，manganese　and　pH　on　the　growth　and　several　enzyme　activities　of　mycorrhizal　fungus　Cenococcum　geophilum　Fr．

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Journal of Environmental Sciences 1996年第4期8卷 419-425页

作者： Kong Fanxiang Zhang Min(department of Environmental Science and Engineering, nanjing university,nanjing {3.china) department of Environmental Science Nanjing University Nanjing 210093 China

he effects of various concentrations of copper,manganese and ph on the growth,protein content and several enzyme activities of mycorrhizal fungus Cenococcum geophilum Fr. Were *** results showed that high concentration of copper (20 mg/L)and low ph (3.0-4.0) inhibited the mycelial growth (dry weight), however, the protein content increased or not significantly reduced in mycelia after copper or manganese was applied. The activities of acid phosphatase and α-mannosidase were induced by high concentration of Mn (200-400 mg/L);but the activities of G6PDH, MTLDH and trehalase were inhibited by high content of copper(10-20 mg/L),both of the responses of these enzymes and mycelial growth under the presence of copper were correlative each other. Measurement of these enzyme activities might therefore provide a useful criterion for the evaluation of the fungitoxicity of soil contaminated by copper.

关键词： copper manganese ph mycorrhizal fungus enzyme activity.

Origin of the Red Earth sequence on the northeastern Tibetan Plateau and its implications for regional aridity since the middle Miocene

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Science china Earth Sciences 2006年第5期49卷 505-517页

作者： WANG Xianyan1,7, LU Huayu1,2, JI Junfeg3. WANG Xiaoyong1,7, ZHAO Jingbo4, HUANG Baochun5 & LI Zhen6 1. SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, china 2. department of Urban and Resources Sciences, nanjing university,{3. 3. department of Earth Sciences, nanjing university,{3. 4. department of Geography, Shaanxi Normal university, Xi’an 710062, china 5. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, china 6 department of Geography, Qinghai Normal university, Xining 810008, china 7. Graduate School of the Chinese Academy of Sciences, Beijing 10003., china SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate School of the Chinese Academy of Sciences Beijing China department of Urban and Resources Sciences Nanjing University Nanjing China department of Earth Sciences Nanjing University Nanjing China department of Geography Shaanxi Normal University Xi’an China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China department of Geography Qinghai Normal University Xining China

The Red Earth deposit around Xining, northeastern Tibetan Plateau, has beenstudied in terms of soil micro-structure, grain-size distribution, major- and trace-elementchemistry and magne-tostratigraphy. Field investigations indicate that the Red Earth sequenceconsists of 25 visually definable yellow-brown and weakly-developed soils interbedded with reddishstrongly-developed soils, and has a similar structure to the aeolian Red Clay deposit on the ChineseLoess Plateau. Grain-size analysis shows that the Red Earth deposit is very fine-grained with anegligible sand fraction ( > 63.μm). Thin-section observations under light microscopy show that thedeposit has a clayey texture and the coarse fraction ( > 10 μm) mainly consists of quartz,feldspar and micas. Pyroxene and hornblende were also observed. This mineralogical composition ofthe coarse fraction is similar to that of the Quaternary loess. In addition, all of the mineralgrains are semi angular semi-angular and are generally finer than 63.μm. There is a good agreementbetween the major and minor trace element chemistry of loess-soil units and the Red Earth *** REE distributions of the loess-soil and the Red Earth deposit are similar in shape, withenriched LREE and fairly flat HREE profiles and a clear negative Eu anomaly. The geochemicalcharacteristics of the Red Earth deposit are also identical to those of upper continental crust,thus indicating a wind-blown origin. Magnetostratigraphic investigation shows that onset of the RedEarth deposition predates 11.4 Ma BP (13.6 Ma at a nearby site). The distribution of the reportedMiocene aeolian loess at Qin''an of the Loess Plateau is still unknown. Our results indicate thatthis aeolian deposit had extended to the northeastern Tibetan Plateau by at least the middleMiocene. The similarity of the element geochemistry between the Red Earth deposit and the overlyingloess shows that they may have similar sources and dynamic transport system, and may indicate thatthe

关键词： Red Earth deposit, Northeastern Tibetan Plateau, aeolian deposit, aridity of Asia, the middle Miocene.

LIMIT CYCLES AND BIFURCATION CURVES FOR THE QUADRATIC DIFFERENTIAL SYSTEM (III)_(m=0) HAVING THREE ANTI-SADDLES (I)

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Chinese Annals of Mathematics,Series B 1996年第2期17卷 167-174页

作者： YE YANQIAN department of Mathematics, nanjing university, nanjing 210008, {3.. 南京大学数学系江苏南京

For the quadratic system: x=-y+δx + lx2 + ny2, y=x(1+ax-y) under conditions -10 the author draws in the (a, ()) parameter plane the global bifurcationdiagram of trajectories around O(0,0). Notice that when na2+l < 0 ... 详细信息

关键词： Quadrtic systen Anti-saddle Bifurcation curve Limit cycle

A COLUMN RECURRENCE ALGORITHM FOR SOLVING LINEAR LEAST SQUARES PROBLEM

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Journal of Computational Mathematics 1996年第4期14卷 301-310页

作者： J.X. Zhao(department of Mathematics, nanjing university, nanjing {3.) 南京大学数学系江苏南京

A new column recurrence algorithm based on the classical Greville method and modified Huang update is proposed for computing generalized inverse matrix and least squares solution. The numerical results have shown the ... 详细信息

关键词： Math A COLUMN RECURRENCE ALGORITHM FOR SOLVING LINEAR LEAST SQUARES PROBLEM ABS