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Growth characteristics and response to climate change of Larix Miller tree-ring in china

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Science china Earth Sciences 2010年第6期53卷 871-879页

作者： SUN Yu1,4. WANG LiLi1,2,3, CHEN Jin5, DUAN JianPing1,4. SHAO XueMei1,2 & CHEN KeLong6 1 institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china 2 institute of Tibetan Plateau Research, Chinese Academy of Sciences, beijing 100085, china 3 institute of Desert and Meteorology, china Meteorological Administration, Urumqi 830002, china 4.Graduate University of Chinese Academy of Sciences, beijing 10004., china 5 institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, beijing 10004., china 6 School of Life and Geography Sciences, Qinghai Normal University, Xining 810008, china 1. institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China4. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China3. Institute of Desert and Meteorology China Meteorological Administration Urumqi 830002 China5. Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China6. School of Life and Geography Sciences Qinghai Normal University Xining 810008 China

As one of the earliest species used in dendrochronological studies, Larix responds sensitively to climate change. In this study, nine larch species and one variety from eleven sites were collected to study the growth characteristics of tree-ring width using dendrochronological methods. Ten residual tree-ring chronologies were developed to analyze their relationships with regional standardized anomaly series by Pearson’s correlation analysis. The results suggest that most of the chronologies had significantly positive correlations with the mean temperature and mean maximum temperature in May. The spring temperature evidently limited the radial growth of the larch species without precipitation control. The largest mean tree-ring width was found in Himalayan Larch in Jilong, whereas Master Larch in Si’er reflected the smallest mean value. Both species presented little climate information in this study. Chinese, Potanin, and Tibetan larches are significantly correlated with climate change, implying a huge potential for climate history reconstruction. The elevation of the sampling sites appears to be an important condition for tree-ring growth of larches responding to climate factors.

关键词： Larix Miller tree-ring climate change mean temperature in May

The information entropy of a static dilaton black hole

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Science china(Physics,Mechanics & Astronomy) 2008年第2期51卷 113-125页

作者： LIU ChengZhou institute of Theoretical Physics, Binzhou University, Binzhou 256600, china Department of Physics, beijing Normal University, beijing 100875, china 1. institute of Theoretical Physics Binzhou University Binzhou 256600 China 2. Department of Physics Beijing Normal University Beijing 100875 China

In accordance with holographic principle, by calculating the statistical entropy of the quantum field just at the event horizon of the Garfinkle-Horowitz-Strominger dilaton black hole, the information entropy of the black hole was investigated and the Bekenstein-Hawking formula was obtained. The results show that black hole entropy is identical with the statistical entropy of the quantum field at the horizon. Using the generalized uncertainty relation, the divergence of the state density near the event horizon in usual quantum field theory was removed, and the cutoffs and the little mass approximation in the heat gas method of black hole entropy were avoided. Thus, the microstates of the massive scalar field just at the event horizon of the static dilaton black hole were studied directly and a description on holograph principle was presented. By using residue theorem, the integral difficulty in the calculation was overcome, and the information entropy and the Bekenstein-Hawking formula were obtained quantitatively. Compared with the black hole entropy from the loop quantum gravity, the consistency of methods and results of calculating black hole entropy in non-commutative quantum field theory and loop quantum gravity was investigated. By this, the gravity correction constant in the generalized uncertainty relation was suggested and the sense of holographic principle was discussed.

关键词： black hole entropy holographic principle non-commutative quantum field theory event horizon loop quantum gravity

iPS cells—Alternative pluripotent cells to embryo stem cells

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Science china(Life Sciences) 2010年第1期53卷 154-156页

作者： PEI XueTao beijing institute of Transfusion Medicine,beijing 100850,china 1. beijing institute of Transfusion Medicine Beijing 100850 China

Since the first murine and human embryonic stem cell lines were established by Drs. Evans and Kaufman [1] and Thomson et al. [2], respectively, great progress has been make in the field

关键词： iPS cells cell Alternative pluripotent cells to embryo stem cells stem

Soil erosion and sediment transport in the gullied Loess Plateau:Scale effects and their mechanisms

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Science china(Technological Sciences) 2009年第5期52卷 1283-1292页

作者： LI TieJian1,WANG GuangQian1,XUE Hai2,3 & WANG Kai4.1 State Key Laboratory of Hydroscience and Engineering,Tsinghua University,beijing 100084.china 2 Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 4.0003,china 3 North china {4. of Water Conservancy and Hydropower,Zhengzhou 4.0008,china 4.3} {4. of Water Resources and Hydropower Research,beijing 100038,china 1. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China 2. Yellow River Engineering Consulting Co. Ltd. Zhengzhou 450003 China 3. North china institute of Water Conservancy and Hydropower Zhengzhou 450008 China 4. china institute of Water Resources and Hydropower Research Beijing 100038 China

Scale effects exist in the whole process of rainfall-3-runoff-3-soil erosion-3-sediment transport in river basins. The differences of hydrographs and sediment graphs in different positions in a river basin are treated as basic scale effects, which are more complex in the gullied Loess Plateau, a region notorious for high intensity soil erosion and hyper-concentrated sediment-laden flow. The up-scaling method of direct extrapolation that maintains dynamical mechanism effective in large scale application was chosen as the methodology of this paper. Firstly, scale effects of hydrographs and sediment graphs were analyzed by using field data, and key sub-processes and their mechanisms contributing to scale effects were clearly defined. Then, the Digital Yellow River Model that integrates sub-models for the subprocesses was used with high resolution to simulate rainfall-3-runoff-3-soil erosion-3-sediment transport response in Chabagou watershed, and the distributed results representing scale effects were obtained. Finally, analysis on the simulation results was carried out. It was shown that gravitational erosion and hyper-concentrated flow contribute most to the spatial variation of hydrographs and sediment graphs in the spatial scale. Different spatial scale distributions and superposition of different sub-processes are the mechanisms of scale effects.

关键词： scale effect soil erosion hyper-concentrated sediment-laden flow the Loess Plateau

Control of Melt Structures on Cu-Au Mineralization in Basic-Ultrabasic Complexes of Northern china

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Acta Geologica Sinica(English Edition) 2000年第4期74卷 786-794页

作者： YUAN Wanming institute of High energy Physics, Chinese Academy of Sciences, beijing 100080and MO Xuanxue china University of Geoscienses, beijing 100083 institute of High energy Physics Chinese Academy of Sciences Beijing 100080 china University of Geoscienses Beijing 100083 [?]3Yuan Wanming Born in April 1956 graduated from Hebei College of Geology in 1982. He was once engaged in teaching in Hebei College of Geology for many years and acquired M.Sc and Ph.D degrees in petrology at china University of Geosciences (Wuhan) and china University of Geosciences (beijing) in 1989 and 1997 respectively. Dr. Yuan now works with the institute of High {4. Physics Chinese Academy of Sciences doing postdoctoral research work. His interests are mainly nuclear techniques and their applications to geology. E-mail: panm@***.

Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+, FeO and MgO values are relatively high and the T, M3+, Fe2O3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2+ values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2+ and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2O3 and SiO2 in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure.

关键词： melt structure Cu-Au mineralization basic-ultrabasic complex

New progress in the principle of nonequilibrium statistical physics

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Chinese Science Bulletin 2001年第6期46卷 448-454页

作者： XING XiusanDepartment of Applied Physics, beijing institute of Technology, beijing 100081, china Department of Applied Physics Beijing Institute of Technology Beijing China

In recent years, a new fundamental equation of nonequilibrium statistical physics was proposed in place of the Liouville equation. That is the anomalous Langevin equation in (?) space or its equivalent Liouville diffusion equation of time-reversal asymmetry. This equation reflects that the form of motion of particles in statistical thermody-namic systems has the drift-diffusion duality and the law of motion of statistical thermodynamics is stochastic in essence, but does not obey the Newton equation of motion, though it is also constrained by dynamics. The stochastic diffusion of the particles is the microscopic origin of macroscopic irre-versibility. Starting from this equation, the BBGKY diffusion equation hierarchy was presented, the hydrodynamic equations, such as the generalized Navier-Stokes equation, the mass drift-diffusion equation and the thermal conductivity equation have been derived succinctly. The unified description of all three level equations of microscopic, kinetic and hydrodynamic

关键词： anomalous Langevin equation in space drift-diffusion duality stochastic law nonequilibrium entropy evolution equation entropy diffusion.

Analysis of forest backscattering characteristics based on polarization coherence tomography

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Science china(Technological Sciences) 2010年第S1期53卷 166-175页

作者： LUO HuanMin 1,LI XiaoWen 1,2,CHEN ErXue 3,CHENG Jian 4.& CAO ChunXiang 21 institute of Geo-Spatial Information Science and Technology,University of Electronic Science and Technology of china,Chengdu 610054.china 2 State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the institute of Remote Sensing Applications of Chinese Academy of Sciences and {4. Normal University,{4. 100101,china 3institute of Forest Resources Information Technique of Chinese Academy of Forestry,{4. 100091,china 4.School of Electronic Engineering,University of Electronic Science and Technology of china,Chengdu 610054.china State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China beijing Normal Univ Beijing 100101 Peoples R China Univ Elect Sci & Technol china Inst Geospatial Informat Sci & Technol Chengdu 610054 Peoples R China Chinese Acad Forestry Inst Forest Resources Informat Tech Beijing 100091 Peoples R China Univ Elect Sci & Technol china Sch Elect Engn Chengdu 610054 Peoples R China

It is difficult to make an inventory of vertical profiles of forest structure parameters in field ***,analysis and understanding of forest backscattering characteristics contribute to estimation and detection of forest vertical structure because of the close relationships between backscattering characteristics and structure *** vertical structure function in the complex interferometric coherence definition,which represents the vertical variation of microwave scattering with the penetration depth at a point in the 2-D radar image and can be used to analyze the forest backscattering characteristics,can be reconstructed from polarization coherence tomography(PCT).Based on PCT,the paper analyzes the forest backscattering characteristics and explores the inherent relationship between the result of PCT and the forest structure parameters from numerical simulation of Random Volume over Ground model(RVoG),Polarimetric SAR interferometry(PolInSAR)simulation of forest scene and PolInSAR data at L-band of the test site ***,the effects of the extinction coefficient and surface-to-volume scattering ratio in RVoG model on vertical backscattering characteristics are analyzed by means of numerical ***,by applying PCT to L-band POLInSAR simulations of forest scene,different variations of vertical backscattering due to different extinction coefficients and the ratios of surface-to-volume scattering resulting from different polarizations,forest types and densities are displayed and *** a concept of relative average backscattering intensity is presented,and the factors which affect its vertical distribution are also *** results show that there is high sensitivity of the vertical distribution of forest relative average backscattering intensity to the polarization,forest type and ***,based on repeat pass DLR E-SAR L-band airborne POLInSAR data,the capability of PCT technology for detection

关键词： backscattering characteristic POLInSAR PCT vertical structure function

Identification and removal of block ambiguities in sea surface wind field with scatterometers

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Science china Earth Sciences 2009年第2期52卷 242-249页

作者： CHEN KeHai1,2, XIE XueTong3 & FANG Yu4.1 South china Sea institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, china 2 Graduate University of Chinese Academy of Sciences, beijing 10004., china 3 School of Electronic Science and Engineering, National University of Defense Technology, Changsha 4.0073, china 4.The institute of Remote Sensing and GIS, Peking University, beijing 100871, china 1. South china Sea institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China 2. Graduate University of Chinese Academy of Sciences Beijing 100049 China 3. School of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China 4. The institute of Remote Sensing and GIS Peking University Beijing 100871 China

The solution of the current wind retrieval algorithm for scatterometers has several wind vector ambi-guities, due to the bi-harmonic relationship between normalized backscattering cross section and the relative wind direction and the existence of the measurement error. In order to remove the ambiguities for a unique wind field, a circular median filter approach (CMF) is usually adopted. But under the con-dition for clustering distribution of the false ambiguities in some local areas, the CMF fails and thus engenders block ambiguities, which degrade the precision of the retrieved wind field. For such a situation, a technique of identification and removal of the block ambiguities is presented to further optimize the retrieved wind field after CMF. It is demonstrated in experiment that this technique can identify and remove most of the block ambiguities.

关键词： scatterometer block ambiguity identification and removal

The Progress of Researches on ADS in china

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工程科学（英文版） 2007年第4期5卷 51-58页

作者： Zhao Zhixiang,Xia Haihong(china institute of atomic energy,{4. 102.1.,china)

The conceptual study of the accelerator driven system(ADS)that lasted for about five years ended in 1999 in *** one project of the National Basic Research Program of china(973 Program)in the energy domain,which is sponsored by the china Ministry of Science and Technology(MOST),a five-year-program of fundamental research of ADS physics and related technology was launched in 2000 and passed national review at the end of *** china {4. of atomic energy(CIAE),the {4. of High energy Physics(IHEP),the {4. of Heavy Ion Physics in Peking University(PKU-IHIP)and other institutions jointly carried out the *** research activities were focused on HPPA physics and technology,reactor physics of external source driven sub-critical assembly,nuclear data base and material *** HPPA,a high current injector consisting of an ECR ion source,LEBT and an RFQ accelerating structure of 3.5 MeV was *** reactor physics study,a series of neutron multiplication experimental study has been carried out and still being *** VENUS facility has been constructed as the basic experimental platform for neutronics study in ADS ***'s a zero power sub-critical neutron multiplying assembly driven by external neutron produced by a pulsed neutron *** theoretical,experimental and simulation study on nuclear data,material properties and nuclear fuel circulation related to ADS is carrying on to provide the database for ADS system *** main results on ADS related researches will be reported.

关键词： nuclear power ADS transmutation