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Environmental characteristics of Mid-Holocene recorded by lacustrine sediments from Lake Daihai, north environment sensitive zone, china

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Science china Earth Sciences 2006年第9期49卷 968-981页

作者： SUN Qianli1,2, ZHOU Jie1, SHEN Ji3. CHEN Peng1,2, WU Feng1,2 & XIE Xiuping1,2 1. State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of Sciences, Xi’an 710075, china 2. {3. {4. of chinese academy of Sciences, beijing 10003., china 3. Nanjing Institute of Geography and Limnology, chinese academy of Sciences, Nanjing 210008, china State Key Lab of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China graduate university of chinese {3. of Sciences Beijing China Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China

Climate proxies, such as total organic carbon and nitrogen (TOC, TN), carbonate content (CaCO3., grain-size and pollen of the sediment core retrieved from enclosed Lake Daihai which lies in the north china environment sensitive zone are analyzed to reconstruct the environment evolution of the area based on high-resolution radiocarbon chronology. The results reveal that the TOC and TN contents of the sediments correlate well with pollen percentage and pollen flux variations during the Holocene, and both reach their peak values simultaneously at 6.7―3.5 ka BP (calendar age, 7.6―3.6 ka BP). Since 6.7 ka BP, both the CaCO3.and organic matter contents of the core have simultaneous variations, and their high values also occur during 6.7―3.5 ka BP. While during 9.0―6.7 ka BP (calendar age, 10―7.6 ka BP) relatively lower level of organic matter content and pollen flux corre- spond to the higher level of carbonate content. The above relations suggest that during 6.7―3.5 ka BP, the productivity and effective precipitation were greatly improved in the lake drainage area, and this would probably strengthen the hydrodynamic conditions, enhancing organic matter, pollen and carbonate inputs from terrestrial sources. Such processes would account for the enrichment of both organic matter and carbonate in the sediments. While during 9.0―6.7 ka BP, the lower level of or- ganic matter, pollen flux but high carbonate content show depressed productivity and declined vege- tation coverage. The higher carbonate content at this stage would have probably resulted from the higher evaporation ratio of the lake water under relatively drier climate conditions. Therefore, it is in- ferred that during 6.7―3.5 ka BP, the climate was more humid with abundant rainfalls and vegetation was more flourishing in the Lake Daihai area. This can be seen as Holocene Climate Optimum (HCO). As a result, this has evident discrepancies with the traditional notion that the HCO occurs at Early Holocene or early Mid

关键词： Lake Daihai, Mid-Holocene, lacustrine sediments, environmental characteristics.

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Cotton pixel identification with CBERS-02 CCD data based on spectral knowledge

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Science china(Technological Sciences) 2005年第S2期48卷 129-144页

作者： LI Jing1,2,3. LIU Qinhuo1,3. LIU Qiang1, CHEN Liangfu1, BO Junhua3.& LI Shaokun3.1. State Key Laboratory of Remote Sensing Science, IRSA, chinese academy of Sciences, beijing 100101,{3. 2. {4. university of chinese academy of Sciences, beijing 100049,{3. 3. The Key Oasis Eco-agriculture Laboratory of Xinjiang Production and Construction Corps, Shi Hezi 83.000,{3. State Key Laboratory of Remote Sensing Science IRSA Chinese Academy of Sciences graduate university of chinese {3. of Sciences The Key Oasis Eco-agriculture Laboratory of Xinjiang Production and Construction Corps

In this paper the in-situ experiment data are collected from the Spectral Library to estimate the possible values of the primary structural parameters in each cotton growing season by statistics. Based on these values the spectra of the cotton major growing seasons were simulated and analyzed using the canopy reflectance model, SAILH. In this way we also simulated the cotton pixel spectra corresponding to CBERS-02 CCD and took them as the reference spectra for spectra fitting. Then No.14. Regiment of No.8 Agricultural Division of Xinjiang Production and Construction Corps (XPCC) was chosen as the study area, and two spectra fitting methods, Mahalanobis distance and spectra angle, were used to identify cotton pixel from CBERS-02 CCD image of the study area. At last we analyzed the effect of the calibration coefficients error on cotton identifying. The results showed that within 4. error the spectral angle classifier can still have a good performance.

关键词： CBERS-02 cotton pixel identification spectra fitting.

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Neogene eolian deposits within the West Qinling Mountains:Climatic and tectonic implications

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chinese Science Bulletin 2010年第15期55卷 1483-1487页

作者： GE JunYi 1,2 & GUO ZhengTang 3.1 State Key Laboratory of Loess and Quaternary Geology (SKLLQG),Institute of Earth Environment,chinese academy of Sciences,Xi’an 710075,china 2 {3. {4. of chinese academy of Sciences,beijing 100049,china 3.Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,chinese academy of Sciences,beijing 100029,china State Key Laboratory of Loess and Quaternary Geology (SKLLQG) Institute of Earth Environment Chinese Academy of Sciences Xi’an China graduate university of chinese {3. of Sciences Beijing China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

The Qinling Mountains constitute a key climate barrier between southern and northern *** recent investigations revealed widely spread eolian deposits of Neogene age mantling the piedmont highlands of the intermountain basins within West ***-mammalian fossils dated a 150.2 m section (NL-VI) near Xihe for the late Miocene to Pliocene (～10-4.Ma).Soil micromorphology,grain-size and geochemical analysis consistently define typical loess-soil alternations for the upper (0-66 m) and lower (98-150.2 m) parts of the section,with the middle section (66-98 m) having been affected by episodic slope *** results add important insights to the earlier studies about the widespread eolian deposition in northern china during the Miocene,prior to 8 *** also suggest that the basic configuration of the ridges and inter-ridge basins of West Qinling has already formed by ～10 *** well-preserved eolian deposits are unlikely to support intense substratum deformation and rapid uplift of West Qinling since the late Miocene.

关键词：秦岭山脉风尘堆积构造意义气候新近纪晚中新世地球化学分析风尘沉积

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A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

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Science china(Technological Sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2 & FENG Xueshang1,3.1. SIGMA Weather Group, Key Laboratory of Space Weather, Center for Space Science and Applied Re-search, chinese academy of Sciences, beijing 100080,{3. 2. {4. School of the chinese academy of Sciences, beijing 10003.,{3. 3. School of Geophysics and Geoinformation Systems,{3. university of Geosciences, beijing 100083.{3. SIGMA Weather Group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China graduate School of the chinese academy of Sciences Beijing China School of Geophysics and Geoinformation Systems China University of Geosciences Beijing China

Using 80 CME-ICME events during 1997.1―2002.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the Earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2) The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3. The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 3.% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

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Transformations and non-degenerate maps

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Science china Mathematics 2005年第z1期48卷 195-205页

作者： LI Baokui & WANG Yuefei Institute of Mathematics, academy of Mathematics and System Sciences, chinese academy of Sciences, {3. 100080,{4. graduate School, chinese academy of Sciences, {3. 100080,{4. Institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China graduate School Chinese Academy of Sciences Beijing China

We shall prove the equivalences of a non-degenerate circle-preserving map and a M(o)bius transformation in ^Rn, of a non-degenerate geodesic-preserving map and an isometry in Hn of a non-degenerate line-preserving map and an affine transformation in Rn. That a map is non-degenerate means that the image of the whole space under the map is not a circle, or geodesic or line respectively. These results hold without either injective or surjective, or even continuous assumptions, which are new and of a fundamental nature in geometry.

关键词： M(o)bius transformation, circle-preserving map, non-degenerate map.

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Risk Analysis on Groundwater Resources Carrying Capacity Based on Blind Number Theory

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Wuhan university Journal of Natural Sciences 2007年第4期12卷 669-676页

作者： ZHANG Ji1,2,YU Sujun3.. Key Laboratory of Mountain Hazards and Surface Process,chinese academy of Sciences/Institute of Mountain Hazards and Environment,chinese academy of Sciences,Chengdu 61004.,Sichuan,{4. 2. graduate university of the chinese academy of Sciences,beijing 100049,{4. 3. School of Environmental Science and Engineering,Southwest Jiaotong university,Chengdu 61004.,Sichuan,{4. Key Laboratory of Mountain Hazards and Surface Process Chinese Academy of Sciences/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China

Blind numbers of evaluation indices about groundwater resources carrying capacity are defined from the concomitancy of randomness, fuzziness, grey property and unascertainment of groundwater system. Based on fuzzy theory, a comprehensive evaluation model on groundwater resources carrying capacity is constructed with blind information. Then a risk assessment model of surcharge about groundwater resources carrying capacity is established on blind reliability theory. The probable value ＂＊＂ matrix of fuzzy membership degree about carrying capacity corresponding to each judgment level can be obtained with the aid of blind algorithm as well as the subjective reliability ＂×＂ matrix. And then a graph of ＂groundwater carrying capacity v.s. accumulative reliability＂ can be gained Based on the graph, fuzzy membership degree of groundwater resources carrying capacity to each judgment level under different risk probability can be got. Thus, a comparatively reasonable judgment to groundwater resources carrying capacity might be obtained, with comprehensive analysis to the state of society, economy technology and ecology.

关键词： blind number theory groundwater resources carrying capacity evaluation risk analysis

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Impact Assessment and Protection of Outstanding Landscape Integrity in a Natural Heritage Site:Fairy Valley,Kanas Nature Reserve,Xinjiang,china

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Journal of Mountain Science 2011年第1期8卷 46-52页

作者： HAN Fang1,2,YANG Zhaoping1,LIU Xinyu1,2,DI Feng3.1 Xinjiang Institute of Ecology and Geography,chinese academy of Sciences,Urumqi 83.011,china 2 {3. {4. of chinese academy of Sciences,beijing 100049,china 3.Xinjiang Department of Science and Technology,Urumqi 83.011,china Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi China graduate university of chinese {3. of Sciences Beijing China Xinjiang Department of Science and Technology Urumqi China

The essential purpose of the Convention Concerning the Protection of World Cultural and Natural Heritage is to protect the integrity of heritage *** landscape is the core embodiment of the aesthetic value of a natural heritage *** paper proposes a new assessment method from the point of view of the protection of heritage *** is used to measure the degree of outstanding landscape integrity under the human and natural impact in natural heritage *** paper employ three indices,a visual index of outstanding landscape,a harmony index of the artificial landscape and a disturbance index of damaged landscape,to measure the impact of landscape *** impact assessment model is based on a weighted combination of the three *** study site is the Fairy Valley,Kanas Nature Reserve,Xinjiang Uygur Autonomous Region in northwest *** information employed is derived from field investigation and a Digital Elevation Model(DEM).A comprehensive evaluation of the Fairy valley was undertaken and it was determined that the outstanding landscape values are being *** protection methods are proposed to reduce the adverse effects and maintain landscape quality,thereby providing site managers with suggestions for the protection of natural heritage *** broadly,the paper contributes novel methods of landscape assessment applicable to natural protected areas.

关键词： Landscape integrity Landscape impact assessment Landscape protection Natural heritage site Kanas Nature Reserve Xinjiang

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Some characteristics of the atmosphere during an adiabatic process

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Progress in Natural Science:Materials International 2006年第6期16卷 644-648页

作者： GAO Li, LI Jianping and REN Hongli (LASG, Institute of Atmospheric Physics, chinese academy of Sciences, beijing 100029,{3. {4. School of chinese academy of Sciences, beijing 100049,{3. National Climate Center, Laboratory of Climate Studies,{3. Meteorological Administration, beijing 100081,{3.) LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China graduate School of chinese academy of Sciences Beijing 100049 China National Climate Center Laboratory of Climate Studies China Meteorological Administration Beijing 100081 China

Some important characteristics of the atmosphere during an adiabatic process are investigated, which include the invariability of atmospheric entropy range and local surface potential temperature, the conservation of the atmospheric mass intervened between any isentropic surface and the ground, and the isentropic surface intersecting with the ground. The analysis shows that the atmospheric reference state (ARS) for investigation on available potential energy (APE) should be defined objectively as the state which could be approached from the existing atmosphere by adiabatic adjustment, and be related to initial atmospheric state before adjustment. For the initial atmosphere state at any time, its corresponding ARS is different from the one at another time. Based on the above-mentioned conclusions, the reference state proposed by Lorenz cannot be obtained physically, so a new conception, the conditional minimum total potential energy, is put forward in order to objectively investigate atmospheric APE.

关键词： available potential energy adiabatic isentropic surface atmospheric reference state conditional minimum total potential energy.

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Validating global hydrological models by ground and space gravimetry

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chinese Science Bulletin 2009年第9期54卷 1534-1542页

作者： ZHOU JiangCun1,2,3. SUN HePing1,2 & XU JianQiao1,2 1 Institute of Geodesy and Geophysics, chinese academy of Sciences, Wuhan 4.0077,{3. 2 Key Laboratory of dynamic geodesy, chinese academy of Sciences, Wuhan 4.0077,{3. 3.graduate university of chinese academy of Sciences, beijing 100049,{3. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Key Laboratory of dynamic geodesy Chinese Academy of Sciences Wuhan 430077 China graduate university of chinese {3. of Sciences Beijing 100049 China

The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth's tides and variations in the Earth's rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water and nontidal ocean loading are also calculated according to the corresponding numerical models. The numerical results show that the gravity changes due to both the air pressure and land water loading are as large as 100×10-9 m s-2 in magnitude, and about 10×10-9 m s-2 for those due to the nontidal ocean loading in the coastal area. On the other hand, the monthly-averaged gravity variations over the area surrounding the stations are derived from the spherical harmonic coefficients of the GRACE-recovered gravity fields, by using Gaussian smoothing technique in which the radius is set to be 600 km. Com-pared the land water induced gravity variations, the SG observations after removal of tides, polar mo-tion effects, air pressure and nontidal ocean loading effects and the GRACE-derived gravity variations with each other, it is inferred that both the ground- and space-based gravity observations can effec-tively detect the seasonal gravity variations with a magnitude of 100×10-9 m s-2 induced by the land water loading. This implies that high precision gravimetry is an effective technique to validate the re-liabilities of the hydrological models.

关键词：重力测量水文模型模型验证和空间地面重力变化季节性波动空气压力

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An analysis of the wide area differential method of geostationary orbit satellites

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 310-314页

作者： CAI ChengLin1,2,3., LI XiaoHui1 & WU HaiTao1 1 National Time Service Center, chinese academy of Sciences, Lintong 710600, china 2 Hunan Institute of Humanities, Science and Technology, Loudi {3.7000, china 3.{{3. university of chinese academy of Sciences, beijing 100049, china National Time Service Center Chinese Academy of Sciences Lintong China Hunan Institute of Humanities Science and Technology Loudi China graduate university of chinese {3. of Sciences Beijing China

This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4.) calculation including sa- tellite clock errors and ephemeris errors and that of three-dimensional (3.) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3. PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephem- eris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseu- do-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation.

关键词： geostationary orbitsatellite dilution of precision satellite ephemeris errors satellite clock errors wide area differential method

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