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Macroscopic relationship for preferential flow in the vadose zone:Theory and validation

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science China(Technological sciences) 2009年第11期52卷 3264-3269页

作者： LIU HuiHai1 & ZHANG RenDuo2.1 earth science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 9472.0, USA 2.{2. of Environmental science and Engineering, Sun Yat-sen university, Guangzhou 5102.5, China earth science Division Lawrence Berkeley National Laboratory Berkeley CA 947200 USA school of Environmental science and Engineering Sun Yat-sen University Guangzhou 510275 China

Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the ground surface or vadose zone to the groundwater, bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination. A variety of evidence indicates that complex preferential flow patterns observed from fields are fractals. This paper discusses a macroscopic relationship for modeling preferential flow in the vadose zone. Conceptually, the flow domain can be divided into active and inactive regions. Flow occurs preferentially in the active region (characterized by fractals), and inactive region is simply bypassed. The portion of the active region was found to be a power function of saturation. The validity of this macroscopic relationship is demonstrated by its consistency with field observations and the related numerical experiments.

关键词： preferential flow constitutive relations vadose zone hydrology

Effective solutions to a global 3D visual system in networking environments

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science China earth {2. 2005年第11期48卷 2032-2039页

作者： ZHANG Liqiang1,2. ZHANG Yan3, YANG Chongjun2. LIU Suhong1, REN Yingchao2. RUI Xiaoping2.& LIU Donglin2.1. State Key Laboratory of Remote Sensing sciences, school of Geography and Remote Sensing, Beijing Normal {2., Beijing 100875, China 2. State Key Laboratory of Remote Sensing sciences, Institute of Remote Sensing Applications, Chinese Academy of sciences, Beijing 101001, China 3. Institute of Geographical sciences and Natural Resources Research, Chinese Academy of sciences, Beijing 101001, China 1. State Key Laboratory of Remote Sensing sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. Chinese Academy of sciences State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3D visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

关键词： massive spatial data, streaming transmission, system architecture, M-band wavelet

Structure of a pair of anticyclonic vortices in northern part of the South China Sea in autumn of 1994

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Acta Oceanologica Sinica 2002年第2期21卷 203-216页

作者： Fu Gang, Toshio Yamagata1. Department of Marine Meteorology, Ocean university of Qingdao, Qingdao 2.6003, China2. Department of earth and {2. Physics, university of Tokyo, japan Department of Marine Meteorology Ocean University of Qingdao Qingdao 266003 China Department of earth and planetary Physics University of Tokyo Japan

A pair of remarkable meso-scale anticyclonic vortices, one formed closely to another, inthe northern part of the South China Sea during the period from the later August to early September of 1994 were documented by the in situ observation data. Their spatial structures were examined in detail from the horizontal and two nearly perpendicular/vertical angles of view. It was shown that the horizontal scales of these two vortices were around 100, 50 km, and their vertical scales were about 500, 1000 m, respectively. Two 'warm core' structures associated with these two vortices were found in their horizontal and vertical analyses. The closer spacing of these two vortices (namely, 60 km), which was smaller than the Rossby radius of deformation, suggested that they might merge with each other during their next evolution stages and form into a larger vortex eventually.

关键词： The South China Sea a pair of anticyclonic vortices warm core Rossby radius of deforma-tion

Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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science China earth {2. 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1,2.3, ZHANG Yili1, BAI Wanqi1, LIU Yanhua4, BAO Weikai5, LIU Linshan1, 2.& ZHENG Du1 1. Institute of Geographic sciences and Natural Resources Research, Chinese Academy of sciences, Beijing 100101, China 2. {2. school of the Chinese Academy of sciences, Beijing 100039, China 3. College of Resources and Environment, Southwest Agricultural university, Chongqing 400716, China 4. The Ministry of science and Technology, P. C. China, Beijing 100862. China 5. Chengdu Institute of Biology, Chinese Academy of sciences, Chengdu 610041, China 1. Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. graduate school of the Chinese Academy of {2. 100039 Beijing China 3. College of Resources and Environment Southwest Agricultural University 400716 Chongqing China 4. The Ministry of science and Technology P. C. China 100862 Beijing China 5. Chengdu Institute of Biology Chinese Academy of Sciences 610041 Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2.00 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2.00, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43%. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2.00, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

Separation of Red (Y_2._3:Eu^(3+)), Blue (BaMgAl_(10)O_(17):Eu^(2.)) and Green (CeMgAl_(10)O_(17):Tb^3) Rare earth Phosphors by Liquid/Liquid Extraction

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Journal of Wuhan university of Technology(Materials science) 2009年第4期24卷 603-607页

作者：梅光军 school of Resource and Environmental Engineering Wuhan University of Technology

A novel process for separation of red （Y2.3：Eu^3＋）, blue（BaMgAl10O17：Eu^2.） and green （CeMgAl10O17：Tb^3） rare earth fluorescent powders was proposed. At first, the blue powder can be extracted selectively from an aqueous solution using a chelating collector 2.thenoyltrifluoroacetone （TTA） dissolved in heptane at alkaline pH condition, then, chloroform was used for extracting the green powder into organic phase. The red phosphor remains in aqueous phase with potassium sodium tartrate depressant （PST）. Therefore, three phosphors can be separated successfully from their artificial mixtures by liquid/liquid extraction, and grades and recovery of separated products reach respectively as follows： red is 96.9% and 95.2., blue is 82.7% and 98.8%, green is 94.6% and 82.6%.

关键词： rare earth phosphor solid-solid separation liquid/liquid extraction

Nitrogen isotopic composition of plant-soil in the Loess Plateau and its responding to environmental change

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Chinese science Bulletin 2009年第2期54卷 272-279页

作者： LIU WeiGuo1,2.& WANG Zheng1,3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710075, China 2.Xi’an Jiaotong {2., school of Human Settlement and Civil Engineering, Xi’an 710049, China 3 graduate {2. of Chinese Academy of sciences, Beijing 100049, China Chinese Acad Sci Inst Earth Environm State Key Lab Loess and Quaternary Geol Xian 710075 Peoples R China.

The nitrogen isotope of soil is of emerging significance as an indicator of climatic change and biogeochemical cycle of nitrogen in nature systems. In this paper, the nitrogen content and isotopic composition of modern ecosystems from arid and semiarid Loess Plateau in northwestern China, including plant roots and surface soil, were determined to investigate trends in δ15N variation of plant roots and soil along a precipitation and temperature gradient in northwestern China under the East Asian Monsoon climate condition. The δ15N values of surface soil from the study area vary from ?1.2. to 5.8‰, but from -5.1‰ to 1.9‰ in the plant roots. Our results indicate that (1) although the isotopic compositions of both plant roots and surface soil change with a similar trend along the climate gradient, the apparent nitrogen difference between plant roots and soil existed, with -δ15N values ranging from 0.3‰ to 7.2. with average of 4.1‰; and (2. mean annual precipitation (MAP) is the dominant factor for isotopic composition of plant-soil nitrogen in the Loess Plateau, and the δ15N values are less correlated with MAT; we suggest that nitrogen isotopic composition of soil is a potential tracer for environmental changes.

关键词：氮同位素物理性质化学性质环境论

Timing and geochemical characters of the Sanchazi magmatic arc in Mianlüe tectonic zone,South Qinling

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science China earth {2. 2004年第4期47卷 317-328页

作者： LI Shuguang1, HOU Zhenhui1, YANG Yongcheng2. SUN Weidong1,1), ZHANG Guowei3, & LI Qiuli1 1. school of earth and Space {2.,university of science and Technology of China ,Hefei 2.002.,China 2. Regional Geological Survey Team of Shaanxi Province,Xianyang 712.00, China 3. Department of Geology, Northwest university,Xi抋n 710069, China Present address: Max-Planck-Institut f. Chemie Postfach 3060 55020 Mainz Germany school of earth and Space {2. University of Science and Technology of China Hefei 230026 China Regional Geological Survey Team of Shaanxi Province Xianyang 712000 China Department of Geology Northwest University Xi’an 710069 China

The Sanchazi mafic-ultramafic complex in Mianlüe tectonic zone,South Qinling can be subdivided into two blocks,*** paleo-magmatic arc and Zhuangkegou paleo-oceanic crust fragment (ophiolite).The Sanchazi paleo-magmatic arc is mainly composed of ande-site,basaltic and basalt-andesitic gabbro(or diorite),andesitic dyke,plagiogranite and minor ul-tramafric rocks,which have typical geochemical features of island arc volcanic rocks,such as high field strength element(***,Ti)depletions and lower Cr,Ni *** Light rare earth element (LREE) and K enrichments of these rocks and zircon xenocrystals of 900 Ma from plagiogranite suggest that this magmatic arc was developed on the South active continental margin of the South Qinling *** U-Pb age of (300±61) Ma for zircons from plagiogranite in-dicates that the Mianlüe paleo-oceanic crust was probably subducted underneath the South Qinling micro-continent in *** is consistent with the formation time (309Ma) of the Huwan eclogite originating form oceanic subduction in Dabie Mountains,suggesting that the Mianlüe paleo-ocean probably extended eastward to the Dabie Mountains in *** high-Mg adakitic rocks in Sanchazi paleo-magmatic arc suggest thet the subducted oceanic crust was relatively young (2.Ma) and hot.

关键词： Qinling orogen, magmatic arc, U-Pb zircon age, ophiolite complex.

Effects of MoO_3 Amounts on Sintering and Electrical Properties of Ce_(0.8)Nd_(0.2.O_(1.9)

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Chemical Research in Chinese Universities 2012年第1期28卷 9-13页

作者： ZHOU De-feng1, ZHAO Gui-chun1, YANG Mei1, XIA Yan-jie2.and MENG Jian2.1. school of Chemistry and Life science, Changchun {2. of Technology, Changchun 130012. P. R. China 2. State Key Laboratory of Rare earth Resources Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of sciences, Changchun 13002., P. R. China school of Chemistry and Life science Changchun University of Technology Changchun 130012 Changchun Institute of Applied Chemistry Chinese Academy of Sciences State Key Laboratory of Rare Earth Resources Utilization Changchun 130022

The high purity （Ce0.8Nd0.2.1.9）1-x（MoO3）x（x=0, 0.005, 0.010, 0.02.; Ce0.8Nd0.2.1.9=NDC） solid solutions were prepared by modified sol-gel method. The structures and electric conductivities were characterized by X-ray diffraction（XRD）, field-emission scanning electron microscopy（FESEM） and electrochemical impedance spectros copy（EIS）. The XRD results show that the materials were pure phase with a cubic fluorite structure. Compared to the undoped-NDC samples, MoO3 doped-NDC showed higher sintered density（over 96%） at reduced sintering tempera ture. The electric conductivity（σt） of （Ce0.8Nd0.2.1.9）1-x（MoO3）x at 400 °C was 9.58×10-4 S/cm when x=0.010, which was higher than that of undoped-NDC samples（σt=3.2.×10-4 S/cm）. The obtained optimal amount of the MoO3 was x=0.010 in this system.

关键词： Neodymium-doped ceria Molybdenum oxide Sol-gel method Grain boundary conductivity

A new Early Cretaceous lizard with well-preserved scale impressions from western Liaoning, China

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Progress in Natural science:Materials International 2005年第2期15卷 67-73页

作者： JI Shu’an*(school of earth and Space {2., Peking university, Beijing 100871, China) school of earth and Space {2. Peking University Beijing 100871 China

A new small lizard, Liaoningolacerta brevirostra gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning is described in detail. The new specimen was preserved not only by the skeleton, but also by the exceptionally clear scale impressions. This lizard can be included within the taxon Scleroglossa based on its 2. or more presacrals, cruciform interclavicle with a large anterior process, moderately elongated pubis, and slightly notched distal end of tibia. The scales vary evidently in size and shape at different parts of body: small and rhomboid ventral scales, tiny and round limb scales, and large and longitudinally rectangular caudal scales that constitute the caudal whorls. This new finding provides us with more information on the lepidosis of the Mesozoic lizards.

关键词： new genus Squamata skeleton lepidosis Early Cretaceous western Liaoning