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The fluxes and controlling factors of N_2O and CH_4 emissions from freshwater marsh in Northeast China

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Science China Earth sciences 2010年第5期53卷 700-709页

作者： YU JunBao1,2, LIU JingShuang2, SUN ZhiGao1, SUN WeiDong3. WANG JinDa2, WANG GuoPing2 & CHEN XiaoBing1 1 Key Lab of Coastal Envionment Processed, Yantai institute of Coastal Zone Research for Sustainable Development, chinese academy of sciences, Yantai 264003. China 2 Key Lab of Wetland Ecology and Environment, Northeast institute of Geography and Agricultural Ecology, chinese academy of sciences, Changchun 13.012, China 3.Key Laboratory of Isotope Geochronology and Geochemistry, guangzhou institute of Geochemistry, chinese academy of sciences, guangzhou 510640, China 1. Key Lab of Coastal Envionment Processed Yantai Institute of Coastal Zone Research for Sustainable Development Chinese Academy of Sciences Yantai 264003 China2. Key Lab of Wetland Ecology and Environment Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 China3. Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

Nitrous oxide (N2O) and methane (CH4) emissions were measured using a static chamber method in two adjacent plots of freshwater marsh predominated by Calamagrostis angustifolia, one is seasonal waterlogged (SW) and the other without surface water accumulation (NW), in Sanjiang Plain wetland (47°3.′N, 13.°3.′E), northeast China, during 2002-2004. The diurnal and seasonal flux variations of both gases were significantly correlated with 5-cm-soil temperature. The NW marsh is a source of N2O and sink of CH4, while the SW marsh is sink of N2O and source of CH4. Remarkably, we observed a N2O emission peak under Eh of +3.0 to +100 mV, and CH4 emission peak under Eh of +3.0 to +400 mV, which indicate additional sources of N2O and CH4 for the freeze-thaw induced emission peaks of N2O and CH4 observed between late July and early August. Further study shows that the additional N2O and CH4 were emitted under the frozen soil after thawing.

关键词： freeze-thaw region freshwater marsh methane nitrous oxide controlling factors

“Tali Glaciation” on Massif Diancang

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Science China Earth sciences 2007年第11期50卷 1685-1692页

作者： YANG JianQiang1, CUI ZhiJiu2, YI ChaoLu1, SUN JiMin3.& YANG LiRong3.1 institute of Tibetan Plateau Research, chinese academy of sciences, Beijing 100085, China 2 College of Environmental sciences, Peking University, Beijing 100871, China 3.institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, China 1. institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. College of Environmental sciences Peking University Beijing 100871 China 3. institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

The term of ''Tali Glaciation'' is nominated from Massif Diancang in Yunnan Province. The confusing process of the term''s being put forward is confirmed through literature checking. Based on several times of field trip, the glacial landforms in this region are studied in detail, and the magnitude of the glaciation was determined. According to the numerical ages from TL, AIMS ^(14)C and OSL dating, the earliest glacial advance on Massif Diancang occurred at 3.—40 ka BP, followed by the advances at the last stage of the last glaciation, the late glacial and neoglations in turn, until glaciers vanished at 1.2—1.5 ca. a BP in this region. It can be concluded that glaciers were limited above 3.00 m a.s.l., and no glaciers existed on the lower part and adjacent mountains since the last glaciation.

关键词： Massif Diancang,Tali Glaciation,glacial landform,glaciation sequence,numerical dating

Phylogenetic studies of the core Alismatales inferred from morphology and rbcL sequences

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Progress in Natural Science:Materials International 2009年第8期19卷 931-945页

作者： Xiaoxian Li, Zhekun Zhou Kunming institute of botany, chinese academy of sciences, Kunming 650204, China [a]Kunming institute of botany Chinese Academy of Sciences Kunming 650204 China

The phylogeny of Alismatales remains an area of deep uncertainty, with different arrangements being found in studies that examined various subsets of genes and taxa. Herein we conducted separate and combined analyses of 103.morphological characters and 52 rbcL sequences to explore the controversial phylogenies of the families. Congruence between the two data sets was explored by computing several indices. Morphological data sets contain poor phylogenetic signals. The homology of morphological characters was tested based on the total evidence of phylogeny. The incongruence between DNA and morphological results; the hypothesis of the ‘Cymodoceaceae complex’; the relationships between Najadaceae and Hydrocharitaceae; the intergeneric relationships of Hydrocharitaceae; and the evo- lutionary convergence of morphological characters were analyzed and discussed.

关键词： Alismatales Morphological phylogeny rbcL sequences Cymodoceaceae complex Najadaceae Hydrocharitaceae

Characterization of plastic flow in two Zr-based bulk metallic glasses

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Science China(Technological sciences) 2006年第4期49卷 414-424页

作者： XING Dongmei1,2, ZHANG Taihua1, LI Weihuo3.& WEI Bingchen3.1. State Key Laboratory of Nonlinear Mechanics (LNM), institute of Mechanics, chinese academy of Sci- ences, Beijing 100080, China 2. College of Physics and Electronic Information Science, Tianjin Normal University, Tianjin 3.0074, China 3. National Microgravity Laboratory, institute of Mechanics, chinese academy of sciences, Beijing 100080, China 1. State Key Laboratory of Nonlinear Mechanics (LNM) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China 2. College of Physics and Electronic Information Science Tianjin Normal University Tianjin 300074 China 3. National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Plastic deformation behaviors of Zr65Al10Ni10Cu15 and Zr52.5Al10Ni10Cu15Be12.5 bulk metallic glasses (BMGs) are studied by using the depth-sensing nanoindentation, microindentation and uniaxial compression. The Be-containing BMG exhibits a signifi- cantly improved overall plastic strain compared with the Be-free alloy during compressive tests. Both BMGs show a loading-rate-dependent serrated flow during nanoindentation measurements, but the Be-containing alloy exhibits a much lower critical loading rate for the disappearance of the serration than the Be-free BMG. The shear band patterns de- veloped during plastic deformation are investigated by microindentation technique, wherein much higher shear band density is found in the Be-containing alloy than in the Be-free alloy, indicating an easier nucleation of shear bands in the former BMG. The dif- ference in the plastic deformation behavior of the two BMGs can be explained by a free volume model.

关键词： Bulk metallic glass, plastic deformation, shear band, nanoindentation.

^(40)Ar/^(3.)Ar chronology and geochemistry of high-K volcanic rocks in the Mangkang basin, Tibet

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Science China Earth sciences 2005年第1期48卷 1-12页

作者： ZHANG Huihua, HE Huaiyu, WANG Jianghai & XIE Guanghong guangzhou institute of Geochemistry, chinese academy of sciences, guangzhou 510640, China institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, China College of Life sciences, Sun Yat-Sen University, guangzhou 510275, China 1. chinese academy of sciences Guangzhou Institute of Geochemistry 510640 Guangzhou China 2. chinese academy of sciences Institute of Geology and Geophysics 100029 Beijing China 3. College of Life sciences Sun Yat-Sen University 510275 Guangzhou China

Our two newly obtained high-quality 40Ar/3.Ar ages suggest that the high-K volcanic rocks of the Lawuxiang Formation in the Mangkang basin, Tibet were formed at 3..5 ( 0.2 Ma. The tracing of elemental and Pb-Sr-Nd isotopic geochemistry indicates that they were derived from an EM2 enriched mantle in continental subduction caused by transpression. Their evidently negative anomalies in HFSEs such as Nb and Ta make clear that there is an input of continental material into the mantle source. The high-K rocks at 3..5 ( 0.2 Ma in the Mangkang basin may temporally, spatially and compositionally compare with the early one of two-pulse high-K rocks in eastern Tibet distinguished by Wang J. H. Et al., implying that they were formed in the same tectonic setting.

关键词： Cenozoic high-K volcanic rocks, 40Ar/3.Ar chronology, Mangkang basin, Tibet.

The role of reservoir mediums in natural oil cracking:Preliminary experimental results in a confined system

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chinese Science Bulletin 2010年第33期55卷 3787-3793页

作者： XIAO QiLin1,2,SUN YongGe1,3.& ZHANG YongDong1,2 1 State Key Laboratory of Organic Geochemistry,guangzhou institute of Geochemistry,chinese {3. of sciences,guangzhou 510640,China 2 Graduate Schools,chinese {3. of sciences,Beijing 100049,China 3.institute of Environmental and Biogeochemistry(eBig),Zhejiang University,Hangzhou 3.0027,China State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Graduate Schools Chinese Academy of Sciences Beijing 100049 China institute of Environmental and Biogeochemistry (eBig) Zhejiang University Hangzhou 310027 China

Large amounts of data regarding the influence of temperature and pressure on the thermal stability of crude oil have been pub-lished;however,the role of reservoir mediums has received little *** involving oil cracking in the presence of montmorillonite,illite,calcite,quartz and water were conducted in closed gold tubes to investigate the effects of these reservoir mediums on oil *** was done by screening variations in the chemical and stable carbon isotopic components of nC10+ and gasoline-range hydrocarbons(nC8-)present in various *** indicated that reservoir mediums have an active role in oil cracking under experimental *** concentrations of nC10+ in the cracked residues progressively decreased in systems containing oil+water+illite,oil+water+montmorillonite,oil+water,oil+water+quartz and oil+water+*** comparison with the system containing oil+water,our results indicated a retardation effect for oil cracking in systems in the presence of illite and montmorillonite,and an acceleration effect on oil destruction in systems in the presence of calcite and ***10+ became increasingly depleted in 13. in systems with oil+water+illite,oil+water+calcite,oil+water+montmorillonite,oil+water+ quartz and oil+*** obvious correlation was observed between concentrations and stable carbon isotopic components of nC6-nC8 and nC10+ in the individual *** discrepancies in chemical and stable carbon isotopic components of nC6-nC8 and nC10+ in the pyrolyzed residues highlighted the important role of reservoir mediums to control carbon-carbon cleavage of nC10+ and then the isomerization,cyclolization and aromatization reactions;as well as governing the occurrence and thermal destruction of nC6-nC8 under experimental *** research may have critical implications in reconstructing chemical kinetic models for natural oil cracking.

关键词：裂解作用实验条件密闭系统原油裂解水库介质天然同位素组成

Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau

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chinese Science Bulletin 1998年第5期43卷 409-412页

作者： TANG Keli+1, ZHANG Keli 1,2 and LEI Aling 1,3.1. institute of Soil and Water Conservation, chinese academy of sciences, Yangling 712100, China 2. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China 3. Water Resources C institute of Soil and Water Conservation Chinese Academy of Sciences Yangling China Department of Hydraulic Engineering Tsinghua University Beijing China Water Resources Conservation Bureau of Yangtze River Ministry of Water Resources Wuhan China

Scientific evidence for the upper limit of farmland is proposed. Shallow gully erosion is one of erosion types distributed extensively on sloping farmland in the hilly regions of the Loess Plateau. Field observation and aerial photos interpretation, as well as laboratory experiments show that the shallow gully erosion occurring on the steeper farmland in the hilly regions of the Loess Plateau is an important factor leading to intensive erosion on slope, because of its extensive distribution and intensive runoff collection. The data on the formation, development and distribution of shallow gullies on sloping farmland indicate that critical slope gradient for shallow gully initiation ranges from 15 to 20 degrees with an average of 18.2 degrees. Therefore, it is suggested that critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau should be kept within the critical slope gradient for shallow gully initiation to prevent shallow gully formation in order to control soil loss more effectively. But as the first step, the cultivation on the slopes with slope larger than 25 degrees where the maximum erosion occurs should be strictly forbidden.

关键词： hilly region of Loess Plateau upper limitation for farmland shallow gully erosion erosion dynamic.

A temporal framework for building up of healthy soils

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Frontiers of Agricultural Science and Engineering 2024年第2期11卷 292-296页

作者： Junling ZHANG Jiangzhou ZHANG Yunlong ZHANG guangzhou WANG State Key Laboratory of Nutrient Use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources College of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018China Key Laboratory of Grassland Management and Utilization Ministry of Agriculture and Rural Affairs of the People’s Republic of ChinaCollege of Grassland Science and TechnologyChina Agricultural UniversityBeijing 100193China

Healthy soils are vital for the diverse services provided by ecosystems to human society~[1], such as provisioning(food,fiber, timber, and fuel), regulation(climate, disease, and natural hazards), waste treatment, nutrient cycling, and cultural services. Soil has a three phase system and the interactions between soil chemical, biological, and physical attributes determine functions(hydraulic, thermal, and gas fluxes).

关键词： soils soil cycling

Size Effects of Nano-crystalline Cellulose

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chinese Chemical Letters 2003年第9期14卷 977-978页

作者： Guo Kang LI, Xiao Fang LI, Yong JIANG, Mei Zhen ZENG, En Yong DINGKey Laboratory of Cellulose and Lignocellulosics Chemistry guangzhou institute of Chemistry, chinese academy of sciences,{3. Key Laboratory of Cellulose and Lignocellulosics Chemistry guangzhou institute of Chemistry Chinese Academy of Sciences Guangzhou 510650

Natural cellulose with the crystal form of cellulose Ⅰ, when treated with condensed lye (e.g. 18%NaOH), can change into new crystal form of cellulose Ⅱ. But the nano-crystalline cellulose (NCC) can do it when only treated with dilute lye (e.g. 1%NaOH) at room temperature and even can dissolve into slightly concentrated lye (e.g. 4%NaOH).

关键词： Cellulose Ⅰ cellulose Ⅱ nano-crystalline cellulose.