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| 1 | Biomass carbon stocks in China's forests between 2000 and 2050:A prediction based on forest biomass-age relationships显示文摘China's forests are characterized by young forest age,low carbon density and a large area of planted forests,and thus have high potential to act as carbon sinks in the future.Using China's national forest inventory data during 1994-1998 and 1999-2003,and direct field measurements,we investigated the relationships between forest biomass density and forest age for 36 major forest types.Statistical approaches and the predicted future forest area from the national forestry development plan were applied to estimate the potential of forest biomass carbon storage in China during 2000-2050.Under an assumption of continuous natural forest growth,China's existing forest biomass carbon(C) stock would increase from 5.86 Pg C(1 Pg=1015 g) in 1999-2003 to 10.23 Pg C in 2050,resulting in a total increase of 4.37 Pg C.Newly planted forests through afforestation and reforestation will sequestrate an additional 2.86 Pg C in biomass.Overall,China's forests will potentially act as a carbon sink for 7.23 Pg C during the period 2000-2050,with an average carbon sink of 0.14 Pg C yr-1.This suggests that China's forests will be a significant carbon sink in the next 50 years. | XU Bing,GUO ZhaoDi,PIAO ShiLong & FANG JingYun* Department of Ecology,College of Urban and Environmental Sciences,and Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China | 2010 | Science China(Life Sciences)2010，53，7： | 61 |
| 2 | Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations显示文摘Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon cycling.However,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon cycling.We investigated biomass allocation patterns across a broad spatial scale.We collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan Plateau.Our results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for alpine.Our results did not support the hypothesis that aboveground biomass scales isometrically with belowground biomass.The R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and communities.This might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead roots.Our findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S. | WANG Liang*,NIU KeChang,YANG YuanHe & ZHOU Peng Department of Ecology,Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China. | 2010 | Science China(Life Sciences)2010，53，7： | 54 |
| 3 | Information granules and entropy theory in information systems显示文摘Information granulation and entropy theory are two main approaches to research uncertainty of an information system,which have been widely applied in many practical issues. In this paper,the characterizations and representations of infor-mation granules under various binary relations are investigated in information systems,an axiom definition of information granulation is presented,and some existing definitions of information granulation become its special forms. Entropy theory in information systems is further developed and the granulation monoton-icity of each of them is proved. Moreover,the complement relationship between information granulation and entropy is established. This investigation unifies the results of measures for uncertainties in complete information systems and incom-plete information systems. | LIANG JiYe & QIAN YuHua Key Laboratory of Computational Intelligence and Chinese Information Processing,Ministry of Education School of Computer & Information Technology,Shanxi University,Taiyuan 030006,China | 2008 | Science in China(Series F)2008，51，10： | 41 |
| 4 | Numerical Simulation on Climate Effects of Freezing-Thawing Processes Using CCM3显示文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere. | Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China | 2008 | Research in Cold and Arid Regions2008，，1： | 44 |
| 5 | A numerical study of the South China Sea deep circulation and its relation to the Luzon Strait transport显示文摘A fine-resolution MOM code is used to study the South China Sea basin-scale circulation and its relation to the mass transport through the Luzon Strait. The modal domain includes the South China Sea, part of the East China Sea, and part of the Philippine Sea so that the currents in the vicinity of the Luzon Strait are free to evolve. In addition, all channels between the South China ,Sea and the Indonesian seas are closed so that the focus is on the Luzon Strait transport. The model is driven by specified Philippine Sea currents and by surface heat and salt flux conditions. For simplicity, no windstress is applied at the surface.The simulated Luzon Strait transport and the South China Sea circulation feature a sandwich vertical structure from the surface to the bottom. The Philippine Sea water is simulated to enter the South China Sea at the surface and in the deep ocean and is carried to the southern basin by western boundary currents. At the intermediate depth, the net Luzon Strait transport is out of the South China Sea and is fed by a western boundary current flowing to the north at the base of the thermocline. Corresponding to the western boundary currents, the basin circulation of the South China Sea is cyclonic gyres at the surface and in the abyss but an anti-cyclonic gyre at the intermediate depth. The vorticity balance of the gyre circulation is between the vortex stretching and the meridional change of the planetary vorticity.Based on these facts, it is hypothesized that the Luzon Strait transports are determined by the diapycnal mixing inside the entire South China Sea. The South China Sea plays the role of a 'mixing mill' that mixes the surface and deep waters to return them to the Luzon Strait at the intermediate depth. The gyre structures are consistent with the Stommel and Arons theory (1960), which suggests that the mixlng-induced circulation inside the South China Sea should be cyclonic gyres at the surface and at the bottom but an anti-cyclonic gyre at the intermediate depth. The simulated gyre circulation at the intermediate depth has been confirmed by the dynamic height calculation based on the Levitns hydrography data.The sandwich transports in the Luzon Strait are consistent with recent hydrographic, al observations.Model results suggest that the Kuroshio tends to form a loop current in the northeastern South China Sea. The simulated Kuroshio Loop Current is generated by the pressure head at the Pacific side of the Luzon Strait and is enhanced by theβ- plane effects. The β- plane appears to be of paramount importance to the South China Sea circulation and to the Luzon Strait translports. Without theβ-plane, the Luzon Strait transports would be greatly reduced and the South China Sea circulation would be complete-ly different. | Yuan Dongliang1. Goddard Earth Science and Technology Center, University of Maryland, Baltimore County Code 971, Laboratory for Hydrospheric Processes, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA | 2002 | Acta Oceanologica Sinica2002，21，2： | 37 |
| 6 | Recovery of Iron From High-Iron Red Mud by Reduction Roasting With Adding Sodium Salt显示文摘Red mud is the waste generated during aluminum production from bauxite, containing lots of iron and other valuable metals. In order to recover iron from red mud, the technology of adding sodium carbonate-reduction roasting-magnetic separation to treat high-iron red mud was developed. The effects of sodium carbonate dosage, reduction temperature and reduction time on the qualities of final product and the phase transformations in reduction process were discussed in detail. The results showed that the final product (mass percent), assaying Fe of 90.87% and Al2O3 of 0.95% and metallization degree of 94.28% was obtained at an overall iron recovery of 95.76% under the following conditions of adding 8% sodium carbonate, reduction roasting at 1 050 ℃ for 80 min and finally magnetic separation of the reduced pellets by grinding up to 90% passing 0.074 mm at magnetic field intensity of 0.08 T. The XRD (X-ray diffraction) results indicated that the iron oxides were transformed into metallic iron. Most of aluminum mineral and silica mineral reacted with sodium carbonate during the reduction roasting and formed nonmagnetic materials. | ZHU De-qing, CHUN Tie-jun, PAN Jian, HE Zhen (School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, Hunan, China) | 2012 | Journal of Iron and Steel Research(International)2012，19，8： | 38 |
| 7 | Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South China显示文摘Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South China, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13C background values are intensively controlled by palaeogeographic environment. In general, δ 13C values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary. | ZUO Jingxun1,2, TONG Jinnan3, QIU Haiou4 & ZHAO Laishi3 1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China 2. Henan Institute of Geological Survey, Zhengzhou 450007, China 3. State Key Laboratory of Geological Processes and Mineral Resources at China University of Geosciences, Wuhan 430074, China 4. Faculty of Material Sciences and Chemical Engineering, China University of Geosciences, Wuhan 430074, China | 2006 | Science China Earth Sciences2006，49，3： | 32 |
| 8 | A study of interaction between surface water and groundwater using environmental isotope in Huaisha River basin显示文摘The surface water and groundwater are important components of water cycle, and the interaction between surface water and groundwater is the important part in water cycle research. As the effective tracers in water cycle research, environmental isotope and hydrochemistry can reveal the interrelationships between surface water and groundwater effectively. The study area is the Huaisha River basin, which is located in Huairou district, Beijing. The field surveying and sampling for spring, river and well water were finished in 2002 and 2003. The hydrogen and oxygen isotopes and water quality were measured at the laboratory. The spatial characteristics in isotope and evolution of water quality along river lines at the different area were analyzed. The altitude effect of oxygen isotope in springs was revealed, and then using this equation, theory foundation for deducing recharge source of spring was estimated. By applying the mass balance method, the annual mean groundwater recharge rate at the catchment was estimated. Based on the groundwater recharge analysis, combining the hydrogeological condition analysis, and comparing the rainfall-runoff coefficients from the 1960s to 1990s in the Huaisha River basin and those in the Chaobai River basin, part of the runoff in the Huaisha River basin is recharged outside of this basin, in other words, this basin is an un-enclosed basin. On the basis of synthetically analyses, combining the compositions of hydrogen and oxygen isotopes and hydrochemistry, geomorphology, geology, and watershed systems characteristics, the relative contributions between surface water and groundwater flow at the different areas at the catchments were evaluated, and the interaction between surface water and groundwater was re- vealed lastly. | SONG Xianfang1, LIU Xiangchao1, 2, XIA Jun1, YU Jingjie1 & TANG Changyuan1, 3 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Re- sources Research, Chinese Academy of Sciences, Beijing 100101, China 2. College of River and Ocean, Chongqing Jiaotong University, Chongqing 400074, China 3. Chiba University, Chiba 263-8522, Japan | 2006 | Science China Earth Sciences2006，49，12： | 34 |
| 9 | Development of distributed time-variant gain model for nonlinear hydrological systems显示文摘In this paper, a rainfall-runoff modeling system is developed based on a nonlinear Volterra functional series and a hydrological conceptual modeling approach. Two models, i.e. the time-variant gain model (TVGM) and the distributed time-variant gain model (DTVGM) that are built on the platform of Digital Elevation Model (DEM), Remote Sensing (RS) and Unit Hydro-logical Process were proposed. The developed DTVGM model was applied to two cases in the Heihe River Basin that is located in the arid and semiarid region of northwestern China and the Chaobai River basin located in the semihumid region of northern China. The results indicate that, in addition to the classic dynamic differential approach to describe nonlinear processes in hy-drological systems, it is possible to study such complex processes through the proposed sys-tematic approach to identify prominent hydrological relations. The DTVGM, coupling the advan-tages of both nonlinear and distributed hydrological models, can simulate variant hydrological processes under different environment conditions. Satisfactory results were obtained in fore-casting the time-space variations of hydrological processes and the relationships between land use/cover change and surface runoff variation. | XIA Jun1, 2, WANG Gangsheng1, TAN Ge1, YE Aizhong2 & G. H. Huang3 1. Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. State Key Laboratory of Water Resources & Hydropower Engineering Sciences, Wuhan University, Wuhan 430072, China 3. Faculty of Engineering, University of Regina, 3737 Wascana Parkway, Regina, Sask., S4S 0A2, Canada Correspondence should be addressed to Xia Jun | 2005 | Science China Earth Sciences2005，48，6： | 32 |
| 10 | SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau显示文摘Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the 'Central Uplift' of the Qiangtang, northern Tibetan Plateau. | ZHAI QingGuo1 WANG Jun1, LI Cai2 & SU Li3 1 Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China 2 College of Earth Sciences, Jilin University, Changchun 130061, China 3 The Geological Laboratory Center and State Key Laboratory of Geological Processes and Mineral Resources, China University of Geo- sciences, Beijing 100083, China | 2010 | Science China Earth Sciences2010，53，5： | 31 |
| 11 | Indian monsoon influences altitude effect of δ^(18)O in precipitation/river water on the Tibetan Plateau显示文摘The δ 18O variation in precipitation acquired from 28 stations within the network of Tibetan Observation and Research Platform(TORP)is studied, with the focus on the altitude effect of δ 18O in river water during monsoon precipitation in an effort to understand the monsoon influence on isotopic composition in annual river water. It is found that δ 18O in precipitation on the Plateau is influenced by different moisture sources, with significant Indian monsoon influence on δ 18O composition in plateau precipitation and river water. The δ 18O of water bodies in the monsoon domain is generally more depleted than that in the westerly domain, suggesting gradual rainout of southwesterly borne marine moisture in the course of long-distance transportation and lifting over the Himalayas. The lapse rate of δ 18O in river water with altitude is the largest during monsoon precipitation, due to the increased temperature vertical gradient over the southern Plateau region controlled by monsoon circulation. The combination of δ 18O in river water in monsoon (wet) and non-monsoon (dry) seasons shows a larger lapse rate than that in non-monsoon (dry) season alone. As the altitude effect of δ 18O in precipitation and river water on the Tibetan Plateau results from the combined effect of monsoon moisture supply and westerly moisture supply, the δ 18O composition and its altitude effect on the Plateau during monsoon seasons should be considered in the reconstruction of paleoelevation of the Tibetan Plateau. | YAO TanDong1,2, ZHOU Hang1,3 & YANG XiaoXin1,3 1 Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2 State Key Laboratory of Cryosphere Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China | 2009 | Chinese Science Bulletin2009，54，16： | 28 |
| 12 | Atmospheric correction for China's coastal water colorremote sensing显示文摘The space satellite programs, such as CZCS/Nimbus - 7, VHRSR/FY - 1, OCFS/ ADEOS and SeaWiFS/SeaStar, have demonstrated and proven that remote sensing is a powerful tool for understanding the spatial and temporal ocean color distribution. In general, there are two main techni-cal keys in the processing ocean color satellite data. They are the atmospheric correction and the inver-sion of water-leaving radiance into water constituents (such as chlorophyll, suspended material and yel low substance) quantitatively. The SeaWiFS (sea-viewing wide field-of-view sensor) atmospheric correc-tion algorithm for China’s coastal waters is discussed. First, the major advantages of SeaWiFS are introduced. Second, in view of the problems of the SeaDAS algorithm applying in China’ s coastal waters, the local atmospheric correction algorithms are discussed and developed. Finally, the advantages of the local algorithms are presented by the compari-son of the results from two different algorithms. | PanDelu, Mao Zhihua 1. Laboratory of Ocean Dynamic Processes and Satellite Oceanography of State Oceanic Administration, Hangzhou 310012, China 2. Laboratory of Submarine Geosciences of State Oceanic Administration, Hangzhou 310012, China | 2001 | Acta Oceanologica Sinica2001，20，3： | 26 |
| 13 | Mesozoic basin evolution and tectonic mechanism in Yanshan, China显示文摘The Mesozoic basins in Yanshan, China underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms. | LIU Shaofeng1,2, LI Zhong3 & ZHANG Jinfang4 1. Key Laboratory of Lithospheric Tectonics, Deep-Level Process and Explovation, Ministry of Education of P. R. China, Beijing 100083, China 2. School of Geosciences and Resources, China University of Geosciences, Beijing 100083, China 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 4. Institute of Software, Chinese Academy of Science, Beijing 100080, China | 2004 | Science China Earth Sciences2004，47，z2： | 24 |
| 14 | Effects of Meat and Phosphate Level on Water-Holding Capacity and Texture of Emulsion-Type Sausage During Storage显示文摘This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat,ageing meat or frozen meat.Pre-rigor pork,ageing pork and frozen pork were pre-blended with five levels of phosphate and made into emulsion-type sausage.The yield,hardness and total expressible fluid (TEF) were measured with texture profile analysis machine and pressiometer when emulsion-type sausage was produced.Meanwhile,hardness and purge loss (PL) were measured during 30 d storage.As emusion-type sausage made by pre-rigor meat,higher yield and relatively stable hardness could be found.It indicated that increasing of phosphate level caused an alleviatable effects in increasing of hardness when emulsion-type sausage made by pre-rigor meat,but opposite effects made by ageing meat or frozen meat.The distribution of PL of emulsion-type sausage was found to be affected by phosphate addition.Significant decrease of PL could not be obtained by increasing of phosphate level during storage.Pre-rigor meat improved WHC and texture of emulsion-type sausage.Problem of WHC and texture of emulsiontype sausage during storage could not be resolved by single use of phosphate at relatively higher level (3%) of NaCl. | WANG Peng,XU Xing-lian and ZHOU Guang-hong Key Laboratory of Meat Processing and Quality Control,Ministry of Education/Nanjing Agricultural University,Nanjing 210095,P.R.China | 2009 | Agricultural Sciences in China2009，8，12： | 24 |
| 15 | Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications显示文摘In order to explore the disputed issue concerning the tectonic affinity of the ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopic compositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzed systematically. The pillow basalts exhibit tholeiitic characteristics, with flat chondrite-normalized REE patterns ((La/Yb)N = 0.98―1.27). They display no Nb, Ta, Zr, Hf negative anomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-Y×3 tectonic discrimination diagrams. These results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridge or mature back-arc basin. Their isotopic data show a relatively broad and enriched 87Sr/86Sr (0.70509 ― 0.70700), restricted 143Nd/144Nd (0.512955―0.512978). Pb isotopes are in the range of 206Pb/204Pb (18.054―20.562), 207Pb/204Pb (15.537―15.743) and 208Pb/204Pb (38.068―38.530). These isotopic data imply that the basalts originated from the depleted mantle (DMM), with the involvement of enriched mantle compo-nents (mainly EMII). Geochemical comparisons between the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the known ancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suite forming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle in both trace elements and isotopic compositions. The North Qilian Mountains should be a part of the Tethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domain can be deduced to early Paleozoic in the study area, which will be helpful to discussing the tectonic affinity and evolution of the North Qilian Mountains. | HOU Qingye1,2, ZHAO Zhidan1,2, ZHANG Hongfei3, ZHANG Benren3 & CHEN Yuelong2 1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China 2. School of Earth Science and Mineral Resources, China University of Geosciences, Beijing 100083, China 3. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China | 2006 | Science China Earth Sciences2006，49，6： | 21 |
| 16 | Forming limits under multi-index constraints in NC bending of aluminum alloy thin-walled tubes with large diameters显示文摘With increasing diameters of aluminum alloy thin-walled tubes (AATTs), the tube forming limits, i.e. the minimum bending factors, and their predictions under multi-index constraints including wrinkling, thinning and flattening have been being a key problem to be urgently solved for improving tube forming potential in numerical control (NC) bending processes of AATTs with large diameters. Thus in this paper, a search algorithm of the forming limits is put forward based on a 3D elastic-plastic finite element (FE) model and a wrinkling energy prediction model for the bending processes under axial compression loading (ACL) or not. This algorithm enables to be considered the effects of process parameter combinations including die, friction parameters on the multi-indices. Based on this algorithm, the forming limits of the different size tubes are obtained, and the roles of the process parameter combinations in enabling the limit bending processes are also revealed. The followings are found: the first, within the appropriate ranges of friction and clearances between the different dies and the tubes enabling the bending processes with smaller bending factors, the ACL enables the tube limit bending processes after a decrease of the mandrel ball thickness and diameters; then, without considering the effects of the tube geometry sizes on the tube constitutive equations, the forming limits will be decided by the limit thinning values for the tubes with diameters smaller than 80 mm, while the wrinkling for the tubes with diameters no less than 80 mm. The forming limits obtained from this algorithm are smaller than the analytical results, and reduced by 57.39%; the last, the roles of the process parameter combinations in enabling the limit bending processes are verified by experimental results. | YAN Jing, YANG He, ZHAN Mei & LI Heng College of Materials Science and Engineering, State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China | 2010 | Science China(Technological Sciences)2010，53，2： | 21 |
| 17 | Transport network and flow mechanism of shallow ore-bearing magma in Tongling ore cluster area显示文摘Abundant studies revealed that shallow intrusions of the Yanshanian epoch resulted in the mass mineralization of the Tongling region. Various evidences showed there existed a concealed magma chamber at ?10 km depth in the middle part of this region during Yanshanian epoch, from which the ore-forming magma was generated and then transported to the superficial layer. Yet the transport network and flow mechanism of the shallow ore-bearing magma, the key problem associ- ated with ore-forming process, was relatively little focused on. Integrate analysis of structural me- chanics, statistical fractal and geological facts suggested that NE trending high-angle fold-related thrust faults and the tessellated basement ones served as the main pathways for the shallow magma’s transporting, moreover, the saddle void spaces among adjacent strata in the folds upon this fault system provided the place for magma’s emplacement. So the folds in the upper part and faults in the lower part of the upper crust constituted the fluid’s transport and emplacement network. During the deformation of geologic body with multi-layer structure, the layers in the upper part tended to fold when received the jacking stress from the lower part, while the lower one inclined to fault undergoing loads of the upper part. And the producing probability of this structure assemblage was highly in- creased in the condition, such as in the Tongling area, that the mechanic rigidity of the lower layers was stronger than that of the upper ones. For the pre-existence of fluid-conducting network, the top magma with high volatile in the magma chamber transported rapidly to the superficial layer in dyking pattern, located in the void spaces of folds, filled and reconstructed them. The sudden drop of pres- sure caused the fluid unmixing from the magma and mass ore-forming elements concentration. Pulse activity of the dyking may be the principal reason why magmatic bodies in the Tongling area were spatially-temporally concomitant and limited flux in chemical compositions. | DENG Jun1,2, WANG Qingfei1,2 , HUANG Dinghua3 , WAN Li4, YANG Liqiang1,2 & GAO Bangfei1,2 1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China 2. Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, China University of Geo- sciences, Beijing 100083, China 3. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China 4. School of Mathematics and Information Science, Guangzhou University, Guangzhou 510405, China | 2006 | Science China Earth Sciences2006，49，4： | 21 |
| 18 | Three-dimensional thermal structure of the Chinese continental crust and upper mantle显示文摘We invert S-wave velocities for the 3D upper-mantle temperatures, in which the position with a temperature crossing the 1300℃ adiabat is corresponding to the top of the seismic low velocity zone. The temperatures down to the depth of 80 km are then calculated by solving steady-state thermal conduction equation with the constraints of the inverted upper-mantle temperatures and the surface temperatures, and then surface heat flows are calculated from the crustal temperatures. The misfit between the calculated and observed surface heat flow is smaller than 20% for most regions. The result shows that, at a depth of 25 km, the crustal temperature of eastern China (500―600℃) is higher than that of western China (<500℃). At a depth of 100 km, temperatures beneath eastern and southeastern China are higher than the adiabatic temperature of 1300℃, while that beneath west China is lower. The Tarim craton and the Sichuan basin show generally low temperature. At a depth of 150 km, temperatures beneath south China, eastern Yangtze craton, North China craton and around the Qiangtang terrane are higher than the adiabatic temperature of 1300℃, but is the lowest beneath the Sichuan basin and the regions near the Indian-Eurasian collision zone. At a depth of 200 km, very low temperature occurs beneath the Qinghai-Tibet Plateau and the south to the Tarim craton. | AN MeiJian1,2? & SHI YaoLin1 1 Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, Beijing 100049, China 2 Key Laboratory of Crust Deformation and Processes and Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China | 2007 | Science China Earth Sciences2007，50，10： | 20 |
| 19 | Geochemistry of the high-Mg andesites at Zhangwu, western Liaoning: Implication for delamination of newly formed lower crust显示文摘Ten volcanic samples at Zhangwu,western Liaoning Province,North China were selected for a sys-tematic geochemical,mineralogical and geochronological study,which provides an opportunity to ex-plore the interaction between the continental crust and mantle beneath the north margin of the North China craton.Except one basalt sample(SiO2= 50.23%),the other nine samples are andesitic with SiO2 contents ranging from 53% to 59%.They have relatively high MgO(3.4%―6.1%,Mg#=50―64) and Ni and Cr contents(Ni 27×10?6―197×10?6,Cr 51×10?6―478×10?6).Other geochemical characteristics of Zhangwu high-Mg andesites(HMAs) include strong fractionation of light rare earth elements(LREE) from heavy rare earth elements(HREE),and Sr from Y,with La/Yb greater than 15,and high Sr/Y(34― 115).Zircons of andesite YX270 yield three age groups with no Precambrian age,which precludes ori-gin of the Zhangwu HMAs from the partial melting of the Precambrian crust.The oldest age group peaking at 253 Ma is interpreted to represent the collision of the Siberia block and the North China block,resulting in formation of the Central Asian orogenic belt by closure of the Mongol-Okhotsk Ocean.The intermediate age group corresponds to the basalt underplating which caused the wide-spread coeval granitoids in the North China craton with a peak 206Pb/238U age of 172 Ma.The youngest age group gives a 206Pb/238U age of 126±2 Ma,which is interpreted as the eruption age of the Zhangwu HMAs.The high 87Sr/86Sri(126 Ma)>0.706 and low εNd(t)= ?6.36―?13.99 of the Zhangwu HMAs are distinct from slab melts.The common presence of reversely zoned clinopyroxene phenocrysts in the Zhangwu HMAs argues against the origin of the Zhangwu HMAs either from melting of the water saturated mantle or melting of the lower crust.In light of the evidence mentioned above,the envisaged scenario for the formation of the Zhangwu HMAs is related to the basaltic underplating at the base of the crust,which led to the thickening of the lower crust and formation of lower crustal eclogite,followed by foundering of the eclogitic lower crust into the asthenosphere.The foundered eclogite then melted and the resul-tant melts interacted with surrounding peridotite during their upward transport,which finally produced the high-Mg andesites.This well explains the high-Mg adakitic characters and absence of ancient in-herited zircon in the Zhangwu lavas. | HUANG Hua1,GAO Shan1,2,HU ZhaoChu1,LIU XiaoMing2 & YUAN HongLing2 1 State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China 2 State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China | 2007 | Science China Earth Sciences2007，50，12： | 20 |
| 20 | Experimental study on hydrodynamic effect of orientation micro-pored surfaces显示文摘The orientation of the dimple increases the flow distance in the dimple and produces fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect as a result. In order to investigate the hydrodynamic effect of orientation dimples, a series of experiments was carried out on a ring-on-ring test. Multi-pored faces were tested with different dimple inclination angles and slender ratios. Film thickness and frictional torque were measured under different conditions of load and rotation speed. Experimental results showed that the orientation dimple could produce obvious dynamic effect by change of the flow direction and the increasing dimple orientation leads to increase of the load capability. The hydrodynamic effect strongly depends on dimple orientation parameters such as inclination angle and slender ratio. A larger load capability can be available by increasing dimple orientation and rotation speed. Experimental results agreed well with the theory that orientation micro-pores can significantly improve hydrodynamic performance of surfaces. | BAI ShaoXian1,2, PENG XuDong1,2, LI JiYun1,2 & MENG XiangKai1,2 1College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310032, China 2Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education, Zhejiang University of Technology, Hangzhou 310032, China | 2011 | Science China(Technological Sciences)2011，54，3： | 20 |
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