Abstract:In order to reveal the vapor origins of generating precipitation over southwest China, the variations of stable isotopes including deuterium excess d and the relationships of the stable isotopes with temperature and humidity at Mengzi, Tengchong and Puer sampling stations are analyzed. Under the monsoon system, d in precipitation has distinct seasonality with lower values in the rainy season and higher values in the dry season. Analyses show that the relationship of d in precipitation with temperature and humidity in the middle and low troposphere has consistency. If taking into account the relationships of d and δ18O in precipitation with atmospheric humidity synthetically, it can be deduced that the main causation of affecting stable isotopic variations in precipitation over southwest China is related to the property of rainfall air mass, whereas the evaporation enrichment action in falling raindrop is relatively light. In the rainy season of southwest China, the vapor of generating precipitation, with high humidity, low stable isotopic ratios owing to the rainout of vapor on the transport way, and small d-values in precipitation, is primarily from low-latitude oceans; in the dry season, the vapor of generating precipitation, with low humidity, great stable isotopic ratios and high d-values in precipitation, is primarily from the westerlies transportation and the replenishment of re-evaporated vapor in inland.

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	1. Deuterium Excess in Precipitation Indicating Vapor Origins over Southwest China
	ZHANG Xinping,ZHANG Xinzhu,WU Huawu,HUANG Yimin
	Earth Science 04 January 2011
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	Abstract:In order to reveal the vapor origins of generating precipitation over southwest China, the variations of stable isotopes including deuterium excess d and the relationships of the stable isotopes with temperature and humidity at Mengzi, Tengchong and Puer sampling stations are analyzed. Under the monsoon system, d in precipitation has distinct seasonality with lower values in the rainy season and higher values in the dry season. Analyses show that the relationship of d in precipitation with temperature and humidity in the middle and low troposphere has consistency. If taking into account the relationships of d and δ18O in precipitation with atmospheric humidity synthetically, it can be deduced that the main causation of affecting stable isotopic variations in precipitation over southwest China is related to the property of rainfall air mass, whereas the evaporation enrichment action in falling raindrop is relatively light. In the rainy season of southwest China, the vapor of generating precipitation, with high humidity, low stable isotopic ratios owing to the rainout of vapor on the transport way, and small d-values in precipitation, is primarily from low-latitude oceans; in the dry season, the vapor of generating precipitation, with low humidity, great stable isotopic ratios and high d-values in precipitation, is primarily from the westerlies transportation and the replenishment of re-evaporated vapor in inland.
	TO cite this article:ZHANG Xinping,ZHANG Xinzhu,WU Huawu, et al. Deuterium Excess in Precipitation Indicating Vapor Origins over Southwest China[OL].[ 4 January 2011] http://en.paper.edu.cn/en_releasepaper/content/4403978


	2. Change in surface latent heat flux over the tropical Pacific
	REN Baohua,LI Gen
	Earth Science 21 December 2010
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	Abstract:Using the Objectively Analyzed air-sea Fluxes (OAFlux) data, we have revisited the causes of the tropical Pacific surface latent heat flux (LHF) trend during 1977-2006. It is suggested that the LHF presents a statistically significant positive trend and its pattern is related to both the ocean warming and the surface wind strengthening. The ocean warming is the direct cause of the LHF trend, while the surface wind strengthening, due to its contribution to the sea surface temperature (SST) trend pattern, is the indirect cause of the LHF trend.
	TO cite this article:REN Baohua,LI Gen. Change in surface latent heat flux over the tropical Pacific[J].

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	3. Numericle simulation of the formation of star dunes with DNS method
	Zhang Ruyan ,Luo Chunmei
	Earth Science 29 October 2010
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	Abstract:In this paper, the star dunes with five arms are simulated numerically in order to make clear the mechanism of the formation. The numerical method employed in this study can be divided into three parts: (1) Calculation of the air flow above the sand dunes; (2) Estimation of the sand transfer caused by the flow through the friction; (3) Determination of the shape of the sand ground. Since the computational area has been changed due to the last step, these procedures are repeated until typical shapes of the sand dunes are formed. When the winds blow from five directions, the sand dune extends at five directions and becomes the shape of a star with five arms.
	TO cite this article:Zhang Ruyan ,Luo Chunmei. Numericle simulation of the formation of star dunes with DNS method[OL].[29 October 2010] http://en.paper.edu.cn/en_releasepaper/content/4389812


	4. Numericle simulation of the formation of linear dunes
	Zhang Ruyan,Luo Chunmei
	Earth Science 17 October 2010
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	Abstract:Three-dimensional flow above the sand dunes have been studied numerically by using Large-Eddy Simulation (LES) method. In the flow direction and span direction cyclic boundary conditions are imposed for velocity and pressure. The movement of the sand which is known as the elemental types of desert have been investigated. The numerical method employed in this study can be divided into three parts: (i) calculation of the air flow above the sand dunes using standard MAC method with a generalized coordinate system; (ii) estimation of the sand transfer caused by the flow through the friction; (iii) determination of the shape of the ground. Since the computational area has been changed due to step (iii), steps (i)-(iii) are repeated until prescribed times. The simulated dunes, which is formed by two directional winds, extends at the converging direction which is known as linear dunes.
	TO cite this article:Zhang Ruyan,Luo Chunmei. Numericle simulation of the formation of linear dunes[OL].[17 October 2010] http://en.paper.edu.cn/en_releasepaper/content/4387969


	5. A unique gymnosperm from the latest Permian of China, and its ecophysiological implications
	Feng Zhuo,Wang Jun,RÖßLE Ronny
	Earth Science 03 October 2010
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	Abstract:A unique probably coniferalean gymnospermous woody stem Shenoxylon mirabile gen. nov. et sp. nov. is described from the very late Late Permian Changhsingian (Lopingian) Sunjiagou Formation of the Shitanjing coalfield, northern China. It is anatomically preserved and is characterized by a regularly arranged sclerenchymatous intramedullary sheath surrounding the wide homogenous central pith, and dense development of the secondary xylem with helically arranged leaf traces. The broad eustelic vascular system consists of the heterogeneous pith and endarch primary xylem, the tracheid elements from the protoxylem to metaxylem showing annular to scalariform/reticulate thickenings. The secondary xylem is pycnoxylic; uniseriate bordered pits are continuous or individually separated present on the radial walls of tracheids, with partially biseriate, alternate or opposite on the tracheid walls; the cross-fields show one or two cupressoid pits; ray cells are parenchymatous with smooth walls; axial parenchyma is also developed. Growth-rings are present and false rings are frequently developed throughout the secondary xylem; resin canals are absent. The leaf traces are comprised of monarch vascular bundles, of circular to longitudinally elongate shape in cross section; they originate from the periphery of the pith and pass through the whole xylem cylinder nearly horizontally. The special anatomical structure of the pith and the large amount of false rings are interpreted as ecophysiological responses of the plant to the serious environmental disturbulences during the latest Permian terrestrial ecosystem.
	TO cite this article:Feng Zhuo,Wang Jun,RÖßLE Ronny. A unique gymnosperm from the latest Permian of China, and its ecophysiological implications[J].


	6. Highly organized aragonite mesorods: A general 3-dimensional oriented attachment and its implication for biomineralization
	Zhou Gentao,Yao Qizhi,Ni Jie,Jin Gu
	Earth Science 15 July 2010
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	Abstract:Highly organized aragonite mesorods were synthesized at low temperatures in a broad range of pH values and in absence of any bio- or organic- macromolecules. The organized mesorods were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scan electron microscope (FESEM), transmission electron microscope (TEM), and selected area electron diffraction (SAED), energy dispersive X-ray spectroscopy (EDX) techniques. FESEM results reveal that the aragonite mesorods are not only assembled with aragonite microrods by end-to-end, and side-to-side, but also partially fused one another, forming flat faceted surfaces. TEM and SAED analyses confirm that the organized mesorods have the same crystallographic symmetry as the single-crystalline aragonite, indicating that the self-assembly process is favorable energetically. Similar assembly process also occurs for mineral strontianite or witherite of aragonite group. The driving force for the self-assembly process may originate from the inherent anisotropic dipole-dipole interactions between the assembled units. As a result, a general 3D oriented attachment process may orchestrate the mesorods self-assembly into quasi-single crystalline microrods, and such mineralization mechanism can generally occur in biomineralization. It appears that the biological genetic and crystallochemical factors may work synergically in biomineralization.
	TO cite this article:Zhou Gentao,Yao Qizhi,Ni Jie, et al. Highly organized aragonite mesorods: A general 3-dimensional oriented attachment and its implication for biomineralization[OL].[15 July 2010] http://en.paper.edu.cn/en_releasepaper/content/4379009


	7. A fully polarimetric borehole radar based numerical modelling: fully polarimetric radar responses to synthesized fractures
	Zhao Jianguo
	Earth Science 09 July 2010
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	Abstract:A fully polarimetric borehole radar system with four combinations of dipole and cylindrical slot antennas was developed to acquire fully polarimetric data sets in drilled boreholes. To better under the fully polarimetric response to subsurface fractures with different roughness, in this study, synthetic fractures with different roughness are generated on a computer via fractal theory based simulation techniques. Quantitative assessment for the roughness of synthetic fractures is possible by use of three main parameters: the fractal dimension, the rms roughness at a reference length, and a length scale describing the degree of mismatch between the two fracture surfaces, allowing future detailed study of mechanical and transport properties of fractures and fully polarimetric radar response on them. Next, a 3D sub-grid FDTD numerical simulation is used to synthesize fully polarimetric data sets with synthetic fractures as primary reflectors. Based on the synthetic data sets, it is possible to evaluate the applicability of different radar polarimetry analysis approaches to physical characterization of subsurface fractures in future.
	TO cite this article:Zhao Jianguo. A fully polarimetric borehole radar based numerical modelling: fully polarimetric radar responses to synthesized fractures[OL].[ 9 July 2010] http://en.paper.edu.cn/en_releasepaper/content/4378517


	8. Implications for OSL dating of young sediments(<100 years old): a comparison of OSL ages with independent ages
	Fan Tianlai,Fan Yuxin
	Earth Science 03 March 2010
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	Abstract:We explore the use of quartz optically stimulated luminescence dating of young aeolian dust deposits for reconstructing high-resolution chronology on a time scale of decadals. Samples potentially experiencing long/short transpotation are taken from surface layer of buildings on the northern bank of the Yellow River, Lanzhou, China. The maxmium ages of dust deposits are known from historical sources. De values were calculated basing on the luminescent signals measured using SAR protocol in middle aliquots, and range from 0.16 Gy to 1.78 Gy, indicating that the residual luminescent signals can not be ignored. The potential Optical Stimulated Luminescence ages were estimated using dose rate obtained in loess samples on the Loess Plateau in China. And the final results show that even the minimal De components were taken into account, the OSL age of the youngest samples is estimated to be 32 years, which is obviously older than the history of the building. It is thus concluded that luminescent signals of dusts are possibly unbleached before they were buried, however, the Optical Stimulated Luminescence ages and high-resolution chronology can be obtained on time scale of decades. Besides, more caution should be paid to the application of quartz OSL dating on decadal timescale.
	TO cite this article:Fan Tianlai,Fan Yuxin. Implications for OSL dating of young sediments(<100 years old): a comparison of OSL ages with independent ages[OL].[ 3 March 2010] http://en.paper.edu.cn/en_releasepaper/content/40386


	9. Uranium-series disequilibria in the groundwater of the Shihongtan sandstone-hosted uranium deposit, NW China
	Min Maozhong,Peng Xinjian,Qiao Haiming
	Earth Science 11 February 2010
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	Abstract:Study on uranium-series disequilibria of groundwater is first reported here in China. Uranium concentration and uranium isotopes 238U，234U and 230Th for groundwaters, spring waters and lake water collected from the Shihongtan sandstone-hosted uranium ore district and in the surrounding area, NW China, were determined. The results show that the groundwaters from the oxidizing aquifer with high dissolved oxygen concentration (O2) and oxidation-reduction potential (Eh) have U enrichment. High U concentration of some groundwaters might result from intersected and dissolved old U orebody by oxidizing or saline groundwaters, inducing U-series disequilibrium. Uranium was most likely precipitated at the reducing barrier as uraninite or absorbed onto the heterochronogenous mineral and organic material particles. It is supported by the fact that new U orebody is locally forming in the sandstone-hosted reducing aquifer. The 234U/ 238U, 230Th/ 234U and 230Th/238U activity ratios (ARs) for most water samples are obvious deviations from secular equilibrium (0.27–2.86), indicating the presence of water–rock/ore interactions during the last 1 Ma and probably longer and 234U enrichment in the waters. The 234U/238U AR increases approximately with the decrease in U concentration of the waters, suggesting that mixing of two water sources may occur in the aquifer. This is consistent with the fact that most of U orebodies in the deposit have a tabular shape originated from mixing between a relatively stagnant saline fluid and a more rapidly flowing uranium-bearing meteoric water.
	TO cite this article:Min Maozhong,Peng Xinjian,Qiao Haiming. Uranium-series disequilibria in the groundwater of the Shihongtan sandstone-hosted uranium deposit, NW China[OL].[11 February 2010] http://en.paper.edu.cn/en_releasepaper/content/40167


	10. Biodegradation of hydrocarbon in Dongsheng sandstone-hosted uranium deposit，North China
	Min Maozhong,Wang Jinping,Xie Hongbing
	Earth Science 09 February 2010
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	Abstract:Organic geochemistry were studied for the ores and altered, unaltered host sandstones at the Dongsheng sandstone-hosted uranium deposit in the Ordos Basin, North China. Interlayer alteration of the host sandstone in the Dongsheng deposit is different from one in the other sandstone-hosted uranium deposits of China and may be divided into four geochemical zones, i.e., the unaltered grey host sandstone in the reducing zone, light purple-red host sandstone in the oxidized zone, grey-green sandstone in the oxidized zone and mineralized grey sandstone (ore) in the oxic-anoxic transition zone. Uranium ore bodies occur, as tabular (mostly) and roll-front in shape, within the grey sandstone of unaltered reducing zone near oxic-anoxic transition zone for industrial mineralization and within the grey-green sandstone of oxic-anoxic transition zone for unindustrial mineralization. The gas chromatograms of total saturated hydrocarbons show unimodal distributions and the normal alkanes C17 to C35 with an odd carbon number preference and maxima concentrate around C25–29, which are typical for terrestrial high plant. The organic matter in the unaltered grey host sandstone and the light purple-red host sandstone in the oxidized zone is immature, while the organic matter in the re-reduced grey-green host sandstone and mineralized grey sandstone (ore) has a maturity equivalent to the main stage of petroleum generation (catagenesis). Evidence of hydrocarbon biodegradation associated with uranium mineralization was found. The biodegradation is a bacterial degradation which can be considered as a catalyst for the reduction of uranium. Occurrence of biodegraded migrated organic matter can be considered as a favourable criterion for the settling of uranium mineralization in searching and prospecting for uranium deposit. Finally, a two-stage genetic model of the uranium deposit based on the mixing of three fluids (brine, meteoric water and oil) has been developed.
	TO cite this article:Min Maozhong,Wang Jinping,Xie Hongbing. Biodegradation of hydrocarbon in Dongsheng sandstone-hosted uranium deposit，North China[OL].[ 9 February 2010] http://en.paper.edu.cn/en_releasepaper/content/40106

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