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Size-dependent hydroxyl radicals generation induced by SiO_2 ultra-fine particles: The role of surface iron

Science China Chemistry 2009年第7期52卷 1033-1041页

作者： SHANG Yu1, ZHU Tong1, LI Yi1,2 & ZHAO JinCai3.1 College of environmental Sciences and Engineering, Peking University, beijing 100871, China 2 Chinese Academy of Meteorological Sciences, beijing 100871, China 3.Institute of Chemistry, Chinese Academy of Sciences, beijing 100871, China College of environmental Sciences and Engineering Peking University Beijing China Chinese Academy of Meteorological Sciences Beijing China Institute of Chemistry Chinese Academy of Sciences Beijing China

Oxidative stress and hydroxyl radicals (·OH) play important roles in adverse health effects caused by inhalable ambient air particles (PM10). The ultra-fine fraction of PM10 has been hypothesized as one of the critical contributors to ·OH generation. Both in vivo and in vitro studies have shown that ultra-fine particles (UFPs) or nano-particles generate more ·OH than larger particles with identical mass and composition. Both the surface area and surface-adsorbed redox-active metals have been suggested as factors to determine the oxidative capacity of UFPs. In this study, the ·OH-generating capability of dif-ferent sizes of SiO2 particles was investigated in order to determine which factor influences particle-induced ·OH generation. The amount of ·OH generated in both acellular and cellular systems was quantified using a capillary electrophoresis method following exposure to SiO2 particles with diameters of 14, 100, and 500 nm. The amount of ·OH was strongly dependent on particle size, and a significant enhancement was observed only with 14 nm particles. Further studies indicated a close association between ·OH and iron ion concentration (R2 = 0.812, p<0.01). Washed particles, with their surface iron being removed, did not generate ·OH. The iron-containing leachate from these washings was able to enhance ·OH production as untreated particles did. Therefore, the presence of adsorbed iron on the surface of the SiO2 particles is presented as a possible mechanism of UPFs-induced ·OH generation. The SiO2 acted as an inert substrate, and the surface of ultra-fine SiO2 particles acted as a carrier for iron.

关键词： ultra-fine particles nano-particles ·OH oxidative stress size-effect

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A land surface model incorporated with soil freeze/thaw and its application in GAME/Tibet

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Science China Earth Sciences 2006年第12期49卷 1311-1322页

作者： HU Heping1, YE Baisheng2, ZHOU Yuhua3.& TIAN Fuqiang1 1. Department of Hydraulic Engineering, Tsinghua University, beijing 100084, China 2. Cold and Arid Regions environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 73.000, China 3. Department of Civil Engineering, Massachusetts Institute of Technology, USA Department of Hydraulic Engineering Tsinghua University Beijing China Cold and Arid Regions environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Department of Civil Engineering Massachusetts Institute of Technology USA

Land surface process is of great importance in global climate change, moisture and heat exchange in the interface of the earth and atmosphere, human impacts on the environment and eco- system, etc. Soil freeze/thaw plays an important role in cold land surface processes. In this work the diurnal freeze/thaw effects on energy partition in the context of GAME/Tibet are studied. A sophisti- cated land surface model is developed, the particular aspect of which is its physical consideration of soil freeze/thaw and vapor flux. The simultaneous water and heat transfer soil sub-model not only reflects the water flow from unfrozen zone to frozen fringe in freezing/thawing soil, but also demon- strates the change of moisture and temperature field induced by vapor flux from high temperature zone to low temperature zone, which makes the model applicable for various circumstances. The modified Picard numerical method is employed to help with the water balance and convergence of the numerical scheme. Finally, the model is applied to analyze the diurnal energy and water cycle char- acteristics over the Tibetan Plateau using the Game/Tibet datasets observed in May and July of 1998. Heat and energy transfer simulation shows that: (i) There exists a negative feedback mechanism between soil freeze/thaw and soil temperature/ground heat flux; (ii) during freezing period all three heat fluxes do not vary apparently, in spite of the fact that the negative soil temperature is higher than that not considering soil freeze; (iii) during thawing period, ground heat flux increases, and sensible heat flux decreases, but latent heat flux does not change much; and (iv) during freezing period, soil temperature decreases, though ground heat flux increases.

关键词： land surface model,soil freeze/thaw,GAME/Tibet,simultaneous liquid,vapor and heat transfer.

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A calculation method of the sensible heat flux by sodar

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Acta Oceanologica Sinica 1989年第2期8卷 191-198页

作者： Lu Naiping, Li Shiming, Chen Jingnan, Zheng Yueming Zhou Mingyu national Recsearch center for marine Environmcntul Forecasts, {3., China national Research center for marine {3. Forecasts Beijing China. China

During the second course of USA - PRC joint air sea interaction experiment in 1986, the temperature structure parameters CT2 were measured by sodar over the Western Pacific Ocean. Based on similarity theory, a method is discussed to calculate the sensible heat flux over the ocean in unstable stratification. Becausehumidity is great over the ocean, so we have to consider the influence of water vapor structure parameter Ce2and the correlation coefficient betweene and T on the calculation of sensible heat flux using CT2 profiles measured by sodar. A new formula is suggested in terms of parameterization. The sensible heat flux calculated by sodar measurements is compared with that by bulk transfer method, and the results agree well.

关键词： heat A calculation method of the sensible heat flux by sodar

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The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2,4, ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3.1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, China 2. Department of Atmospheric Sciences, Yunnan University, Kunming 650091, China 3. China Meteorological Administration Training Centre, beijing 100081, China 4. Graduate School of Chinese Academy of Sciences, beijing 10003., China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Atmospheric Sciences Yunnan University Kunming China Graduate School of Chinese Academy of Sciences Beijing China China Meteorological Administration Training Centre Beijing China

Based on the daily outgoing longwave radiation (OLR) data from national Oceanic and At- mospheric Administration (NOAA) satellites, the Cli- mate Prediction center’s merged analysis of pre- cipitation (CMAP) data and the national centers for environmental Prediction/national center for At- mospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indo- china Peninsula, the east coast of Bay of Bengal, the South China Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

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The study on Sanmenxia annual flow forecasting in the Yellow River with mix regression model

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Science China(Technological Sciences) 2004年第Z1期47卷 118-126页

作者： JIANG Xiaohui1, LIU Changming1,2, WANG Yu3.& WANG Hongrui1 1. beijing Normal University, beijing 100875, China 2. Institute of Geographic Science and Natural Resources, Chinese Academy of Sciences, beijing 100101, China 3. Reconnaissance, Planning, Design and Research Institute, YRCC, Zhengzhou 450003. China beijing Normal University Beijing China Institute of Geographic Science and Natural Resources Chinese Academy of Sciences Beijing China Reconnaissance Planning Design and Research Institute YRCC Zhengzhou China

This paper established mix regression model for simulating annual flow, in which annual runoff is auto-regression factor, precipitation, air temperature and water consumption are regression factors; we adopted 9 hypothesis climate change schemes to forecast the change of annual flow of Sanmenxia Station. The results show : (1) When temperature is steady, the average annual runoff will increase by 8.3. if precipitation increases by 10%; when precipitation decreases by 10%, the average annual runoff will decrease by 8.2%; when precipitation is steady, the average annual runoff will decrease by 2.4% if temperature increases 1℃; if temperature decreases 1℃, runoff will increase by 1.2%. The mix regression model can well simulate annual runoff. (2) As to 9 different temperature and precipitation scenarios, scenario 9 is the most adverse to the runoff of Sanmenxia Station of Yellow River; i.e. temperature increases 1℃ and precipitation decreases by 10%. Under this condition, the simulated average annual runoff decreases by 10.8%. On the contrary, scenario 1 is the best to the enhancement of runoff; i.e. when temperature decreases 1 ℃ precipitation will increase by 10%, which will make the annual runoff of Sanmenxia increase by 10.6%.

关键词： forecast annual flow, mix regression model, Sanmenxia Station

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Ocean color products retrieval and validation around China coast with MODIS

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Acta Oceanologica Sinica 2010年第4期29卷 21-27页

作者： SUN Lingt GUO Maohua WANG Xiaomei Key Laboratory of Radiometric Calibration and Validation for environmental Satellites China Meteorological Administration （LRCVES/CMA） National Satellite Meteorological Center China Meteorological Administration Beijing 100081 China national Satellite Ocean Application Service State Oceanic Administration Beijing 100081 China

Waters along China coast are very turbid with high concentrations of suspended sediment nearly all the time,especially at the Hangzhou Bay,the Changjiang （Yangtze） River Estuary and the shoal along Jiangsu *** these turbid and optically complex waters,the standard MODIS ocean color products tend to have invalid *** the water-leaving radiances in the near-infrared （NIR） are significant resulting from the strong scattering of suspended particles,the standard MODIS atmospheric correction algorithm often gets no results or produces significant *** because of the complex water optical properties,the OC3.model used in the standard MODIS data processing tends to get extremely high chlorophyll-a （Chl-a） *** this paper,we present an atmospheric correction approach using MODIS short wave infrared （SWIR） bands based on the fact that water-leaving radiances are negligible in the SWIR region because of the extreme strong absorption of water even in turbid waters.A regional Chl-a concentration estimation model is also constructed for MODIS from in situ *** algorithms are applied to MODIS Aqua data processing in the China coastal *** situ data collected in the Yellow Sea and the East China Sea in spring and autumn,2003.are used to validate the *** good results have been *** is noted that water-leaving reflectance in the NIR bands are significant in waters along the China coast with high sediment *** satellite derived and in-situ reflectance spectra can match in the turbid waters along China coast,and there is relatively good linear relationship between satellite derived and in-situ *** RMSE value of Rrs（λ） is 0.003. sr ？1 for all the nine ocean color bands （412 to 869 nm）.The satellite-derived Chl-a value is in the reasonable range and the root mean square percentage difference is 46.1%.

关键词： ocean color atmospheric correction chlorophyll-a MODIS China coastal region validation

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Induction of EROD activity in Paralichthys olivaceus by polychlorinated biphenyl CB-28

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Acta Oceanologica Sinica 2003年第2期22卷 281-286页

作者： WangJuying HuoChuanlin HanGengchen GuanDaoming YanQilun CollegeofChemnistryandChemicalEngineering OceanUniversityofChinaQingdao266003China nationalmarineenvironmentalMonitoring{3. Dalian116023China InstituteofenvironmentalScience BeijingNormalUniversityBeijing100875China

The test organisms (Paralichthys olivaceus) were exposed to CB - 28 with differentspiked concentrations. After 72 h, EROD activities in livers of the test organisms were measured. It was found that EROD activities significantly mounted up with the increase of spiked quantity. Therefore, there existed a dose-response relationship between EROD activities and specific pollutant concentrations. In the meantime, the optimal conditions for the analysis of EROD activity were discussed. The limitation of EROD activities as a monitoring parameter was also analyzed.

关键词： PCBs EROD flounder bio-effect cytochrome P-450

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Effect of dissolved phosphorus on alkaline phosphatase activity in marine microalgae

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Acta Oceanologica Sinica 2000年第2期19卷 29-35页

作者： Huang Bangqin1,2 Huang Shiyu3.Weng Yan2 Hong Huasheng1,2 (1. Research Laboratory of SEDC on marine Ecological Environment, Xiamen University, Xiamen 3.1005, China 2. environmental Science Research center, Xiamen University, Xiamen 3.1005, China 3. Fis Res. Lab. of SEDC on Mar. Eco. Env Xiamen University Xiamen 361005 China

Alkaline phosphatase activity (APA) and dissolved phosphorus were monitored during the batch cultures of two bone microalgae. Results indicate that variation of APA was in the shape of 'S' curve. Different specs of dissolved phaphorus had different effects on APA. The concentrations of dis solved inorganic phosphorus (DIP) and and molecular dissolved organic phosphorus (SDOP) had a sig nificant effect on APA, while the concentration of large molecular dissolved organic phosphorus (LDOP) had a little effect on APA., and the increase of APA could accelerate the decomposing of LDOP in the medium. Results also show that algae species and abundance had why a little effect on APA.

关键词： Alkaline phosphatase activity dissolved inorganic phosphorus small molecular dissolved or ganic phophorus large molecular dissolved organic phosphorus microalgae

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Progress and review of the studies on the end-Triassic mass extinction event

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Science China Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2, LU Yuanzheng1,2,3.& XU Daoyi4 1. Research Institute of Petroleum Exploration and Development, beijing 100083. China 2. Key Laboratory of Oil and Gas Reservoir of PetroChina, beijing 100083. China 3. China University of Geosciences, beijing 100083. China 4. Institute of Geology, China Earthquake Administration, beijing 100029, China Research Institute of Petroleum Exploration and Development Beijing China Key Laboratory of Oil and Gas Reservoir of PetroChina Beijing China China University of Geosciences Beijing China Institute of Geology China Earthquake Administration Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. China has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.

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STATISTICAL RELATIONSHIP BETWEEN THE FREQUENCY OF TYPHOON OVER NORTHWEST PACIFIC AND FIELD OF MONTHLY MEAN SEA SURFACE TEMPERATURE

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Acta Oceanologica Sinica 1982年第1期 40-46页

作者：王景毅 marine forecasting center national Bureau of Oceanography beijing

In reccent years,much attention has paid to the effiect of the large scale variations of the ocean temperature on the atmospheric citculation

关键词： SST CCF STATISTICAL RELATIONSHIP BETWEEN THE FREQUENCY OF TYPHOON OVER NORTHWEST PACIFIC AND FIELD OF MONTHLY MEAN SEA SURFACE TEMPERATURE over

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